xref: /llvm-project/llvm/lib/Target/Mips/MipsISelLowering.cpp (revision 26b87aad9e2d34d53df67522dc5aea5f7c54a458)
1 //===- MipsISelLowering.cpp - Mips DAG Lowering Implementation ------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the interfaces that Mips uses to lower LLVM code into a
10 // selection DAG.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MipsISelLowering.h"
15 #include "MCTargetDesc/MipsBaseInfo.h"
16 #include "MCTargetDesc/MipsInstPrinter.h"
17 #include "MCTargetDesc/MipsMCTargetDesc.h"
18 #include "MipsCCState.h"
19 #include "MipsInstrInfo.h"
20 #include "MipsMachineFunction.h"
21 #include "MipsRegisterInfo.h"
22 #include "MipsSubtarget.h"
23 #include "MipsTargetMachine.h"
24 #include "MipsTargetObjectFile.h"
25 #include "llvm/ADT/APFloat.h"
26 #include "llvm/ADT/ArrayRef.h"
27 #include "llvm/ADT/SmallVector.h"
28 #include "llvm/ADT/Statistic.h"
29 #include "llvm/ADT/StringRef.h"
30 #include "llvm/ADT/StringSwitch.h"
31 #include "llvm/CodeGen/CallingConvLower.h"
32 #include "llvm/CodeGen/FunctionLoweringInfo.h"
33 #include "llvm/CodeGen/ISDOpcodes.h"
34 #include "llvm/CodeGen/MachineBasicBlock.h"
35 #include "llvm/CodeGen/MachineFrameInfo.h"
36 #include "llvm/CodeGen/MachineFunction.h"
37 #include "llvm/CodeGen/MachineInstr.h"
38 #include "llvm/CodeGen/MachineInstrBuilder.h"
39 #include "llvm/CodeGen/MachineJumpTableInfo.h"
40 #include "llvm/CodeGen/MachineMemOperand.h"
41 #include "llvm/CodeGen/MachineOperand.h"
42 #include "llvm/CodeGen/MachineRegisterInfo.h"
43 #include "llvm/CodeGen/SelectionDAG.h"
44 #include "llvm/CodeGen/SelectionDAGNodes.h"
45 #include "llvm/CodeGen/TargetFrameLowering.h"
46 #include "llvm/CodeGen/TargetInstrInfo.h"
47 #include "llvm/CodeGen/TargetRegisterInfo.h"
48 #include "llvm/CodeGen/ValueTypes.h"
49 #include "llvm/CodeGenTypes/MachineValueType.h"
50 #include "llvm/IR/CallingConv.h"
51 #include "llvm/IR/Constants.h"
52 #include "llvm/IR/DataLayout.h"
53 #include "llvm/IR/DebugLoc.h"
54 #include "llvm/IR/DerivedTypes.h"
55 #include "llvm/IR/Function.h"
56 #include "llvm/IR/GlobalValue.h"
57 #include "llvm/IR/Module.h"
58 #include "llvm/IR/Type.h"
59 #include "llvm/IR/Value.h"
60 #include "llvm/MC/MCContext.h"
61 #include "llvm/Support/Casting.h"
62 #include "llvm/Support/CodeGen.h"
63 #include "llvm/Support/CommandLine.h"
64 #include "llvm/Support/Compiler.h"
65 #include "llvm/Support/ErrorHandling.h"
66 #include "llvm/Support/MathExtras.h"
67 #include "llvm/Target/TargetMachine.h"
68 #include "llvm/Target/TargetOptions.h"
69 #include <algorithm>
70 #include <cassert>
71 #include <cctype>
72 #include <cstdint>
73 #include <deque>
74 #include <iterator>
75 #include <utility>
76 #include <vector>
77 
78 using namespace llvm;
79 
80 #define DEBUG_TYPE "mips-lower"
81 
82 STATISTIC(NumTailCalls, "Number of tail calls");
83 
84 static cl::opt<bool>
85 NoZeroDivCheck("mno-check-zero-division", cl::Hidden,
86                cl::desc("MIPS: Don't trap on integer division by zero."),
87                cl::init(false));
88 
89 extern cl::opt<bool> EmitJalrReloc;
90 
91 static const MCPhysReg Mips64DPRegs[8] = {
92   Mips::D12_64, Mips::D13_64, Mips::D14_64, Mips::D15_64,
93   Mips::D16_64, Mips::D17_64, Mips::D18_64, Mips::D19_64
94 };
95 
96 // The MIPS MSA ABI passes vector arguments in the integer register set.
97 // The number of integer registers used is dependant on the ABI used.
98 MVT MipsTargetLowering::getRegisterTypeForCallingConv(LLVMContext &Context,
99                                                       CallingConv::ID CC,
100                                                       EVT VT) const {
101   if (!VT.isVector())
102     return getRegisterType(Context, VT);
103 
104   if (VT.isPow2VectorType() && VT.getVectorElementType().isRound())
105     return Subtarget.isABI_O32() || VT.getSizeInBits() == 32 ? MVT::i32
106                                                              : MVT::i64;
107   return getRegisterType(Context, VT.getVectorElementType());
108 }
109 
110 unsigned MipsTargetLowering::getNumRegistersForCallingConv(LLVMContext &Context,
111                                                            CallingConv::ID CC,
112                                                            EVT VT) const {
113   if (VT.isVector()) {
114     if (VT.isPow2VectorType() && VT.getVectorElementType().isRound())
115       return divideCeil(VT.getSizeInBits(), Subtarget.isABI_O32() ? 32 : 64);
116     return VT.getVectorNumElements() *
117            getNumRegisters(Context, VT.getVectorElementType());
118   }
119   return MipsTargetLowering::getNumRegisters(Context, VT);
120 }
121 
122 unsigned MipsTargetLowering::getVectorTypeBreakdownForCallingConv(
123     LLVMContext &Context, CallingConv::ID CC, EVT VT, EVT &IntermediateVT,
124     unsigned &NumIntermediates, MVT &RegisterVT) const {
125   if (VT.isPow2VectorType() && VT.getVectorElementType().isRound()) {
126     IntermediateVT = getRegisterTypeForCallingConv(Context, CC, VT);
127     RegisterVT = IntermediateVT.getSimpleVT();
128     NumIntermediates = getNumRegistersForCallingConv(Context, CC, VT);
129     return NumIntermediates;
130   }
131   IntermediateVT = VT.getVectorElementType();
132   NumIntermediates = VT.getVectorNumElements();
133   RegisterVT = getRegisterType(Context, IntermediateVT);
134   return NumIntermediates * getNumRegisters(Context, IntermediateVT);
135 }
136 
137 SDValue MipsTargetLowering::getGlobalReg(SelectionDAG &DAG, EVT Ty) const {
138   MachineFunction &MF = DAG.getMachineFunction();
139   MipsFunctionInfo *FI = MF.getInfo<MipsFunctionInfo>();
140   return DAG.getRegister(FI->getGlobalBaseReg(MF), Ty);
141 }
142 
143 SDValue MipsTargetLowering::getTargetNode(GlobalAddressSDNode *N, EVT Ty,
144                                           SelectionDAG &DAG,
145                                           unsigned Flag) const {
146   return DAG.getTargetGlobalAddress(N->getGlobal(), SDLoc(N), Ty, 0, Flag);
147 }
148 
149 SDValue MipsTargetLowering::getTargetNode(ExternalSymbolSDNode *N, EVT Ty,
150                                           SelectionDAG &DAG,
151                                           unsigned Flag) const {
152   return DAG.getTargetExternalSymbol(N->getSymbol(), Ty, Flag);
153 }
154 
155 SDValue MipsTargetLowering::getTargetNode(BlockAddressSDNode *N, EVT Ty,
156                                           SelectionDAG &DAG,
157                                           unsigned Flag) const {
158   return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, 0, Flag);
159 }
160 
161 SDValue MipsTargetLowering::getTargetNode(JumpTableSDNode *N, EVT Ty,
162                                           SelectionDAG &DAG,
163                                           unsigned Flag) const {
164   return DAG.getTargetJumpTable(N->getIndex(), Ty, Flag);
165 }
166 
167 SDValue MipsTargetLowering::getTargetNode(ConstantPoolSDNode *N, EVT Ty,
168                                           SelectionDAG &DAG,
169                                           unsigned Flag) const {
170   return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlign(),
171                                    N->getOffset(), Flag);
172 }
173 
174 const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
175   switch ((MipsISD::NodeType)Opcode) {
176   case MipsISD::FIRST_NUMBER:      break;
177   case MipsISD::JmpLink:           return "MipsISD::JmpLink";
178   case MipsISD::TailCall:          return "MipsISD::TailCall";
179   case MipsISD::Highest:           return "MipsISD::Highest";
180   case MipsISD::Higher:            return "MipsISD::Higher";
181   case MipsISD::Hi:                return "MipsISD::Hi";
182   case MipsISD::Lo:                return "MipsISD::Lo";
183   case MipsISD::GotHi:             return "MipsISD::GotHi";
184   case MipsISD::TlsHi:             return "MipsISD::TlsHi";
185   case MipsISD::GPRel:             return "MipsISD::GPRel";
186   case MipsISD::ThreadPointer:     return "MipsISD::ThreadPointer";
187   case MipsISD::Ret:               return "MipsISD::Ret";
188   case MipsISD::ERet:              return "MipsISD::ERet";
189   case MipsISD::EH_RETURN:         return "MipsISD::EH_RETURN";
190   case MipsISD::FAbs:              return "MipsISD::FAbs";
191   case MipsISD::FMS:               return "MipsISD::FMS";
192   case MipsISD::FPBrcond:          return "MipsISD::FPBrcond";
193   case MipsISD::FPCmp:             return "MipsISD::FPCmp";
194   case MipsISD::FSELECT:           return "MipsISD::FSELECT";
195   case MipsISD::MTC1_D64:          return "MipsISD::MTC1_D64";
196   case MipsISD::CMovFP_T:          return "MipsISD::CMovFP_T";
197   case MipsISD::CMovFP_F:          return "MipsISD::CMovFP_F";
198   case MipsISD::TruncIntFP:        return "MipsISD::TruncIntFP";
199   case MipsISD::MFHI:              return "MipsISD::MFHI";
200   case MipsISD::MFLO:              return "MipsISD::MFLO";
201   case MipsISD::MTLOHI:            return "MipsISD::MTLOHI";
202   case MipsISD::Mult:              return "MipsISD::Mult";
203   case MipsISD::Multu:             return "MipsISD::Multu";
204   case MipsISD::MAdd:              return "MipsISD::MAdd";
205   case MipsISD::MAddu:             return "MipsISD::MAddu";
206   case MipsISD::MSub:              return "MipsISD::MSub";
207   case MipsISD::MSubu:             return "MipsISD::MSubu";
208   case MipsISD::DivRem:            return "MipsISD::DivRem";
209   case MipsISD::DivRemU:           return "MipsISD::DivRemU";
210   case MipsISD::DivRem16:          return "MipsISD::DivRem16";
211   case MipsISD::DivRemU16:         return "MipsISD::DivRemU16";
212   case MipsISD::BuildPairF64:      return "MipsISD::BuildPairF64";
213   case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
214   case MipsISD::Wrapper:           return "MipsISD::Wrapper";
215   case MipsISD::DynAlloc:          return "MipsISD::DynAlloc";
216   case MipsISD::Sync:              return "MipsISD::Sync";
217   case MipsISD::Ext:               return "MipsISD::Ext";
218   case MipsISD::Ins:               return "MipsISD::Ins";
219   case MipsISD::CIns:              return "MipsISD::CIns";
220   case MipsISD::LWL:               return "MipsISD::LWL";
221   case MipsISD::LWR:               return "MipsISD::LWR";
222   case MipsISD::SWL:               return "MipsISD::SWL";
223   case MipsISD::SWR:               return "MipsISD::SWR";
224   case MipsISD::LDL:               return "MipsISD::LDL";
225   case MipsISD::LDR:               return "MipsISD::LDR";
226   case MipsISD::SDL:               return "MipsISD::SDL";
227   case MipsISD::SDR:               return "MipsISD::SDR";
228   case MipsISD::EXTP:              return "MipsISD::EXTP";
229   case MipsISD::EXTPDP:            return "MipsISD::EXTPDP";
230   case MipsISD::EXTR_S_H:          return "MipsISD::EXTR_S_H";
231   case MipsISD::EXTR_W:            return "MipsISD::EXTR_W";
232   case MipsISD::EXTR_R_W:          return "MipsISD::EXTR_R_W";
233   case MipsISD::EXTR_RS_W:         return "MipsISD::EXTR_RS_W";
234   case MipsISD::SHILO:             return "MipsISD::SHILO";
235   case MipsISD::MTHLIP:            return "MipsISD::MTHLIP";
236   case MipsISD::MULSAQ_S_W_PH:     return "MipsISD::MULSAQ_S_W_PH";
237   case MipsISD::MAQ_S_W_PHL:       return "MipsISD::MAQ_S_W_PHL";
238   case MipsISD::MAQ_S_W_PHR:       return "MipsISD::MAQ_S_W_PHR";
239   case MipsISD::MAQ_SA_W_PHL:      return "MipsISD::MAQ_SA_W_PHL";
240   case MipsISD::MAQ_SA_W_PHR:      return "MipsISD::MAQ_SA_W_PHR";
241   case MipsISD::DOUBLE_SELECT_I:   return "MipsISD::DOUBLE_SELECT_I";
242   case MipsISD::DOUBLE_SELECT_I64: return "MipsISD::DOUBLE_SELECT_I64";
243   case MipsISD::DPAU_H_QBL:        return "MipsISD::DPAU_H_QBL";
244   case MipsISD::DPAU_H_QBR:        return "MipsISD::DPAU_H_QBR";
245   case MipsISD::DPSU_H_QBL:        return "MipsISD::DPSU_H_QBL";
246   case MipsISD::DPSU_H_QBR:        return "MipsISD::DPSU_H_QBR";
247   case MipsISD::DPAQ_S_W_PH:       return "MipsISD::DPAQ_S_W_PH";
248   case MipsISD::DPSQ_S_W_PH:       return "MipsISD::DPSQ_S_W_PH";
249   case MipsISD::DPAQ_SA_L_W:       return "MipsISD::DPAQ_SA_L_W";
250   case MipsISD::DPSQ_SA_L_W:       return "MipsISD::DPSQ_SA_L_W";
251   case MipsISD::DPA_W_PH:          return "MipsISD::DPA_W_PH";
252   case MipsISD::DPS_W_PH:          return "MipsISD::DPS_W_PH";
253   case MipsISD::DPAQX_S_W_PH:      return "MipsISD::DPAQX_S_W_PH";
254   case MipsISD::DPAQX_SA_W_PH:     return "MipsISD::DPAQX_SA_W_PH";
255   case MipsISD::DPAX_W_PH:         return "MipsISD::DPAX_W_PH";
256   case MipsISD::DPSX_W_PH:         return "MipsISD::DPSX_W_PH";
257   case MipsISD::DPSQX_S_W_PH:      return "MipsISD::DPSQX_S_W_PH";
258   case MipsISD::DPSQX_SA_W_PH:     return "MipsISD::DPSQX_SA_W_PH";
259   case MipsISD::MULSA_W_PH:        return "MipsISD::MULSA_W_PH";
260   case MipsISD::MULT:              return "MipsISD::MULT";
261   case MipsISD::MULTU:             return "MipsISD::MULTU";
262   case MipsISD::MADD_DSP:          return "MipsISD::MADD_DSP";
263   case MipsISD::MADDU_DSP:         return "MipsISD::MADDU_DSP";
264   case MipsISD::MSUB_DSP:          return "MipsISD::MSUB_DSP";
265   case MipsISD::MSUBU_DSP:         return "MipsISD::MSUBU_DSP";
266   case MipsISD::SHLL_DSP:          return "MipsISD::SHLL_DSP";
267   case MipsISD::SHRA_DSP:          return "MipsISD::SHRA_DSP";
268   case MipsISD::SHRL_DSP:          return "MipsISD::SHRL_DSP";
269   case MipsISD::SETCC_DSP:         return "MipsISD::SETCC_DSP";
270   case MipsISD::SELECT_CC_DSP:     return "MipsISD::SELECT_CC_DSP";
271   case MipsISD::VALL_ZERO:         return "MipsISD::VALL_ZERO";
272   case MipsISD::VANY_ZERO:         return "MipsISD::VANY_ZERO";
273   case MipsISD::VALL_NONZERO:      return "MipsISD::VALL_NONZERO";
274   case MipsISD::VANY_NONZERO:      return "MipsISD::VANY_NONZERO";
275   case MipsISD::VCEQ:              return "MipsISD::VCEQ";
276   case MipsISD::VCLE_S:            return "MipsISD::VCLE_S";
277   case MipsISD::VCLE_U:            return "MipsISD::VCLE_U";
278   case MipsISD::VCLT_S:            return "MipsISD::VCLT_S";
279   case MipsISD::VCLT_U:            return "MipsISD::VCLT_U";
280   case MipsISD::VEXTRACT_SEXT_ELT: return "MipsISD::VEXTRACT_SEXT_ELT";
281   case MipsISD::VEXTRACT_ZEXT_ELT: return "MipsISD::VEXTRACT_ZEXT_ELT";
282   case MipsISD::VNOR:              return "MipsISD::VNOR";
283   case MipsISD::VSHF:              return "MipsISD::VSHF";
284   case MipsISD::SHF:               return "MipsISD::SHF";
285   case MipsISD::ILVEV:             return "MipsISD::ILVEV";
286   case MipsISD::ILVOD:             return "MipsISD::ILVOD";
287   case MipsISD::ILVL:              return "MipsISD::ILVL";
288   case MipsISD::ILVR:              return "MipsISD::ILVR";
289   case MipsISD::PCKEV:             return "MipsISD::PCKEV";
290   case MipsISD::PCKOD:             return "MipsISD::PCKOD";
291   case MipsISD::INSVE:             return "MipsISD::INSVE";
292   }
293   return nullptr;
294 }
295 
296 MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM,
297                                        const MipsSubtarget &STI)
298     : TargetLowering(TM), Subtarget(STI), ABI(TM.getABI()) {
299   // Mips does not have i1 type, so use i32 for
300   // setcc operations results (slt, sgt, ...).
301   setBooleanContents(ZeroOrOneBooleanContent);
302   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
303   // The cmp.cond.fmt instruction in MIPS32r6/MIPS64r6 uses 0 and -1 like MSA
304   // does. Integer booleans still use 0 and 1.
305   if (Subtarget.hasMips32r6())
306     setBooleanContents(ZeroOrOneBooleanContent,
307                        ZeroOrNegativeOneBooleanContent);
308 
309   // Load extented operations for i1 types must be promoted
310   for (MVT VT : MVT::integer_valuetypes()) {
311     setLoadExtAction(ISD::EXTLOAD,  VT, MVT::i1,  Promote);
312     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1,  Promote);
313     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1,  Promote);
314   }
315 
316   // MIPS doesn't have extending float->double load/store.  Set LoadExtAction
317   // for f32, f16
318   for (MVT VT : MVT::fp_valuetypes()) {
319     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
320     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
321   }
322 
323   // Set LoadExtAction for f16 vectors to Expand
324   for (MVT VT : MVT::fp_fixedlen_vector_valuetypes()) {
325     MVT F16VT = MVT::getVectorVT(MVT::f16, VT.getVectorNumElements());
326     if (F16VT.isValid())
327       setLoadExtAction(ISD::EXTLOAD, VT, F16VT, Expand);
328   }
329 
330   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
331   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
332 
333   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
334 
335   // Used by legalize types to correctly generate the setcc result.
336   // Without this, every float setcc comes with a AND/OR with the result,
337   // we don't want this, since the fpcmp result goes to a flag register,
338   // which is used implicitly by brcond and select operations.
339   AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
340 
341   // Mips Custom Operations
342   setOperationAction(ISD::BR_JT,              MVT::Other, Expand);
343   setOperationAction(ISD::GlobalAddress,      MVT::i32,   Custom);
344   setOperationAction(ISD::BlockAddress,       MVT::i32,   Custom);
345   setOperationAction(ISD::GlobalTLSAddress,   MVT::i32,   Custom);
346   setOperationAction(ISD::JumpTable,          MVT::i32,   Custom);
347   setOperationAction(ISD::ConstantPool,       MVT::i32,   Custom);
348   setOperationAction(ISD::SELECT,             MVT::f32,   Custom);
349   setOperationAction(ISD::SELECT,             MVT::f64,   Custom);
350   setOperationAction(ISD::SELECT,             MVT::i32,   Custom);
351   setOperationAction(ISD::SETCC,              MVT::f32,   Custom);
352   setOperationAction(ISD::SETCC,              MVT::f64,   Custom);
353   setOperationAction(ISD::BRCOND,             MVT::Other, Custom);
354   setOperationAction(ISD::FABS,               MVT::f32,   Custom);
355   setOperationAction(ISD::FABS,               MVT::f64,   Custom);
356   setOperationAction(ISD::FCOPYSIGN,          MVT::f32,   Custom);
357   setOperationAction(ISD::FCOPYSIGN,          MVT::f64,   Custom);
358   setOperationAction(ISD::FP_TO_SINT,         MVT::i32,   Custom);
359 
360   // Lower fmin/fmax/fclass operations for MIPS R6.
361   if (Subtarget.hasMips32r6()) {
362     setOperationAction(ISD::FMINNUM_IEEE, MVT::f32, Legal);
363     setOperationAction(ISD::FMAXNUM_IEEE, MVT::f32, Legal);
364     setOperationAction(ISD::FMINNUM, MVT::f32, Expand);
365     setOperationAction(ISD::FMAXNUM, MVT::f32, Expand);
366     setOperationAction(ISD::FMINNUM_IEEE, MVT::f64, Legal);
367     setOperationAction(ISD::FMAXNUM_IEEE, MVT::f64, Legal);
368     setOperationAction(ISD::FMINNUM, MVT::f64, Expand);
369     setOperationAction(ISD::FMAXNUM, MVT::f64, Expand);
370     setOperationAction(ISD::IS_FPCLASS, MVT::f32, Legal);
371     setOperationAction(ISD::IS_FPCLASS, MVT::f64, Legal);
372   } else {
373     setOperationAction(ISD::FCANONICALIZE, MVT::f32, Custom);
374     setOperationAction(ISD::FCANONICALIZE, MVT::f64, Custom);
375   }
376 
377   if (Subtarget.isGP64bit()) {
378     setOperationAction(ISD::GlobalAddress,      MVT::i64,   Custom);
379     setOperationAction(ISD::BlockAddress,       MVT::i64,   Custom);
380     setOperationAction(ISD::GlobalTLSAddress,   MVT::i64,   Custom);
381     setOperationAction(ISD::JumpTable,          MVT::i64,   Custom);
382     setOperationAction(ISD::ConstantPool,       MVT::i64,   Custom);
383     setOperationAction(ISD::SELECT,             MVT::i64,   Custom);
384     if (Subtarget.hasMips64r6()) {
385       setOperationAction(ISD::LOAD,               MVT::i64,   Legal);
386       setOperationAction(ISD::STORE,              MVT::i64,   Legal);
387     } else {
388       setOperationAction(ISD::LOAD,               MVT::i64,   Custom);
389       setOperationAction(ISD::STORE,              MVT::i64,   Custom);
390     }
391     setOperationAction(ISD::FP_TO_SINT,         MVT::i64,   Custom);
392     setOperationAction(ISD::SHL_PARTS,          MVT::i64,   Custom);
393     setOperationAction(ISD::SRA_PARTS,          MVT::i64,   Custom);
394     setOperationAction(ISD::SRL_PARTS,          MVT::i64,   Custom);
395   }
396 
397   if (!Subtarget.isGP64bit()) {
398     setOperationAction(ISD::SHL_PARTS,          MVT::i32,   Custom);
399     setOperationAction(ISD::SRA_PARTS,          MVT::i32,   Custom);
400     setOperationAction(ISD::SRL_PARTS,          MVT::i32,   Custom);
401   }
402 
403   setOperationAction(ISD::EH_DWARF_CFA,         MVT::i32,   Custom);
404   if (Subtarget.isGP64bit())
405     setOperationAction(ISD::EH_DWARF_CFA,       MVT::i64,   Custom);
406 
407   setOperationAction(ISD::SDIV, MVT::i32, Expand);
408   setOperationAction(ISD::SREM, MVT::i32, Expand);
409   setOperationAction(ISD::UDIV, MVT::i32, Expand);
410   setOperationAction(ISD::UREM, MVT::i32, Expand);
411   setOperationAction(ISD::SDIV, MVT::i64, Expand);
412   setOperationAction(ISD::SREM, MVT::i64, Expand);
413   setOperationAction(ISD::UDIV, MVT::i64, Expand);
414   setOperationAction(ISD::UREM, MVT::i64, Expand);
415 
416   // Operations not directly supported by Mips.
417   setOperationAction(ISD::BR_CC,             MVT::f32,   Expand);
418   setOperationAction(ISD::BR_CC,             MVT::f64,   Expand);
419   setOperationAction(ISD::BR_CC,             MVT::i32,   Expand);
420   setOperationAction(ISD::BR_CC,             MVT::i64,   Expand);
421   setOperationAction(ISD::SELECT_CC,         MVT::i32,   Expand);
422   setOperationAction(ISD::SELECT_CC,         MVT::i64,   Expand);
423   setOperationAction(ISD::SELECT_CC,         MVT::f32,   Expand);
424   setOperationAction(ISD::SELECT_CC,         MVT::f64,   Expand);
425   setOperationAction(ISD::UINT_TO_FP,        MVT::i32,   Expand);
426   setOperationAction(ISD::UINT_TO_FP,        MVT::i64,   Expand);
427   setOperationAction(ISD::FP_TO_UINT,        MVT::i32,   Expand);
428   setOperationAction(ISD::FP_TO_UINT,        MVT::i64,   Expand);
429   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1,    Expand);
430   if (Subtarget.hasCnMips()) {
431     setOperationAction(ISD::CTPOP,           MVT::i32,   Legal);
432     setOperationAction(ISD::CTPOP,           MVT::i64,   Legal);
433   } else {
434     setOperationAction(ISD::CTPOP,           MVT::i32,   Expand);
435     setOperationAction(ISD::CTPOP,           MVT::i64,   Expand);
436   }
437   setOperationAction(ISD::CTTZ,              MVT::i32,   Expand);
438   setOperationAction(ISD::CTTZ,              MVT::i64,   Expand);
439   setOperationAction(ISD::ROTL,              MVT::i32,   Expand);
440   setOperationAction(ISD::ROTL,              MVT::i64,   Expand);
441   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32,  Expand);
442   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64,  Expand);
443 
444   if (!Subtarget.hasMips32r2())
445     setOperationAction(ISD::ROTR, MVT::i32,   Expand);
446 
447   if (!Subtarget.hasMips64r2())
448     setOperationAction(ISD::ROTR, MVT::i64,   Expand);
449 
450   setOperationAction(ISD::FSIN,              MVT::f32,   Expand);
451   setOperationAction(ISD::FSIN,              MVT::f64,   Expand);
452   setOperationAction(ISD::FCOS,              MVT::f32,   Expand);
453   setOperationAction(ISD::FCOS,              MVT::f64,   Expand);
454   setOperationAction(ISD::FSINCOS,           MVT::f32,   Expand);
455   setOperationAction(ISD::FSINCOS,           MVT::f64,   Expand);
456   setOperationAction(ISD::FPOW,              MVT::f32,   Expand);
457   setOperationAction(ISD::FPOW,              MVT::f64,   Expand);
458   setOperationAction(ISD::FLOG,              MVT::f32,   Expand);
459   setOperationAction(ISD::FLOG2,             MVT::f32,   Expand);
460   setOperationAction(ISD::FLOG10,            MVT::f32,   Expand);
461   setOperationAction(ISD::FEXP,              MVT::f32,   Expand);
462   setOperationAction(ISD::FMA,               MVT::f32,   Expand);
463   setOperationAction(ISD::FMA,               MVT::f64,   Expand);
464   setOperationAction(ISD::FREM,              MVT::f32,   Expand);
465   setOperationAction(ISD::FREM,              MVT::f64,   Expand);
466 
467   // Lower f16 conversion operations into library calls
468   setOperationAction(ISD::FP16_TO_FP,        MVT::f32,   Expand);
469   setOperationAction(ISD::FP_TO_FP16,        MVT::f32,   Expand);
470   setOperationAction(ISD::FP16_TO_FP,        MVT::f64,   Expand);
471   setOperationAction(ISD::FP_TO_FP16,        MVT::f64,   Expand);
472 
473   setOperationAction(ISD::EH_RETURN, MVT::Other, Custom);
474 
475   setOperationAction(ISD::VASTART,           MVT::Other, Custom);
476   setOperationAction(ISD::VAARG,             MVT::Other, Custom);
477   setOperationAction(ISD::VACOPY,            MVT::Other, Expand);
478   setOperationAction(ISD::VAEND,             MVT::Other, Expand);
479 
480   // Use the default for now
481   setOperationAction(ISD::STACKSAVE,         MVT::Other, Expand);
482   setOperationAction(ISD::STACKRESTORE,      MVT::Other, Expand);
483 
484   if (!Subtarget.isGP64bit()) {
485     setOperationAction(ISD::ATOMIC_LOAD,     MVT::i64,   Expand);
486     setOperationAction(ISD::ATOMIC_STORE,    MVT::i64,   Expand);
487   }
488 
489   if (!Subtarget.hasMips32r2()) {
490     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
491     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
492   }
493 
494   // MIPS16 lacks MIPS32's clz and clo instructions.
