xref: /freebsd-src/contrib/llvm-project/llvm/lib/Target/Mips/MipsISelLowering.cpp (revision 753f127f3ace09432b2baeffd71a308760641a62)
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/RuntimeLibcalls.h"
44 #include "llvm/CodeGen/SelectionDAG.h"
45 #include "llvm/CodeGen/SelectionDAGNodes.h"
46 #include "llvm/CodeGen/TargetFrameLowering.h"
47 #include "llvm/CodeGen/TargetInstrInfo.h"
48 #include "llvm/CodeGen/TargetRegisterInfo.h"
49 #include "llvm/CodeGen/ValueTypes.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/Type.h"
58 #include "llvm/IR/Value.h"
59 #include "llvm/MC/MCContext.h"
60 #include "llvm/MC/MCRegisterInfo.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/MachineValueType.h"
67 #include "llvm/Support/MathExtras.h"
68 #include "llvm/Target/TargetMachine.h"
69 #include "llvm/Target/TargetOptions.h"
70 #include <algorithm>
71 #include <cassert>
72 #include <cctype>
73 #include <cstdint>
74 #include <deque>
75 #include <iterator>
76 #include <utility>
77 #include <vector>
78 
79 using namespace llvm;
80 
81 #define DEBUG_TYPE "mips-lower"
82 
83 STATISTIC(NumTailCalls, "Number of tail calls");
84 
85 static cl::opt<bool>
86 NoZeroDivCheck("mno-check-zero-division", cl::Hidden,
87                cl::desc("MIPS: Don't trap on integer division by zero."),
88                cl::init(false));
89 
90 extern cl::opt<bool> EmitJalrReloc;
91 
92 static const MCPhysReg Mips64DPRegs[8] = {
93   Mips::D12_64, Mips::D13_64, Mips::D14_64, Mips::D15_64,
94   Mips::D16_64, Mips::D17_64, Mips::D18_64, Mips::D19_64
95 };
96 
97 // The MIPS MSA ABI passes vector arguments in the integer register set.
98 // The number of integer registers used is dependant on the ABI used.
99 MVT MipsTargetLowering::getRegisterTypeForCallingConv(LLVMContext &Context,
100                                                       CallingConv::ID CC,
101                                                       EVT VT) const {
102   if (!VT.isVector())
103     return getRegisterType(Context, VT);
104 
105   return Subtarget.isABI_O32() || VT.getSizeInBits() == 32 ? MVT::i32
106                                                            : MVT::i64;
107 }
108 
109 unsigned MipsTargetLowering::getNumRegistersForCallingConv(LLVMContext &Context,
110                                                            CallingConv::ID CC,
111                                                            EVT VT) const {
112   if (VT.isVector())
113     return divideCeil(VT.getSizeInBits(), Subtarget.isABI_O32() ? 32 : 64);
114   return MipsTargetLowering::getNumRegisters(Context, VT);
115 }
116 
117 unsigned MipsTargetLowering::getVectorTypeBreakdownForCallingConv(
118     LLVMContext &Context, CallingConv::ID CC, EVT VT, EVT &IntermediateVT,
119     unsigned &NumIntermediates, MVT &RegisterVT) const {
120   // Break down vector types to either 2 i64s or 4 i32s.
121   RegisterVT = getRegisterTypeForCallingConv(Context, CC, VT);
122   IntermediateVT = RegisterVT;
123   NumIntermediates =
124       VT.getFixedSizeInBits() < RegisterVT.getFixedSizeInBits()
125           ? VT.getVectorNumElements()
126           : divideCeil(VT.getSizeInBits(), RegisterVT.getSizeInBits());
127   return NumIntermediates;
128 }
129 
130 SDValue MipsTargetLowering::getGlobalReg(SelectionDAG &DAG, EVT Ty) const {
131   MachineFunction &MF = DAG.getMachineFunction();
132   MipsFunctionInfo *FI = MF.getInfo<MipsFunctionInfo>();
133   return DAG.getRegister(FI->getGlobalBaseReg(MF), Ty);
134 }
135 
136 SDValue MipsTargetLowering::getTargetNode(GlobalAddressSDNode *N, EVT Ty,
137                                           SelectionDAG &DAG,
138                                           unsigned Flag) const {
139   return DAG.getTargetGlobalAddress(N->getGlobal(), SDLoc(N), Ty, 0, Flag);
140 }
141 
142 SDValue MipsTargetLowering::getTargetNode(ExternalSymbolSDNode *N, EVT Ty,
143                                           SelectionDAG &DAG,
144                                           unsigned Flag) const {
145   return DAG.getTargetExternalSymbol(N->getSymbol(), Ty, Flag);
146 }
147 
148 SDValue MipsTargetLowering::getTargetNode(BlockAddressSDNode *N, EVT Ty,
149                                           SelectionDAG &DAG,
150                                           unsigned Flag) const {
151   return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, 0, Flag);
152 }
153 
154 SDValue MipsTargetLowering::getTargetNode(JumpTableSDNode *N, EVT Ty,
155                                           SelectionDAG &DAG,
156                                           unsigned Flag) const {
157   return DAG.getTargetJumpTable(N->getIndex(), Ty, Flag);
158 }
159 
160 SDValue MipsTargetLowering::getTargetNode(ConstantPoolSDNode *N, EVT Ty,
161                                           SelectionDAG &DAG,
162                                           unsigned Flag) const {
163   return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlign(),