495   if (!Subtarget.hasMips32() || Subtarget.inMips16Mode())
496     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
497   if (!Subtarget.hasMips64())
498     setOperationAction(ISD::CTLZ, MVT::i64, Expand);
499 
500   if (!Subtarget.hasMips32r2())
501     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
502   if (!Subtarget.hasMips64r2())
503     setOperationAction(ISD::BSWAP, MVT::i64, Expand);
504 
505   if (Subtarget.isGP64bit() && Subtarget.hasMips64r6()) {
506     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, MVT::i32, Legal);
507     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, MVT::i32, Legal);
508     setLoadExtAction(ISD::EXTLOAD, MVT::i64, MVT::i32, Legal);
509     setTruncStoreAction(MVT::i64, MVT::i32, Legal);
510   } else if (Subtarget.isGP64bit()) {
511     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, MVT::i32, Custom);
512     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, MVT::i32, Custom);
513     setLoadExtAction(ISD::EXTLOAD, MVT::i64, MVT::i32, Custom);
514     setTruncStoreAction(MVT::i64, MVT::i32, Custom);
515   }
516 
517   setOperationAction(ISD::TRAP, MVT::Other, Legal);
518 
519   setTargetDAGCombine({ISD::SDIVREM, ISD::UDIVREM, ISD::SELECT, ISD::AND,
520                        ISD::OR, ISD::ADD, ISD::SUB, ISD::AssertZext, ISD::SHL});
521 
522   if (Subtarget.isGP64bit())
523     setMaxAtomicSizeInBitsSupported(64);
524   else
525     setMaxAtomicSizeInBitsSupported(32);
526 
527   setMinFunctionAlignment(Subtarget.isGP64bit() ? Align(8) : Align(4));
528 
529   // The arguments on the stack are defined in terms of 4-byte slots on O32
530   // and 8-byte slots on N32/N64.
531   setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? Align(8)
532                                                             : Align(4));
533 
534   setStackPointerRegisterToSaveRestore(ABI.IsN64() ? Mips::SP_64 : Mips::SP);
535 
536   MaxStoresPerMemcpy = 16;
537 
538   isMicroMips = Subtarget.inMicroMipsMode();
539 }
540 
541 const MipsTargetLowering *
542 MipsTargetLowering::create(const MipsTargetMachine &TM,
543                            const MipsSubtarget &STI) {
544   if (STI.inMips16Mode())
545     return createMips16TargetLowering(TM, STI);
546 
547   return createMipsSETargetLowering(TM, STI);
548 }
549 
550 // Create a fast isel object.
551 FastISel *
552 MipsTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
553                                   const TargetLibraryInfo *libInfo) const {
554   const MipsTargetMachine &TM =
555       static_cast<const MipsTargetMachine &>(funcInfo.MF->getTarget());
556 
557   // We support only the standard encoding [MIPS32,MIPS32R5] ISAs.
558   bool UseFastISel = TM.Options.EnableFastISel && Subtarget.hasMips32() &&
559                      !Subtarget.hasMips32r6() && !Subtarget.inMips16Mode() &&
560                      !Subtarget.inMicroMipsMode();
561 
562   // Disable if either of the following is true:
563   // We do not generate PIC, the ABI is not O32, XGOT is being used.
564   if (!TM.isPositionIndependent() || !TM.getABI().IsO32() ||
565       Subtarget.useXGOT())
566     UseFastISel = false;
567 
568   return UseFastISel ? Mips::createFastISel(funcInfo, libInfo) : nullptr;
569 }
570 
571 EVT MipsTargetLowering::getSetCCResultType(const DataLayout &, LLVMContext &,
572                                            EVT VT) const {
573   if (!VT.isVector())
574     return MVT::i32;
575   return VT.changeVectorElementTypeToInteger();
576 }
577 
578 static SDValue performDivRemCombine(SDNode *N, SelectionDAG &DAG,
579                                     TargetLowering::DAGCombinerInfo &DCI,
580                                     const MipsSubtarget &Subtarget) {
581   if (DCI.isBeforeLegalizeOps())
582     return SDValue();
583 
584   EVT Ty = N->getValueType(0);
585   unsigned LO = (Ty == MVT::i32) ? Mips::LO0 : Mips::LO0_64;
586   unsigned HI = (Ty == MVT::i32) ? Mips::HI0 : Mips::HI0_64;
587   unsigned Opc = N->getOpcode() == ISD::SDIVREM ? MipsISD::DivRem16 :
588                                                   MipsISD::DivRemU16;
589   SDLoc DL(N);
590 
591   SDValue DivRem = DAG.getNode(Opc, DL, MVT::Glue,
592                                N->getOperand(0), N->getOperand(1));
593   SDValue InChain = DAG.getEntryNode();
594   SDValue InGlue = DivRem;
595 
596   // insert MFLO
597   if (N->hasAnyUseOfValue(0)) {
598     SDValue CopyFromLo = DAG.getCopyFromReg(InChain, DL, LO, Ty,
599                                             InGlue);
600     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), CopyFromLo);
601     InChain = CopyFromLo.getValue(1);
602     InGlue = CopyFromLo.getValue(2);
603   }
604 
605   // insert MFHI
606   if (N->hasAnyUseOfValue(1)) {
607     SDValue CopyFromHi = DAG.getCopyFromReg(InChain, DL,
608                                             HI, Ty, InGlue);
609     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi);
610   }
611 
612   return SDValue();
613 }
614 
615 static Mips::CondCode condCodeToFCC(ISD::CondCode CC) {
616   switch (CC) {
617   default: llvm_unreachable("Unknown fp condition code!");
618   case ISD::SETEQ:
619   case ISD::SETOEQ: return Mips::FCOND_OEQ;
620   case ISD::SETUNE: return Mips::FCOND_UNE;
621   case ISD::SETLT:
622   case ISD::SETOLT: return Mips::FCOND_OLT;
623   case ISD::SETGT:
624   case ISD::SETOGT: return Mips::FCOND_OGT;
625   case ISD::SETLE:
626   case ISD::SETOLE: return Mips::FCOND_OLE;
627   case ISD::SETGE:
628   case ISD::SETOGE: return Mips::FCOND_OGE;
629   case ISD::SETULT: return Mips::FCOND_ULT;
630   case ISD::SETULE: return Mips::FCOND_ULE;
631   case ISD::SETUGT: return Mips::FCOND_UGT;
632   case ISD::SETUGE: return Mips::FCOND_UGE;
633   case ISD::SETUO:  return Mips::FCOND_UN;
634   case ISD::SETO:   return Mips::FCOND_OR;
635   case ISD::SETNE:
636   case ISD::SETONE: return Mips::FCOND_ONE;
637   case ISD::SETUEQ: return Mips::FCOND_UEQ;
638   }
639 }
640 
641 /// This function returns true if the floating point conditional branches and
642 /// conditional moves which use condition code CC should be inverted.
643 static bool invertFPCondCodeUser(Mips::CondCode CC) {
644   if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT)
645     return false;
646 
647   assert((CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) &&
648          "Illegal Condition Code");
649 
650   return true;
651 }
652 
653 // Creates and returns an FPCmp node from a setcc node.
654 // Returns Op if setcc is not a floating point comparison.
655 static SDValue createFPCmp(SelectionDAG &DAG, const SDValue &Op) {
656   // must be a SETCC node
657   if (Op.getOpcode() != ISD::SETCC)
658     return Op;
659 
660   SDValue LHS = Op.getOperand(0);
661 
662   if (!LHS.getValueType().isFloatingPoint())
663     return Op;
664 
665   SDValue RHS = Op.getOperand(1);
666   SDLoc DL(Op);
667 
668   // Assume the 3rd operand is a CondCodeSDNode. Add code to check the type of
669   // node if necessary.
670   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
671 
672   return DAG.getNode(MipsISD::FPCmp, DL, MVT::Glue, LHS, RHS,
673                      DAG.getConstant(condCodeToFCC(CC), DL, MVT::i32));
674 }
675 
676 // Creates and returns a CMovFPT/F node.
677 static SDValue createCMovFP(SelectionDAG &DAG, SDValue Cond, SDValue True,
678                             SDValue False, const SDLoc &DL) {
679   ConstantSDNode *CC = cast<ConstantSDNode>(Cond.getOperand(2));
680   bool invert = invertFPCondCodeUser((Mips::CondCode)CC->getSExtValue());
681   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
682 
683   return DAG.getNode((invert ? MipsISD::CMovFP_F : MipsISD::CMovFP_T), DL,
684                      True.getValueType(), True, FCC0, False, Cond);
685 }
686 
687 static SDValue performSELECTCombine(SDNode *N, SelectionDAG &DAG,
688                                     TargetLowering::DAGCombinerInfo &DCI,
689                                     const MipsSubtarget &Subtarget) {
690   if (DCI.isBeforeLegalizeOps())
691     return SDValue();
692 
693   SDValue SetCC = N->getOperand(0);
694 
695   if ((SetCC.getOpcode() != ISD::SETCC) ||
696       !SetCC.getOperand(0).getValueType().isInteger())
697     return SDValue();
698 
699   SDValue False = N->getOperand(2);
700   EVT FalseTy = False.getValueType();
701 
702   if (!FalseTy.isInteger())
703     return SDValue();
704 
705   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(False);
706 
707   // If the RHS (False) is 0, we swap the order of the operands
708   // of ISD::SELECT (obviously also inverting the condition) so that we can
709   // take advantage of conditional moves using the $0 register.
710   // Example:
711   //   return (a != 0) ? x : 0;
712   //     load $reg, x
713   //     movz $reg, $0, a
714   if (!FalseC)
715     return SDValue();
716 
717   const SDLoc DL(N);
718 
719   if (!FalseC->getZExtValue()) {
720     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
721     SDValue True = N->getOperand(1);
722 
723     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
724                          SetCC.getOperand(1),
725                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
726 
727     return DAG.getNode(ISD::SELECT, DL, FalseTy, SetCC, False, True);
728   }
729 
730   // If both operands are integer constants there's a possibility that we
731   // can do some interesting optimizations.
732   SDValue True = N->getOperand(1);
733   ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(True);
734 
735   if (!TrueC || !True.getValueType().isInteger())
736     return SDValue();
737 
738   // We'll also ignore MVT::i64 operands as this optimizations proves
739   // to be ineffective because of the required sign extensions as the result
740   // of a SETCC operator is always MVT::i32 for non-vector types.
741   if (True.getValueType() == MVT::i64)
742     return SDValue();
743 
744   int64_t Diff = TrueC->getSExtValue() - FalseC->getSExtValue();
745 
746   // 1)  (a < x) ? y : y-1
747   //  slti $reg1, a, x
748   //  addiu $reg2, $reg1, y-1
749   if (Diff == 1)
750     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, False);
751 
752   // 2)  (a < x) ? y-1 : y
753   //  slti $reg1, a, x
754   //  xor $reg1, $reg1, 1
755   //  addiu $reg2, $reg1, y-1
756   if (Diff == -1) {
757     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
758     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
759                          SetCC.getOperand(1),
760                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
761     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, True);
762   }
763 
764   // Could not optimize.
765   return SDValue();
766 }
767 
768 static SDValue performCMovFPCombine(SDNode *N, SelectionDAG &DAG,
769                                     TargetLowering::DAGCombinerInfo &DCI,
770                                     const MipsSubtarget &Subtarget) {
771   if (DCI.isBeforeLegalizeOps())
772     return SDValue();
773 
774   SDValue ValueIfTrue = N->getOperand(0), ValueIfFalse = N->getOperand(2);
775 
776   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(ValueIfFalse);
777   if (!FalseC || FalseC->getZExtValue())
778     return SDValue();
779 
780   // Since RHS (False) is 0, we swap the order of the True/False operands
781   // (obviously also inverting the condition) so that we can
782   // take advantage of conditional moves using the $0 register.
783   // Example:
784   //   return (a != 0) ? x : 0;
785   //     load $reg, x
786   //     movz $reg, $0, a
787   unsigned Opc = (N->getOpcode() == MipsISD::CMovFP_T) ? MipsISD::CMovFP_F :
788                                                          MipsISD::CMovFP_T;
789 
790   SDValue FCC = N->getOperand(1), Glue = N->getOperand(3);
791   return DAG.getNode(Opc, SDLoc(N), ValueIfFalse.getValueType(),
792                      ValueIfFalse, FCC, ValueIfTrue, Glue);
793 }
794 
795 static SDValue performANDCombine(SDNode *N, SelectionDAG &DAG,
796                                  TargetLowering::DAGCombinerInfo &DCI,
797                                  const MipsSubtarget &Subtarget) {
798   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
799     return SDValue();
800 
801   SDValue FirstOperand = N->getOperand(0);
802   unsigned FirstOperandOpc = FirstOperand.getOpcode();
803   SDValue Mask = N->getOperand(1);
804   EVT ValTy = N->getValueType(0);
805   SDLoc DL(N);
806 
807   uint64_t Pos = 0;
808   unsigned SMPos, SMSize;
809   ConstantSDNode *CN;
810   SDValue NewOperand;
811   unsigned Opc;
812 
813   // Op's second operand must be a shifted mask.
814   if (!(CN = dyn_cast<ConstantSDNode>(Mask)) ||
815       !isShiftedMask_64(CN->getZExtValue(), SMPos, SMSize))
816     return SDValue();
817 
818   if (FirstOperandOpc == ISD::SRA || FirstOperandOpc == ISD::SRL) {
819     // Pattern match EXT.
820     //  $dst = and ((sra or srl) $src , pos), (2**size - 1)
821     //  => ext $dst, $src, pos, size
822 
823     // The second operand of the shift must be an immediate.
824     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
825       return SDValue();
826 
827     Pos = CN->getZExtValue();
828 
829     // Return if the shifted mask does not start at bit 0 or the sum of its size
830     // and Pos exceeds the word's size.
831     if (SMPos != 0 || Pos + SMSize > ValTy.getSizeInBits())
832       return SDValue();
833 
834     Opc = MipsISD::Ext;
835     NewOperand = FirstOperand.getOperand(0);
836   } else if (FirstOperandOpc == ISD::SHL && Subtarget.hasCnMips()) {
837     // Pattern match CINS.
838     //  $dst = and (shl $src , pos), mask
839     //  => cins $dst, $src, pos, size
840     // mask is a shifted mask with consecutive 1's, pos = shift amount,
841     // size = population count.
842 
843     // The second operand of the shift must be an immediate.
844     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
845       return SDValue();
846 
847     Pos = CN->getZExtValue();
848 
849     if (SMPos != Pos || Pos >= ValTy.getSizeInBits() || SMSize >= 32 ||
850         Pos + SMSize > ValTy.getSizeInBits())
851       return SDValue();
852 
853     NewOperand = FirstOperand.getOperand(0);
854     // SMSize is 'location' (position) in this case, not size.
855     SMSize--;
856     Opc = MipsISD::CIns;
857   } else {
858     // Pattern match EXT.
859     //  $dst = and $src, (2**size - 1) , if size > 16
860     //  => ext $dst, $src, pos, size , pos = 0
861 
862     // If the mask is <= 0xffff, andi can be used instead.
863     if (CN->getZExtValue() <= 0xffff)
864       return SDValue();
865 
866     // Return if the mask doesn't start at position 0.
867     if (SMPos)
868       return SDValue();
869 
870     Opc = MipsISD::Ext;
871     NewOperand = FirstOperand;
872   }
873   return DAG.getNode(Opc, DL, ValTy, NewOperand,
874                      DAG.getConstant(Pos, DL, MVT::i32),
875                      DAG.getConstant(SMSize, DL, MVT::i32));
876 }
877 
878 static SDValue performORCombine(SDNode *N, SelectionDAG &DAG,
879                                 TargetLowering::DAGCombinerInfo &DCI,
880                                 const MipsSubtarget &Subtarget) {
881   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
882     return SDValue();
883 
884   SDValue FirstOperand = N->getOperand(0), SecondOperand = N->getOperand(1);
885   unsigned SMPos0, SMSize0, SMPos1, SMSize1;
886   ConstantSDNode *CN, *CN1;
887 
888   if ((FirstOperand.getOpcode() == ISD::AND &&
889        SecondOperand.getOpcode() == ISD::SHL) ||
890       (FirstOperand.getOpcode() == ISD::SHL &&
891        SecondOperand.getOpcode() == ISD::AND)) {
892     // Pattern match INS.
893     //   $dst = or (and $src1, (2**size0 - 1)), (shl $src2, size0)
894     //   ==> ins $src1, $src2, pos, size, pos = size0, size = 32 - pos;
895     //   Or:
896     //   $dst = or (shl $src2, size0), (and $src1, (2**size0 - 1))
897     //   ==> ins $src1, $src2, pos, size, pos = size0, size = 32 - pos;
898     SDValue AndOperand0 = FirstOperand.getOpcode() == ISD::AND
899                               ? FirstOperand.getOperand(0)
900                               : SecondOperand.getOperand(0);
901     SDValue ShlOperand0 = FirstOperand.getOpcode() == ISD::AND
902                               ? SecondOperand.getOperand(0)
903                               : FirstOperand.getOperand(0);
904     SDValue AndMask = FirstOperand.getOpcode() == ISD::AND
905                           ? FirstOperand.getOperand(1)
906                           : SecondOperand.getOperand(1);
907     if (!(CN = dyn_cast<ConstantSDNode>(AndMask)) ||
908         !isShiftedMask_64(CN->getZExtValue(), SMPos0, SMSize0))
909       return SDValue();
910 
911     SDValue ShlShift = FirstOperand.getOpcode() == ISD::AND
912                            ? SecondOperand.getOperand(1)
913                            : FirstOperand.getOperand(1);
914     if (!(CN = dyn_cast<ConstantSDNode>(ShlShift)))
915       return SDValue();
916     uint64_t ShlShiftValue = CN->getZExtValue();
917 
918     if (SMPos0 != 0 || SMSize0 != ShlShiftValue)
919       return SDValue();
920 
921     SDLoc DL(N);
922     EVT ValTy = N->getValueType(0);
923     SMPos1 = ShlShiftValue;
924     assert(SMPos1 < ValTy.getSizeInBits());
925     SMSize1 = (ValTy == MVT::i64 ? 64 : 32) - SMPos1;
926     return DAG.getNode(MipsISD::Ins, DL, ValTy, ShlOperand0,
927                        DAG.getConstant(SMPos1, DL, MVT::i32),
928                        DAG.getConstant(SMSize1, DL, MVT::i32), AndOperand0);
929   }
930 
931   // See if Op's first operand matches (and $src1 , mask0).
932   if (FirstOperand.getOpcode() != ISD::AND)
933     return SDValue();
934 
935   // Pattern match INS.
936   //  $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1),
937   //  where mask1 = (2**size - 1) << pos, mask0 = ~mask1
938   //  => ins $dst, $src, size, pos, $src1
939   if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))) ||
940       !isShiftedMask_64(~CN->getSExtValue(), SMPos0, SMSize0))
941     return SDValue();
942 
943   // See if Op's second operand matches (and (shl $src, pos), mask1).
944   if (SecondOperand.getOpcode() == ISD::AND &&
945       SecondOperand.getOperand(0).getOpcode() == ISD::SHL) {
946 
947     if (!(CN = dyn_cast<ConstantSDNode>(SecondOperand.getOperand(1))) ||
948         !isShiftedMask_64(CN->getZExtValue(), SMPos1, SMSize1))
949       return SDValue();
950 
951     // The shift masks must have the same position and size.
952     if (SMPos0 != SMPos1 || SMSize0 != SMSize1)
953       return SDValue();
954 
955     SDValue Shl = SecondOperand.getOperand(0);
956 
957     if (!(CN = dyn_cast<ConstantSDNode>(Shl.getOperand(1))))
958       return SDValue();
959 
960     unsigned Shamt = CN->getZExtValue();
961 
962     // Return if the shift amount and the first bit position of mask are not the
963     // same.
964     EVT ValTy = N->getValueType(0);
965     if ((Shamt != SMPos0) || (SMPos0 + SMSize0 > ValTy.getSizeInBits()))
966       return SDValue();
967 
968     SDLoc DL(N);
969     return DAG.getNode(MipsISD::Ins, DL, ValTy, Shl.getOperand(0),
970                        DAG.getConstant(SMPos0, DL, MVT::i32),
971                        DAG.getConstant(SMSize0, DL, MVT::i32),
972                        FirstOperand.getOperand(0));
973   } else {
974     // Pattern match DINS.
975     //  $dst = or (and $src, mask0), mask1
976     //  where mask0 = ((1 << SMSize0) -1) << SMPos0
977     //  => dins $dst, $src, pos, size
978     if (~CN->getSExtValue() == ((((int64_t)1 << SMSize0) - 1) << SMPos0) &&
979         ((SMSize0 + SMPos0 <= 64 && Subtarget.hasMips64r2()) ||
980          (SMSize0 + SMPos0 <= 32))) {
981       // Check if AND instruction has constant as argument
982       bool isConstCase = SecondOperand.getOpcode() != ISD::AND;
983       if (SecondOperand.getOpcode() == ISD::AND) {
984         if (!(CN1 = dyn_cast<ConstantSDNode>(SecondOperand->getOperand(1))))
985           return SDValue();
986       } else {
987         if (!(CN1 = dyn_cast<ConstantSDNode>(N->getOperand(1))))
988           return SDValue();
989       }
990       // Don't generate INS if constant OR operand doesn't fit into bits
991       // cleared by constant AND operand.
992       if (CN->getSExtValue() & CN1->getSExtValue())
993         return SDValue();
994 
995       SDLoc DL(N);
996       EVT ValTy = N->getOperand(0)->getValueType(0);
997       SDValue Const1;
998       SDValue SrlX;
999       if (!isConstCase) {
1000         Const1 = DAG.getConstant(SMPos0, DL, MVT::i32);
1001         SrlX = DAG.getNode(ISD::SRL, DL, SecondOperand->getValueType(0),
1002                            SecondOperand, Const1);
1003       }
1004       return DAG.getNode(
1005           MipsISD::Ins, DL, N->getValueType(0),
1006           isConstCase
1007               ? DAG.getConstant(CN1->getSExtValue() >> SMPos0, DL, ValTy)
1008               : SrlX,
1009           DAG.getConstant(SMPos0, DL, MVT::i32),
1010           DAG.getConstant(ValTy.getSizeInBits() / 8 < 8 ? SMSize0 & 31
1011                                                         : SMSize0,
1012                           DL, MVT::i32),
1013           FirstOperand->getOperand(0));
1014     }
1015     return SDValue();
1016   }
1017 }
1018 
1019 static SDValue performMADD_MSUBCombine(SDNode *ROOTNode, SelectionDAG &CurDAG,
1020                                        const MipsSubtarget &Subtarget) {
1021   // ROOTNode must have a multiplication as an operand for the match to be
1022   // successful.
1023   if (ROOTNode->getOperand(0).getOpcode() != ISD::MUL &&
1024       ROOTNode->getOperand(1).getOpcode() != ISD::MUL)
1025     return SDValue();
1026 
1027   // In the case where we have a multiplication as the left operand of
1028   // of a subtraction, we can't combine into a MipsISD::MSub node as the
1029   // the instruction definition of msub(u) places the multiplication on
1030   // on the right.
1031   if (ROOTNode->getOpcode() == ISD::SUB &&
1032       ROOTNode->getOperand(0).getOpcode() == ISD::MUL)
1033     return SDValue();
1034 
1035   // We don't handle vector types here.
1036   if (ROOTNode->getValueType(0).isVector())
1037     return SDValue();
1038 
1039   // For MIPS64, madd / msub instructions are inefficent to use with 64 bit
1040   // arithmetic. E.g.
1041   // (add (mul a b) c) =>
1042   //   let res = (madd (mthi (drotr c 32))x(mtlo c) a b) in
1043   //   MIPS64:   (or (dsll (mfhi res) 32) (dsrl (dsll (mflo res) 32) 32)
1044   //   or
1045   //   MIPS64R2: (dins (mflo res) (mfhi res) 32 32)
1046   //
1047   // The overhead of setting up the Hi/Lo registers and reassembling the
1048   // result makes this a dubious optimzation for MIPS64. The core of the
1049   // problem is that Hi/Lo contain the upper and lower 32 bits of the
1050   // operand and result.
1051   //
1052   // It requires a chain of 4 add/mul for MIPS64R2 to get better code
1053   // density than doing it naively, 5 for MIPS64. Additionally, using
1054   // madd/msub on MIPS64 requires the operands actually be 32 bit sign
1055   // extended operands, not true 64 bit values.
1056   //
1057   // FIXME: For the moment, disable this completely for MIPS64.
1058   if (Subtarget.hasMips64())
1059     return SDValue();
1060 
1061   SDValue Mult = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
1062                      ? ROOTNode->getOperand(0)
1063                      : ROOTNode->getOperand(1);
1064 
1065   SDValue AddOperand = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
1066                      ? ROOTNode->getOperand(1)
1067                      : ROOTNode->getOperand(0);
1068 
1069   // Transform this to a MADD only if the user of this node is the add.
1070   // If there are other users of the mul, this function returns here.
1071   if (!Mult.hasOneUse())
1072     return SDValue();
1073 
1074   // maddu and madd are unusual instructions in that on MIPS64 bits 63..31
1075   // must be in canonical form, i.e. sign extended. For MIPS32, the operands
1076   // of the multiply must have 32 or more sign bits, otherwise we cannot
1077   // perform this optimization. We have to check this here as we're performing
1078   // this optimization pre-legalization.
1079   SDValue MultLHS = Mult->getOperand(0);
1080   SDValue MultRHS = Mult->getOperand(1);
1081 
1082   bool IsSigned = MultLHS->getOpcode() == ISD::SIGN_EXTEND &&
1083                   MultRHS->getOpcode() == ISD::SIGN_EXTEND;
1084   bool IsUnsigned = MultLHS->getOpcode() == ISD::ZERO_EXTEND &&
1085                     MultRHS->getOpcode() == ISD::ZERO_EXTEND;
1086 
1087   if (!IsSigned && !IsUnsigned)
1088     return SDValue();
1089 
1090   // Initialize accumulator.
1091   SDLoc DL(ROOTNode);
1092   SDValue BottomHalf, TopHalf;
1093   std::tie(BottomHalf, TopHalf) =
1094       CurDAG.SplitScalar(AddOperand, DL, MVT::i32, MVT::i32);
1095   SDValue ACCIn =
1096       CurDAG.getNode(MipsISD::MTLOHI, DL, MVT::Untyped, BottomHalf, TopHalf);
1097 
1098   // Create MipsMAdd(u) / MipsMSub(u) node.