164                                    N->getOffset(), Flag);
165 }
166 
167 const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
168   switch ((MipsISD::NodeType)Opcode) {
169   case MipsISD::FIRST_NUMBER:      break;
170   case MipsISD::JmpLink:           return "MipsISD::JmpLink";
171   case MipsISD::TailCall:          return "MipsISD::TailCall";
172   case MipsISD::Highest:           return "MipsISD::Highest";
173   case MipsISD::Higher:            return "MipsISD::Higher";
174   case MipsISD::Hi:                return "MipsISD::Hi";
175   case MipsISD::Lo:                return "MipsISD::Lo";
176   case MipsISD::GotHi:             return "MipsISD::GotHi";
177   case MipsISD::TlsHi:             return "MipsISD::TlsHi";
178   case MipsISD::GPRel:             return "MipsISD::GPRel";
179   case MipsISD::ThreadPointer:     return "MipsISD::ThreadPointer";
180   case MipsISD::Ret:               return "MipsISD::Ret";
181   case MipsISD::ERet:              return "MipsISD::ERet";
182   case MipsISD::EH_RETURN:         return "MipsISD::EH_RETURN";
183   case MipsISD::FAbs:              return "MipsISD::FAbs";
184   case MipsISD::FMS:               return "MipsISD::FMS";
185   case MipsISD::FPBrcond:          return "MipsISD::FPBrcond";
186   case MipsISD::FPCmp:             return "MipsISD::FPCmp";
187   case MipsISD::FSELECT:           return "MipsISD::FSELECT";
188   case MipsISD::MTC1_D64:          return "MipsISD::MTC1_D64";
189   case MipsISD::CMovFP_T:          return "MipsISD::CMovFP_T";
190   case MipsISD::CMovFP_F:          return "MipsISD::CMovFP_F";
191   case MipsISD::TruncIntFP:        return "MipsISD::TruncIntFP";
192   case MipsISD::MFHI:              return "MipsISD::MFHI";
193   case MipsISD::MFLO:              return "MipsISD::MFLO";
194   case MipsISD::MTLOHI:            return "MipsISD::MTLOHI";
195   case MipsISD::Mult:              return "MipsISD::Mult";
196   case MipsISD::Multu:             return "MipsISD::Multu";
197   case MipsISD::MAdd:              return "MipsISD::MAdd";
198   case MipsISD::MAddu:             return "MipsISD::MAddu";
199   case MipsISD::MSub:              return "MipsISD::MSub";
200   case MipsISD::MSubu:             return "MipsISD::MSubu";
201   case MipsISD::DivRem:            return "MipsISD::DivRem";
202   case MipsISD::DivRemU:           return "MipsISD::DivRemU";
203   case MipsISD::DivRem16:          return "MipsISD::DivRem16";
204   case MipsISD::DivRemU16:         return "MipsISD::DivRemU16";
205   case MipsISD::BuildPairF64:      return "MipsISD::BuildPairF64";
206   case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
207   case MipsISD::Wrapper:           return "MipsISD::Wrapper";
208   case MipsISD::DynAlloc:          return "MipsISD::DynAlloc";
209   case MipsISD::Sync:              return "MipsISD::Sync";
210   case MipsISD::Ext:               return "MipsISD::Ext";
211   case MipsISD::Ins:               return "MipsISD::Ins";
212   case MipsISD::CIns:              return "MipsISD::CIns";
213   case MipsISD::LWL:               return "MipsISD::LWL";
214   case MipsISD::LWR:               return "MipsISD::LWR";
215   case MipsISD::SWL:               return "MipsISD::SWL";
216   case MipsISD::SWR:               return "MipsISD::SWR";
217   case MipsISD::LDL:               return "MipsISD::LDL";
218   case MipsISD::LDR:               return "MipsISD::LDR";
219   case MipsISD::SDL:               return "MipsISD::SDL";
220   case MipsISD::SDR:               return "MipsISD::SDR";
221   case MipsISD::EXTP:              return "MipsISD::EXTP";
222   case MipsISD::EXTPDP:            return "MipsISD::EXTPDP";
223   case MipsISD::EXTR_S_H:          return "MipsISD::EXTR_S_H";
224   case MipsISD::EXTR_W:            return "MipsISD::EXTR_W";
225   case MipsISD::EXTR_R_W:          return "MipsISD::EXTR_R_W";
226   case MipsISD::EXTR_RS_W:         return "MipsISD::EXTR_RS_W";
227   case MipsISD::SHILO:             return "MipsISD::SHILO";
228   case MipsISD::MTHLIP:            return "MipsISD::MTHLIP";
229   case MipsISD::MULSAQ_S_W_PH:     return "MipsISD::MULSAQ_S_W_PH";
230   case MipsISD::MAQ_S_W_PHL:       return "MipsISD::MAQ_S_W_PHL";
231   case MipsISD::MAQ_S_W_PHR:       return "MipsISD::MAQ_S_W_PHR";
232   case MipsISD::MAQ_SA_W_PHL:      return "MipsISD::MAQ_SA_W_PHL";
233   case MipsISD::MAQ_SA_W_PHR:      return "MipsISD::MAQ_SA_W_PHR";
234   case MipsISD::DPAU_H_QBL:        return "MipsISD::DPAU_H_QBL";
235   case MipsISD::DPAU_H_QBR:        return "MipsISD::DPAU_H_QBR";
236   case MipsISD::DPSU_H_QBL:        return "MipsISD::DPSU_H_QBL";
237   case MipsISD::DPSU_H_QBR:        return "MipsISD::DPSU_H_QBR";
238   case MipsISD::DPAQ_S_W_PH:       return "MipsISD::DPAQ_S_W_PH";
239   case MipsISD::DPSQ_S_W_PH:       return "MipsISD::DPSQ_S_W_PH";
240   case MipsISD::DPAQ_SA_L_W:       return "MipsISD::DPAQ_SA_L_W";
241   case MipsISD::DPSQ_SA_L_W:       return "MipsISD::DPSQ_SA_L_W";
242   case MipsISD::DPA_W_PH:          return "MipsISD::DPA_W_PH";
243   case MipsISD::DPS_W_PH:          return "MipsISD::DPS_W_PH";
244   case MipsISD::DPAQX_S_W_PH:      return "MipsISD::DPAQX_S_W_PH";
245   case MipsISD::DPAQX_SA_W_PH:     return "MipsISD::DPAQX_SA_W_PH";
246   case MipsISD::DPAX_W_PH:         return "MipsISD::DPAX_W_PH";
247   case MipsISD::DPSX_W_PH:         return "MipsISD::DPSX_W_PH";
248   case MipsISD::DPSQX_S_W_PH:      return "MipsISD::DPSQX_S_W_PH";
249   case MipsISD::DPSQX_SA_W_PH:     return "MipsISD::DPSQX_SA_W_PH";
250   case MipsISD::MULSA_W_PH:        return "MipsISD::MULSA_W_PH";
251   case MipsISD::MULT:              return "MipsISD::MULT";
252   case MipsISD::MULTU:             return "MipsISD::MULTU";
253   case MipsISD::MADD_DSP:          return "MipsISD::MADD_DSP";
254   case MipsISD::MADDU_DSP:         return "MipsISD::MADDU_DSP";
255   case MipsISD::MSUB_DSP:          return "MipsISD::MSUB_DSP";
256   case MipsISD::MSUBU_DSP:         return "MipsISD::MSUBU_DSP";
257   case MipsISD::SHLL_DSP:          return "MipsISD::SHLL_DSP";
258   case MipsISD::SHRA_DSP:          return "MipsISD::SHRA_DSP";
259   case MipsISD::SHRL_DSP:          return "MipsISD::SHRL_DSP";
260   case MipsISD::SETCC_DSP:         return "MipsISD::SETCC_DSP";
261   case MipsISD::SELECT_CC_DSP:     return "MipsISD::SELECT_CC_DSP";
262   case MipsISD::VALL_ZERO:         return "MipsISD::VALL_ZERO";
263   case MipsISD::VANY_ZERO:         return "MipsISD::VANY_ZERO";
264   case MipsISD::VALL_NONZERO:      return "MipsISD::VALL_NONZERO";
265   case MipsISD::VANY_NONZERO:      return "MipsISD::VANY_NONZERO";
266   case MipsISD::VCEQ:              return "MipsISD::VCEQ";
267   case MipsISD::VCLE_S:            return "MipsISD::VCLE_S";
268   case MipsISD::VCLE_U:            return "MipsISD::VCLE_U";
269   case MipsISD::VCLT_S:            return "MipsISD::VCLT_S";
270   case MipsISD::VCLT_U:            return "MipsISD::VCLT_U";
271   case MipsISD::VEXTRACT_SEXT_ELT: return "MipsISD::VEXTRACT_SEXT_ELT";
272   case MipsISD::VEXTRACT_ZEXT_ELT: return "MipsISD::VEXTRACT_ZEXT_ELT";
273   case MipsISD::VNOR:              return "MipsISD::VNOR";
274   case MipsISD::VSHF:              return "MipsISD::VSHF";
275   case MipsISD::SHF:               return "MipsISD::SHF";
276   case MipsISD::ILVEV:             return "MipsISD::ILVEV";
277   case MipsISD::ILVOD:             return "MipsISD::ILVOD";
278   case MipsISD::ILVL:              return "MipsISD::ILVL";
279   case MipsISD::ILVR:              return "MipsISD::ILVR";
280   case MipsISD::PCKEV:             return "MipsISD::PCKEV";
281   case MipsISD::PCKOD:             return "MipsISD::PCKOD";
282   case MipsISD::INSVE:             return "MipsISD::INSVE";
283   }
284   return nullptr;
285 }
286 
287 MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM,
288                                        const MipsSubtarget &STI)
289     : TargetLowering(TM), Subtarget(STI), ABI(TM.getABI()) {
290   // Mips does not have i1 type, so use i32 for
291   // setcc operations results (slt, sgt, ...).
292   setBooleanContents(ZeroOrOneBooleanContent);
293   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
294   // The cmp.cond.fmt instruction in MIPS32r6/MIPS64r6 uses 0 and -1 like MSA
295   // does. Integer booleans still use 0 and 1.
296   if (Subtarget.hasMips32r6())
297     setBooleanContents(ZeroOrOneBooleanContent,
298                        ZeroOrNegativeOneBooleanContent);
299 
300   // Load extented operations for i1 types must be promoted
301   for (MVT VT : MVT::integer_valuetypes()) {
302     setLoadExtAction(ISD::EXTLOAD,  VT, MVT::i1,  Promote);
303     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1,  Promote);
304     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1,  Promote);
305   }
306 
307   // MIPS doesn't have extending float->double load/store.  Set LoadExtAction
308   // for f32, f16
309   for (MVT VT : MVT::fp_valuetypes()) {
310     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
311     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
312   }
313 
314   // Set LoadExtAction for f16 vectors to Expand
315   for (MVT VT : MVT::fp_fixedlen_vector_valuetypes()) {
316     MVT F16VT = MVT::getVectorVT(MVT::f16, VT.getVectorNumElements());
317     if (F16VT.isValid())
318       setLoadExtAction(ISD::EXTLOAD, VT, F16VT, Expand);
319   }
320 
321   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
322   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
323 
324   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
325 
326   // Used by legalize types to correctly generate the setcc result.
327   // Without this, every float setcc comes with a AND/OR with the result,
328   // we don't want this, since the fpcmp result goes to a flag register,
329   // which is used implicitly by brcond and select operations.