1099   bool IsAdd = ROOTNode->getOpcode() == ISD::ADD;
1100   unsigned Opcode = IsAdd ? (IsUnsigned ? MipsISD::MAddu : MipsISD::MAdd)
1101                           : (IsUnsigned ? MipsISD::MSubu : MipsISD::MSub);
1102   SDValue MAddOps[3] = {
1103       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(0)),
1104       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(1)), ACCIn};
1105   SDValue MAdd = CurDAG.getNode(Opcode, DL, MVT::Untyped, MAddOps);
1106 
1107   SDValue ResLo = CurDAG.getNode(MipsISD::MFLO, DL, MVT::i32, MAdd);
1108   SDValue ResHi = CurDAG.getNode(MipsISD::MFHI, DL, MVT::i32, MAdd);
1109   SDValue Combined =
1110       CurDAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, ResLo, ResHi);
1111   return Combined;
1112 }
1113 
1114 static SDValue performSUBCombine(SDNode *N, SelectionDAG &DAG,
1115                                  TargetLowering::DAGCombinerInfo &DCI,
1116                                  const MipsSubtarget &Subtarget) {
1117   // (sub v0 (mul v1, v2)) => (msub v1, v2, v0)
1118   if (DCI.isBeforeLegalizeOps()) {
1119     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1120         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1121       return performMADD_MSUBCombine(N, DAG, Subtarget);
1122 
1123     return SDValue();
1124   }
1125 
1126   return SDValue();
1127 }
1128 
1129 static SDValue performADDCombine(SDNode *N, SelectionDAG &DAG,
1130                                  TargetLowering::DAGCombinerInfo &DCI,
1131                                  const MipsSubtarget &Subtarget) {
1132   // (add v0 (mul v1, v2)) => (madd v1, v2, v0)
1133   if (DCI.isBeforeLegalizeOps()) {
1134     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1135         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1136       return performMADD_MSUBCombine(N, DAG, Subtarget);
1137 
1138     return SDValue();
1139   }
1140 
1141   // (add v0, (add v1, abs_lo(tjt))) => (add (add v0, v1), abs_lo(tjt))
1142   SDValue Add = N->getOperand(1);
1143 
1144   if (Add.getOpcode() != ISD::ADD)
1145     return SDValue();
1146 
1147   SDValue Lo = Add.getOperand(1);
1148 
1149   if ((Lo.getOpcode() != MipsISD::Lo) ||
1150       (Lo.getOperand(0).getOpcode() != ISD::TargetJumpTable))
1151     return SDValue();
1152 
1153   EVT ValTy = N->getValueType(0);
1154   SDLoc DL(N);
1155 
1156   SDValue Add1 = DAG.getNode(ISD::ADD, DL, ValTy, N->getOperand(0),
1157                              Add.getOperand(0));
1158   return DAG.getNode(ISD::ADD, DL, ValTy, Add1, Lo);
1159 }
1160 
1161 static SDValue performSHLCombine(SDNode *N, SelectionDAG &DAG,
1162                                  TargetLowering::DAGCombinerInfo &DCI,
1163                                  const MipsSubtarget &Subtarget) {
1164   // Pattern match CINS.
1165   //  $dst = shl (and $src , imm), pos
1166   //  => cins $dst, $src, pos, size
1167 
1168   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasCnMips())
1169     return SDValue();
1170 
1171   SDValue FirstOperand = N->getOperand(0);
1172   unsigned FirstOperandOpc = FirstOperand.getOpcode();
1173   SDValue SecondOperand = N->getOperand(1);
1174   EVT ValTy = N->getValueType(0);
1175   SDLoc DL(N);
1176 
1177   uint64_t Pos = 0;
1178   unsigned SMPos, SMSize;
1179   ConstantSDNode *CN;
1180   SDValue NewOperand;
1181 
1182   // The second operand of the shift must be an immediate.
1183   if (!(CN = dyn_cast<ConstantSDNode>(SecondOperand)))
1184     return SDValue();
1185 
1186   Pos = CN->getZExtValue();
1187 
1188   if (Pos >= ValTy.getSizeInBits())
1189     return SDValue();
1190 
1191   if (FirstOperandOpc != ISD::AND)
1192     return SDValue();
1193 
1194   // AND's second operand must be a shifted mask.
1195   if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))) ||
1196       !isShiftedMask_64(CN->getZExtValue(), SMPos, SMSize))
1197     return SDValue();
1198 
1199   // Return if the shifted mask does not start at bit 0 or the sum of its size
1200   // and Pos exceeds the word's size.
1201   if (SMPos != 0 || SMSize > 32 || Pos + SMSize > ValTy.getSizeInBits())
1202     return SDValue();
1203 
1204   NewOperand = FirstOperand.getOperand(0);
1205   // SMSize is 'location' (position) in this case, not size.
1206   SMSize--;
1207 
1208   return DAG.getNode(MipsISD::CIns, DL, ValTy, NewOperand,
1209                      DAG.getConstant(Pos, DL, MVT::i32),
1210                      DAG.getConstant(SMSize, DL, MVT::i32));
1211 }
1212 
1213 SDValue  MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI)
1214   const {
1215   SelectionDAG &DAG = DCI.DAG;
1216   unsigned Opc = N->getOpcode();
1217 
1218   switch (Opc) {
1219   default: break;
1220   case ISD::SDIVREM:
1221   case ISD::UDIVREM:
1222     return performDivRemCombine(N, DAG, DCI, Subtarget);
1223   case ISD::SELECT:
1224     return performSELECTCombine(N, DAG, DCI, Subtarget);
1225   case MipsISD::CMovFP_F:
1226   case MipsISD::CMovFP_T:
1227     return performCMovFPCombine(N, DAG, DCI, Subtarget);
1228   case ISD::AND:
1229     return performANDCombine(N, DAG, DCI, Subtarget);
1230   case ISD::OR:
1231     return performORCombine(N, DAG, DCI, Subtarget);
1232   case ISD::ADD:
1233     return performADDCombine(N, DAG, DCI, Subtarget);
1234   case ISD::SHL:
1235     return performSHLCombine(N, DAG, DCI, Subtarget);
1236   case ISD::SUB:
1237     return performSUBCombine(N, DAG, DCI, Subtarget);
1238   }
1239 
1240   return SDValue();
1241 }
1242 
1243 bool MipsTargetLowering::isCheapToSpeculateCttz(Type *Ty) const {
1244   return Subtarget.hasMips32();
1245 }
1246 
1247 bool MipsTargetLowering::isCheapToSpeculateCtlz(Type *Ty) const {
1248   return Subtarget.hasMips32();
1249 }
1250 
1251 bool MipsTargetLowering::hasBitTest(SDValue X, SDValue Y) const {
1252   // We can use ANDI+SLTIU as a bit test. Y contains the bit position.
1253   // For MIPSR2 or later, we may be able to use the `ext` instruction or its'
1254   // double-word variants.
1255   if (auto *C = dyn_cast<ConstantSDNode>(Y))
1256     return C->getAPIntValue().ule(15);
1257 
1258   return false;
1259 }
1260 
1261 bool MipsTargetLowering::shouldFoldConstantShiftPairToMask(
1262     const SDNode *N, CombineLevel Level) const {
1263   assert(((N->getOpcode() == ISD::SHL &&
1264            N->getOperand(0).getOpcode() == ISD::SRL) ||
1265           (N->getOpcode() == ISD::SRL &&
1266            N->getOperand(0).getOpcode() == ISD::SHL)) &&
1267          "Expected shift-shift mask");
1268 
1269   if (N->getOperand(0).getValueType().isVector())
1270     return false;
1271   return true;
1272 }
1273 
1274 void
1275 MipsTargetLowering::ReplaceNodeResults(SDNode *N,
1276                                        SmallVectorImpl<SDValue> &Results,
1277                                        SelectionDAG &DAG) const {
1278   return LowerOperationWrapper(N, Results, DAG);
1279 }
1280 
1281 SDValue MipsTargetLowering::
1282 LowerOperation(SDValue Op, SelectionDAG &DAG) const
1283 {
1284   switch (Op.getOpcode())
1285   {
1286   case ISD::BRCOND:             return lowerBRCOND(Op, DAG);
1287   case ISD::ConstantPool:       return lowerConstantPool(Op, DAG);
1288   case ISD::GlobalAddress:      return lowerGlobalAddress(Op, DAG);
1289   case ISD::BlockAddress:       return lowerBlockAddress(Op, DAG);
1290   case ISD::GlobalTLSAddress:   return lowerGlobalTLSAddress(Op, DAG);
1291   case ISD::JumpTable:          return lowerJumpTable(Op, DAG);
1292   case ISD::SELECT:             return lowerSELECT(Op, DAG);
1293   case ISD::SETCC:              return lowerSETCC(Op, DAG);
1294   case ISD::VASTART:            return lowerVASTART(Op, DAG);
1295   case ISD::VAARG:              return lowerVAARG(Op, DAG);
1296   case ISD::FCOPYSIGN:          return lowerFCOPYSIGN(Op, DAG);
1297   case ISD::FABS:               return lowerFABS(Op, DAG);
1298   case ISD::FCANONICALIZE:
1299     return lowerFCANONICALIZE(Op, DAG);
1300   case ISD::FRAMEADDR:          return lowerFRAMEADDR(Op, DAG);
1301   case ISD::RETURNADDR:         return lowerRETURNADDR(Op, DAG);
1302   case ISD::EH_RETURN:          return lowerEH_RETURN(Op, DAG);
1303   case ISD::ATOMIC_FENCE:       return lowerATOMIC_FENCE(Op, DAG);
1304   case ISD::SHL_PARTS:          return lowerShiftLeftParts(Op, DAG);
1305   case ISD::SRA_PARTS:          return lowerShiftRightParts(Op, DAG, true);
1306   case ISD::SRL_PARTS:          return lowerShiftRightParts(Op, DAG, false);
1307   case ISD::LOAD:               return lowerLOAD(Op, DAG);
1308   case ISD::STORE:              return lowerSTORE(Op, DAG);
1309   case ISD::EH_DWARF_CFA:       return lowerEH_DWARF_CFA(Op, DAG);
1310   case ISD::FP_TO_SINT:         return lowerFP_TO_SINT(Op, DAG);
1311   }
1312   return SDValue();
1313 }
1314 
1315 //===----------------------------------------------------------------------===//
1316 //  Lower helper functions
1317 //===----------------------------------------------------------------------===//
1318 
1319 // addLiveIn - This helper function adds the specified physical register to the
1320 // MachineFunction as a live in value.  It also creates a corresponding
1321 // virtual register for it.
1322 static unsigned
1323 addLiveIn(MachineFunction &MF, unsigned PReg, const TargetRegisterClass *RC)
1324 {
1325   Register VReg = MF.getRegInfo().createVirtualRegister(RC);
1326   MF.getRegInfo().addLiveIn(PReg, VReg);
1327   return VReg;
1328 }
1329 
1330 static MachineBasicBlock *insertDivByZeroTrap(MachineInstr &MI,
1331                                               MachineBasicBlock &MBB,
1332                                               const TargetInstrInfo &TII,
1333                                               bool Is64Bit, bool IsMicroMips) {
1334   if (NoZeroDivCheck)
1335     return &MBB;
1336 
1337   // Insert instruction "teq $divisor_reg, $zero, 7".
1338   MachineBasicBlock::iterator I(MI);
1339   MachineInstrBuilder MIB;
1340   MachineOperand &Divisor = MI.getOperand(2);
1341   MIB = BuildMI(MBB, std::next(I), MI.getDebugLoc(),
1342                 TII.get(IsMicroMips ? Mips::TEQ_MM : Mips::TEQ))
1343             .addReg(Divisor.getReg(), getKillRegState(Divisor.isKill()))
1344             .addReg(Mips::ZERO)
1345             .addImm(7);
1346 
1347   // Use the 32-bit sub-register if this is a 64-bit division.
1348   if (Is64Bit)
1349     MIB->getOperand(0).setSubReg(Mips::sub_32);
1350 
1351   // Clear Divisor's kill flag.
1352   Divisor.setIsKill(false);
1353 
1354   // We would normally delete the original instruction here but in this case
1355   // we only needed to inject an additional instruction rather than replace it.
1356 
1357   return &MBB;
1358 }
1359 
1360 MachineBasicBlock *
1361 MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
1362                                                 MachineBasicBlock *BB) const {
1363   switch (MI.getOpcode()) {
1364   default:
1365     llvm_unreachable("Unexpected instr type to insert");
1366   case Mips::ATOMIC_LOAD_ADD_I8:
1367     return emitAtomicBinaryPartword(MI, BB, 1);
1368   case Mips::ATOMIC_LOAD_ADD_I16:
1369     return emitAtomicBinaryPartword(MI, BB, 2);
1370   case Mips::ATOMIC_LOAD_ADD_I32:
1371     return emitAtomicBinary(MI, BB);
1372   case Mips::ATOMIC_LOAD_ADD_I64:
1373     return emitAtomicBinary(MI, BB);
1374 
1375   case Mips::ATOMIC_LOAD_AND_I8:
1376     return emitAtomicBinaryPartword(MI, BB, 1);
1377   case Mips::ATOMIC_LOAD_AND_I16:
1378     return emitAtomicBinaryPartword(MI, BB, 2);
1379   case Mips::ATOMIC_LOAD_AND_I32:
1380     return emitAtomicBinary(MI, BB);
1381   case Mips::ATOMIC_LOAD_AND_I64:
1382     return emitAtomicBinary(MI, BB);
1383 
1384   case Mips::ATOMIC_LOAD_OR_I8:
1385     return emitAtomicBinaryPartword(MI, BB, 1);
1386   case Mips::ATOMIC_LOAD_OR_I16:
1387     return emitAtomicBinaryPartword(MI, BB, 2);
1388   case Mips::ATOMIC_LOAD_OR_I32:
1389     return emitAtomicBinary(MI, BB);
1390   case Mips::ATOMIC_LOAD_OR_I64:
1391     return emitAtomicBinary(MI, BB);
1392 
1393   case Mips::ATOMIC_LOAD_XOR_I8:
1394     return emitAtomicBinaryPartword(MI, BB, 1);
1395   case Mips::ATOMIC_LOAD_XOR_I16:
1396     return emitAtomicBinaryPartword(MI, BB, 2);
1397   case Mips::ATOMIC_LOAD_XOR_I32:
1398     return emitAtomicBinary(MI, BB);
1399   case Mips::ATOMIC_LOAD_XOR_I64:
1400     return emitAtomicBinary(MI, BB);
1401 
1402   case Mips::ATOMIC_LOAD_NAND_I8:
1403     return emitAtomicBinaryPartword(MI, BB, 1);
1404   case Mips::ATOMIC_LOAD_NAND_I16:
1405     return emitAtomicBinaryPartword(MI, BB, 2);
1406   case Mips::ATOMIC_LOAD_NAND_I32:
1407     return emitAtomicBinary(MI, BB);
1408   case Mips::ATOMIC_LOAD_NAND_I64:
1409     return emitAtomicBinary(MI, BB);
1410 
1411   case Mips::ATOMIC_LOAD_SUB_I8:
1412     return emitAtomicBinaryPartword(MI, BB, 1);
1413   case Mips::ATOMIC_LOAD_SUB_I16:
1414     return emitAtomicBinaryPartword(MI, BB, 2);
1415   case Mips::ATOMIC_LOAD_SUB_I32:
1416     return emitAtomicBinary(MI, BB);
1417   case Mips::ATOMIC_LOAD_SUB_I64:
1418     return emitAtomicBinary(MI, BB);
1419 
1420   case Mips::ATOMIC_SWAP_I8:
1421     return emitAtomicBinaryPartword(MI, BB, 1);
1422   case Mips::ATOMIC_SWAP_I16:
1423     return emitAtomicBinaryPartword(MI, BB, 2);
1424   case Mips::ATOMIC_SWAP_I32:
1425     return emitAtomicBinary(MI, BB);
1426   case Mips::ATOMIC_SWAP_I64:
1427     return emitAtomicBinary(MI, BB);
1428 
1429   case Mips::ATOMIC_CMP_SWAP_I8:
1430     return emitAtomicCmpSwapPartword(MI, BB, 1);
1431   case Mips::ATOMIC_CMP_SWAP_I16:
1432     return emitAtomicCmpSwapPartword(MI, BB, 2);
1433   case Mips::ATOMIC_CMP_SWAP_I32:
1434     return emitAtomicCmpSwap(MI, BB);
1435   case Mips::ATOMIC_CMP_SWAP_I64:
1436     return emitAtomicCmpSwap(MI, BB);
1437 
1438   case Mips::ATOMIC_LOAD_MIN_I8:
1439     return emitAtomicBinaryPartword(MI, BB, 1);
1440   case Mips::ATOMIC_LOAD_MIN_I16:
1441     return emitAtomicBinaryPartword(MI, BB, 2);
1442   case Mips::ATOMIC_LOAD_MIN_I32:
1443     return emitAtomicBinary(MI, BB);
1444   case Mips::ATOMIC_LOAD_MIN_I64:
1445     return emitAtomicBinary(MI, BB);
1446 
1447   case Mips::ATOMIC_LOAD_MAX_I8:
1448     return emitAtomicBinaryPartword(MI, BB, 1);
1449   case Mips::ATOMIC_LOAD_MAX_I16:
1450     return emitAtomicBinaryPartword(MI, BB, 2);
1451   case Mips::ATOMIC_LOAD_MAX_I32:
1452     return emitAtomicBinary(MI, BB);
1453   case Mips::ATOMIC_LOAD_MAX_I64:
1454     return emitAtomicBinary(MI, BB);
1455 
1456   case Mips::ATOMIC_LOAD_UMIN_I8:
1457     return emitAtomicBinaryPartword(MI, BB, 1);
1458   case Mips::ATOMIC_LOAD_UMIN_I16:
1459     return emitAtomicBinaryPartword(MI, BB, 2);
1460   case Mips::ATOMIC_LOAD_UMIN_I32:
1461     return emitAtomicBinary(MI, BB);
1462   case Mips::ATOMIC_LOAD_UMIN_I64:
1463     return emitAtomicBinary(MI, BB);
1464 
1465   case Mips::ATOMIC_LOAD_UMAX_I8:
1466     return emitAtomicBinaryPartword(MI, BB, 1);
1467   case Mips::ATOMIC_LOAD_UMAX_I16:
1468     return emitAtomicBinaryPartword(MI, BB, 2);
1469   case Mips::ATOMIC_LOAD_UMAX_I32:
1470     return emitAtomicBinary(MI, BB);
1471   case Mips::ATOMIC_LOAD_UMAX_I64:
1472     return emitAtomicBinary(MI, BB);
1473 
1474   case Mips::PseudoSDIV:
1475   case Mips::PseudoUDIV:
1476   case Mips::DIV:
1477   case Mips::DIVU:
1478   case Mips::MOD:
1479   case Mips::MODU:
1480     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false,
1481                                false);
1482   case Mips::SDIV_MM_Pseudo:
1483   case Mips::UDIV_MM_Pseudo:
1484   case Mips::SDIV_MM:
1485   case Mips::UDIV_MM:
1486   case Mips::DIV_MMR6:
1487   case Mips::DIVU_MMR6:
1488   case Mips::MOD_MMR6:
1489   case Mips::MODU_MMR6:
1490     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false, true);
1491   case Mips::PseudoDSDIV:
1492   case Mips::PseudoDUDIV:
1493   case Mips::DDIV:
1494   case Mips::DDIVU:
1495   case Mips::DMOD:
1496   case Mips::DMODU:
1497     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, false);
1498 
1499   case Mips::PseudoSELECT_I:
1500   case Mips::PseudoSELECT_I64:
1501   case Mips::PseudoSELECT_S:
1502   case Mips::PseudoSELECT_D32:
1503   case Mips::PseudoSELECT_D64:
1504     return emitPseudoSELECT(MI, BB, false, Mips::BNE);
1505   case Mips::PseudoSELECTFP_F_I:
1506   case Mips::PseudoSELECTFP_F_I64:
1507   case Mips::PseudoSELECTFP_F_S:
1508   case Mips::PseudoSELECTFP_F_D32:
1509   case Mips::PseudoSELECTFP_F_D64:
1510     return emitPseudoSELECT(MI, BB, true, Mips::BC1F);
1511   case Mips::PseudoSELECTFP_T_I:
1512   case Mips::PseudoSELECTFP_T_I64:
1513   case Mips::PseudoSELECTFP_T_S:
1514   case Mips::PseudoSELECTFP_T_D32:
1515   case Mips::PseudoSELECTFP_T_D64:
1516     return emitPseudoSELECT(MI, BB, true, Mips::BC1T);
1517   case Mips::PseudoD_SELECT_I:
1518   case Mips::PseudoD_SELECT_I64:
1519     return emitPseudoD_SELECT(MI, BB);
1520   case Mips::LDR_W:
1521     return emitLDR_W(MI, BB);
1522   case Mips::LDR_D:
1523     return emitLDR_D(MI, BB);
1524   case Mips::STR_W:
1525     return emitSTR_W(MI, BB);
1526   case Mips::STR_D:
1527     return emitSTR_D(MI, BB);
1528   }
1529 }
1530 
1531 // This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and
1532 // Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true)
1533 MachineBasicBlock *
1534 MipsTargetLowering::emitAtomicBinary(MachineInstr &MI,
1535                                      MachineBasicBlock *BB) const {
1536 
1537   MachineFunction *MF = BB->getParent();
1538   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1539   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1540   DebugLoc DL = MI.getDebugLoc();
1541 
1542   unsigned AtomicOp;
1543   bool NeedsAdditionalReg = false;
1544   switch (MI.getOpcode()) {
1545   case Mips::ATOMIC_LOAD_ADD_I32:
1546     AtomicOp = Mips::ATOMIC_LOAD_ADD_I32_POSTRA;
1547     break;
1548   case Mips::ATOMIC_LOAD_SUB_I32:
1549     AtomicOp = Mips::ATOMIC_LOAD_SUB_I32_POSTRA;
1550     break;
1551   case Mips::ATOMIC_LOAD_AND_I32:
1552     AtomicOp = Mips::ATOMIC_LOAD_AND_I32_POSTRA;
1553     break;
1554   case Mips::ATOMIC_LOAD_OR_I32:
1555     AtomicOp = Mips::ATOMIC_LOAD_OR_I32_POSTRA;
1556     break;
1557   case Mips::ATOMIC_LOAD_XOR_I32:
1558     AtomicOp = Mips::ATOMIC_LOAD_XOR_I32_POSTRA;
1559     break;
1560   case Mips::ATOMIC_LOAD_NAND_I32:
1561     AtomicOp = Mips::ATOMIC_LOAD_NAND_I32_POSTRA;
1562     break;
1563   case Mips::ATOMIC_SWAP_I32:
1564     AtomicOp = Mips::ATOMIC_SWAP_I32_POSTRA;
1565     break;
1566   case Mips::ATOMIC_LOAD_ADD_I64:
1567     AtomicOp = Mips::ATOMIC_LOAD_ADD_I64_POSTRA;
1568     break;
1569   case Mips::ATOMIC_LOAD_SUB_I64:
1570     AtomicOp = Mips::ATOMIC_LOAD_SUB_I64_POSTRA;
1571     break;
1572   case Mips::ATOMIC_LOAD_AND_I64:
1573     AtomicOp = Mips::ATOMIC_LOAD_AND_I64_POSTRA;
1574     break;
1575   case Mips::ATOMIC_LOAD_OR_I64:
1576     AtomicOp = Mips::ATOMIC_LOAD_OR_I64_POSTRA;
1577     break;
1578   case Mips::ATOMIC_LOAD_XOR_I64:
1579     AtomicOp = Mips::ATOMIC_LOAD_XOR_I64_POSTRA;
1580     break;
1581   case Mips::ATOMIC_LOAD_NAND_I64:
1582     AtomicOp = Mips::ATOMIC_LOAD_NAND_I64_POSTRA;
1583     break;
1584   case Mips::ATOMIC_SWAP_I64:
1585     AtomicOp = Mips::ATOMIC_SWAP_I64_POSTRA;
1586     break;
1587   case Mips::ATOMIC_LOAD_MIN_I32:
1588     AtomicOp = Mips::ATOMIC_LOAD_MIN_I32_POSTRA;
1589     NeedsAdditionalReg = true;
1590     break;
1591   case Mips::ATOMIC_LOAD_MAX_I32:
1592     AtomicOp = Mips::ATOMIC_LOAD_MAX_I32_POSTRA;
1593     NeedsAdditionalReg = true;
1594     break;
1595   case Mips::ATOMIC_LOAD_UMIN_I32:
1596     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I32_POSTRA;
1597     NeedsAdditionalReg = true;
1598     break;
1599   case Mips::ATOMIC_LOAD_UMAX_I32:
1600     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I32_POSTRA;
1601     NeedsAdditionalReg = true;
1602     break;
1603   case Mips::ATOMIC_LOAD_MIN_I64:
1604     AtomicOp = Mips::ATOMIC_LOAD_MIN_I64_POSTRA;
1605     NeedsAdditionalReg = true;
1606     break;
1607   case Mips::ATOMIC_LOAD_MAX_I64:
1608     AtomicOp = Mips::ATOMIC_LOAD_MAX_I64_POSTRA;
1609     NeedsAdditionalReg = true;
1610     break;
1611   case Mips::ATOMIC_LOAD_UMIN_I64:
1612     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I64_POSTRA;
1613     NeedsAdditionalReg = true;
1614     break;
1615   case Mips::ATOMIC_LOAD_UMAX_I64:
1616     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I64_POSTRA;
1617     NeedsAdditionalReg = true;
1618     break;
1619   default:
1620     llvm_unreachable("Unknown pseudo atomic for replacement!");
1621   }
1622 
1623   Register OldVal = MI.getOperand(0).getReg();
1624   Register Ptr = MI.getOperand(1).getReg();
1625   Register Incr = MI.getOperand(2).getReg();
1626   Register Scratch = RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1627 
1628   MachineBasicBlock::iterator II(MI);
1629 
1630   // The scratch registers here with the EarlyClobber | Define | Implicit
1631   // flags is used to persuade the register allocator and the machine
1632   // verifier to accept the usage of this register. This has to be a real
1633   // register which has an UNDEF value but is dead after the instruction which
1634   // is unique among the registers chosen for the instruction.
1635 
1636   // The EarlyClobber flag has the semantic properties that the operand it is
1637   // attached to is clobbered before the rest of the inputs are read. Hence it
1638   // must be unique among the operands to the instruction.
1639   // The Define flag is needed to coerce the machine verifier that an Undef
1640   // value isn't a problem.
1641   // The Dead flag is needed as the value in scratch isn't used by any other
1642   // instruction. Kill isn't used as Dead is more precise.
1643   // The implicit flag is here due to the interaction between the other flags
1644   // and the machine verifier.
1645 
1646   // For correctness purpose, a new pseudo is introduced here. We need this
1647   // new pseudo, so that FastRegisterAllocator does not see an ll/sc sequence
1648   // that is spread over >1 basic blocks. A register allocator which
1649   // introduces (or any codegen infact) a store, can violate the expectations
1650   // of the hardware.
1651   //
1652   // An atomic read-modify-write sequence starts with a linked load
1653   // instruction and ends with a store conditional instruction. The atomic
1654   // read-modify-write sequence fails if any of the following conditions
1655   // occur between the execution of ll and sc:
1656   //   * A coherent store is completed by another process or coherent I/O
1657   //     module into the block of synchronizable physical memory containing
1658   //     the word. The size and alignment of the block is
1659   //     implementation-dependent.
1660   //   * A coherent store is executed between an LL and SC sequence on the
1661   //     same processor to the block of synchornizable physical memory
1662   //     containing the word.