330   AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
331 
332   // Mips Custom Operations
333   setOperationAction(ISD::BR_JT,              MVT::Other, Expand);
334   setOperationAction(ISD::GlobalAddress,      MVT::i32,   Custom);
335   setOperationAction(ISD::BlockAddress,       MVT::i32,   Custom);
336   setOperationAction(ISD::GlobalTLSAddress,   MVT::i32,   Custom);
337   setOperationAction(ISD::JumpTable,          MVT::i32,   Custom);
338   setOperationAction(ISD::ConstantPool,       MVT::i32,   Custom);
339   setOperationAction(ISD::SELECT,             MVT::f32,   Custom);
340   setOperationAction(ISD::SELECT,             MVT::f64,   Custom);
341   setOperationAction(ISD::SELECT,             MVT::i32,   Custom);
342   setOperationAction(ISD::SETCC,              MVT::f32,   Custom);
343   setOperationAction(ISD::SETCC,              MVT::f64,   Custom);
344   setOperationAction(ISD::BRCOND,             MVT::Other, Custom);
345   setOperationAction(ISD::FABS,               MVT::f32,   Custom);
346   setOperationAction(ISD::FABS,               MVT::f64,   Custom);
347   setOperationAction(ISD::FCOPYSIGN,          MVT::f32,   Custom);
348   setOperationAction(ISD::FCOPYSIGN,          MVT::f64,   Custom);
349   setOperationAction(ISD::FP_TO_SINT,         MVT::i32,   Custom);
350 
351   if (Subtarget.isGP64bit()) {
352     setOperationAction(ISD::GlobalAddress,      MVT::i64,   Custom);
353     setOperationAction(ISD::BlockAddress,       MVT::i64,   Custom);
354     setOperationAction(ISD::GlobalTLSAddress,   MVT::i64,   Custom);
355     setOperationAction(ISD::JumpTable,          MVT::i64,   Custom);
356     setOperationAction(ISD::ConstantPool,       MVT::i64,   Custom);
357     setOperationAction(ISD::SELECT,             MVT::i64,   Custom);
358     setOperationAction(ISD::LOAD,               MVT::i64,   Custom);
359     setOperationAction(ISD::STORE,              MVT::i64,   Custom);
360     setOperationAction(ISD::FP_TO_SINT,         MVT::i64,   Custom);
361     setOperationAction(ISD::SHL_PARTS,          MVT::i64,   Custom);
362     setOperationAction(ISD::SRA_PARTS,          MVT::i64,   Custom);
363     setOperationAction(ISD::SRL_PARTS,          MVT::i64,   Custom);
364   }
365 
366   if (!Subtarget.isGP64bit()) {
367     setOperationAction(ISD::SHL_PARTS,          MVT::i32,   Custom);
368     setOperationAction(ISD::SRA_PARTS,          MVT::i32,   Custom);
369     setOperationAction(ISD::SRL_PARTS,          MVT::i32,   Custom);
370   }
371 
372   setOperationAction(ISD::EH_DWARF_CFA,         MVT::i32,   Custom);
373   if (Subtarget.isGP64bit())
374     setOperationAction(ISD::EH_DWARF_CFA,       MVT::i64,   Custom);
375 
376   setOperationAction(ISD::SDIV, MVT::i32, Expand);
377   setOperationAction(ISD::SREM, MVT::i32, Expand);
378   setOperationAction(ISD::UDIV, MVT::i32, Expand);
379   setOperationAction(ISD::UREM, MVT::i32, Expand);
380   setOperationAction(ISD::SDIV, MVT::i64, Expand);
381   setOperationAction(ISD::SREM, MVT::i64, Expand);
382   setOperationAction(ISD::UDIV, MVT::i64, Expand);
383   setOperationAction(ISD::UREM, MVT::i64, Expand);
384 
385   // Operations not directly supported by Mips.
386   setOperationAction(ISD::BR_CC,             MVT::f32,   Expand);
387   setOperationAction(ISD::BR_CC,             MVT::f64,   Expand);
388   setOperationAction(ISD::BR_CC,             MVT::i32,   Expand);
389   setOperationAction(ISD::BR_CC,             MVT::i64,   Expand);
390   setOperationAction(ISD::SELECT_CC,         MVT::i32,   Expand);
391   setOperationAction(ISD::SELECT_CC,         MVT::i64,   Expand);
392   setOperationAction(ISD::SELECT_CC,         MVT::f32,   Expand);
393   setOperationAction(ISD::SELECT_CC,         MVT::f64,   Expand);
394   setOperationAction(ISD::UINT_TO_FP,        MVT::i32,   Expand);
395   setOperationAction(ISD::UINT_TO_FP,        MVT::i64,   Expand);
396   setOperationAction(ISD::FP_TO_UINT,        MVT::i32,   Expand);
397   setOperationAction(ISD::FP_TO_UINT,        MVT::i64,   Expand);
398   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1,    Expand);
399   if (Subtarget.hasCnMips()) {
400     setOperationAction(ISD::CTPOP,           MVT::i32,   Legal);
401     setOperationAction(ISD::CTPOP,           MVT::i64,   Legal);
402   } else {
403     setOperationAction(ISD::CTPOP,           MVT::i32,   Expand);
404     setOperationAction(ISD::CTPOP,           MVT::i64,   Expand);
405   }
406   setOperationAction(ISD::CTTZ,              MVT::i32,   Expand);
407   setOperationAction(ISD::CTTZ,              MVT::i64,   Expand);
408   setOperationAction(ISD::ROTL,              MVT::i32,   Expand);
409   setOperationAction(ISD::ROTL,              MVT::i64,   Expand);
410   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32,  Expand);
411   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64,  Expand);
412 
413   if (!Subtarget.hasMips32r2())
414     setOperationAction(ISD::ROTR, MVT::i32,   Expand);
415 
416   if (!Subtarget.hasMips64r2())
417     setOperationAction(ISD::ROTR, MVT::i64,   Expand);
418 
419   setOperationAction(ISD::FSIN,              MVT::f32,   Expand);
420   setOperationAction(ISD::FSIN,              MVT::f64,   Expand);
421   setOperationAction(ISD::FCOS,              MVT::f32,   Expand);
422   setOperationAction(ISD::FCOS,              MVT::f64,   Expand);
423   setOperationAction(ISD::FSINCOS,           MVT::f32,   Expand);
424   setOperationAction(ISD::FSINCOS,           MVT::f64,   Expand);
425   setOperationAction(ISD::FPOW,              MVT::f32,   Expand);
426   setOperationAction(ISD::FPOW,              MVT::f64,   Expand);
427   setOperationAction(ISD::FLOG,              MVT::f32,   Expand);
428   setOperationAction(ISD::FLOG2,             MVT::f32,   Expand);
429   setOperationAction(ISD::FLOG10,            MVT::f32,   Expand);
430   setOperationAction(ISD::FEXP,              MVT::f32,   Expand);
431   setOperationAction(ISD::FMA,               MVT::f32,   Expand);
432   setOperationAction(ISD::FMA,               MVT::f64,   Expand);
433   setOperationAction(ISD::FREM,              MVT::f32,   Expand);
434   setOperationAction(ISD::FREM,              MVT::f64,   Expand);
435 
436   // Lower f16 conversion operations into library calls
437   setOperationAction(ISD::FP16_TO_FP,        MVT::f32,   Expand);
438   setOperationAction(ISD::FP_TO_FP16,        MVT::f32,   Expand);
439   setOperationAction(ISD::FP16_TO_FP,        MVT::f64,   Expand);
440   setOperationAction(ISD::FP_TO_FP16,        MVT::f64,   Expand);
441 
442   setOperationAction(ISD::EH_RETURN, MVT::Other, Custom);
443 
444   setOperationAction(ISD::VASTART,           MVT::Other, Custom);
445   setOperationAction(ISD::VAARG,             MVT::Other, Custom);
446   setOperationAction(ISD::VACOPY,            MVT::Other, Expand);
447   setOperationAction(ISD::VAEND,             MVT::Other, Expand);
448 
449   // Use the default for now
450   setOperationAction(ISD::STACKSAVE,         MVT::Other, Expand);
451   setOperationAction(ISD::STACKRESTORE,      MVT::Other, Expand);
452 
453   if (!Subtarget.isGP64bit()) {
454     setOperationAction(ISD::ATOMIC_LOAD,     MVT::i64,   Expand);
455     setOperationAction(ISD::ATOMIC_STORE,    MVT::i64,   Expand);
456   }
457 
458   if (!Subtarget.hasMips32r2()) {
459     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
460     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
461   }
462 
463   // MIPS16 lacks MIPS32's clz and clo instructions.
464   if (!Subtarget.hasMips32() || Subtarget.inMips16Mode())
465     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
466   if (!Subtarget.hasMips64())
467     setOperationAction(ISD::CTLZ, MVT::i64, Expand);
468 
469   if (!Subtarget.hasMips32r2())
470     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
471   if (!Subtarget.hasMips64r2())
472     setOperationAction(ISD::BSWAP, MVT::i64, Expand);
473 
474   if (Subtarget.isGP64bit()) {
475     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, MVT::i32, Custom);
476     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, MVT::i32, Custom);
477     setLoadExtAction(ISD::EXTLOAD, MVT::i64, MVT::i32, Custom);
478     setTruncStoreAction(MVT::i64, MVT::i32, Custom);
479   }
480 
481   setOperationAction(ISD::TRAP, MVT::Other, Legal);
482 
483   setTargetDAGCombine({ISD::SDIVREM, ISD::UDIVREM, ISD::SELECT, ISD::AND,
484                        ISD::OR, ISD::ADD, ISD::SUB, ISD::AssertZext, ISD::SHL});
485 
486   if (ABI.IsO32()) {
487     // These libcalls are not available in 32-bit.
488     setLibcallName(RTLIB::SHL_I128, nullptr);
489     setLibcallName(RTLIB::SRL_I128, nullptr);
490     setLibcallName(RTLIB::SRA_I128, nullptr);
491     setLibcallName(RTLIB::MUL_I128, nullptr);
492     setLibcallName(RTLIB::MULO_I64, nullptr);
493     setLibcallName(RTLIB::MULO_I128, nullptr);
494   }
495 
496   setMinFunctionAlignment(Subtarget.isGP64bit() ? Align(8) : Align(4));
497 
498   // The arguments on the stack are defined in terms of 4-byte slots on O32
499   // and 8-byte slots on N32/N64.
500   setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? Align(8)
501                                                             : Align(4));
502 
503   setStackPointerRegisterToSaveRestore(ABI.IsN64() ? Mips::SP_64 : Mips::SP);
504 
505   MaxStoresPerMemcpy = 16;
506 
507   isMicroMips = Subtarget.inMicroMipsMode();
508 }
509 
510 const MipsTargetLowering *
511 MipsTargetLowering::create(const MipsTargetMachine &TM,
512                            const MipsSubtarget &STI) {
513   if (STI.inMips16Mode())
514     return createMips16TargetLowering(TM, STI);
515 
516   return createMipsSETargetLowering(TM, STI);
517 }
518 
519 // Create a fast isel object.
520 FastISel *
521 MipsTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
522                                   const TargetLibraryInfo *libInfo) const {
523   const MipsTargetMachine &TM =
524       static_cast<const MipsTargetMachine &>(funcInfo.MF->getTarget());
525 
526   // We support only the standard encoding [MIPS32,MIPS32R5] ISAs.