1663   //
1664 
1665   Register PtrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Ptr));
1666   Register IncrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Incr));
1667 
1668   BuildMI(*BB, II, DL, TII->get(Mips::COPY), IncrCopy).addReg(Incr);
1669   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1670 
1671   MachineInstrBuilder MIB =
1672       BuildMI(*BB, II, DL, TII->get(AtomicOp))
1673           .addReg(OldVal, RegState::Define | RegState::EarlyClobber)
1674           .addReg(PtrCopy)
1675           .addReg(IncrCopy)
1676           .addReg(Scratch, RegState::Define | RegState::EarlyClobber |
1677                                RegState::Implicit | RegState::Dead);
1678   if (NeedsAdditionalReg) {
1679     Register Scratch2 =
1680         RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1681     MIB.addReg(Scratch2, RegState::Define | RegState::EarlyClobber |
1682                              RegState::Implicit | RegState::Dead);
1683   }
1684 
1685   MI.eraseFromParent();
1686 
1687   return BB;
1688 }
1689 
1690 MachineBasicBlock *MipsTargetLowering::emitSignExtendToI32InReg(
1691     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned DstReg,
1692     unsigned SrcReg) const {
1693   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1694   const DebugLoc &DL = MI.getDebugLoc();
1695 
1696   if (Subtarget.hasMips32r2() && Size == 1) {
1697     BuildMI(BB, DL, TII->get(Mips::SEB), DstReg).addReg(SrcReg);
1698     return BB;
1699   }
1700 
1701   if (Subtarget.hasMips32r2() && Size == 2) {
1702     BuildMI(BB, DL, TII->get(Mips::SEH), DstReg).addReg(SrcReg);
1703     return BB;
1704   }
1705 
1706   MachineFunction *MF = BB->getParent();
1707   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1708   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1709   Register ScrReg = RegInfo.createVirtualRegister(RC);
1710 
1711   assert(Size < 32);
1712   int64_t ShiftImm = 32 - (Size * 8);
1713 
1714   BuildMI(BB, DL, TII->get(Mips::SLL), ScrReg).addReg(SrcReg).addImm(ShiftImm);
1715   BuildMI(BB, DL, TII->get(Mips::SRA), DstReg).addReg(ScrReg).addImm(ShiftImm);
1716 
1717   return BB;
1718 }
1719 
1720 MachineBasicBlock *MipsTargetLowering::emitAtomicBinaryPartword(
1721     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1722   assert((Size == 1 || Size == 2) &&
1723          "Unsupported size for EmitAtomicBinaryPartial.");
1724 
1725   MachineFunction *MF = BB->getParent();
1726   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1727   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1728   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1729   const TargetRegisterClass *RCp =
1730     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1731   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1732   DebugLoc DL = MI.getDebugLoc();
1733 
1734   Register Dest = MI.getOperand(0).getReg();
1735   Register Ptr = MI.getOperand(1).getReg();
1736   Register Incr = MI.getOperand(2).getReg();
1737 
1738   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1739   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1740   Register Mask = RegInfo.createVirtualRegister(RC);
1741   Register Mask2 = RegInfo.createVirtualRegister(RC);
1742   Register Incr2 = RegInfo.createVirtualRegister(RC);
1743   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1744   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1745   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1746   Register Scratch = RegInfo.createVirtualRegister(RC);
1747   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1748   Register Scratch3 = RegInfo.createVirtualRegister(RC);
1749 
1750   unsigned AtomicOp = 0;
1751   bool NeedsAdditionalReg = false;
1752   switch (MI.getOpcode()) {
1753   case Mips::ATOMIC_LOAD_NAND_I8:
1754     AtomicOp = Mips::ATOMIC_LOAD_NAND_I8_POSTRA;
1755     break;
1756   case Mips::ATOMIC_LOAD_NAND_I16:
1757     AtomicOp = Mips::ATOMIC_LOAD_NAND_I16_POSTRA;
1758     break;
1759   case Mips::ATOMIC_SWAP_I8:
1760     AtomicOp = Mips::ATOMIC_SWAP_I8_POSTRA;
1761     break;
1762   case Mips::ATOMIC_SWAP_I16:
1763     AtomicOp = Mips::ATOMIC_SWAP_I16_POSTRA;
1764     break;
1765   case Mips::ATOMIC_LOAD_ADD_I8:
1766     AtomicOp = Mips::ATOMIC_LOAD_ADD_I8_POSTRA;
1767     break;
1768   case Mips::ATOMIC_LOAD_ADD_I16:
1769     AtomicOp = Mips::ATOMIC_LOAD_ADD_I16_POSTRA;
1770     break;
1771   case Mips::ATOMIC_LOAD_SUB_I8:
1772     AtomicOp = Mips::ATOMIC_LOAD_SUB_I8_POSTRA;
1773     break;
1774   case Mips::ATOMIC_LOAD_SUB_I16:
1775     AtomicOp = Mips::ATOMIC_LOAD_SUB_I16_POSTRA;
1776     break;
1777   case Mips::ATOMIC_LOAD_AND_I8:
1778     AtomicOp = Mips::ATOMIC_LOAD_AND_I8_POSTRA;
1779     break;
1780   case Mips::ATOMIC_LOAD_AND_I16:
1781     AtomicOp = Mips::ATOMIC_LOAD_AND_I16_POSTRA;
1782     break;
1783   case Mips::ATOMIC_LOAD_OR_I8:
1784     AtomicOp = Mips::ATOMIC_LOAD_OR_I8_POSTRA;
1785     break;
1786   case Mips::ATOMIC_LOAD_OR_I16:
1787     AtomicOp = Mips::ATOMIC_LOAD_OR_I16_POSTRA;
1788     break;
1789   case Mips::ATOMIC_LOAD_XOR_I8:
1790     AtomicOp = Mips::ATOMIC_LOAD_XOR_I8_POSTRA;
1791     break;
1792   case Mips::ATOMIC_LOAD_XOR_I16:
1793     AtomicOp = Mips::ATOMIC_LOAD_XOR_I16_POSTRA;
1794     break;
1795   case Mips::ATOMIC_LOAD_MIN_I8:
1796     AtomicOp = Mips::ATOMIC_LOAD_MIN_I8_POSTRA;
1797     NeedsAdditionalReg = true;
1798     break;
1799   case Mips::ATOMIC_LOAD_MIN_I16:
1800     AtomicOp = Mips::ATOMIC_LOAD_MIN_I16_POSTRA;
1801     NeedsAdditionalReg = true;
1802     break;
1803   case Mips::ATOMIC_LOAD_MAX_I8:
1804     AtomicOp = Mips::ATOMIC_LOAD_MAX_I8_POSTRA;
1805     NeedsAdditionalReg = true;
1806     break;
1807   case Mips::ATOMIC_LOAD_MAX_I16:
1808     AtomicOp = Mips::ATOMIC_LOAD_MAX_I16_POSTRA;
1809     NeedsAdditionalReg = true;
1810     break;
1811   case Mips::ATOMIC_LOAD_UMIN_I8:
1812     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I8_POSTRA;
1813     NeedsAdditionalReg = true;
1814     break;
1815   case Mips::ATOMIC_LOAD_UMIN_I16:
1816     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I16_POSTRA;
1817     NeedsAdditionalReg = true;
1818     break;
1819   case Mips::ATOMIC_LOAD_UMAX_I8:
1820     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I8_POSTRA;
1821     NeedsAdditionalReg = true;
1822     break;
1823   case Mips::ATOMIC_LOAD_UMAX_I16:
1824     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I16_POSTRA;
1825     NeedsAdditionalReg = true;
1826     break;
1827   default:
1828     llvm_unreachable("Unknown subword atomic pseudo for expansion!");
1829   }
1830 
1831   // insert new blocks after the current block
1832   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1833   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1834   MachineFunction::iterator It = ++BB->getIterator();
1835   MF->insert(It, exitMBB);
1836 
1837   // Transfer the remainder of BB and its successor edges to exitMBB.
1838   exitMBB->splice(exitMBB->begin(), BB,
1839                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1840   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1841 
1842   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1843 
1844   //  thisMBB:
1845   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1846   //    and     alignedaddr,ptr,masklsb2
1847   //    andi    ptrlsb2,ptr,3
1848   //    sll     shiftamt,ptrlsb2,3
1849   //    ori     maskupper,$0,255               # 0xff
1850   //    sll     mask,maskupper,shiftamt
1851   //    nor     mask2,$0,mask
1852   //    sll     incr2,incr,shiftamt
1853 
1854   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1855   BuildMI(BB, DL, TII->get(ABI.GetPtrAddiuOp()), MaskLSB2)
1856     .addReg(ABI.GetNullPtr()).addImm(-4);
1857   BuildMI(BB, DL, TII->get(ABI.GetPtrAndOp()), AlignedAddr)
1858     .addReg(Ptr).addReg(MaskLSB2);
1859   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1860       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1861   if (Subtarget.isLittle()) {
1862     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1863   } else {
1864     Register Off = RegInfo.createVirtualRegister(RC);
1865     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1866       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1867     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1868   }
1869   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1870     .addReg(Mips::ZERO).addImm(MaskImm);
1871   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1872     .addReg(MaskUpper).addReg(ShiftAmt);
1873   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1874   BuildMI(BB, DL, TII->get(Mips::SLLV), Incr2).addReg(Incr).addReg(ShiftAmt);
1875 
1876 
1877   // The purposes of the flags on the scratch registers is explained in
1878   // emitAtomicBinary. In summary, we need a scratch register which is going to
1879   // be undef, that is unique among registers chosen for the instruction.
1880 
1881   MachineInstrBuilder MIB =
1882       BuildMI(BB, DL, TII->get(AtomicOp))
1883           .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1884           .addReg(AlignedAddr)
1885           .addReg(Incr2)
1886           .addReg(Mask)
1887           .addReg(Mask2)
1888           .addReg(ShiftAmt)
1889           .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1890                                RegState::Dead | RegState::Implicit)
1891           .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
1892                                 RegState::Dead | RegState::Implicit)
1893           .addReg(Scratch3, RegState::EarlyClobber | RegState::Define |
1894                                 RegState::Dead | RegState::Implicit);
1895   if (NeedsAdditionalReg) {
1896     Register Scratch4 = RegInfo.createVirtualRegister(RC);
1897     MIB.addReg(Scratch4, RegState::EarlyClobber | RegState::Define |
1898                              RegState::Dead | RegState::Implicit);
1899   }
1900 
1901   MI.eraseFromParent(); // The instruction is gone now.
1902 
1903   return exitMBB;
1904 }
1905 
1906 // Lower atomic compare and swap to a pseudo instruction, taking care to
1907 // define a scratch register for the pseudo instruction's expansion. The
1908 // instruction is expanded after the register allocator as to prevent
1909 // the insertion of stores between the linked load and the store conditional.
1910 
1911 MachineBasicBlock *
1912 MipsTargetLowering::emitAtomicCmpSwap(MachineInstr &MI,
1913                                       MachineBasicBlock *BB) const {
1914 
1915   assert((MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ||
1916           MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I64) &&
1917          "Unsupported atomic pseudo for EmitAtomicCmpSwap.");
1918 
1919   const unsigned Size = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ? 4 : 8;
1920 
1921   MachineFunction *MF = BB->getParent();
1922   MachineRegisterInfo &MRI = MF->getRegInfo();
1923   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1924   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1925   DebugLoc DL = MI.getDebugLoc();
1926 
1927   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32
1928                           ? Mips::ATOMIC_CMP_SWAP_I32_POSTRA
1929                           : Mips::ATOMIC_CMP_SWAP_I64_POSTRA;
1930   Register Dest = MI.getOperand(0).getReg();
1931   Register Ptr = MI.getOperand(1).getReg();
1932   Register OldVal = MI.getOperand(2).getReg();
1933   Register NewVal = MI.getOperand(3).getReg();
1934 
1935   Register Scratch = MRI.createVirtualRegister(RC);
1936   MachineBasicBlock::iterator II(MI);
1937 
1938   // We need to create copies of the various registers and kill them at the
1939   // atomic pseudo. If the copies are not made, when the atomic is expanded
1940   // after fast register allocation, the spills will end up outside of the
1941   // blocks that their values are defined in, causing livein errors.
1942 
1943   Register PtrCopy = MRI.createVirtualRegister(MRI.getRegClass(Ptr));
1944   Register OldValCopy = MRI.createVirtualRegister(MRI.getRegClass(OldVal));
1945   Register NewValCopy = MRI.createVirtualRegister(MRI.getRegClass(NewVal));
1946 
1947   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1948   BuildMI(*BB, II, DL, TII->get(Mips::COPY), OldValCopy).addReg(OldVal);
1949   BuildMI(*BB, II, DL, TII->get(Mips::COPY), NewValCopy).addReg(NewVal);
1950 
1951   // The purposes of the flags on the scratch registers is explained in
1952   // emitAtomicBinary. In summary, we need a scratch register which is going to
1953   // be undef, that is unique among registers chosen for the instruction.
1954 
1955   BuildMI(*BB, II, DL, TII->get(AtomicOp))
1956       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1957       .addReg(PtrCopy, RegState::Kill)
1958       .addReg(OldValCopy, RegState::Kill)
1959       .addReg(NewValCopy, RegState::Kill)
1960       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1961                            RegState::Dead | RegState::Implicit);
1962 
1963   MI.eraseFromParent(); // The instruction is gone now.
1964 
1965   return BB;
1966 }
1967 
1968 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwapPartword(
1969     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1970   assert((Size == 1 || Size == 2) &&
1971       "Unsupported size for EmitAtomicCmpSwapPartial.");
1972 
1973   MachineFunction *MF = BB->getParent();
1974   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1975   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1976   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1977   const TargetRegisterClass *RCp =
1978     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1979   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1980   DebugLoc DL = MI.getDebugLoc();
1981 
1982   Register Dest = MI.getOperand(0).getReg();
1983   Register Ptr = MI.getOperand(1).getReg();
1984   Register CmpVal = MI.getOperand(2).getReg();
1985   Register NewVal = MI.getOperand(3).getReg();
1986 
1987   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1988   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1989   Register Mask = RegInfo.createVirtualRegister(RC);
1990   Register Mask2 = RegInfo.createVirtualRegister(RC);
1991   Register ShiftedCmpVal = RegInfo.createVirtualRegister(RC);
1992   Register ShiftedNewVal = RegInfo.createVirtualRegister(RC);
1993   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1994   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1995   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1996   Register MaskedCmpVal = RegInfo.createVirtualRegister(RC);
1997   Register MaskedNewVal = RegInfo.createVirtualRegister(RC);
1998   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I8
1999                           ? Mips::ATOMIC_CMP_SWAP_I8_POSTRA
2000                           : Mips::ATOMIC_CMP_SWAP_I16_POSTRA;
2001 
2002   // The scratch registers here with the EarlyClobber | Define | Dead | Implicit
2003   // flags are used to coerce the register allocator and the machine verifier to
2004   // accept the usage of these registers.
2005   // The EarlyClobber flag has the semantic properties that the operand it is
2006   // attached to is clobbered before the rest of the inputs are read. Hence it
2007   // must be unique among the operands to the instruction.
2008   // The Define flag is needed to coerce the machine verifier that an Undef
2009   // value isn't a problem.
2010   // The Dead flag is needed as the value in scratch isn't used by any other
2011   // instruction. Kill isn't used as Dead is more precise.
2012   Register Scratch = RegInfo.createVirtualRegister(RC);
2013   Register Scratch2 = RegInfo.createVirtualRegister(RC);
2014 
2015   // insert new blocks after the current block
2016   const BasicBlock *LLVM_BB = BB->getBasicBlock();
2017   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
2018   MachineFunction::iterator It = ++BB->getIterator();
2019   MF->insert(It, exitMBB);
2020 
2021   // Transfer the remainder of BB and its successor edges to exitMBB.
2022   exitMBB->splice(exitMBB->begin(), BB,
2023                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
2024   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
2025 
2026   BB->addSuccessor(exitMBB, BranchProbability::getOne());
2027 
2028   //  thisMBB:
2029   //    addiu   masklsb2,$0,-4                # 0xfffffffc
2030   //    and     alignedaddr,ptr,masklsb2
2031   //    andi    ptrlsb2,ptr,3
2032   //    xori    ptrlsb2,ptrlsb2,3              # Only for BE
2033   //    sll     shiftamt,ptrlsb2,3
2034   //    ori     maskupper,$0,255               # 0xff
2035   //    sll     mask,maskupper,shiftamt
2036   //    nor     mask2,$0,mask
2037   //    andi    maskedcmpval,cmpval,255
2038   //    sll     shiftedcmpval,maskedcmpval,shiftamt
2039   //    andi    maskednewval,newval,255
2040   //    sll     shiftednewval,maskednewval,shiftamt
2041   int64_t MaskImm = (Size == 1) ? 255 : 65535;
2042   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::DADDiu : Mips::ADDiu), MaskLSB2)
2043     .addReg(ABI.GetNullPtr()).addImm(-4);
2044   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::AND64 : Mips::AND), AlignedAddr)
2045     .addReg(Ptr).addReg(MaskLSB2);
2046   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
2047       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
2048   if (Subtarget.isLittle()) {
2049     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
2050   } else {
2051     Register Off = RegInfo.createVirtualRegister(RC);
2052     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
2053       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
2054     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
2055   }
2056   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
2057     .addReg(Mips::ZERO).addImm(MaskImm);
2058   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
2059     .addReg(MaskUpper).addReg(ShiftAmt);
2060   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
2061   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedCmpVal)
2062     .addReg(CmpVal).addImm(MaskImm);
2063   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedCmpVal)
2064     .addReg(MaskedCmpVal).addReg(ShiftAmt);
2065   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedNewVal)
2066     .addReg(NewVal).addImm(MaskImm);
2067   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedNewVal)
2068     .addReg(MaskedNewVal).addReg(ShiftAmt);
2069 
2070   // The purposes of the flags on the scratch registers are explained in
2071   // emitAtomicBinary. In summary, we need a scratch register which is going to
2072   // be undef, that is unique among the register chosen for the instruction.
2073 
2074   BuildMI(BB, DL, TII->get(AtomicOp))
2075       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
2076       .addReg(AlignedAddr)
2077       .addReg(Mask)
2078       .addReg(ShiftedCmpVal)
2079       .addReg(Mask2)
2080       .addReg(ShiftedNewVal)
2081       .addReg(ShiftAmt)
2082       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
2083                            RegState::Dead | RegState::Implicit)
2084       .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
2085                             RegState::Dead | RegState::Implicit);
2086 
2087   MI.eraseFromParent(); // The instruction is gone now.
2088 
2089   return exitMBB;
2090 }
2091 
2092 SDValue MipsTargetLowering::lowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
2093   // The first operand is the chain, the second is the condition, the third is
2094   // the block to branch to if the condition is true.
2095   SDValue Chain = Op.getOperand(0);
2096   SDValue Dest = Op.getOperand(2);
2097   SDLoc DL(Op);
2098 
2099   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2100   SDValue CondRes = createFPCmp(DAG, Op.getOperand(1));
2101 
2102   // Return if flag is not set by a floating point comparison.
2103   if (CondRes.getOpcode() != MipsISD::FPCmp)
2104     return Op;
2105 
2106   SDValue CCNode  = CondRes.getOperand(2);
2107   Mips::CondCode CC = (Mips::CondCode)CCNode->getAsZExtVal();
2108   unsigned Opc = invertFPCondCodeUser(CC) ? Mips::BRANCH_F : Mips::BRANCH_T;
2109   SDValue BrCode = DAG.getConstant(Opc, DL, MVT::i32);
2110   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
2111   return DAG.getNode(MipsISD::FPBrcond, DL, Op.getValueType(), Chain, BrCode,
2112                      FCC0, Dest, CondRes);
2113 }
2114 
2115 SDValue MipsTargetLowering::
2116 lowerSELECT(SDValue Op, SelectionDAG &DAG) const
2117 {
2118   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2119   SDValue Cond = createFPCmp(DAG, Op.getOperand(0));
2120 
2121   // Return if flag is not set by a floating point comparison.
2122   if (Cond.getOpcode() != MipsISD::FPCmp)
2123     return Op;
2124 
2125   return createCMovFP(DAG, Cond, Op.getOperand(1), Op.getOperand(2),
2126                       SDLoc(Op));
2127 }
2128 
2129 SDValue MipsTargetLowering::lowerSETCC(SDValue Op, SelectionDAG &DAG) const {
2130   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2131   SDValue Cond = createFPCmp(DAG, Op);
2132 
2133   assert(Cond.getOpcode() == MipsISD::FPCmp &&
2134          "Floating point operand expected.");
2135 
2136   SDLoc DL(Op);
2137   SDValue True  = DAG.getConstant(1, DL, MVT::i32);
2138   SDValue False = DAG.getConstant(0, DL, MVT::i32);
2139 
2140   return createCMovFP(DAG, Cond, True, False, DL);
2141 }
2142 
2143 SDValue MipsTargetLowering::lowerGlobalAddress(SDValue Op,
2144                                                SelectionDAG &DAG) const {
2145   EVT Ty = Op.getValueType();
2146   GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
2147   const GlobalValue *GV = N->getGlobal();
2148 
2149   if (GV->hasDLLImportStorageClass()) {
2150     assert(Subtarget.isTargetWindows() &&
2151            "Windows is the only supported COFF target");
2152     return getDllimportVariable(
2153         N, SDLoc(N), Ty, DAG, DAG.getEntryNode(),
2154         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2155   }
2156 
2157   if (!isPositionIndependent()) {
2158     const MipsTargetObjectFile *TLOF =
2159         static_cast<const MipsTargetObjectFile *>(
2160             getTargetMachine().getObjFileLowering());
2161     const GlobalObject *GO = GV->getAliaseeObject();
2162     if (GO && TLOF->IsGlobalInSmallSection(GO, getTargetMachine()))
2163       // %gp_rel relocation
2164       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2165 
2166                                 // %hi/%lo relocation
2167     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2168                                 // %highest/%higher/%hi/%lo relocation
2169                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2170   }
2171 
2172   // Every other architecture would use shouldAssumeDSOLocal in here, but
2173   // mips is special.
2174   // * In PIC code mips requires got loads even for local statics!
2175   // * To save on got entries, for local statics the got entry contains the
2176   //   page and an additional add instruction takes care of the low bits.
2177   // * It is legal to access a hidden symbol with a non hidden undefined,
2178   //   so one cannot guarantee that all access to a hidden symbol will know
2179   //   it is hidden.
2180   // * Mips linkers don't support creating a page and a full got entry for
2181   //   the same symbol.
2182   // * Given all that, we have to use a full got entry for hidden symbols :-(
2183   if (GV->hasLocalLinkage())
2184     return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2185 
2186   if (Subtarget.useXGOT())
2187     return getAddrGlobalLargeGOT(
2188         N, SDLoc(N), Ty, DAG, MipsII::MO_GOT_HI16, MipsII::MO_GOT_LO16,
2189         DAG.getEntryNode(),
2190         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2191 
2192   return getAddrGlobal(
2193       N, SDLoc(N), Ty, DAG,
2194       (ABI.IsN32() || ABI.IsN64()) ? MipsII::MO_GOT_DISP : MipsII::MO_GOT,
2195       DAG.getEntryNode(), MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2196 }
2197 
2198 SDValue MipsTargetLowering::lowerBlockAddress(SDValue Op,
2199                                               SelectionDAG &DAG) const {
2200   BlockAddressSDNode *N = cast<BlockAddressSDNode>(Op);
2201   EVT Ty = Op.getValueType();
2202 
2203   if (!isPositionIndependent())
2204     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2205                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2206 
2207   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2208 }
2209 
2210 SDValue MipsTargetLowering::
2211 lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
2212 {
2213   // If the relocation model is PIC, use the General Dynamic TLS Model or
2214   // Local Dynamic TLS model, otherwise use the Initial Exec or
2215   // Local Exec TLS Model.
2216 
2217   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
2218   if (DAG.getTarget().useEmulatedTLS())
2219     return LowerToTLSEmulatedModel(GA, DAG);
2220 
2221   SDLoc DL(GA);
2222   const GlobalValue *GV = GA->getGlobal();
2223   EVT PtrVT = getPointerTy(DAG.getDataLayout());
2224 
2225   TLSModel::Model model = getTargetMachine().getTLSModel(GV);
2226 
2227   if (model == TLSModel::GeneralDynamic || model == TLSModel::LocalDynamic) {
2228     // General Dynamic and Local Dynamic TLS Model.
2229     unsigned Flag = (model == TLSModel::LocalDynamic) ? MipsII::MO_TLSLDM
2230                                                       : MipsII::MO_TLSGD;
2231 
2232     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, Flag);
2233     SDValue Argument = DAG.getNode(MipsISD::Wrapper, DL, PtrVT,
2234                                    getGlobalReg(DAG, PtrVT), TGA);
2235     unsigned PtrSize = PtrVT.getSizeInBits();
2236     IntegerType *PtrTy = Type::getIntNTy(*DAG.getContext(), PtrSize);
2237 
2238     SDValue TlsGetAddr = DAG.getExternalSymbol("__tls_get_addr", PtrVT);
2239 
2240     ArgListTy Args;
2241     ArgListEntry Entry;
2242     Entry.Node = Argument;
2243     Entry.Ty = PtrTy;
2244     Args.push_back(Entry);
2245 
2246     TargetLowering::CallLoweringInfo CLI(DAG);
2247     CLI.setDebugLoc(DL)
2248         .setChain(DAG.getEntryNode())
2249         .setLibCallee(CallingConv::C, PtrTy, TlsGetAddr, std::move(Args));
2250     std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
2251 
2252     SDValue Ret = CallResult.first;
2253 
2254     if (model != TLSModel::LocalDynamic)
2255       return Ret;
2256 
2257     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2258                                                MipsII::MO_DTPREL_HI);
2259     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2260     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2261                                                MipsII::MO_DTPREL_LO);
2262     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2263     SDValue Add = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Ret);
2264     return DAG.getNode(ISD::ADD, DL, PtrVT, Add, Lo);
2265   }
2266 
2267   SDValue Offset;
2268   if (model == TLSModel::InitialExec) {
2269     // Initial Exec TLS Model
2270     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2271                                              MipsII::MO_GOTTPREL);
2272     TGA = DAG.getNode(MipsISD::Wrapper, DL, PtrVT, getGlobalReg(DAG, PtrVT),
2273                       TGA);
2274     Offset =
2275         DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), TGA, MachinePointerInfo());
2276   } else {
2277     // Local Exec TLS Model
2278     assert(model == TLSModel::LocalExec);
2279     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2280                                                MipsII::MO_TPREL_HI);
2281     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2282                                                MipsII::MO_TPREL_LO);
2283     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2284     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2285     Offset = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Lo);
2286   }
2287 
2288   SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, DL, PtrVT);
2289   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadPointer, Offset);
2290 }
2291 
2292 SDValue MipsTargetLowering::
2293 lowerJumpTable(SDValue Op, SelectionDAG &DAG) const
2294 {
2295   JumpTableSDNode *N = cast<JumpTableSDNode>(Op);
2296   EVT Ty = Op.getValueType();
2297 
2298   if (!isPositionIndependent())
2299     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2300                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2301 
2302   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2303 }
2304 
2305 SDValue MipsTargetLowering::
2306 lowerConstantPool(SDValue Op, SelectionDAG &DAG) const
2307 {
2308   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
2309   EVT Ty = Op.getValueType();
2310 
2311   if (!isPositionIndependent()) {
2312     const MipsTargetObjectFile *TLOF =
2313         static_cast<const MipsTargetObjectFile *>(
2314             getTargetMachine().getObjFileLowering());
2315 
2316     if (TLOF->IsConstantInSmallSection(DAG.getDataLayout(), N->getConstVal(),
2317                                        getTargetMachine()))
2318       // %gp_rel relocation
2319       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2320 
2321     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2322                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2323   }
2324 
2325  return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2326 }
2327 
2328 SDValue MipsTargetLowering::lowerVASTART(SDValue Op, SelectionDAG &DAG) const {
2329   MachineFunction &MF = DAG.getMachineFunction();
2330   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
2331 
2332   SDLoc DL(Op);
2333   SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
2334                                  getPointerTy(MF.getDataLayout()));
2335 
2336   // vastart just stores the address of the VarArgsFrameIndex slot into the
2337   // memory location argument.
2338   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
2339   return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
2340                       MachinePointerInfo(SV));
2341 }
2342 
2343 SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
2344   SDNode *Node = Op.getNode();
2345   EVT VT = Node->getValueType(0);
2346   SDValue Chain = Node->getOperand(0);
2347   SDValue VAListPtr = Node->getOperand(1);
2348   const Align Align =
2349       llvm::MaybeAlign(Node->getConstantOperandVal(3)).valueOrOne();
2350   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
2351   SDLoc DL(Node);
2352   unsigned ArgSlotSizeInBytes = (ABI.IsN32() || ABI.IsN64()) ? 8 : 4;
2353 
2354   SDValue VAListLoad = DAG.getLoad(getPointerTy(DAG.getDataLayout()), DL, Chain,
2355                                    VAListPtr, MachinePointerInfo(SV));
2356   SDValue VAList = VAListLoad;
2357 
2358   // Re-align the pointer if necessary.
2359   // It should only ever be necessary for 64-bit types on O32 since the minimum
2360   // argument alignment is the same as the maximum type alignment for N32/N64.
2361   //
2362   // FIXME: We currently align too often. The code generator doesn't notice
2363   //        when the pointer is still aligned from the last va_arg (or pair of
2364   //        va_args for the i64 on O32 case).
2365   if (Align > getMinStackArgumentAlignment()) {
2366     VAList = DAG.getNode(
2367         ISD::ADD, DL, VAList.getValueType(), VAList,
2368         DAG.getConstant(Align.value() - 1, DL, VAList.getValueType()));
2369 
2370     VAList = DAG.getNode(ISD::AND, DL, VAList.getValueType(), VAList,
2371                          DAG.getSignedConstant(-(int64_t)Align.value(), DL,
2372                                                VAList.getValueType()));
2373   }
2374 
2375   // Increment the pointer, VAList, to the next vaarg.
2376   auto &TD = DAG.getDataLayout();
2377   unsigned ArgSizeInBytes =
2378       TD.getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext()));
2379   SDValue Tmp3 =
2380       DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
2381                   DAG.getConstant(alignTo(ArgSizeInBytes, ArgSlotSizeInBytes),
2382                                   DL, VAList.getValueType()));
2383   // Store the incremented VAList to the legalized pointer
2384   Chain = DAG.getStore(VAListLoad.getValue(1), DL, Tmp3, VAListPtr,
2385                        MachinePointerInfo(SV));
2386 
2387   // In big-endian mode we must adjust the pointer when the load size is smaller
2388   // than the argument slot size. We must also reduce the known alignment to
2389   // match. For example in the N64 ABI, we must add 4 bytes to the offset to get
2390   // the correct half of the slot, and reduce the alignment from 8 (slot
2391   // alignment) down to 4 (type alignment).