527   bool UseFastISel = TM.Options.EnableFastISel && Subtarget.hasMips32() &&
528                      !Subtarget.hasMips32r6() && !Subtarget.inMips16Mode() &&
529                      !Subtarget.inMicroMipsMode();
530 
531   // Disable if either of the following is true:
532   // We do not generate PIC, the ABI is not O32, XGOT is being used.
533   if (!TM.isPositionIndependent() || !TM.getABI().IsO32() ||
534       Subtarget.useXGOT())
535     UseFastISel = false;
536 
537   return UseFastISel ? Mips::createFastISel(funcInfo, libInfo) : nullptr;
538 }
539 
540 EVT MipsTargetLowering::getSetCCResultType(const DataLayout &, LLVMContext &,
541                                            EVT VT) const {
542   if (!VT.isVector())
543     return MVT::i32;
544   return VT.changeVectorElementTypeToInteger();
545 }
546 
547 static SDValue performDivRemCombine(SDNode *N, SelectionDAG &DAG,
548                                     TargetLowering::DAGCombinerInfo &DCI,
549                                     const MipsSubtarget &Subtarget) {
550   if (DCI.isBeforeLegalizeOps())
551     return SDValue();
552 
553   EVT Ty = N->getValueType(0);
554   unsigned LO = (Ty == MVT::i32) ? Mips::LO0 : Mips::LO0_64;
555   unsigned HI = (Ty == MVT::i32) ? Mips::HI0 : Mips::HI0_64;
556   unsigned Opc = N->getOpcode() == ISD::SDIVREM ? MipsISD::DivRem16 :
557                                                   MipsISD::DivRemU16;
558   SDLoc DL(N);
559 
560   SDValue DivRem = DAG.getNode(Opc, DL, MVT::Glue,
561                                N->getOperand(0), N->getOperand(1));
562   SDValue InChain = DAG.getEntryNode();
563   SDValue InGlue = DivRem;
564 
565   // insert MFLO
566   if (N->hasAnyUseOfValue(0)) {
567     SDValue CopyFromLo = DAG.getCopyFromReg(InChain, DL, LO, Ty,
568                                             InGlue);
569     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), CopyFromLo);
570     InChain = CopyFromLo.getValue(1);
571     InGlue = CopyFromLo.getValue(2);
572   }
573 
574   // insert MFHI
575   if (N->hasAnyUseOfValue(1)) {
576     SDValue CopyFromHi = DAG.getCopyFromReg(InChain, DL,
577                                             HI, Ty, InGlue);
578     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi);
579   }
580 
581   return SDValue();
582 }
583 
584 static Mips::CondCode condCodeToFCC(ISD::CondCode CC) {
585   switch (CC) {
586   default: llvm_unreachable("Unknown fp condition code!");
587   case ISD::SETEQ:
588   case ISD::SETOEQ: return Mips::FCOND_OEQ;
589   case ISD::SETUNE: return Mips::FCOND_UNE;
590   case ISD::SETLT:
591   case ISD::SETOLT: return Mips::FCOND_OLT;
592   case ISD::SETGT:
593   case ISD::SETOGT: return Mips::FCOND_OGT;
594   case ISD::SETLE:
595   case ISD::SETOLE: return Mips::FCOND_OLE;
596   case ISD::SETGE:
597   case ISD::SETOGE: return Mips::FCOND_OGE;
598   case ISD::SETULT: return Mips::FCOND_ULT;
599   case ISD::SETULE: return Mips::FCOND_ULE;
600   case ISD::SETUGT: return Mips::FCOND_UGT;
601   case ISD::SETUGE: return Mips::FCOND_UGE;
602   case ISD::SETUO:  return Mips::FCOND_UN;
603   case ISD::SETO:   return Mips::FCOND_OR;
604   case ISD::SETNE:
605   case ISD::SETONE: return Mips::FCOND_ONE;
606   case ISD::SETUEQ: return Mips::FCOND_UEQ;
607   }
608 }
609 
610 /// This function returns true if the floating point conditional branches and
611 /// conditional moves which use condition code CC should be inverted.
612 static bool invertFPCondCodeUser(Mips::CondCode CC) {
613   if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT)
614     return false;
615 
616   assert((CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) &&
617          "Illegal Condition Code");
618 
619   return true;
620 }
621 
622 // Creates and returns an FPCmp node from a setcc node.
623 // Returns Op if setcc is not a floating point comparison.
624 static SDValue createFPCmp(SelectionDAG &DAG, const SDValue &Op) {
625   // must be a SETCC node
626   if (Op.getOpcode() != ISD::SETCC)
627     return Op;
628 
629   SDValue LHS = Op.getOperand(0);
630 
631   if (!LHS.getValueType().isFloatingPoint())
632     return Op;
633 
634   SDValue RHS = Op.getOperand(1);
635   SDLoc DL(Op);
636 
637   // Assume the 3rd operand is a CondCodeSDNode. Add code to check the type of
638   // node if necessary.
639   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
640 
641   return DAG.getNode(MipsISD::FPCmp, DL, MVT::Glue, LHS, RHS,
642                      DAG.getConstant(condCodeToFCC(CC), DL, MVT::i32));
643 }
644 
645 // Creates and returns a CMovFPT/F node.
646 static SDValue createCMovFP(SelectionDAG &DAG, SDValue Cond, SDValue True,
647                             SDValue False, const SDLoc &DL) {
648   ConstantSDNode *CC = cast<ConstantSDNode>(Cond.getOperand(2));
649   bool invert = invertFPCondCodeUser((Mips::CondCode)CC->getSExtValue());
650   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
651 
652   return DAG.getNode((invert ? MipsISD::CMovFP_F : MipsISD::CMovFP_T), DL,
653                      True.getValueType(), True, FCC0, False, Cond);
654 }
655 
656 static SDValue performSELECTCombine(SDNode *N, SelectionDAG &DAG,
657                                     TargetLowering::DAGCombinerInfo &DCI,
658                                     const MipsSubtarget &Subtarget) {
659   if (DCI.isBeforeLegalizeOps())
660     return SDValue();
661 
662   SDValue SetCC = N->getOperand(0);
663 
664   if ((SetCC.getOpcode() != ISD::SETCC) ||
665       !SetCC.getOperand(0).getValueType().isInteger())
666     return SDValue();
667 
668   SDValue False = N->getOperand(2);
669   EVT FalseTy = False.getValueType();
670 
671   if (!FalseTy.isInteger())
672     return SDValue();
673 
674   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(False);
675 
676   // If the RHS (False) is 0, we swap the order of the operands
677   // of ISD::SELECT (obviously also inverting the condition) so that we can
678   // take advantage of conditional moves using the $0 register.
679   // Example:
680   //   return (a != 0) ? x : 0;
681   //     load $reg, x
682   //     movz $reg, $0, a
683   if (!FalseC)
684     return SDValue();
685 
686   const SDLoc DL(N);
687 
688   if (!FalseC->getZExtValue()) {
689     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
690     SDValue True = N->getOperand(1);
691 
692     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
693                          SetCC.getOperand(1),
694                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
695 
696     return DAG.getNode(ISD::SELECT, DL, FalseTy, SetCC, False, True);
697   }
698 
699   // If both operands are integer constants there's a possibility that we
700   // can do some interesting optimizations.
701   SDValue True = N->getOperand(1);
702   ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(True);
703 
704   if (!TrueC || !True.getValueType().isInteger())
705     return SDValue();
706 
707   // We'll also ignore MVT::i64 operands as this optimizations proves
708   // to be ineffective because of the required sign extensions as the result
709   // of a SETCC operator is always MVT::i32 for non-vector types.
710   if (True.getValueType() == MVT::i64)
711     return SDValue();
712 
713   int64_t Diff = TrueC->getSExtValue() - FalseC->getSExtValue();
714 
715   // 1)  (a < x) ? y : y-1
716   //  slti $reg1, a, x
717   //  addiu $reg2, $reg1, y-1
718   if (Diff == 1)
719     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, False);
720 
721   // 2)  (a < x) ? y-1 : y
722   //  slti $reg1, a, x
723   //  xor $reg1, $reg1, 1
724   //  addiu $reg2, $reg1, y-1
725   if (Diff == -1) {
726     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
727     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
728                          SetCC.getOperand(1),
729                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
730     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, True);
731   }
732 
733   // Could not optimize.
734   return SDValue();
735 }
736 
737 static SDValue performCMovFPCombine(SDNode *N, SelectionDAG &DAG,
738                                     TargetLowering::DAGCombinerInfo &DCI,
739                                     const MipsSubtarget &Subtarget) {
740   if (DCI.isBeforeLegalizeOps())
741     return SDValue();
742 
743   SDValue ValueIfTrue = N->getOperand(0), ValueIfFalse = N->getOperand(2);
744 
745   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(ValueIfFalse);
746   if (!FalseC || FalseC->getZExtValue())
747     return SDValue();
748 
749   // Since RHS (False) is 0, we swap the order of the True/False operands
750   // (obviously also inverting the condition) so that we can
751   // take advantage of conditional moves using the $0 register.
752   // Example:
753   //   return (a != 0) ? x : 0;
754   //     load $reg, x
755   //     movz $reg, $0, a
756   unsigned Opc = (N->getOpcode() == MipsISD::CMovFP_T) ? MipsISD::CMovFP_F :
757                                                          MipsISD::CMovFP_T;
758 
759   SDValue FCC = N->getOperand(1), Glue = N->getOperand(3);
760   return DAG.getNode(Opc, SDLoc(N), ValueIfFalse.getValueType(),
761                      ValueIfFalse, FCC, ValueIfTrue, Glue);
762 }
763 
764 static SDValue performANDCombine(SDNode *N, SelectionDAG &DAG,
765                                  TargetLowering::DAGCombinerInfo &DCI,
766                                  const MipsSubtarget &Subtarget) {
767   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
768     return SDValue();
769 
770   SDValue FirstOperand = N->getOperand(0);
771   unsigned FirstOperandOpc = FirstOperand.getOpcode();
772   SDValue Mask = N->getOperand(1);
773   EVT ValTy = N->getValueType(0);
774   SDLoc DL(N);
775 
776   uint64_t Pos = 0;
777   unsigned SMPos, SMSize;
778   ConstantSDNode *CN;
779   SDValue NewOperand;
780   unsigned Opc;
781 
782   // Op's second operand must be a shifted mask.
783   if (!(CN = dyn_cast<ConstantSDNode>(Mask)) ||
784       !isShiftedMask_64(CN->getZExtValue(), SMPos, SMSize))
785     return SDValue();
786 
787   if (FirstOperandOpc == ISD::SRA || FirstOperandOpc == ISD::SRL) {
788     // Pattern match EXT.
789     //  $dst = and ((sra or srl) $src , pos), (2**size - 1)
790     //  => ext $dst, $src, pos, size
791 
792     // The second operand of the shift must be an immediate.
793     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
794       return SDValue();
795 
796     Pos = CN->getZExtValue();
797 
798     // Return if the shifted mask does not start at bit 0 or the sum of its size
799     // and Pos exceeds the word's size.
800     if (SMPos != 0 || Pos + SMSize > ValTy.getSizeInBits())
801       return SDValue();
802 
803     Opc = MipsISD::Ext;
804     NewOperand = FirstOperand.getOperand(0);
805   } else if (FirstOperandOpc == ISD::SHL && Subtarget.hasCnMips()) {
806     // Pattern match CINS.
807     //  $dst = and (shl $src , pos), mask
808     //  => cins $dst, $src, pos, size
809     // mask is a shifted mask with consecutive 1's, pos = shift amount,
810     // size = population count.