2392   if (!Subtarget.isLittle() && ArgSizeInBytes < ArgSlotSizeInBytes) {
2393     unsigned Adjustment = ArgSlotSizeInBytes - ArgSizeInBytes;
2394     VAList = DAG.getNode(ISD::ADD, DL, VAListPtr.getValueType(), VAList,
2395                          DAG.getIntPtrConstant(Adjustment, DL));
2396   }
2397   // Load the actual argument out of the pointer VAList
2398   return DAG.getLoad(VT, DL, Chain, VAList, MachinePointerInfo());
2399 }
2400 
2401 static SDValue lowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG,
2402                                 bool HasExtractInsert) {
2403   EVT TyX = Op.getOperand(0).getValueType();
2404   EVT TyY = Op.getOperand(1).getValueType();
2405   SDLoc DL(Op);
2406   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2407   SDValue Const31 = DAG.getConstant(31, DL, MVT::i32);
2408   SDValue Res;
2409 
2410   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2411   // to i32.
2412   SDValue X = (TyX == MVT::f32) ?
2413     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0)) :
2414     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2415                 Const1);
2416   SDValue Y = (TyY == MVT::f32) ?
2417     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(1)) :
2418     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(1),
2419                 Const1);
2420 
2421   if (HasExtractInsert) {
2422     // ext  E, Y, 31, 1  ; extract bit31 of Y
2423     // ins  X, E, 31, 1  ; insert extracted bit at bit31 of X
2424     SDValue E = DAG.getNode(MipsISD::Ext, DL, MVT::i32, Y, Const31, Const1);
2425     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32, E, Const31, Const1, X);
2426   } else {
2427     // sll SllX, X, 1
2428     // srl SrlX, SllX, 1
2429     // srl SrlY, Y, 31
2430     // sll SllY, SrlX, 31
2431     // or  Or, SrlX, SllY
2432     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2433     SDValue SrlX = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2434     SDValue SrlY = DAG.getNode(ISD::SRL, DL, MVT::i32, Y, Const31);
2435     SDValue SllY = DAG.getNode(ISD::SHL, DL, MVT::i32, SrlY, Const31);
2436     Res = DAG.getNode(ISD::OR, DL, MVT::i32, SrlX, SllY);
2437   }
2438 
2439   if (TyX == MVT::f32)
2440     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Res);
2441 
2442   SDValue LowX = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2443                              Op.getOperand(0),
2444                              DAG.getConstant(0, DL, MVT::i32));
2445   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2446 }
2447 
2448 static SDValue lowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG,
2449                                 bool HasExtractInsert) {
2450   unsigned WidthX = Op.getOperand(0).getValueSizeInBits();
2451   unsigned WidthY = Op.getOperand(1).getValueSizeInBits();
2452   EVT TyX = MVT::getIntegerVT(WidthX), TyY = MVT::getIntegerVT(WidthY);
2453   SDLoc DL(Op);
2454   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2455 
2456   // Bitcast to integer nodes.
2457   SDValue X = DAG.getNode(ISD::BITCAST, DL, TyX, Op.getOperand(0));
2458   SDValue Y = DAG.getNode(ISD::BITCAST, DL, TyY, Op.getOperand(1));
2459 
2460   if (HasExtractInsert) {
2461     // ext  E, Y, width(Y) - 1, 1  ; extract bit width(Y)-1 of Y
2462     // ins  X, E, width(X) - 1, 1  ; insert extracted bit at bit width(X)-1 of X
2463     SDValue E = DAG.getNode(MipsISD::Ext, DL, TyY, Y,
2464                             DAG.getConstant(WidthY - 1, DL, MVT::i32), Const1);
2465 
2466     if (WidthX > WidthY)
2467       E = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, E);
2468     else if (WidthY > WidthX)
2469       E = DAG.getNode(ISD::TRUNCATE, DL, TyX, E);
2470 
2471     SDValue I = DAG.getNode(MipsISD::Ins, DL, TyX, E,
2472                             DAG.getConstant(WidthX - 1, DL, MVT::i32), Const1,
2473                             X);
2474     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), I);
2475   }
2476 
2477   // (d)sll SllX, X, 1
2478   // (d)srl SrlX, SllX, 1
2479   // (d)srl SrlY, Y, width(Y)-1
2480   // (d)sll SllY, SrlX, width(Y)-1
2481   // or     Or, SrlX, SllY
2482   SDValue SllX = DAG.getNode(ISD::SHL, DL, TyX, X, Const1);
2483   SDValue SrlX = DAG.getNode(ISD::SRL, DL, TyX, SllX, Const1);
2484   SDValue SrlY = DAG.getNode(ISD::SRL, DL, TyY, Y,
2485                              DAG.getConstant(WidthY - 1, DL, MVT::i32));
2486 
2487   if (WidthX > WidthY)
2488     SrlY = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, SrlY);
2489   else if (WidthY > WidthX)
2490     SrlY = DAG.getNode(ISD::TRUNCATE, DL, TyX, SrlY);
2491 
2492   SDValue SllY = DAG.getNode(ISD::SHL, DL, TyX, SrlY,
2493                              DAG.getConstant(WidthX - 1, DL, MVT::i32));
2494   SDValue Or = DAG.getNode(ISD::OR, DL, TyX, SrlX, SllY);
2495   return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Or);
2496 }
2497 
2498 SDValue
2499 MipsTargetLowering::lowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
2500   if (Subtarget.isGP64bit())
2501     return lowerFCOPYSIGN64(Op, DAG, Subtarget.hasExtractInsert());
2502 
2503   return lowerFCOPYSIGN32(Op, DAG, Subtarget.hasExtractInsert());
2504 }
2505 
2506 SDValue MipsTargetLowering::lowerFABS32(SDValue Op, SelectionDAG &DAG,
2507                                         bool HasExtractInsert) const {
2508   SDLoc DL(Op);
2509   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2510 
2511   if (DAG.getTarget().Options.NoNaNsFPMath || Subtarget.inAbs2008Mode())
2512     return DAG.getNode(MipsISD::FAbs, DL, Op.getValueType(), Op.getOperand(0));
2513 
2514   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2515   // to i32.
2516   SDValue X = (Op.getValueType() == MVT::f32)
2517                   ? DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0))
2518                   : DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2519                                 Op.getOperand(0), Const1);
2520 
2521   // Clear MSB.
2522   if (HasExtractInsert)
2523     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32,
2524                       DAG.getRegister(Mips::ZERO, MVT::i32),
2525                       DAG.getConstant(31, DL, MVT::i32), Const1, X);
2526   else {
2527     // TODO: Provide DAG patterns which transform (and x, cst)
2528     // back to a (shl (srl x (clz cst)) (clz cst)) sequence.
2529     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2530     Res = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2531   }
2532 
2533   if (Op.getValueType() == MVT::f32)
2534     return DAG.getNode(ISD::BITCAST, DL, MVT::f32, Res);
2535 
2536   // FIXME: For mips32r2, the sequence of (BuildPairF64 (ins (ExtractElementF64
2537   // Op 1), $zero, 31 1) (ExtractElementF64 Op 0)) and the Op has one use, we
2538   // should be able to drop the usage of mfc1/mtc1 and rewrite the register in
2539   // place.
2540   SDValue LowX =
2541       DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2542                   DAG.getConstant(0, DL, MVT::i32));
2543   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2544 }
2545 
2546 SDValue MipsTargetLowering::lowerFABS64(SDValue Op, SelectionDAG &DAG,
2547                                         bool HasExtractInsert) const {
2548   SDLoc DL(Op);
2549   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2550 
2551   if (DAG.getTarget().Options.NoNaNsFPMath || Subtarget.inAbs2008Mode())
2552     return DAG.getNode(MipsISD::FAbs, DL, Op.getValueType(), Op.getOperand(0));
2553 
2554   // Bitcast to integer node.
2555   SDValue X = DAG.getNode(ISD::BITCAST, DL, MVT::i64, Op.getOperand(0));
2556 
2557   // Clear MSB.
2558   if (HasExtractInsert)
2559     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i64,
2560                       DAG.getRegister(Mips::ZERO_64, MVT::i64),
2561                       DAG.getConstant(63, DL, MVT::i32), Const1, X);
2562   else {
2563     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i64, X, Const1);
2564     Res = DAG.getNode(ISD::SRL, DL, MVT::i64, SllX, Const1);
2565   }
2566 
2567   return DAG.getNode(ISD::BITCAST, DL, MVT::f64, Res);
2568 }
2569 
2570 SDValue MipsTargetLowering::lowerFABS(SDValue Op, SelectionDAG &DAG) const {
2571   if ((ABI.IsN32() || ABI.IsN64()) && (Op.getValueType() == MVT::f64))
2572     return lowerFABS64(Op, DAG, Subtarget.hasExtractInsert());
2573 
2574   return lowerFABS32(Op, DAG, Subtarget.hasExtractInsert());
2575 }
2576 
2577 SDValue MipsTargetLowering::lowerFCANONICALIZE(SDValue Op,
2578                                                SelectionDAG &DAG) const {
2579   SDLoc DL(Op);
2580   EVT VT = Op.getValueType();
2581   SDValue Operand = Op.getOperand(0);
2582   SDNodeFlags Flags = Op->getFlags();
2583 
2584   if (Flags.hasNoNaNs() || DAG.isKnownNeverNaN(Operand))
2585     return Operand;
2586 
2587   SDValue Quiet = DAG.getNode(ISD::FADD, DL, VT, Operand, Operand);
2588   return DAG.getSelectCC(DL, Operand, Operand, Quiet, Operand, ISD::SETUO);
2589 }
2590 
2591 SDValue MipsTargetLowering::
2592 lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2593   // check the depth
2594   if (Op.getConstantOperandVal(0) != 0) {
2595     DAG.getContext()->emitError(
2596         "return address can be determined only for current frame");
2597     return SDValue();
2598   }
2599 
2600   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2601   MFI.setFrameAddressIsTaken(true);
2602   EVT VT = Op.getValueType();
2603   SDLoc DL(Op);
2604   SDValue FrameAddr = DAG.getCopyFromReg(
2605       DAG.getEntryNode(), DL, ABI.IsN64() ? Mips::FP_64 : Mips::FP, VT);
2606   return FrameAddr;
2607 }
2608 
2609 SDValue MipsTargetLowering::lowerRETURNADDR(SDValue Op,
2610                                             SelectionDAG &DAG) const {
2611   if (verifyReturnAddressArgumentIsConstant(Op, DAG))
2612     return SDValue();
2613 
2614   // check the depth
2615   if (Op.getConstantOperandVal(0) != 0) {
2616     DAG.getContext()->emitError(
2617         "return address can be determined only for current frame");
2618     return SDValue();
2619   }
2620 
2621   MachineFunction &MF = DAG.getMachineFunction();
2622   MachineFrameInfo &MFI = MF.getFrameInfo();
2623   MVT VT = Op.getSimpleValueType();
2624   unsigned RA = ABI.IsN64() ? Mips::RA_64 : Mips::RA;
2625   MFI.setReturnAddressIsTaken(true);
2626 
2627   // Return RA, which contains the return address. Mark it an implicit live-in.
2628   Register Reg = MF.addLiveIn(RA, getRegClassFor(VT));
2629   return DAG.getCopyFromReg(DAG.getEntryNode(), SDLoc(Op), Reg, VT);
2630 }
2631 
2632 // An EH_RETURN is the result of lowering llvm.eh.return which in turn is
2633 // generated from __builtin_eh_return (offset, handler)
2634 // The effect of this is to adjust the stack pointer by "offset"
2635 // and then branch to "handler".
2636 SDValue MipsTargetLowering::lowerEH_RETURN(SDValue Op, SelectionDAG &DAG)
2637                                                                      const {
2638   MachineFunction &MF = DAG.getMachineFunction();
2639   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
2640 
2641   MipsFI->setCallsEhReturn();
2642   SDValue Chain     = Op.getOperand(0);
2643   SDValue Offset    = Op.getOperand(1);
2644   SDValue Handler   = Op.getOperand(2);
2645   SDLoc DL(Op);
2646   EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2647 
2648   // Store stack offset in V1, store jump target in V0. Glue CopyToReg and
2649   // EH_RETURN nodes, so that instructions are emitted back-to-back.
2650   unsigned OffsetReg = ABI.IsN64() ? Mips::V1_64 : Mips::V1;
2651   unsigned AddrReg = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
2652   Chain = DAG.getCopyToReg(Chain, DL, OffsetReg, Offset, SDValue());
2653   Chain = DAG.getCopyToReg(Chain, DL, AddrReg, Handler, Chain.getValue(1));
2654   return DAG.getNode(MipsISD::EH_RETURN, DL, MVT::Other, Chain,
2655                      DAG.getRegister(OffsetReg, Ty),
2656                      DAG.getRegister(AddrReg, getPointerTy(MF.getDataLayout())),
2657                      Chain.getValue(1));
2658 }
2659 
2660 SDValue MipsTargetLowering::lowerATOMIC_FENCE(SDValue Op,
2661                                               SelectionDAG &DAG) const {
2662   // FIXME: Need pseudo-fence for 'singlethread' fences
2663   // FIXME: Set SType for weaker fences where supported/appropriate.
2664   unsigned SType = 0;
2665   SDLoc DL(Op);
2666   return DAG.getNode(MipsISD::Sync, DL, MVT::Other, Op.getOperand(0),
2667                      DAG.getConstant(SType, DL, MVT::i32));
2668 }
2669 
2670 SDValue MipsTargetLowering::lowerShiftLeftParts(SDValue Op,
2671                                                 SelectionDAG &DAG) const {
2672   SDLoc DL(Op);
2673   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2674 
2675   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2676   SDValue Shamt = Op.getOperand(2);
2677   // if shamt < (VT.bits):
2678   //  lo = (shl lo, shamt)
2679   //  hi = (or (shl hi, shamt) (srl (srl lo, 1), (xor shamt, (VT.bits-1))))
2680   // else:
2681   //  lo = 0
2682   //  hi = (shl lo, shamt[4:0])
2683   SDValue Not =
2684       DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2685                   DAG.getConstant(VT.getSizeInBits() - 1, DL, MVT::i32));
2686   SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo,
2687                                       DAG.getConstant(1, DL, VT));
2688   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, Not);
2689   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
2690   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2691   SDValue ShiftLeftLo = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
2692   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2693                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2694   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2695                    DAG.getConstant(0, DL, VT), ShiftLeftLo);
2696   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftLeftLo, Or);
2697 
2698   SDValue Ops[2] = {Lo, Hi};
2699   return DAG.getMergeValues(Ops, DL);
2700 }
2701 
2702 SDValue MipsTargetLowering::lowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
2703                                                  bool IsSRA) const {
2704   SDLoc DL(Op);
2705   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2706   SDValue Shamt = Op.getOperand(2);
2707   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2708 
2709   // if shamt < (VT.bits):
2710   //  lo = (or (shl (shl hi, 1), (xor shamt, (VT.bits-1))) (srl lo, shamt))
2711   //  if isSRA:
2712   //    hi = (sra hi, shamt)
2713   //  else:
2714   //    hi = (srl hi, shamt)
2715   // else:
2716   //  if isSRA:
2717   //   lo = (sra hi, shamt[4:0])
2718   //   hi = (sra hi, 31)
2719   //  else:
2720   //   lo = (srl hi, shamt[4:0])
2721   //   hi = 0
2722   SDValue Not =
2723       DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2724                   DAG.getConstant(VT.getSizeInBits() - 1, DL, MVT::i32));
2725   SDValue ShiftLeft1Hi = DAG.getNode(ISD::SHL, DL, VT, Hi,
2726                                      DAG.getConstant(1, DL, VT));
2727   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, ShiftLeft1Hi, Not);
2728   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
2729   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2730   SDValue ShiftRightHi = DAG.getNode(IsSRA ? ISD::SRA : ISD::SRL,
2731                                      DL, VT, Hi, Shamt);
2732   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2733                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2734   SDValue Ext = DAG.getNode(ISD::SRA, DL, VT, Hi,
2735                             DAG.getConstant(VT.getSizeInBits() - 1, DL, VT));
2736 
2737   if (!(Subtarget.hasMips4() || Subtarget.hasMips32())) {
2738     SDVTList VTList = DAG.getVTList(VT, VT);
2739     return DAG.getNode(Subtarget.isGP64bit() ? MipsISD::DOUBLE_SELECT_I64
2740                                              : MipsISD::DOUBLE_SELECT_I,
2741                        DL, VTList, Cond, ShiftRightHi,
2742                        IsSRA ? Ext : DAG.getConstant(0, DL, VT), Or,
2743                        ShiftRightHi);
2744   }
2745 
2746   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftRightHi, Or);
2747   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2748                    IsSRA ? Ext : DAG.getConstant(0, DL, VT), ShiftRightHi);
2749 
2750   SDValue Ops[2] = {Lo, Hi};
2751   return DAG.getMergeValues(Ops, DL);
2752 }
2753 
2754 static SDValue createLoadLR(unsigned Opc, SelectionDAG &DAG, LoadSDNode *LD,
2755                             SDValue Chain, SDValue Src, unsigned Offset) {
2756   SDValue Ptr = LD->getBasePtr();
2757   EVT VT = LD->getValueType(0), MemVT = LD->getMemoryVT();
2758   EVT BasePtrVT = Ptr.getValueType();
2759   SDLoc DL(LD);
2760   SDVTList VTList = DAG.getVTList(VT, MVT::Other);
2761 
2762   if (Offset)
2763     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2764                       DAG.getConstant(Offset, DL, BasePtrVT));
2765 
2766   SDValue Ops[] = { Chain, Ptr, Src };
2767   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2768                                  LD->getMemOperand());
2769 }
2770 
2771 // Expand an unaligned 32 or 64-bit integer load node.
2772 SDValue MipsTargetLowering::lowerLOAD(SDValue Op, SelectionDAG &DAG) const {
2773   LoadSDNode *LD = cast<LoadSDNode>(Op);
2774   EVT MemVT = LD->getMemoryVT();
2775 
2776   if (Subtarget.systemSupportsUnalignedAccess())
2777     return Op;
2778 
2779   // Return if load is aligned or if MemVT is neither i32 nor i64.
2780   if ((LD->getAlign().value() >= (MemVT.getSizeInBits() / 8)) ||
2781       ((MemVT != MVT::i32) && (MemVT != MVT::i64)))
2782     return SDValue();
2783 
2784   bool IsLittle = Subtarget.isLittle();
2785   EVT VT = Op.getValueType();
2786   ISD::LoadExtType ExtType = LD->getExtensionType();
2787   SDValue Chain = LD->getChain(), Undef = DAG.getUNDEF(VT);
2788 
2789   assert((VT == MVT::i32) || (VT == MVT::i64));
2790 
2791   // Expand
2792   //  (set dst, (i64 (load baseptr)))
2793   // to
2794   //  (set tmp, (ldl (add baseptr, 7), undef))
2795   //  (set dst, (ldr baseptr, tmp))
2796   if ((VT == MVT::i64) && (ExtType == ISD::NON_EXTLOAD)) {
2797     SDValue LDL = createLoadLR(MipsISD::LDL, DAG, LD, Chain, Undef,
2798                                IsLittle ? 7 : 0);
2799     return createLoadLR(MipsISD::LDR, DAG, LD, LDL.getValue(1), LDL,
2800                         IsLittle ? 0 : 7);
2801   }
2802 
2803   SDValue LWL = createLoadLR(MipsISD::LWL, DAG, LD, Chain, Undef,
2804                              IsLittle ? 3 : 0);
2805   SDValue LWR = createLoadLR(MipsISD::LWR, DAG, LD, LWL.getValue(1), LWL,
2806                              IsLittle ? 0 : 3);
2807 
2808   // Expand
2809   //  (set dst, (i32 (load baseptr))) or
2810   //  (set dst, (i64 (sextload baseptr))) or
2811   //  (set dst, (i64 (extload baseptr)))
2812   // to
2813   //  (set tmp, (lwl (add baseptr, 3), undef))
2814   //  (set dst, (lwr baseptr, tmp))
2815   if ((VT == MVT::i32) || (ExtType == ISD::SEXTLOAD) ||
2816       (ExtType == ISD::EXTLOAD))
2817     return LWR;
2818 
2819   assert((VT == MVT::i64) && (ExtType == ISD::ZEXTLOAD));
2820 
2821   // Expand
2822   //  (set dst, (i64 (zextload baseptr)))
2823   // to
2824   //  (set tmp0, (lwl (add baseptr, 3), undef))
2825   //  (set tmp1, (lwr baseptr, tmp0))
2826   //  (set tmp2, (shl tmp1, 32))
2827   //  (set dst, (srl tmp2, 32))
2828   SDLoc DL(LD);
2829   SDValue Const32 = DAG.getConstant(32, DL, MVT::i32);
2830   SDValue SLL = DAG.getNode(ISD::SHL, DL, MVT::i64, LWR, Const32);
2831   SDValue SRL = DAG.getNode(ISD::SRL, DL, MVT::i64, SLL, Const32);
2832   SDValue Ops[] = { SRL, LWR.getValue(1) };
2833   return DAG.getMergeValues(Ops, DL);
2834 }
2835 
2836 static SDValue createStoreLR(unsigned Opc, SelectionDAG &DAG, StoreSDNode *SD,
2837                              SDValue Chain, unsigned Offset) {
2838   SDValue Ptr = SD->getBasePtr(), Value = SD->getValue();
2839   EVT MemVT = SD->getMemoryVT(), BasePtrVT = Ptr.getValueType();
2840   SDLoc DL(SD);
2841   SDVTList VTList = DAG.getVTList(MVT::Other);
2842 
2843   if (Offset)
2844     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2845                       DAG.getConstant(Offset, DL, BasePtrVT));
2846 
2847   SDValue Ops[] = { Chain, Value, Ptr };
2848   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2849                                  SD->getMemOperand());
2850 }
2851 
2852 // Expand an unaligned 32 or 64-bit integer store node.
2853 static SDValue lowerUnalignedIntStore(StoreSDNode *SD, SelectionDAG &DAG,
2854                                       bool IsLittle) {
2855   SDValue Value = SD->getValue(), Chain = SD->getChain();
2856   EVT VT = Value.getValueType();
2857 
2858   // Expand
2859   //  (store val, baseptr) or
2860   //  (truncstore val, baseptr)
2861   // to
2862   //  (swl val, (add baseptr, 3))
2863   //  (swr val, baseptr)
2864   if ((VT == MVT::i32) || SD->isTruncatingStore()) {
2865     SDValue SWL = createStoreLR(MipsISD::SWL, DAG, SD, Chain,
2866                                 IsLittle ? 3 : 0);
2867     return createStoreLR(MipsISD::SWR, DAG, SD, SWL, IsLittle ? 0 : 3);
2868   }
2869 
2870   assert(VT == MVT::i64);
2871 
2872   // Expand
2873   //  (store val, baseptr)
2874   // to
2875   //  (sdl val, (add baseptr, 7))
2876   //  (sdr val, baseptr)
2877   SDValue SDL = createStoreLR(MipsISD::SDL, DAG, SD, Chain, IsLittle ? 7 : 0);
2878   return createStoreLR(MipsISD::SDR, DAG, SD, SDL, IsLittle ? 0 : 7);
2879 }
2880 
2881 // Lower (store (fp_to_sint $fp) $ptr) to (store (TruncIntFP $fp), $ptr).
2882 static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG,
2883                                      bool SingleFloat) {
2884   SDValue Val = SD->getValue();
2885 
2886   if (Val.getOpcode() != ISD::FP_TO_SINT ||
2887       (Val.getValueSizeInBits() > 32 && SingleFloat))
2888     return SDValue();
2889 
2890   EVT FPTy = EVT::getFloatingPointVT(Val.getValueSizeInBits());
2891   SDValue Tr = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Val), FPTy,
2892                            Val.getOperand(0));
2893   return DAG.getStore(SD->getChain(), SDLoc(SD), Tr, SD->getBasePtr(),
2894                       SD->getPointerInfo(), SD->getAlign(),
2895                       SD->getMemOperand()->getFlags());
2896 }
2897 
2898 SDValue MipsTargetLowering::lowerSTORE(SDValue Op, SelectionDAG &DAG) const {
2899   StoreSDNode *SD = cast<StoreSDNode>(Op);
2900   EVT MemVT = SD->getMemoryVT();
2901 
2902   // Lower unaligned integer stores.
2903   if (!Subtarget.systemSupportsUnalignedAccess() &&
2904       (SD->getAlign().value() < (MemVT.getSizeInBits() / 8)) &&
2905       ((MemVT == MVT::i32) || (MemVT == MVT::i64)))
2906     return lowerUnalignedIntStore(SD, DAG, Subtarget.isLittle());
2907 
2908   return lowerFP_TO_SINT_STORE(SD, DAG, Subtarget.isSingleFloat());
2909 }
2910 
2911 SDValue MipsTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
2912                                               SelectionDAG &DAG) const {
2913 
2914   // Return a fixed StackObject with offset 0 which points to the old stack
2915   // pointer.
2916   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2917   EVT ValTy = Op->getValueType(0);
2918   int FI = MFI.CreateFixedObject(Op.getValueSizeInBits() / 8, 0, false);
2919   return DAG.getFrameIndex(FI, ValTy);
2920 }
2921 
2922 SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op,
2923                                             SelectionDAG &DAG) const {
2924   if (Op.getValueSizeInBits() > 32 && Subtarget.isSingleFloat())
2925     return SDValue();
2926 
2927   EVT FPTy = EVT::getFloatingPointVT(Op.getValueSizeInBits());
2928   SDValue Trunc = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Op), FPTy,
2929                               Op.getOperand(0));
2930   return DAG.getNode(ISD::BITCAST, SDLoc(Op), Op.getValueType(), Trunc);
2931 }
2932 
2933 //===----------------------------------------------------------------------===//
2934 //                      Calling Convention Implementation
2935 //===----------------------------------------------------------------------===//
2936 
2937 //===----------------------------------------------------------------------===//
2938 // TODO: Implement a generic logic using tblgen that can support this.
2939 // Mips O32 ABI rules:
2940 // ---
2941 // i32 - Passed in A0, A1, A2, A3 and stack
2942 // f32 - Only passed in f32 registers if no int reg has been used yet to hold
2943 //       an argument. Otherwise, passed in A1, A2, A3 and stack.
2944 // f64 - Only passed in two aliased f32 registers if no int reg has been used
2945 //       yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is
2946 //       not used, it must be shadowed. If only A3 is available, shadow it and
2947 //       go to stack.
2948 // vXiX - Received as scalarized i32s, passed in A0 - A3 and the stack.
2949 // vXf32 - Passed in either a pair of registers {A0, A1}, {A2, A3} or {A0 - A3}
2950 //         with the remainder spilled to the stack.
2951 // vXf64 - Passed in either {A0, A1, A2, A3} or {A2, A3} and in both cases
2952 //         spilling the remainder to the stack.
2953 //
2954 //  For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack.
2955 //===----------------------------------------------------------------------===//
2956 
2957 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2958                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2959                        CCState &State, ArrayRef<MCPhysReg> F64Regs) {
2960   const MipsSubtarget &Subtarget = static_cast<const MipsSubtarget &>(
2961       State.getMachineFunction().getSubtarget());
2962 
2963   static const MCPhysReg IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 };
2964 
2965   const MipsCCState * MipsState = static_cast<MipsCCState *>(&State);
2966 
2967   static const MCPhysReg F32Regs[] = { Mips::F12, Mips::F14 };
2968 
2969   static const MCPhysReg FloatVectorIntRegs[] = { Mips::A0, Mips::A2 };
2970 
2971   // Do not process byval args here.
2972   if (ArgFlags.isByVal())
2973     return true;
2974 
2975   // Promote i8 and i16
2976   if (ArgFlags.isInReg() && !Subtarget.isLittle()) {
2977     if (LocVT == MVT::i8 || LocVT == MVT::i16 || LocVT == MVT::i32) {
2978       LocVT = MVT::i32;
2979       if (ArgFlags.isSExt())
2980         LocInfo = CCValAssign::SExtUpper;
2981       else if (ArgFlags.isZExt())
2982         LocInfo = CCValAssign::ZExtUpper;
2983       else
2984         LocInfo = CCValAssign::AExtUpper;
2985     }
2986   }
2987 
2988   // Promote i8 and i16
2989   if (LocVT == MVT::i8 || LocVT == MVT::i16) {
2990     LocVT = MVT::i32;
2991     if (ArgFlags.isSExt())
2992       LocInfo = CCValAssign::SExt;
2993     else if (ArgFlags.isZExt())
2994       LocInfo = CCValAssign::ZExt;
2995     else
2996       LocInfo = CCValAssign::AExt;
2997   }
2998 
2999   unsigned Reg;
3000 
3001   // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following
3002   // is true: function is vararg, argument is 3rd or higher, there is previous
3003   // argument which is not f32 or f64.
3004   bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1 ||
3005                                 State.getFirstUnallocated(F32Regs) != ValNo;
3006   Align OrigAlign = ArgFlags.getNonZeroOrigAlign();
3007   bool isI64 = (ValVT == MVT::i32 && OrigAlign == Align(8));
3008   bool isVectorFloat = MipsState->WasOriginalArgVectorFloat(ValNo);
3009 
3010   // The MIPS vector ABI for floats passes them in a pair of registers
3011   if (ValVT == MVT::i32 && isVectorFloat) {
3012     // This is the start of an vector that was scalarized into an unknown number
3013     // of components. It doesn't matter how many there are. Allocate one of the
3014     // notional 8 byte aligned registers which map onto the argument stack, and
3015     // shadow the register lost to alignment requirements.
3016     if (ArgFlags.isSplit()) {
3017       Reg = State.AllocateReg(FloatVectorIntRegs);
3018       if (Reg == Mips::A2)
3019         State.AllocateReg(Mips::A1);
3020       else if (Reg == 0)
3021         State.AllocateReg(Mips::A3);
3022     } else {
3023       // If we're an intermediate component of the split, we can just attempt to
3024       // allocate a register directly.
3025       Reg = State.AllocateReg(IntRegs);
3026     }
3027   } else if (ValVT == MVT::i32 ||
3028              (ValVT == MVT::f32 && AllocateFloatsInIntReg)) {
3029     Reg = State.AllocateReg(IntRegs);
3030     // If this is the first part of an i64 arg,
3031     // the allocated register must be either A0 or A2.
3032     if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3))
3033       Reg = State.AllocateReg(IntRegs);
3034     LocVT = MVT::i32;
3035   } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) {
3036     // Allocate int register and shadow next int register. If first
3037     // available register is Mips::A1 or Mips::A3, shadow it too.
3038     Reg = State.AllocateReg(IntRegs);
3039     if (Reg == Mips::A1 || Reg == Mips::A3)
3040       Reg = State.AllocateReg(IntRegs);
3041 
3042     if (Reg) {
3043       LocVT = MVT::i32;
3044 
3045       State.addLoc(
3046           CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
3047       MCRegister HiReg = State.AllocateReg(IntRegs);
3048       assert(HiReg);
3049       State.addLoc(
3050           CCValAssign::getCustomReg(ValNo, ValVT, HiReg, LocVT, LocInfo));
3051       return false;
3052     }
3053   } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) {
3054     // we are guaranteed to find an available float register
3055     if (ValVT == MVT::f32) {
3056       Reg = State.AllocateReg(F32Regs);
3057       // Shadow int register
3058       State.AllocateReg(IntRegs);
3059     } else {
3060       Reg = State.AllocateReg(F64Regs);
3061       // Shadow int registers
3062       MCRegister Reg2 = State.AllocateReg(IntRegs);
3063       if (Reg2 == Mips::A1 || Reg2 == Mips::A3)
3064         State.AllocateReg(IntRegs);
3065       State.AllocateReg(IntRegs);
3066     }
3067   } else
3068     llvm_unreachable("Cannot handle this ValVT.");
3069 
3070   if (!Reg) {
3071     unsigned Offset = State.AllocateStack(ValVT.getStoreSize(), OrigAlign);
3072     State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
3073   } else
3074     State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
3075 
3076   return false;
3077 }
3078 
3079 static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT,
3080                             MVT LocVT, CCValAssign::LocInfo LocInfo,
3081                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
3082   static const MCPhysReg F64Regs[] = { Mips::D6, Mips::D7 };
3083 
3084   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
3085 }
3086 
3087 static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT,
3088                             MVT LocVT, CCValAssign::LocInfo LocInfo,
3089                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
3090   static const MCPhysReg F64Regs[] = { Mips::D12_64, Mips::D14_64 };
3091 
3092   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
3093 }
3094 
3095 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
3096                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
3097                        CCState &State) LLVM_ATTRIBUTE_UNUSED;
3098 
3099 #include "MipsGenCallingConv.inc"
3100 
3101  CCAssignFn *MipsTargetLowering::CCAssignFnForCall() const{
3102    return CC_Mips_FixedArg;
3103  }
3104 
3105  CCAssignFn *MipsTargetLowering::CCAssignFnForReturn() const{
3106    return RetCC_Mips;
3107  }
3108 //===----------------------------------------------------------------------===//
3109 //                  Call Calling Convention Implementation
3110 //===----------------------------------------------------------------------===//
3111 
3112 SDValue MipsTargetLowering::passArgOnStack(SDValue StackPtr, unsigned Offset,
3113                                            SDValue Chain, SDValue Arg,
3114                                            const SDLoc &DL, bool IsTailCall,
3115                                            SelectionDAG &DAG) const {
3116   if (!IsTailCall) {
3117     SDValue PtrOff =
3118         DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr,
3119                     DAG.getIntPtrConstant(Offset, DL));
3120     return DAG.getStore(Chain, DL, Arg, PtrOff, MachinePointerInfo());
3121   }
3122 
3123   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
3124   int FI = MFI.CreateFixedObject(Arg.getValueSizeInBits() / 8, Offset, false);
3125   SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3126   return DAG.getStore(Chain, DL, Arg, FIN, MachinePointerInfo(), MaybeAlign(),
3127                       MachineMemOperand::MOVolatile);
3128 }
3129 
3130 void MipsTargetLowering::
3131 getOpndList(SmallVectorImpl<SDValue> &Ops,
3132             std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
3133             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
3134             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
3135             SDValue Chain) const {
3136   // Insert node "GP copy globalreg" before call to function.
3137   //
3138   // R_MIPS_CALL* operators (emitted when non-internal functions are called
3139   // in PIC mode) allow symbols to be resolved via lazy binding.
3140   // The lazy binding stub requires GP to point to the GOT.
3141   // Note that we don't need GP to point to the GOT for indirect calls
3142   // (when R_MIPS_CALL* is not used for the call) because Mips linker generates
3143   // lazy binding stub for a function only when R_MIPS_CALL* are the only relocs
3144   // used for the function (that is, Mips linker doesn't generate lazy binding
3145   // stub for a function whose address is taken in the program).
3146   if (IsPICCall && !InternalLinkage && IsCallReloc) {
3147     unsigned GPReg = ABI.IsN64() ? Mips::GP_64 : Mips::GP;
3148     EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
3149     RegsToPass.push_back(std::make_pair(GPReg, getGlobalReg(CLI.DAG, Ty)));
3150   }
3151 
3152   // Build a sequence of copy-to-reg nodes chained together with token
3153   // chain and flag operands which copy the outgoing args into registers.
3154   // The InGlue in necessary since all emitted instructions must be
3155   // stuck together.
3156   SDValue InGlue;
3157 
3158   for (auto &R : RegsToPass) {
3159     Chain = CLI.DAG.getCopyToReg(Chain, CLI.DL, R.first, R.second, InGlue);
3160     InGlue = Chain.getValue(1);
3161   }
3162 
3163   // Add argument registers to the end of the list so that they are
3164   // known live into the call.
3165   for (auto &R : RegsToPass)
3166     Ops.push_back(CLI.DAG.getRegister(R.first, R.second.getValueType()));
3167 
3168   // Add a register mask operand representing the call-preserved registers.
3169   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
3170   const uint32_t *Mask =
3171       TRI->getCallPreservedMask(CLI.DAG.getMachineFunction(), CLI.CallConv);
3172   assert(Mask && "Missing call preserved mask for calling convention");
3173   if (Subtarget.inMips16HardFloat()) {
3174     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
3175       StringRef Sym = G->getGlobal()->getName();
3176       Function *F = G->getGlobal()->getParent()->getFunction(Sym);
3177       if (F && F->hasFnAttribute("__Mips16RetHelper")) {
3178         Mask = MipsRegisterInfo::getMips16RetHelperMask();
3179       }
3180     }
3181   }
3182   Ops.push_back(CLI.DAG.getRegisterMask(Mask));
3183 
3184   if (InGlue.getNode())
3185     Ops.push_back(InGlue);
3186 }
3187 
3188 void MipsTargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
3189                                                        SDNode *Node) const {
3190   switch (MI.getOpcode()) {
3191     default:
3192       return;
3193     case Mips::JALR:
3194     case Mips::JALRPseudo:
3195     case Mips::JALR64:
3196     case Mips::JALR64Pseudo:
3197     case Mips::JALR16_MM:
3198     case Mips::JALRC16_MMR6:
3199     case Mips::TAILCALLREG:
3200     case Mips::TAILCALLREG64:
3201     case Mips::TAILCALLR6REG:
3202     case Mips::TAILCALL64R6REG:
3203     case Mips::TAILCALLREG_MM:
3204     case Mips::TAILCALLREG_MMR6: {
3205       if (!EmitJalrReloc ||
3206           Subtarget.inMips16Mode() ||
3207           !isPositionIndependent() ||
3208           Node->getNumOperands() < 1 ||
3209           Node->getOperand(0).getNumOperands() < 2) {
3210         return;
3211       }
3212       // We are after the callee address, set by LowerCall().
3213       // If added to MI, asm printer will emit .reloc R_MIPS_JALR for the
3214       // symbol.
3215       const SDValue TargetAddr = Node->getOperand(0).getOperand(1);
3216       StringRef Sym;
3217       if (const GlobalAddressSDNode *G =
3218               dyn_cast_or_null<const GlobalAddressSDNode>(TargetAddr)) {
3219         // We must not emit the R_MIPS_JALR relocation against data symbols
3220         // since this will cause run-time crashes if the linker replaces the
3221         // call instruction with a relative branch to the data symbol.
3222         if (!isa<Function>(G->getGlobal())) {
3223           LLVM_DEBUG(dbgs() << "Not adding R_MIPS_JALR against data symbol "
3224                             << G->getGlobal()->getName() << "\n");
3225           return;
3226         }
3227         Sym = G->getGlobal()->getName();
3228       }
3229       else if (const ExternalSymbolSDNode *ES =
3230                    dyn_cast_or_null<const ExternalSymbolSDNode>(TargetAddr)) {
3231         Sym = ES->getSymbol();
3232       }
3233 
3234       if (Sym.empty())
3235         return;
3236 
3237       MachineFunction *MF = MI.getParent()->getParent();
3238       MCSymbol *S = MF->getContext().getOrCreateSymbol(Sym);
3239       LLVM_DEBUG(dbgs() << "Adding R_MIPS_JALR against " << Sym << "\n");
3240       MI.addOperand(MachineOperand::CreateMCSymbol(S, MipsII::MO_JALR));
3241     }
3242   }
3243 }
3244 
3245 /// LowerCall - functions arguments are copied from virtual regs to
3246 /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
3247 SDValue
3248 MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
3249                               SmallVectorImpl<SDValue> &InVals) const {
3250   SelectionDAG &DAG                     = CLI.DAG;
3251   SDLoc DL                              = CLI.DL;
3252   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
3253   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
3254   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
3255   SDValue Chain                         = CLI.Chain;
3256   SDValue Callee                        = CLI.Callee;
3257   bool &IsTailCall                      = CLI.IsTailCall;
3258   CallingConv::ID CallConv              = CLI.CallConv;
3259   bool IsVarArg                         = CLI.IsVarArg;
3260 
3261   MachineFunction &MF = DAG.getMachineFunction();
3262   MachineFrameInfo &MFI = MF.getFrameInfo();
3263   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
3264   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
3265   bool IsPIC = isPositionIndependent();
3266 
3267   // Analyze operands of the call, assigning locations to each operand.
3268   SmallVector<CCValAssign, 16> ArgLocs;
3269   MipsCCState CCInfo(
3270       CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext(),
3271       MipsCCState::getSpecialCallingConvForCallee(Callee.getNode(), Subtarget));
3272 
3273   const ExternalSymbolSDNode *ES =
3274       dyn_cast_or_null<const ExternalSymbolSDNode>(Callee.getNode());
3275 
3276   // There is one case where CALLSEQ_START..CALLSEQ_END can be nested, which
3277   // is during the lowering of a call with a byval argument which produces
3278   // a call to memcpy. For the O32 case, this causes the caller to allocate
3279   // stack space for the reserved argument area for the callee, then recursively
3280   // again for the memcpy call. In the NEWABI case, this doesn't occur as those
3281   // ABIs mandate that the callee allocates the reserved argument area. We do
3282   // still produce nested CALLSEQ_START..CALLSEQ_END with zero space though.
3283   //
3284   // If the callee has a byval argument and memcpy is used, we are mandated
3285   // to already have produced a reserved argument area for the callee for O32.
3286   // Therefore, the reserved argument area can be reused for both calls.
3287   //
3288   // Other cases of calling memcpy cannot have a chain with a CALLSEQ_START
3289   // present, as we have yet to hook that node onto the chain.
3290   //
3291   // Hence, the CALLSEQ_START and CALLSEQ_END nodes can be eliminated in this
3292   // case. GCC does a similar trick, in that wherever possible, it calculates
3293   // the maximum out going argument area (including the reserved area), and
3294   // preallocates the stack space on entrance to the caller.
3295   //
3296   // FIXME: We should do the same for efficiency and space.
3297 
3298   // Note: The check on the calling convention below must match
3299   //       MipsABIInfo::GetCalleeAllocdArgSizeInBytes().
3300   bool MemcpyInByVal = ES && StringRef(ES->getSymbol()) == "memcpy" &&
3301                        CallConv != CallingConv::Fast &&
3302                        Chain.getOpcode() == ISD::CALLSEQ_START;
3303 
3304   // Allocate the reserved argument area. It seems strange to do this from the
3305   // caller side but removing it breaks the frame size calculation.
3306   unsigned ReservedArgArea =
3307       MemcpyInByVal ? 0 : ABI.GetCalleeAllocdArgSizeInBytes(CallConv);
3308   CCInfo.AllocateStack(ReservedArgArea, Align(1));
3309 
3310   CCInfo.AnalyzeCallOperands(Outs, CC_Mips, CLI.getArgs(),
3311                              ES ? ES->getSymbol() : nullptr);
3312 
3313   // Get a count of how many bytes are to be pushed on the stack.
3314   unsigned StackSize = CCInfo.getStackSize();
3315 
3316   // Call site info for function parameters tracking.
3317   MachineFunction::CallSiteInfo CSInfo;
3318 
3319   // Check if it's really possible to do a tail call. Restrict it to functions
3320   // that are part of this compilation unit.
3321   bool InternalLinkage = false;
3322   if (IsTailCall) {
3323     IsTailCall = isEligibleForTailCallOptimization(
3324         CCInfo, StackSize, *MF.getInfo<MipsFunctionInfo>());
3325     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3326       InternalLinkage = G->getGlobal()->hasInternalLinkage();
3327       IsTailCall &= (InternalLinkage || G->getGlobal()->hasLocalLinkage() ||
3328                      G->getGlobal()->hasPrivateLinkage() ||
3329                      G->getGlobal()->hasHiddenVisibility() ||
3330                      G->getGlobal()->hasProtectedVisibility());
3331      }
3332   }
3333   if (!IsTailCall && CLI.CB && CLI.CB->isMustTailCall())
3334     report_fatal_error("failed to perform tail call elimination on a call "
3335                        "site marked musttail");
3336 
3337   if (IsTailCall)
3338     ++NumTailCalls;
3339 
3340   // Chain is the output chain of the last Load/Store or CopyToReg node.
3341   // ByValChain is the output chain of the last Memcpy node created for copying
3342   // byval arguments to the stack.
3343   unsigned StackAlignment = TFL->getStackAlignment();
3344   StackSize = alignTo(StackSize, StackAlignment);
3345 
3346   if (!(IsTailCall || MemcpyInByVal))
3347     Chain = DAG.getCALLSEQ_START(Chain, StackSize, 0, DL);
3348 
3349   SDValue StackPtr =
3350       DAG.getCopyFromReg(Chain, DL, ABI.IsN64() ? Mips::SP_64 : Mips::SP,
3351                          getPointerTy(DAG.getDataLayout()));
3352 
3353   std::deque<std::pair<unsigned, SDValue>> RegsToPass;
3354   SmallVector<SDValue, 8> MemOpChains;
3355 
3356   CCInfo.rewindByValRegsInfo();
3357 
3358   // Walk the register/memloc assignments, inserting copies/loads.
3359   for (unsigned i = 0, e = ArgLocs.size(), OutIdx = 0; i != e; ++i, ++OutIdx) {
3360     SDValue Arg = OutVals[OutIdx];
3361     CCValAssign &VA = ArgLocs[i];
3362     MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
3363     ISD::ArgFlagsTy Flags = Outs[OutIdx].Flags;
3364     bool UseUpperBits = false;
3365 
3366     // ByVal Arg.
3367     if (Flags.isByVal()) {
3368       unsigned FirstByValReg, LastByValReg;
3369       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3370       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3371 
3372       assert(Flags.getByValSize() &&
3373              "ByVal args of size 0 should have been ignored by front-end.");
3374       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3375       assert(!IsTailCall &&
3376              "Do not tail-call optimize if there is a byval argument.");
3377       passByValArg(Chain, DL, RegsToPass, MemOpChains, StackPtr, MFI, DAG, Arg,
3378                    FirstByValReg, LastByValReg, Flags, Subtarget.isLittle(),
3379                    VA);
3380       CCInfo.nextInRegsParam();
3381       continue;
3382     }
3383 
3384     // Promote the value if needed.
3385     switch (VA.getLocInfo()) {
3386     default:
3387       llvm_unreachable("Unknown loc info!");
3388     case CCValAssign::Full:
3389       if (VA.isRegLoc()) {
3390         if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
3391             (ValVT == MVT::f64 && LocVT == MVT::i64) ||
3392             (ValVT == MVT::i64 && LocVT == MVT::f64))
3393           Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3394         else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
3395           SDValue Lo = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3396                                    Arg, DAG.getConstant(0, DL, MVT::i32));
3397           SDValue Hi = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3398                                    Arg, DAG.getConstant(1, DL, MVT::i32));
3399           if (!Subtarget.isLittle())
3400             std::swap(Lo, Hi);
3401 
3402           assert(VA.needsCustom());
3403 
3404           Register LocRegLo = VA.getLocReg();
3405           Register LocRegHigh = ArgLocs[++i].getLocReg();
3406           RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
3407           RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
3408           continue;
3409         }
3410       }
3411       break;
3412     case CCValAssign::BCvt:
3413       Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3414       break;
3415     case CCValAssign::SExtUpper:
3416       UseUpperBits = true;
3417       [[fallthrough]];
3418     case CCValAssign::SExt:
3419       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, LocVT, Arg);
3420       break;
3421     case CCValAssign::ZExtUpper:
3422       UseUpperBits = true;
3423       [[fallthrough]];
3424     case CCValAssign::ZExt:
3425       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, LocVT, Arg);
3426       break;
3427     case CCValAssign::AExtUpper:
3428       UseUpperBits = true;
3429       [[fallthrough]];
3430     case CCValAssign::AExt:
3431       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, LocVT, Arg);
3432       break;
3433     }
3434 
3435     if (UseUpperBits) {
3436       unsigned ValSizeInBits = Outs[OutIdx].ArgVT.getSizeInBits();
3437       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3438       Arg = DAG.getNode(
3439           ISD::SHL, DL, VA.getLocVT(), Arg,
3440           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3441     }
3442 
3443     // Arguments that can be passed on register must be kept at
3444     // RegsToPass vector
3445     if (VA.isRegLoc()) {
3446       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
3447 
3448       // If the parameter is passed through reg $D, which splits into
3449       // two physical registers, avoid creating call site info.
3450       if (Mips::AFGR64RegClass.contains(VA.getLocReg()))
3451         continue;
3452 
3453       // Collect CSInfo about which register passes which parameter.
3454       const TargetOptions &Options = DAG.getTarget().Options;
3455       if (Options.EmitCallSiteInfo)
3456         CSInfo.ArgRegPairs.emplace_back(VA.getLocReg(), i);
3457 
3458       continue;
3459     }
3460 
3461     // Register can't get to this point...
3462     assert(VA.isMemLoc());
3463 
3464     // emit ISD::STORE whichs stores the
3465     // parameter value to a stack Location
3466     MemOpChains.push_back(passArgOnStack(StackPtr, VA.getLocMemOffset(),
3467                                          Chain, Arg, DL, IsTailCall, DAG));
3468   }
3469 
3470   // Transform all store nodes into one single node because all store
3471   // nodes are independent of each other.
3472   if (!MemOpChains.empty())
3473     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
3474 
3475   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
3476   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
3477   // node so that legalize doesn't hack it.
3478 
3479   EVT Ty = Callee.getValueType();
3480   bool GlobalOrExternal = false, IsCallReloc = false;
3481 
3482   // The long-calls feature is ignored in case of PIC.
3483   // While we do not support -mshared / -mno-shared properly,
3484   // ignore long-calls in case of -mabicalls too.
3485   if (!Subtarget.isABICalls() && !IsPIC) {
3486     // If the function should be called using "long call",
3487     // get its address into a register to prevent using
3488     // of the `jal` instruction for the direct call.
3489     if (auto *N = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3490       if (Subtarget.useLongCalls())
3491         Callee = Subtarget.hasSym32()
3492                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3493                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3494     } else if (auto *N = dyn_cast<GlobalAddressSDNode>(Callee)) {
3495       bool UseLongCalls = Subtarget.useLongCalls();
3496       // If the function has long-call/far/near attribute
3497       // it overrides command line switch pased to the backend.
3498       if (auto *F = dyn_cast<Function>(N->getGlobal())) {
3499         if (F->hasFnAttribute("long-call"))
3500           UseLongCalls = true;
3501         else if (F->hasFnAttribute("short-call"))
3502           UseLongCalls = false;
3503       }
3504       if (UseLongCalls)
3505         Callee = Subtarget.hasSym32()
3506                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3507                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3508     }
3509   }
3510 
3511   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3512     if (Subtarget.isTargetCOFF() &&
3513         G->getGlobal()->hasDLLImportStorageClass()) {
3514       assert(Subtarget.isTargetWindows() &&
3515              "Windows is the only supported COFF target");
3516       auto PtrInfo = MachinePointerInfo();
3517       Callee = DAG.getLoad(Ty, DL, Chain,
3518                            getDllimportSymbol(G, SDLoc(G), Ty, DAG), PtrInfo);
3519     } else if (IsPIC) {
3520       const GlobalValue *Val = G->getGlobal();
3521       InternalLinkage = Val->hasInternalLinkage();
3522 
3523       if (InternalLinkage)
3524         Callee = getAddrLocal(G, DL, Ty, DAG, ABI.IsN32() || ABI.IsN64());
3525       else if (Subtarget.useXGOT()) {
3526         Callee = getAddrGlobalLargeGOT(G, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3527                                        MipsII::MO_CALL_LO16, Chain,
3528                                        FuncInfo->callPtrInfo(MF, Val));
3529         IsCallReloc = true;
3530       } else {
3531         Callee = getAddrGlobal(G, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3532                                FuncInfo->callPtrInfo(MF, Val));
3533         IsCallReloc = true;
3534       }
3535     } else
3536       Callee = DAG.getTargetGlobalAddress(G->getGlobal(), DL,
3537                                           getPointerTy(DAG.getDataLayout()), 0,
3538                                           MipsII::MO_NO_FLAG);
3539     GlobalOrExternal = true;
3540   }
3541   else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3542     const char *Sym = S->getSymbol();
3543 
3544     if (!IsPIC) // static
3545       Callee = DAG.getTargetExternalSymbol(
3546           Sym, getPointerTy(DAG.getDataLayout()), MipsII::MO_NO_FLAG);
3547     else if (Subtarget.useXGOT()) {
3548       Callee = getAddrGlobalLargeGOT(S, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3549                                      MipsII::MO_CALL_LO16, Chain,
3550                                      FuncInfo->callPtrInfo(MF, Sym));
3551       IsCallReloc = true;
3552     } else { // PIC
3553       Callee = getAddrGlobal(S, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3554                              FuncInfo->callPtrInfo(MF, Sym));
3555       IsCallReloc = true;
3556     }
3557 
3558     GlobalOrExternal = true;
3559   }
3560 
3561   SmallVector<SDValue, 8> Ops(1, Chain);
3562   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
3563 
3564   getOpndList(Ops, RegsToPass, IsPIC, GlobalOrExternal, InternalLinkage,
3565               IsCallReloc, CLI, Callee, Chain);
3566 
3567   if (IsTailCall) {
3568     MF.getFrameInfo().setHasTailCall();
3569     SDValue Ret = DAG.getNode(MipsISD::TailCall, DL, MVT::Other, Ops);
3570     DAG.addCallSiteInfo(Ret.getNode(), std::move(CSInfo));
3571     return Ret;
3572   }
3573 
3574   Chain = DAG.getNode(MipsISD::JmpLink, DL, NodeTys, Ops);
3575   SDValue InGlue = Chain.getValue(1);
3576 
3577   DAG.addCallSiteInfo(Chain.getNode(), std::move(CSInfo));
3578 
3579   // Create the CALLSEQ_END node in the case of where it is not a call to
3580   // memcpy.
3581   if (!(MemcpyInByVal)) {
3582     Chain = DAG.getCALLSEQ_END(Chain, StackSize, 0, InGlue, DL);
3583     InGlue = Chain.getValue(1);
3584   }
3585 
3586   // Handle result values, copying them out of physregs into vregs that we
3587   // return.
3588   return LowerCallResult(Chain, InGlue, CallConv, IsVarArg, Ins, DL, DAG,
3589                          InVals, CLI);
3590 }
3591 
3592 /// LowerCallResult - Lower the result values of a call into the
3593 /// appropriate copies out of appropriate physical registers.
3594 SDValue MipsTargetLowering::LowerCallResult(
3595     SDValue Chain, SDValue InGlue, CallingConv::ID CallConv, bool IsVarArg,
3596     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3597     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
3598     TargetLowering::CallLoweringInfo &CLI) const {
3599   // Assign locations to each value returned by this call.
3600   SmallVector<CCValAssign, 16> RVLocs;
3601   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
3602                      *DAG.getContext());
3603 
3604   const ExternalSymbolSDNode *ES =
3605       dyn_cast_or_null<const ExternalSymbolSDNode>(CLI.Callee.getNode());
3606   CCInfo.AnalyzeCallResult(Ins, RetCC_Mips, CLI.RetTy,
3607                            ES ? ES->getSymbol() : nullptr);
3608 
3609   // Copy all of the result registers out of their specified physreg.
3610   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3611     CCValAssign &VA = RVLocs[i];
3612     assert(VA.isRegLoc() && "Can only return in registers!");
3613 
3614     SDValue Val = DAG.getCopyFromReg(Chain, DL, RVLocs[i].getLocReg(),
3615                                      RVLocs[i].getLocVT(), InGlue);
3616     Chain = Val.getValue(1);
3617     InGlue = Val.getValue(2);
3618 
3619     if (VA.isUpperBitsInLoc()) {
3620       unsigned ValSizeInBits = Ins[i].ArgVT.getSizeInBits();
3621       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3622       unsigned Shift =
3623           VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3624       Val = DAG.getNode(
3625           Shift, DL, VA.getLocVT(), Val,
3626           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3627     }
3628 
3629     switch (VA.getLocInfo()) {
3630     default:
3631       llvm_unreachable("Unknown loc info!");
3632     case CCValAssign::Full:
3633       break;
3634     case CCValAssign::BCvt:
3635       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
3636       break;
3637     case CCValAssign::AExt:
3638     case CCValAssign::AExtUpper:
3639       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3640       break;
3641     case CCValAssign::ZExt:
3642     case CCValAssign::ZExtUpper:
3643       Val = DAG.getNode(ISD::AssertZext, DL, VA.getLocVT(), Val,
3644                         DAG.getValueType(VA.getValVT()));
3645       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3646       break;
3647     case CCValAssign::SExt:
3648     case CCValAssign::SExtUpper:
3649       Val = DAG.getNode(ISD::AssertSext, DL, VA.getLocVT(), Val,
3650                         DAG.getValueType(VA.getValVT()));
3651       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3652       break;
3653     }
3654 
3655     InVals.push_back(Val);
3656   }
3657 
3658   return Chain;
3659 }
3660 
3661 static SDValue UnpackFromArgumentSlot(SDValue Val, const CCValAssign &VA,
3662                                       EVT ArgVT, const SDLoc &DL,
3663                                       SelectionDAG &DAG) {
3664   MVT LocVT = VA.getLocVT();
3665   EVT ValVT = VA.getValVT();
3666 
3667   // Shift into the upper bits if necessary.
3668   switch (VA.getLocInfo()) {
3669   default:
3670     break;
3671   case CCValAssign::AExtUpper:
3672   case CCValAssign::SExtUpper:
3673   case CCValAssign::ZExtUpper: {
3674     unsigned ValSizeInBits = ArgVT.getSizeInBits();
3675     unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3676     unsigned Opcode =
3677         VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3678     Val = DAG.getNode(
3679         Opcode, DL, VA.getLocVT(), Val,
3680         DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3681     break;
3682   }
3683   }
3684 
3685   // If this is an value smaller than the argument slot size (32-bit for O32,
3686   // 64-bit for N32/N64), it has been promoted in some way to the argument slot
3687   // size. Extract the value and insert any appropriate assertions regarding
3688   // sign/zero extension.
3689   switch (VA.getLocInfo()) {
3690   default:
3691     llvm_unreachable("Unknown loc info!");
3692   case CCValAssign::Full:
3693     break;
3694   case CCValAssign::AExtUpper:
3695   case CCValAssign::AExt:
3696     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3697     break;
3698   case CCValAssign::SExtUpper:
3699   case CCValAssign::SExt:
3700     Val = DAG.getNode(ISD::AssertSext, DL, LocVT, Val, DAG.getValueType(ValVT));
3701     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3702     break;
3703   case CCValAssign::ZExtUpper:
3704   case CCValAssign::ZExt:
3705     Val = DAG.getNode(ISD::AssertZext, DL, LocVT, Val, DAG.getValueType(ValVT));
3706     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3707     break;
3708   case CCValAssign::BCvt:
3709     Val = DAG.getNode(ISD::BITCAST, DL, ValVT, Val);
3710     break;
3711   }
3712 
3713   return Val;
3714 }
3715 
3716 //===----------------------------------------------------------------------===//
3717 //             Formal Arguments Calling Convention Implementation
3718 //===----------------------------------------------------------------------===//
3719 /// LowerFormalArguments - transform physical registers into virtual registers
3720 /// and generate load operations for arguments places on the stack.
3721 SDValue MipsTargetLowering::LowerFormalArguments(
3722     SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
3723     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3724     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
3725   MachineFunction &MF = DAG.getMachineFunction();
3726   MachineFrameInfo &MFI = MF.getFrameInfo();
3727   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3728 
3729   MipsFI->setVarArgsFrameIndex(0);
3730 
3731   // Used with vargs to acumulate store chains.
3732   std::vector<SDValue> OutChains;
3733 
3734   // Assign locations to all of the incoming arguments.
3735   SmallVector<CCValAssign, 16> ArgLocs;
3736   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
3737                      *DAG.getContext());
3738   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), Align(1));
3739   const Function &Func = DAG.getMachineFunction().getFunction();
3740   Function::const_arg_iterator FuncArg = Func.arg_begin();
3741 
3742   if (Func.hasFnAttribute("interrupt") && !Func.arg_empty())
3743     report_fatal_error(
3744         "Functions with the interrupt attribute cannot have arguments!");
3745 
3746   CCInfo.AnalyzeFormalArguments(Ins, CC_Mips_FixedArg);
3747   MipsFI->setFormalArgInfo(CCInfo.getStackSize(),
3748                            CCInfo.getInRegsParamsCount() > 0);
3749 
3750   unsigned CurArgIdx = 0;
3751   CCInfo.rewindByValRegsInfo();
3752 
3753   for (unsigned i = 0, e = ArgLocs.size(), InsIdx = 0; i != e; ++i, ++InsIdx) {
3754     CCValAssign &VA = ArgLocs[i];
3755     if (Ins[InsIdx].isOrigArg()) {
3756       std::advance(FuncArg, Ins[InsIdx].getOrigArgIndex() - CurArgIdx);
3757       CurArgIdx = Ins[InsIdx].getOrigArgIndex();
3758     }
3759     EVT ValVT = VA.getValVT();
3760     ISD::ArgFlagsTy Flags = Ins[InsIdx].Flags;
3761     bool IsRegLoc = VA.isRegLoc();
3762 
3763     if (Flags.isByVal()) {
3764       assert(Ins[InsIdx].isOrigArg() && "Byval arguments cannot be implicit");
3765       unsigned FirstByValReg, LastByValReg;
3766       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3767       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3768 
3769       assert(Flags.getByValSize() &&
3770              "ByVal args of size 0 should have been ignored by front-end.");
3771       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3772       copyByValRegs(Chain, DL, OutChains, DAG, Flags, InVals, &*FuncArg,
3773                     FirstByValReg, LastByValReg, VA, CCInfo);
3774       CCInfo.nextInRegsParam();
3775       continue;
3776     }
3777 
3778     // Arguments stored on registers
3779     if (IsRegLoc) {
3780       MVT RegVT = VA.getLocVT();
3781       Register ArgReg = VA.getLocReg();
3782       const TargetRegisterClass *RC = getRegClassFor(RegVT);
3783 
3784       // Transform the arguments stored on
3785       // physical registers into virtual ones
3786       unsigned Reg = addLiveIn(DAG.getMachineFunction(), ArgReg, RC);
3787       SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
3788 
3789       ArgValue =
3790           UnpackFromArgumentSlot(ArgValue, VA, Ins[InsIdx].ArgVT, DL, DAG);
3791 
3792       // Handle floating point arguments passed in integer registers and
3793       // long double arguments passed in floating point registers.
3794       if ((RegVT == MVT::i32 && ValVT == MVT::f32) ||
3795           (RegVT == MVT::i64 && ValVT == MVT::f64) ||
3796           (RegVT == MVT::f64 && ValVT == MVT::i64))
3797         ArgValue = DAG.getNode(ISD::BITCAST, DL, ValVT, ArgValue);
3798       else if (ABI.IsO32() && RegVT == MVT::i32 &&
3799                ValVT == MVT::f64) {
3800         assert(VA.needsCustom() && "Expected custom argument for f64 split");
3801         CCValAssign &NextVA = ArgLocs[++i];
3802         unsigned Reg2 =
3803             addLiveIn(DAG.getMachineFunction(), NextVA.getLocReg(), RC);
3804         SDValue ArgValue2 = DAG.getCopyFromReg(Chain, DL, Reg2, RegVT);
3805         if (!Subtarget.isLittle())
3806           std::swap(ArgValue, ArgValue2);
3807         ArgValue = DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64,
3808                                ArgValue, ArgValue2);
3809       }
3810 
3811       InVals.push_back(ArgValue);
3812     } else { // VA.isRegLoc()
3813       MVT LocVT = VA.getLocVT();
3814 
3815       assert(!VA.needsCustom() && "unexpected custom memory argument");
3816 
3817       // Only arguments pased on the stack should make it here.
3818       assert(VA.isMemLoc());
3819 
3820       // The stack pointer offset is relative to the caller stack frame.
3821       int FI = MFI.CreateFixedObject(LocVT.getSizeInBits() / 8,
3822                                      VA.getLocMemOffset(), true);
3823 
3824       // Create load nodes to retrieve arguments from the stack
3825       SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3826       SDValue ArgValue = DAG.getLoad(
3827           LocVT, DL, Chain, FIN,
3828           MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI));
3829       OutChains.push_back(ArgValue.getValue(1));
3830 
3831       ArgValue =
3832           UnpackFromArgumentSlot(ArgValue, VA, Ins[InsIdx].ArgVT, DL, DAG);
3833 
3834       InVals.push_back(ArgValue);
3835     }
3836   }
3837 
3838   for (unsigned i = 0, e = ArgLocs.size(), InsIdx = 0; i != e; ++i, ++InsIdx) {
3839 
3840     if (ArgLocs[i].needsCustom()) {
3841       ++i;
3842       continue;
3843     }
3844 
3845     // The mips ABIs for returning structs by value requires that we copy
3846     // the sret argument into $v0 for the return. Save the argument into
3847     // a virtual register so that we can access it from the return points.
3848     if (Ins[InsIdx].Flags.isSRet()) {
3849       unsigned Reg = MipsFI->getSRetReturnReg();
3850       if (!Reg) {
3851         Reg = MF.getRegInfo().createVirtualRegister(
3852             getRegClassFor(ABI.IsN64() ? MVT::i64 : MVT::i32));
3853         MipsFI->setSRetReturnReg(Reg);
3854       }
3855       SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), DL, Reg, InVals[i]);
3856       Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Copy, Chain);
3857       break;
3858     }
3859   }
3860 
3861   if (IsVarArg)
3862     writeVarArgRegs(OutChains, Chain, DL, DAG, CCInfo);
3863 
3864   // All stores are grouped in one node to allow the matching between
3865   // the size of Ins and InVals. This only happens when on varg functions
3866   if (!OutChains.empty()) {
3867     OutChains.push_back(Chain);
3868     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
3869   }
3870 
3871   return Chain;
3872 }
3873 
3874 //===----------------------------------------------------------------------===//
3875 //               Return Value Calling Convention Implementation
3876 //===----------------------------------------------------------------------===//
3877 
3878 bool
3879 MipsTargetLowering::CanLowerReturn(CallingConv::ID CallConv,
3880                                    MachineFunction &MF, bool IsVarArg,
3881                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
3882                                    LLVMContext &Context, const Type *RetTy) const {
3883   SmallVector<CCValAssign, 16> RVLocs;
3884   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context);
3885   return CCInfo.CheckCallReturn(Outs, RetCC_Mips, RetTy);
3886 }
3887 
3888 bool MipsTargetLowering::shouldSignExtendTypeInLibCall(Type *Ty,
3889                                                        bool IsSigned) const {
3890   if ((ABI.IsN32() || ABI.IsN64()) && Ty->isIntegerTy(32))
3891     return true;
3892 
3893   return IsSigned;
3894 }
3895 
3896 SDValue
3897 MipsTargetLowering::LowerInterruptReturn(SmallVectorImpl<SDValue> &RetOps,
3898                                          const SDLoc &DL,
3899                                          SelectionDAG &DAG) const {
3900   MachineFunction &MF = DAG.getMachineFunction();
3901   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3902 
3903   MipsFI->setISR();
3904 
3905   return DAG.getNode(MipsISD::ERet, DL, MVT::Other, RetOps);
3906 }
3907 
3908 SDValue
3909 MipsTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
3910                                 bool IsVarArg,
3911                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
3912                                 const SmallVectorImpl<SDValue> &OutVals,
3913                                 const SDLoc &DL, SelectionDAG &DAG) const {
3914   // CCValAssign - represent the assignment of
3915   // the return value to a location
3916   SmallVector<CCValAssign, 16> RVLocs;
3917   MachineFunction &MF = DAG.getMachineFunction();
3918 
3919   // CCState - Info about the registers and stack slot.
3920   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, *DAG.getContext());
3921 
3922   // Analyze return values.
3923   CCInfo.AnalyzeReturn(Outs, RetCC_Mips);
3924 
3925   SDValue Glue;
3926   SmallVector<SDValue, 4> RetOps(1, Chain);
3927 
3928   // Copy the result values into the output registers.
3929   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3930     SDValue Val = OutVals[i];
3931     CCValAssign &VA = RVLocs[i];
3932     assert(VA.isRegLoc() && "Can only return in registers!");
3933     bool UseUpperBits = false;
3934 
3935     switch (VA.getLocInfo()) {
3936     default:
3937       llvm_unreachable("Unknown loc info!");
3938     case CCValAssign::Full:
3939       break;
3940     case CCValAssign::BCvt:
3941       Val = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Val);
3942       break;
3943     case CCValAssign::AExtUpper:
3944       UseUpperBits = true;
3945       [[fallthrough]];
3946     case CCValAssign::AExt:
3947       Val = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Val);
3948       break;
3949     case CCValAssign::ZExtUpper:
3950       UseUpperBits = true;
3951       [[fallthrough]];
3952     case CCValAssign::ZExt:
3953       Val = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Val);
3954       break;
3955     case CCValAssign::SExtUpper:
3956       UseUpperBits = true;
3957       [[fallthrough]];
3958     case CCValAssign::SExt:
3959       Val = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Val);
3960       break;
3961     }
3962 
3963     if (UseUpperBits) {
3964       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
3965       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3966       Val = DAG.getNode(
3967           ISD::SHL, DL, VA.getLocVT(), Val,
3968           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3969     }
3970 
3971     Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Val, Glue);
3972 
3973     // Guarantee that all emitted copies are stuck together with flags.
3974     Glue = Chain.getValue(1);
3975     RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3976   }
3977 
3978   // The mips ABIs for returning structs by value requires that we copy
3979   // the sret argument into $v0 for the return. We saved the argument into
3980   // a virtual register in the entry block, so now we copy the value out
3981   // and into $v0.
3982   if (MF.getFunction().hasStructRetAttr()) {
3983     MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3984     unsigned Reg = MipsFI->getSRetReturnReg();
3985 
3986     if (!Reg)
3987       llvm_unreachable("sret virtual register not created in the entry block");
3988     SDValue Val =
3989         DAG.getCopyFromReg(Chain, DL, Reg, getPointerTy(DAG.getDataLayout()));
3990     unsigned V0 = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
3991 
3992     Chain = DAG.getCopyToReg(Chain, DL, V0, Val, Glue);
3993     Glue = Chain.getValue(1);
3994     RetOps.push_back(DAG.getRegister(V0, getPointerTy(DAG.getDataLayout())));
3995   }
3996 
3997   RetOps[0] = Chain;  // Update chain.
3998 
3999   // Add the glue if we have it.
4000   if (Glue.getNode())
4001     RetOps.push_back(Glue);
4002 
4003   // ISRs must use "eret".
4004   if (DAG.getMachineFunction().getFunction().hasFnAttribute("interrupt"))
4005     return LowerInterruptReturn(RetOps, DL, DAG);
4006 
4007   // Standard return on Mips is a "jr $ra"
4008   return DAG.getNode(MipsISD::Ret, DL, MVT::Other, RetOps);
4009 }
4010 
4011 //===----------------------------------------------------------------------===//
4012 //                           Mips Inline Assembly Support
4013 //===----------------------------------------------------------------------===//
4014 
4015 /// getConstraintType - Given a constraint letter, return the type of
4016 /// constraint it is for this target.
4017 MipsTargetLowering::ConstraintType
4018 MipsTargetLowering::getConstraintType(StringRef Constraint) const {
4019   // Mips specific constraints
4020   // GCC config/mips/constraints.md
4021   //
4022   // 'd' : An address register. Equivalent to r
4023   //       unless generating MIPS16 code.
4024   // 'y' : Equivalent to r; retained for
4025   //       backwards compatibility.
4026   // 'c' : A register suitable for use in an indirect
4027   //       jump. This will always be $25 for -mabicalls.
4028   // 'l' : The lo register. 1 word storage.
4029   // 'x' : The hilo register pair. Double word storage.
4030   if (Constraint.size() == 1) {
4031     switch (Constraint[0]) {
4032       default : break;
4033       case 'd':
4034       case 'y':
4035       case 'f':
4036       case 'c':
4037       case 'l':
4038       case 'x':
4039         return C_RegisterClass;
4040       case 'R':
4041         return C_Memory;
4042     }
4043   }
4044 
4045   if (Constraint == "ZC")
4046     return C_Memory;
4047 
4048   return TargetLowering::getConstraintType(Constraint);
4049 }
4050 
4051 /// Examine constraint type and operand type and determine a weight value.
4052 /// This object must already have been set up with the operand type
4053 /// and the current alternative constraint selected.
4054 TargetLowering::ConstraintWeight
4055 MipsTargetLowering::getSingleConstraintMatchWeight(
4056     AsmOperandInfo &info, const char *constraint) const {
4057   ConstraintWeight weight = CW_Invalid;
4058   Value *CallOperandVal = info.CallOperandVal;
4059     // If we don't have a value, we can't do a match,
4060     // but allow it at the lowest weight.
4061   if (!CallOperandVal)
4062     return CW_Default;
4063   Type *type = CallOperandVal->getType();
4064   // Look at the constraint type.
4065   switch (*constraint) {
4066   default:
4067     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
4068     break;
4069   case 'd':
4070   case 'y':
4071     if (type->isIntegerTy())
4072       weight = CW_Register;
4073     break;
4074   case 'f': // FPU or MSA register
4075     if (Subtarget.hasMSA() && type->isVectorTy() &&
4076         type->getPrimitiveSizeInBits().getFixedValue() == 128)
4077       weight = CW_Register;
4078     else if (type->isFloatTy())
4079       weight = CW_Register;
4080     break;
4081   case 'c': // $25 for indirect jumps
4082   case 'l': // lo register
4083   case 'x': // hilo register pair
4084     if (type->isIntegerTy())
4085       weight = CW_SpecificReg;
4086     break;
4087   case 'I': // signed 16 bit immediate
4088   case 'J': // integer zero
4089   case 'K': // unsigned 16 bit immediate
4090   case 'L': // signed 32 bit immediate where lower 16 bits are 0
4091   case 'N': // immediate in the range of -65535 to -1 (inclusive)
4092   case 'O': // signed 15 bit immediate (+- 16383)
4093   case 'P': // immediate in the range of 65535 to 1 (inclusive)
4094     if (isa<ConstantInt>(CallOperandVal))
4095       weight = CW_Constant;
4096     break;
4097   case 'R':
4098     weight = CW_Memory;
4099     break;
4100   }
4101   return weight;
4102 }
4103 
4104 /// This is a helper function to parse a physical register string and split it
4105 /// into non-numeric and numeric parts (Prefix and Reg). The first boolean flag
4106 /// that is returned indicates whether parsing was successful. The second flag
4107 /// is true if the numeric part exists.
4108 static std::pair<bool, bool> parsePhysicalReg(StringRef C, StringRef &Prefix,
4109                                               unsigned long long &Reg) {
4110   if (C.front() != '{' || C.back() != '}')
4111     return std::make_pair(false, false);
4112 
4113   // Search for the first numeric character.
4114   StringRef::const_iterator I, B = C.begin() + 1, E = C.end() - 1;
4115   I = std::find_if(B, E, isdigit);
4116 
4117   Prefix = StringRef(B, I - B);
4118 
4119   // The second flag is set to false if no numeric characters were found.
4120   if (I == E)
4121     return std::make_pair(true, false);
4122 
4123   // Parse the numeric characters.
4124   return std::make_pair(!getAsUnsignedInteger(StringRef(I, E - I), 10, Reg),
4125                         true);
4126 }
4127 
4128 EVT MipsTargetLowering::getTypeForExtReturn(LLVMContext &Context, EVT VT,
4129                                             ISD::NodeType) const {
4130   bool Cond = !Subtarget.isABI_O32() && VT.getSizeInBits() == 32;
4131   EVT MinVT = getRegisterType(Cond ? MVT::i64 : MVT::i32);
4132   return VT.bitsLT(MinVT) ? MinVT : VT;
4133 }
4134 
4135 std::pair<unsigned, const TargetRegisterClass *> MipsTargetLowering::
4136 parseRegForInlineAsmConstraint(StringRef C, MVT VT) const {
4137   const TargetRegisterInfo *TRI =
4138       Subtarget.getRegisterInfo();
4139   const TargetRegisterClass *RC;
4140   StringRef Prefix;
4141   unsigned long long Reg;
4142 
4143   std::pair<bool, bool> R = parsePhysicalReg(C, Prefix, Reg);
4144 
4145   if (!R.first)
4146     return std::make_pair(0U, nullptr);
4147 
4148   if ((Prefix == "hi" || Prefix == "lo")) { // Parse hi/lo.
4149     // No numeric characters follow "hi" or "lo".
4150     if (R.second)
4151       return std::make_pair(0U, nullptr);
4152 
4153     RC = TRI->getRegClass(Prefix == "hi" ?
4154                           Mips::HI32RegClassID : Mips::LO32RegClassID);
4155     return std::make_pair(*(RC->begin()), RC);
4156   } else if (Prefix.starts_with("$msa")) {
4157     // Parse $msa(ir|csr|access|save|modify|request|map|unmap)
4158 
4159     // No numeric characters follow the name.
4160     if (R.second)
4161       return std::make_pair(0U, nullptr);
4162 
4163     Reg = StringSwitch<unsigned long long>(Prefix)
4164               .Case("$msair", Mips::MSAIR)
4165               .Case("$msacsr", Mips::MSACSR)
4166               .Case("$msaaccess", Mips::MSAAccess)
4167               .Case("$msasave", Mips::MSASave)
4168               .Case("$msamodify", Mips::MSAModify)
4169               .Case("$msarequest", Mips::MSARequest)
4170               .Case("$msamap", Mips::MSAMap)
4171               .Case("$msaunmap", Mips::MSAUnmap)
4172               .Default(0);
4173 
4174     if (!Reg)
4175       return std::make_pair(0U, nullptr);
4176 
4177     RC = TRI->getRegClass(Mips::MSACtrlRegClassID);
4178     return std::make_pair(Reg, RC);
4179   }
4180 
4181   if (!R.second)
4182     return std::make_pair(0U, nullptr);
4183 
4184   if (Prefix == "$f") { // Parse $f0-$f31.
4185     // If the size of FP registers is 64-bit or Reg is an even number, select
4186     // the 64-bit register class. Otherwise, select the 32-bit register class.
4187     if (VT == MVT::Other)
4188       VT = (Subtarget.isFP64bit() || !(Reg % 2)) ? MVT::f64 : MVT::f32;
4189 
4190     RC = getRegClassFor(VT);
4191 
4192     if (RC == &Mips::AFGR64RegClass) {
4193       assert(Reg % 2 == 0);
4194       Reg >>= 1;
4195     }
4196   } else if (Prefix == "$fcc") // Parse $fcc0-$fcc7.
4197     RC = TRI->getRegClass(Mips::FCCRegClassID);
4198   else if (Prefix == "$w") { // Parse $w0-$w31.
4199     RC = getRegClassFor((VT == MVT::Other) ? MVT::v16i8 : VT);
4200   } else { // Parse $0-$31.
4201     assert(Prefix == "$");
4202     RC = getRegClassFor((VT == MVT::Other) ? MVT::i32 : VT);
4203   }
4204 
4205   assert(Reg < RC->getNumRegs());
4206   return std::make_pair(*(RC->begin() + Reg), RC);
4207 }
4208 
4209 /// Given a register class constraint, like 'r', if this corresponds directly
4210 /// to an LLVM register class, return a register of 0 and the register class
4211 /// pointer.
4212 std::pair<unsigned, const TargetRegisterClass *>
4213 MipsTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
4214                                                  StringRef Constraint,
4215                                                  MVT VT) const {
4216   if (Constraint.size() == 1) {
4217     switch (Constraint[0]) {
4218     case 'd': // Address register. Same as 'r' unless generating MIPS16 code.
4219     case 'y': // Same as 'r'. Exists for compatibility.
4220     case 'r':
4221       if ((VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8 ||
4222            VT == MVT::i1) ||
4223           (VT == MVT::f32 && Subtarget.useSoftFloat())) {
4224         if (Subtarget.inMips16Mode())
4225           return std::make_pair(0U, &Mips::CPU16RegsRegClass);
4226         return std::make_pair(0U, &Mips::GPR32RegClass);
4227       }
4228       if ((VT == MVT::i64 || (VT == MVT::f64 && Subtarget.useSoftFloat())) &&
4229           !Subtarget.isGP64bit())
4230         return std::make_pair(0U, &Mips::GPR32RegClass);
4231       if ((VT == MVT::i64 || (VT == MVT::f64 && Subtarget.useSoftFloat())) &&
4232           Subtarget.isGP64bit())
4233         return std::make_pair(0U, &Mips::GPR64RegClass);
4234       // This will generate an error message
4235       return std::make_pair(0U, nullptr);
4236     case 'f': // FPU or MSA register
4237       if (VT == MVT::v16i8)
4238         return std::make_pair(0U, &Mips::MSA128BRegClass);
4239       else if (VT == MVT::v8i16 || VT == MVT::v8f16)
4240         return std::make_pair(0U, &Mips::MSA128HRegClass);
4241       else if (VT == MVT::v4i32 || VT == MVT::v4f32)
4242         return std::make_pair(0U, &Mips::MSA128WRegClass);
4243       else if (VT == MVT::v2i64 || VT == MVT::v2f64)
4244         return std::make_pair(0U, &Mips::MSA128DRegClass);
4245       else if (VT == MVT::f32)
4246         return std::make_pair(0U, &Mips::FGR32RegClass);
4247       else if ((VT == MVT::f64) && (!Subtarget.isSingleFloat())) {
4248         if (Subtarget.isFP64bit())
4249           return std::make_pair(0U, &Mips::FGR64RegClass);
4250         return std::make_pair(0U, &Mips::AFGR64RegClass);
4251       }
4252       break;
4253     case 'c': // register suitable for indirect jump
4254       if (VT == MVT::i32)
4255         return std::make_pair((unsigned)Mips::T9, &Mips::GPR32RegClass);
4256       if (VT == MVT::i64)
4257         return std::make_pair((unsigned)Mips::T9_64, &Mips::GPR64RegClass);
4258       // This will generate an error message
4259       return std::make_pair(0U, nullptr);
4260     case 'l': // use the `lo` register to store values
4261               // that are no bigger than a word
4262       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8)
4263         return std::make_pair((unsigned)Mips::LO0, &Mips::LO32RegClass);
4264       return std::make_pair((unsigned)Mips::LO0_64, &Mips::LO64RegClass);
4265     case 'x': // use the concatenated `hi` and `lo` registers
4266               // to store doubleword values
4267       // Fixme: Not triggering the use of both hi and low
4268       // This will generate an error message
4269       return std::make_pair(0U, nullptr);
4270     }
4271   }
4272 
4273   if (!Constraint.empty()) {
4274     std::pair<unsigned, const TargetRegisterClass *> R;
4275     R = parseRegForInlineAsmConstraint(Constraint, VT);
4276 
4277     if (R.second)
4278       return R;
4279   }
4280 
4281   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
4282 }
4283 
4284 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
4285 /// vector.  If it is invalid, don't add anything to Ops.
4286 void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
4287                                                       StringRef Constraint,
4288                                                       std::vector<SDValue> &Ops,
4289                                                       SelectionDAG &DAG) const {
4290   SDLoc DL(Op);
4291   SDValue Result;
4292 
4293   // Only support length 1 constraints for now.
4294   if (Constraint.size() > 1)
4295     return;
4296 
4297   char ConstraintLetter = Constraint[0];
4298   switch (ConstraintLetter) {
4299   default: break; // This will fall through to the generic implementation
4300   case 'I': // Signed 16 bit constant
4301     // If this fails, the parent routine will give an error
4302     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4303       EVT Type = Op.getValueType();
4304       int64_t Val = C->getSExtValue();
4305       if (isInt<16>(Val)) {
4306         Result = DAG.getSignedTargetConstant(Val, DL, Type);
4307         break;
4308       }
4309     }
4310     return;
4311   case 'J': // integer zero
4312     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4313       EVT Type = Op.getValueType();
4314       int64_t Val = C->getZExtValue();
4315       if (Val == 0) {
4316         Result = DAG.getTargetConstant(0, DL, Type);
4317         break;
4318       }
4319     }
4320     return;
4321   case 'K': // unsigned 16 bit immediate
4322     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4323       EVT Type = Op.getValueType();
4324       uint64_t Val = (uint64_t)C->getZExtValue();
4325       if (isUInt<16>(Val)) {
4326         Result = DAG.getTargetConstant(Val, DL, Type);
4327         break;
4328       }
4329     }
4330     return;
4331   case 'L': // signed 32 bit immediate where lower 16 bits are 0
4332     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4333       EVT Type = Op.getValueType();
4334       int64_t Val = C->getSExtValue();
4335       if ((isInt<32>(Val)) && ((Val & 0xffff) == 0)){
4336         Result = DAG.getSignedTargetConstant(Val, DL, Type);
4337         break;
4338       }
4339     }
4340     return;
4341   case 'N': // immediate in the range of -65535 to -1 (inclusive)
4342     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4343       EVT Type = Op.getValueType();
4344       int64_t Val = C->getSExtValue();
4345       if ((Val >= -65535) && (Val <= -1)) {
4346         Result = DAG.getSignedTargetConstant(Val, DL, Type);
4347         break;
4348       }
4349     }
4350     return;
4351   case 'O': // signed 15 bit immediate
4352     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4353       EVT Type = Op.getValueType();
4354       int64_t Val = C->getSExtValue();
4355       if ((isInt<15>(Val))) {
4356         Result = DAG.getSignedTargetConstant(Val, DL, Type);
4357         break;
4358       }
4359     }
4360     return;
4361   case 'P': // immediate in the range of 1 to 65535 (inclusive)
4362     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4363       EVT Type = Op.getValueType();
4364       int64_t Val = C->getSExtValue();
4365       if ((Val <= 65535) && (Val >= 1)) {
4366         Result = DAG.getTargetConstant(Val, DL, Type);
4367         break;
4368       }
4369     }
4370     return;
4371   }
4372 
4373   if (Result.getNode()) {
4374     Ops.push_back(Result);
4375     return;
4376   }
4377 
4378   TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
4379 }
4380 
4381 bool MipsTargetLowering::isLegalAddressingMode(const DataLayout &DL,
4382                                                const AddrMode &AM, Type *Ty,
4383                                                unsigned AS,
4384                                                Instruction *I) const {
4385   // No global is ever allowed as a base.
4386   if (AM.BaseGV)
4387     return false;
4388 
4389   switch (AM.Scale) {
4390   case 0: // "r+i" or just "i", depending on HasBaseReg.
4391     break;
4392   case 1:
4393     if (!AM.HasBaseReg) // allow "r+i".
4394       break;
4395     return false; // disallow "r+r" or "r+r+i".
4396   default:
4397     return false;
4398   }
4399 
4400   return true;
4401 }
4402 
4403 bool
4404 MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
4405   // The Mips target isn't yet aware of offsets.
4406   return false;
4407 }
4408 
4409 EVT MipsTargetLowering::getOptimalMemOpType(
4410     const MemOp &Op, const AttributeList &FuncAttributes) const {
4411   if (Subtarget.hasMips64())
4412     return MVT::i64;
4413 
4414   return MVT::i32;
4415 }
4416 
4417 bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
4418                                       bool ForCodeSize) const {
4419   if (VT != MVT::f32 && VT != MVT::f64)
4420     return false;
4421   if (Imm.isNegZero())
4422     return false;
4423   return Imm.isZero();
4424 }
4425 
4426 unsigned MipsTargetLowering::getJumpTableEncoding() const {
4427 
4428   // FIXME: For space reasons this should be: EK_GPRel32BlockAddress.
4429   if (ABI.IsN64() && isPositionIndependent())
4430     return MachineJumpTableInfo::EK_GPRel64BlockAddress;
4431 
4432   return TargetLowering::getJumpTableEncoding();
4433 }
4434 
4435 bool MipsTargetLowering::useSoftFloat() const {
4436   return Subtarget.useSoftFloat();
4437 }
4438 
4439 void MipsTargetLowering::copyByValRegs(
4440     SDValue Chain, const SDLoc &DL, std::vector<SDValue> &OutChains,
4441     SelectionDAG &DAG, const ISD::ArgFlagsTy &Flags,
4442     SmallVectorImpl<SDValue> &InVals, const Argument *FuncArg,
4443     unsigned FirstReg, unsigned LastReg, const CCValAssign &VA,
4444     MipsCCState &State) const {
4445   MachineFunction &MF = DAG.getMachineFunction();
4446   MachineFrameInfo &MFI = MF.getFrameInfo();
4447   unsigned GPRSizeInBytes = Subtarget.getGPRSizeInBytes();
4448   unsigned NumRegs = LastReg - FirstReg;
4449   unsigned RegAreaSize = NumRegs * GPRSizeInBytes;
4450   unsigned FrameObjSize = std::max(Flags.getByValSize(), RegAreaSize);
4451   int FrameObjOffset;
4452   ArrayRef<MCPhysReg> ByValArgRegs = ABI.GetByValArgRegs();
4453 
4454   if (RegAreaSize)
4455     FrameObjOffset =
4456         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4457         (int)((ByValArgRegs.size() - FirstReg) * GPRSizeInBytes);
4458   else
4459     FrameObjOffset = VA.getLocMemOffset();
4460 
4461   // Create frame object.
4462   EVT PtrTy = getPointerTy(DAG.getDataLayout());
4463   // Make the fixed object stored to mutable so that the load instructions
4464   // referencing it have their memory dependencies added.
4465   // Set the frame object as isAliased which clears the underlying objects
4466   // vector in ScheduleDAGInstrs::buildSchedGraph() resulting in addition of all
4467   // stores as dependencies for loads referencing this fixed object.
4468   int FI = MFI.CreateFixedObject(FrameObjSize, FrameObjOffset, false, true);
4469   SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
4470   InVals.push_back(FIN);
4471 
4472   if (!NumRegs)
4473     return;
4474 
4475   // Copy arg registers.
4476   MVT RegTy = MVT::getIntegerVT(GPRSizeInBytes * 8);
4477   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4478 
4479   for (unsigned I = 0; I < NumRegs; ++I) {
4480     unsigned ArgReg = ByValArgRegs[FirstReg + I];
4481     unsigned VReg = addLiveIn(MF, ArgReg, RC);
4482     unsigned Offset = I * GPRSizeInBytes;
4483     SDValue StorePtr = DAG.getNode(ISD::ADD, DL, PtrTy, FIN,
4484                                    DAG.getConstant(Offset, DL, PtrTy));
4485     SDValue Store = DAG.getStore(Chain, DL, DAG.getRegister(VReg, RegTy),
4486                                  StorePtr, MachinePointerInfo(FuncArg, Offset));
4487     OutChains.push_back(Store);
4488   }
4489 }
4490 
4491 // Copy byVal arg to registers and stack.
4492 void MipsTargetLowering::passByValArg(
4493     SDValue Chain, const SDLoc &DL,
4494     std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
4495     SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
4496     MachineFrameInfo &MFI, SelectionDAG &DAG, SDValue Arg, unsigned FirstReg,
4497     unsigned LastReg, const ISD::ArgFlagsTy &Flags, bool isLittle,
4498     const CCValAssign &VA) const {
4499   unsigned ByValSizeInBytes = Flags.getByValSize();
4500   unsigned OffsetInBytes = 0; // From beginning of struct
4501   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4502   Align Alignment =
4503       std::min(Flags.getNonZeroByValAlign(), Align(RegSizeInBytes));
4504   EVT PtrTy = getPointerTy(DAG.getDataLayout()),
4505       RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4506   unsigned NumRegs = LastReg - FirstReg;
4507 
4508   if (NumRegs) {
4509     ArrayRef<MCPhysReg> ArgRegs = ABI.GetByValArgRegs();
4510     bool LeftoverBytes = (NumRegs * RegSizeInBytes > ByValSizeInBytes);
4511     unsigned I = 0;
4512 
4513     // Copy words to registers.
4514     for (; I < NumRegs - LeftoverBytes; ++I, OffsetInBytes += RegSizeInBytes) {
4515       SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4516                                     DAG.getConstant(OffsetInBytes, DL, PtrTy));
4517       SDValue LoadVal = DAG.getLoad(RegTy, DL, Chain, LoadPtr,
4518                                     MachinePointerInfo(), Alignment);
4519       MemOpChains.push_back(LoadVal.getValue(1));
4520       unsigned ArgReg = ArgRegs[FirstReg + I];
4521       RegsToPass.push_back(std::make_pair(ArgReg, LoadVal));
4522     }
4523 
4524     // Return if the struct has been fully copied.
4525     if (ByValSizeInBytes == OffsetInBytes)
4526       return;
4527 
4528     // Copy the remainder of the byval argument with sub-word loads and shifts.
4529     if (LeftoverBytes) {
4530       SDValue Val;
4531 
4532       for (unsigned LoadSizeInBytes = RegSizeInBytes / 2, TotalBytesLoaded = 0;
4533            OffsetInBytes < ByValSizeInBytes; LoadSizeInBytes /= 2) {
4534         unsigned RemainingSizeInBytes = ByValSizeInBytes - OffsetInBytes;
4535 
4536         if (RemainingSizeInBytes < LoadSizeInBytes)
4537           continue;
4538 
4539         // Load subword.
4540         SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4541                                       DAG.getConstant(OffsetInBytes, DL,
4542                                                       PtrTy));
4543         SDValue LoadVal = DAG.getExtLoad(
4544             ISD::ZEXTLOAD, DL, RegTy, Chain, LoadPtr, MachinePointerInfo(),
4545             MVT::getIntegerVT(LoadSizeInBytes * 8), Alignment);
4546         MemOpChains.push_back(LoadVal.getValue(1));
4547 
4548         // Shift the loaded value.
4549         unsigned Shamt;
4550 
4551         if (isLittle)
4552           Shamt = TotalBytesLoaded * 8;
4553         else
4554           Shamt = (RegSizeInBytes - (TotalBytesLoaded + LoadSizeInBytes)) * 8;
4555 
4556         SDValue Shift = DAG.getNode(ISD::SHL, DL, RegTy, LoadVal,
4557                                     DAG.getConstant(Shamt, DL, MVT::i32));
4558 
4559         if (Val.getNode())
4560           Val = DAG.getNode(ISD::OR, DL, RegTy, Val, Shift);
4561         else
4562           Val = Shift;
4563 
4564         OffsetInBytes += LoadSizeInBytes;
4565         TotalBytesLoaded += LoadSizeInBytes;
4566         Alignment = std::min(Alignment, Align(LoadSizeInBytes));
4567       }
4568 
4569       unsigned ArgReg = ArgRegs[FirstReg + I];
4570       RegsToPass.push_back(std::make_pair(ArgReg, Val));
4571       return;
4572     }
4573   }
4574 
4575   // Copy remainder of byval arg to it with memcpy.
4576   unsigned MemCpySize = ByValSizeInBytes - OffsetInBytes;
4577   SDValue Src = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4578                             DAG.getConstant(OffsetInBytes, DL, PtrTy));
4579   SDValue Dst = DAG.getNode(ISD::ADD, DL, PtrTy, StackPtr,
4580                             DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
4581   Chain = DAG.getMemcpy(
4582       Chain, DL, Dst, Src, DAG.getConstant(MemCpySize, DL, PtrTy),
4583       Align(Alignment), /*isVolatile=*/false, /*AlwaysInline=*/false,
4584       /*CI=*/nullptr, std::nullopt, MachinePointerInfo(), MachinePointerInfo());
4585   MemOpChains.push_back(Chain);
4586 }
4587 
4588 void MipsTargetLowering::writeVarArgRegs(std::vector<SDValue> &OutChains,
4589                                          SDValue Chain, const SDLoc &DL,
4590                                          SelectionDAG &DAG,
4591                                          CCState &State) const {
4592   ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();
4593   unsigned Idx = State.getFirstUnallocated(ArgRegs);
4594   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4595   MVT RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4596   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4597   MachineFunction &MF = DAG.getMachineFunction();
4598   MachineFrameInfo &MFI = MF.getFrameInfo();
4599   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
4600 
4601   // Offset of the first variable argument from stack pointer.
4602   int VaArgOffset;
4603 
4604   if (ArgRegs.size() == Idx)
4605     VaArgOffset = alignTo(State.getStackSize(), RegSizeInBytes);
4606   else {
4607     VaArgOffset =
4608         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4609         (int)(RegSizeInBytes * (ArgRegs.size() - Idx));
4610   }
4611 
4612   // Record the frame index of the first variable argument
4613   // which is a value necessary to VASTART.
4614   int FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4615   MipsFI->setVarArgsFrameIndex(FI);
4616 
4617   // Copy the integer registers that have not been used for argument passing
4618   // to the argument register save area. For O32, the save area is allocated
4619   // in the caller's stack frame, while for N32/64, it is allocated in the
4620   // callee's stack frame.
4621   for (unsigned I = Idx; I < ArgRegs.size();
4622        ++I, VaArgOffset += RegSizeInBytes) {
4623     unsigned Reg = addLiveIn(MF, ArgRegs[I], RC);
4624     SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegTy);
4625     FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4626     SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
4627     SDValue Store =
4628         DAG.getStore(Chain, DL, ArgValue, PtrOff, MachinePointerInfo());
4629     cast<StoreSDNode>(Store.getNode())->getMemOperand()->setValue(
4630         (Value *)nullptr);
4631     OutChains.push_back(Store);
4632   }
4633 }
4634 
4635 void MipsTargetLowering::HandleByVal(CCState *State, unsigned &Size,
4636                                      Align Alignment) const {
4637   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
4638 
4639   assert(Size && "Byval argument's size shouldn't be 0.");
4640 
4641   Alignment = std::min(Alignment, TFL->getStackAlign());
4642 
4643   unsigned FirstReg = 0;
4644   unsigned NumRegs = 0;
4645 
4646   if (State->getCallingConv() != CallingConv::Fast) {
4647     unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4648     ArrayRef<MCPhysReg> IntArgRegs = ABI.GetByValArgRegs();
4649     // FIXME: The O32 case actually describes no shadow registers.
4650     const MCPhysReg *ShadowRegs =
4651         ABI.IsO32() ? IntArgRegs.data() : Mips64DPRegs;
4652 
4653     // We used to check the size as well but we can't do that anymore since
4654     // CCState::HandleByVal() rounds up the size after calling this function.
4655     assert(
4656         Alignment >= Align(RegSizeInBytes) &&
4657         "Byval argument's alignment should be a multiple of RegSizeInBytes.");
4658 
4659     FirstReg = State->getFirstUnallocated(IntArgRegs);
4660 
4661     // If Alignment > RegSizeInBytes, the first arg register must be even.
4662     // FIXME: This condition happens to do the right thing but it's not the
4663     //        right way to test it. We want to check that the stack frame offset
4664     //        of the register is aligned.
4665     if ((Alignment > RegSizeInBytes) && (FirstReg % 2)) {
4666       State->AllocateReg(IntArgRegs[FirstReg], ShadowRegs[FirstReg]);
4667       ++FirstReg;
4668     }
4669 
4670     // Mark the registers allocated.
4671     Size = alignTo(Size, RegSizeInBytes);
4672     for (unsigned I = FirstReg; Size > 0 && (I < IntArgRegs.size());
4673          Size -= RegSizeInBytes, ++I, ++NumRegs)
4674       State->AllocateReg(IntArgRegs[I], ShadowRegs[I]);
4675   }
4676 
4677   State->addInRegsParamInfo(FirstReg, FirstReg + NumRegs);
4678 }
4679 
4680 MachineBasicBlock *MipsTargetLowering::emitPseudoSELECT(MachineInstr &MI,
4681                                                         MachineBasicBlock *BB,
4682                                                         bool isFPCmp,
4683                                                         unsigned Opc) const {
4684   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4685          "Subtarget already supports SELECT nodes with the use of"
4686          "conditional-move instructions.");
4687 
4688   const TargetInstrInfo *TII =
4689       Subtarget.getInstrInfo();
4690   DebugLoc DL = MI.getDebugLoc();
4691 
4692   // To "insert" a SELECT instruction, we actually have to insert the
4693   // diamond control-flow pattern.  The incoming instruction knows the
4694   // destination vreg to set, the condition code register to branch on, the
4695   // true/false values to select between, and a branch opcode to use.
4696   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4697   MachineFunction::iterator It = ++BB->getIterator();
4698 
4699   //  thisMBB:
4700   //  ...
4701   //   TrueVal = ...
4702   //   setcc r1, r2, r3
4703   //   bNE   r1, r0, copy1MBB
4704   //   fallthrough --> copy0MBB
4705   MachineBasicBlock *thisMBB  = BB;
4706   MachineFunction *F = BB->getParent();
4707   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4708   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
4709   F->insert(It, copy0MBB);
4710   F->insert(It, sinkMBB);
4711 
4712   // Transfer the remainder of BB and its successor edges to sinkMBB.
4713   sinkMBB->splice(sinkMBB->begin(), BB,
4714                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4715   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4716 
4717   // Next, add the true and fallthrough blocks as its successors.
4718   BB->addSuccessor(copy0MBB);
4719   BB->addSuccessor(sinkMBB);
4720 
4721   if (isFPCmp) {
4722     // bc1[tf] cc, sinkMBB
4723     BuildMI(BB, DL, TII->get(Opc))
4724         .addReg(MI.getOperand(1).getReg())
4725         .addMBB(sinkMBB);
4726   } else {
4727     // bne rs, $0, sinkMBB
4728     BuildMI(BB, DL, TII->get(Opc))
4729         .addReg(MI.getOperand(1).getReg())
4730         .addReg(Mips::ZERO)
4731         .addMBB(sinkMBB);
4732   }
4733 
4734   //  copy0MBB:
4735   //   %FalseValue = ...
4736   //   # fallthrough to sinkMBB
4737   BB = copy0MBB;
4738 
4739   // Update machine-CFG edges
4740   BB->addSuccessor(sinkMBB);
4741 
4742   //  sinkMBB:
4743   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4744   //  ...
4745   BB = sinkMBB;
4746 
4747   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4748       .addReg(MI.getOperand(2).getReg())
4749       .addMBB(thisMBB)
4750       .addReg(MI.getOperand(3).getReg())
4751       .addMBB(copy0MBB);
4752 
4753   MI.eraseFromParent(); // The pseudo instruction is gone now.
4754 
4755   return BB;
4756 }
4757 
4758 MachineBasicBlock *
4759 MipsTargetLowering::emitPseudoD_SELECT(MachineInstr &MI,
4760                                        MachineBasicBlock *BB) const {
4761   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4762          "Subtarget already supports SELECT nodes with the use of"
4763          "conditional-move instructions.");
4764 
4765   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4766   DebugLoc DL = MI.getDebugLoc();
4767 
4768   // D_SELECT substitutes two SELECT nodes that goes one after another and
4769   // have the same condition operand. On machines which don't have
4770   // conditional-move instruction, it reduces unnecessary branch instructions
4771   // which are result of using two diamond patterns that are result of two
4772   // SELECT pseudo instructions.
4773   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4774   MachineFunction::iterator It = ++BB->getIterator();
4775 
4776   //  thisMBB:
4777   //  ...
4778   //   TrueVal = ...
4779   //   setcc r1, r2, r3
4780   //   bNE   r1, r0, copy1MBB
4781   //   fallthrough --> copy0MBB
4782   MachineBasicBlock *thisMBB = BB;
4783   MachineFunction *F = BB->getParent();
4784   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4785   MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
4786   F->insert(It, copy0MBB);
4787   F->insert(It, sinkMBB);
4788 
4789   // Transfer the remainder of BB and its successor edges to sinkMBB.
4790   sinkMBB->splice(sinkMBB->begin(), BB,
4791                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4792   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4793 
4794   // Next, add the true and fallthrough blocks as its successors.
4795   BB->addSuccessor(copy0MBB);
4796   BB->addSuccessor(sinkMBB);
4797 
4798   // bne rs, $0, sinkMBB
4799   BuildMI(BB, DL, TII->get(Mips::BNE))
4800       .addReg(MI.getOperand(2).getReg())
4801       .addReg(Mips::ZERO)
4802       .addMBB(sinkMBB);
4803 
4804   //  copy0MBB:
4805   //   %FalseValue = ...
4806   //   # fallthrough to sinkMBB
4807   BB = copy0MBB;
4808 
4809   // Update machine-CFG edges
4810   BB->addSuccessor(sinkMBB);
4811 
4812   //  sinkMBB:
4813   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4814   //  ...
4815   BB = sinkMBB;
4816 
4817   // Use two PHI nodes to select two reults
4818   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4819       .addReg(MI.getOperand(3).getReg())
4820       .addMBB(thisMBB)
4821       .addReg(MI.getOperand(5).getReg())
4822       .addMBB(copy0MBB);
4823   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(1).getReg())
4824       .addReg(MI.getOperand(4).getReg())
4825       .addMBB(thisMBB)
4826       .addReg(MI.getOperand(6).getReg())
4827       .addMBB(copy0MBB);
4828 
4829   MI.eraseFromParent(); // The pseudo instruction is gone now.
4830 
4831   return BB;
4832 }
4833 
4834 // FIXME? Maybe this could be a TableGen attribute on some registers and
4835 // this table could be generated automatically from RegInfo.
4836 Register
4837 MipsTargetLowering::getRegisterByName(const char *RegName, LLT VT,
4838                                       const MachineFunction &MF) const {
4839   // The Linux kernel uses $28 and sp.
4840   if (Subtarget.isGP64bit()) {
4841     Register Reg = StringSwitch<Register>(RegName)
4842                        .Case("$28", Mips::GP_64)
4843                        .Case("sp", Mips::SP_64)
4844                        .Default(Register());
4845     if (Reg)
4846       return Reg;
4847   } else {
4848     Register Reg = StringSwitch<Register>(RegName)
4849                        .Case("$28", Mips::GP)
4850                        .Case("sp", Mips::SP)
4851                        .Default(Register());
4852     if (Reg)
4853       return Reg;
4854   }
4855   report_fatal_error("Invalid register name global variable");
4856 }
4857 
4858 MachineBasicBlock *MipsTargetLowering::emitLDR_W(MachineInstr &MI,
4859                                                  MachineBasicBlock *BB) const {
4860   MachineFunction *MF = BB->getParent();
4861   MachineRegisterInfo &MRI = MF->getRegInfo();
4862   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4863   const bool IsLittle = Subtarget.isLittle();
4864   DebugLoc DL = MI.getDebugLoc();
4865 
4866   Register Dest = MI.getOperand(0).getReg();
4867   Register Address = MI.getOperand(1).getReg();
4868   unsigned Imm = MI.getOperand(2).getImm();
4869 
4870   MachineBasicBlock::iterator I(MI);
4871 
4872   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4873     // Mips release 6 can load from adress that is not naturally-aligned.
4874     Register Temp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4875     BuildMI(*BB, I, DL, TII->get(Mips::LW))
4876         .addDef(Temp)
4877         .addUse(Address)
4878         .addImm(Imm);
4879     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(Temp);
4880   } else {
4881     // Mips release 5 needs to use instructions that can load from an unaligned
4882     // memory address.
4883     Register LoadHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4884     Register LoadFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4885     Register Undef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4886     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(Undef);
4887     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4888         .addDef(LoadHalf)
4889         .addUse(Address)
4890         .addImm(Imm + (IsLittle ? 0 : 3))
4891         .addUse(Undef);
4892     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4893         .addDef(LoadFull)
4894         .addUse(Address)
4895         .addImm(Imm + (IsLittle ? 3 : 0))
4896         .addUse(LoadHalf);
4897     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(LoadFull);
4898   }
4899 
4900   MI.eraseFromParent();
4901   return BB;
4902 }
4903 
4904 MachineBasicBlock *MipsTargetLowering::emitLDR_D(MachineInstr &MI,
4905                                                  MachineBasicBlock *BB) const {
4906   MachineFunction *MF = BB->getParent();
4907   MachineRegisterInfo &MRI = MF->getRegInfo();
4908   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4909   const bool IsLittle = Subtarget.isLittle();
4910   DebugLoc DL = MI.getDebugLoc();
4911 
4912   Register Dest = MI.getOperand(0).getReg();
4913   Register Address = MI.getOperand(1).getReg();
4914   unsigned Imm = MI.getOperand(2).getImm();
4915 
4916   MachineBasicBlock::iterator I(MI);
4917 
4918   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4919     // Mips release 6 can load from adress that is not naturally-aligned.
4920     if (Subtarget.isGP64bit()) {
4921       Register Temp = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4922       BuildMI(*BB, I, DL, TII->get(Mips::LD))
4923           .addDef(Temp)
4924           .addUse(Address)
4925           .addImm(Imm);
4926       BuildMI(*BB, I, DL, TII->get(Mips::FILL_D)).addDef(Dest).addUse(Temp);
4927     } else {
4928       Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4929       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4930       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4931       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4932           .addDef(Lo)
4933           .addUse(Address)
4934           .addImm(Imm + (IsLittle ? 0 : 4));
4935       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4936           .addDef(Hi)
4937           .addUse(Address)
4938           .addImm(Imm + (IsLittle ? 4 : 0));
4939       BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(Lo);
4940       BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4941           .addUse(Wtemp)
4942           .addUse(Hi)
4943           .addImm(1);
4944     }
4945   } else {
4946     // Mips release 5 needs to use instructions that can load from an unaligned
4947     // memory address.
4948     Register LoHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4949     Register LoFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4950     Register LoUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4951     Register HiHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4952     Register HiFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4953     Register HiUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4954     Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4955     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(LoUndef);
4956     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4957         .addDef(LoHalf)
4958         .addUse(Address)
4959         .addImm(Imm + (IsLittle ? 0 : 7))
4960         .addUse(LoUndef);
4961     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4962         .addDef(LoFull)
4963         .addUse(Address)
4964         .addImm(Imm + (IsLittle ? 3 : 4))
4965         .addUse(LoHalf);
4966     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(HiUndef);
4967     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4968         .addDef(HiHalf)
4969         .addUse(Address)
4970         .addImm(Imm + (IsLittle ? 4 : 3))
4971         .addUse(HiUndef);
4972     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4973         .addDef(HiFull)
4974         .addUse(Address)
4975         .addImm(Imm + (IsLittle ? 7 : 0))
4976         .addUse(HiHalf);
4977     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(LoFull);
4978     BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4979         .addUse(Wtemp)
4980         .addUse(HiFull)
4981         .addImm(1);
4982   }
4983 
4984   MI.eraseFromParent();
4985   return BB;
4986 }
4987 
4988 MachineBasicBlock *MipsTargetLowering::emitSTR_W(MachineInstr &MI,
4989                                                  MachineBasicBlock *BB) const {
4990   MachineFunction *MF = BB->getParent();
4991   MachineRegisterInfo &MRI = MF->getRegInfo();
4992   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4993   const bool IsLittle = Subtarget.isLittle();
4994   DebugLoc DL = MI.getDebugLoc();
4995 
4996   Register StoreVal = MI.getOperand(0).getReg();
4997   Register Address = MI.getOperand(1).getReg();
4998   unsigned Imm = MI.getOperand(2).getImm();
4999 
5000   MachineBasicBlock::iterator I(MI);
5001 
5002   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
5003     // Mips release 6 can store to adress that is not naturally-aligned.
5004     Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
5005     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
5006     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(BitcastW).addUse(StoreVal);
5007     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5008         .addDef(Tmp)
5009         .addUse(BitcastW)
5010         .addImm(0);
5011     BuildMI(*BB, I, DL, TII->get(Mips::SW))
5012         .addUse(Tmp)
5013         .addUse(Address)
5014         .addImm(Imm);
5015   } else {
5016     // Mips release 5 needs to use instructions that can store to an unaligned
5017     // memory address.
5018     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
5019     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5020         .addDef(Tmp)
5021         .addUse(StoreVal)
5022         .addImm(0);
5023     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5024         .addUse(Tmp)
5025         .addUse(Address)
5026         .addImm(Imm + (IsLittle ? 0 : 3));
5027     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5028         .addUse(Tmp)
5029         .addUse(Address)
5030         .addImm(Imm + (IsLittle ? 3 : 0));
5031   }
5032 
5033   MI.eraseFromParent();
5034 
5035   return BB;
5036 }
5037 
5038 MachineBasicBlock *MipsTargetLowering::emitSTR_D(MachineInstr &MI,
5039                                                  MachineBasicBlock *BB) const {
5040   MachineFunction *MF = BB->getParent();
5041   MachineRegisterInfo &MRI = MF->getRegInfo();
5042   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
5043   const bool IsLittle = Subtarget.isLittle();
5044   DebugLoc DL = MI.getDebugLoc();
5045 
5046   Register StoreVal = MI.getOperand(0).getReg();
5047   Register Address = MI.getOperand(1).getReg();
5048   unsigned Imm = MI.getOperand(2).getImm();
5049 
5050   MachineBasicBlock::iterator I(MI);
5051 
5052   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
5053     // Mips release 6 can store to adress that is not naturally-aligned.
5054     if (Subtarget.isGP64bit()) {
5055       Register BitcastD = MRI.createVirtualRegister(&Mips::MSA128DRegClass);
5056       Register Lo = MRI.createVirtualRegister(&Mips::GPR64RegClass);
5057       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
5058           .addDef(BitcastD)
5059           .addUse(StoreVal);
5060       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_D))
5061           .addDef(Lo)
5062           .addUse(BitcastD)
5063           .addImm(0);
5064       BuildMI(*BB, I, DL, TII->get(Mips::SD))
5065           .addUse(Lo)
5066           .addUse(Address)
5067           .addImm(Imm);
5068     } else {
5069       Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
5070       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
5071       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
5072       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
5073           .addDef(BitcastW)
5074           .addUse(StoreVal);
5075       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5076           .addDef(Lo)
5077           .addUse(BitcastW)
5078           .addImm(0);
5079       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5080           .addDef(Hi)
5081           .addUse(BitcastW)
5082           .addImm(1);
5083       BuildMI(*BB, I, DL, TII->get(Mips::SW))
5084           .addUse(Lo)
5085           .addUse(Address)
5086           .addImm(Imm + (IsLittle ? 0 : 4));
5087       BuildMI(*BB, I, DL, TII->get(Mips::SW))
5088           .addUse(Hi)
5089           .addUse(Address)
5090           .addImm(Imm + (IsLittle ? 4 : 0));
5091     }
5092   } else {
5093     // Mips release 5 needs to use instructions that can store to an unaligned
5094     // memory address.
5095     Register Bitcast = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
5096     Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
5097     Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
5098     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(Bitcast).addUse(StoreVal);
5099     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5100         .addDef(Lo)
5101         .addUse(Bitcast)
5102         .addImm(0);
5103     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5104         .addDef(Hi)
5105         .addUse(Bitcast)
5106         .addImm(1);
5107     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5108         .addUse(Lo)
5109         .addUse(Address)
5110         .addImm(Imm + (IsLittle ? 0 : 3));
5111     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5112         .addUse(Lo)
5113         .addUse(Address)
5114         .addImm(Imm + (IsLittle ? 3 : 0));
5115     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5116         .addUse(Hi)
5117         .addUse(Address)
5118         .addImm(Imm + (IsLittle ? 4 : 7));
5119     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5120         .addUse(Hi)
5121         .addUse(Address)
5122         .addImm(Imm + (IsLittle ? 7 : 4));
5123   }
5124 
5125   MI.eraseFromParent();
5126   return BB;
5127 }
5128