811 
812     // The second operand of the shift must be an immediate.
813     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
814       return SDValue();
815 
816     Pos = CN->getZExtValue();
817 
818     if (SMPos != Pos || Pos >= ValTy.getSizeInBits() || SMSize >= 32 ||
819         Pos + SMSize > ValTy.getSizeInBits())
820       return SDValue();
821 
822     NewOperand = FirstOperand.getOperand(0);
823     // SMSize is 'location' (position) in this case, not size.
824     SMSize--;
825     Opc = MipsISD::CIns;
826   } else {
827     // Pattern match EXT.
828     //  $dst = and $src, (2**size - 1) , if size > 16
829     //  => ext $dst, $src, pos, size , pos = 0
830 
831     // If the mask is <= 0xffff, andi can be used instead.
832     if (CN->getZExtValue() <= 0xffff)
833       return SDValue();
834 
835     // Return if the mask doesn't start at position 0.
836     if (SMPos)
837       return SDValue();
838 
839     Opc = MipsISD::Ext;
840     NewOperand = FirstOperand;
841   }
842   return DAG.getNode(Opc, DL, ValTy, NewOperand,
843                      DAG.getConstant(Pos, DL, MVT::i32),
844                      DAG.getConstant(SMSize, DL, MVT::i32));
845 }
846 
847 static SDValue performORCombine(SDNode *N, SelectionDAG &DAG,
848                                 TargetLowering::DAGCombinerInfo &DCI,
849                                 const MipsSubtarget &Subtarget) {
850   // Pattern match INS.
851   //  $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1),
852   //  where mask1 = (2**size - 1) << pos, mask0 = ~mask1
853   //  => ins $dst, $src, size, pos, $src1
854   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
855     return SDValue();
856 
857   SDValue And0 = N->getOperand(0), And1 = N->getOperand(1);
858   unsigned SMPos0, SMSize0, SMPos1, SMSize1;
859   ConstantSDNode *CN, *CN1;
860 
861   // See if Op's first operand matches (and $src1 , mask0).
862   if (And0.getOpcode() != ISD::AND)
863     return SDValue();
864 
865   if (!(CN = dyn_cast<ConstantSDNode>(And0.getOperand(1))) ||
866       !isShiftedMask_64(~CN->getSExtValue(), SMPos0, SMSize0))
867     return SDValue();
868 
869   // See if Op's second operand matches (and (shl $src, pos), mask1).
870   if (And1.getOpcode() == ISD::AND &&
871       And1.getOperand(0).getOpcode() == ISD::SHL) {
872 
873     if (!(CN = dyn_cast<ConstantSDNode>(And1.getOperand(1))) ||
874         !isShiftedMask_64(CN->getZExtValue(), SMPos1, SMSize1))
875       return SDValue();
876 
877     // The shift masks must have the same position and size.
878     if (SMPos0 != SMPos1 || SMSize0 != SMSize1)
879       return SDValue();
880 
881     SDValue Shl = And1.getOperand(0);
882 
883     if (!(CN = dyn_cast<ConstantSDNode>(Shl.getOperand(1))))
884       return SDValue();
885 
886     unsigned Shamt = CN->getZExtValue();
887 
888     // Return if the shift amount and the first bit position of mask are not the
889     // same.
890     EVT ValTy = N->getValueType(0);
891     if ((Shamt != SMPos0) || (SMPos0 + SMSize0 > ValTy.getSizeInBits()))
892       return SDValue();
893 
894     SDLoc DL(N);
895     return DAG.getNode(MipsISD::Ins, DL, ValTy, Shl.getOperand(0),
896                        DAG.getConstant(SMPos0, DL, MVT::i32),
897                        DAG.getConstant(SMSize0, DL, MVT::i32),
898                        And0.getOperand(0));
899   } else {
900     // Pattern match DINS.
901     //  $dst = or (and $src, mask0), mask1
902     //  where mask0 = ((1 << SMSize0) -1) << SMPos0
903     //  => dins $dst, $src, pos, size
904     if (~CN->getSExtValue() == ((((int64_t)1 << SMSize0) - 1) << SMPos0) &&
905         ((SMSize0 + SMPos0 <= 64 && Subtarget.hasMips64r2()) ||
906          (SMSize0 + SMPos0 <= 32))) {
907       // Check if AND instruction has constant as argument
908       bool isConstCase = And1.getOpcode() != ISD::AND;
909       if (And1.getOpcode() == ISD::AND) {
910         if (!(CN1 = dyn_cast<ConstantSDNode>(And1->getOperand(1))))
911           return SDValue();
912       } else {
913         if (!(CN1 = dyn_cast<ConstantSDNode>(N->getOperand(1))))
914           return SDValue();
915       }
916       // Don't generate INS if constant OR operand doesn't fit into bits
917       // cleared by constant AND operand.
918       if (CN->getSExtValue() & CN1->getSExtValue())
919         return SDValue();
920 
921       SDLoc DL(N);
922       EVT ValTy = N->getOperand(0)->getValueType(0);
923       SDValue Const1;
924       SDValue SrlX;
925       if (!isConstCase) {
926         Const1 = DAG.getConstant(SMPos0, DL, MVT::i32);
927         SrlX = DAG.getNode(ISD::SRL, DL, And1->getValueType(0), And1, Const1);
928       }
929       return DAG.getNode(
930           MipsISD::Ins, DL, N->getValueType(0),
931           isConstCase
932               ? DAG.getConstant(CN1->getSExtValue() >> SMPos0, DL, ValTy)
933               : SrlX,
934           DAG.getConstant(SMPos0, DL, MVT::i32),
935           DAG.getConstant(ValTy.getSizeInBits() / 8 < 8 ? SMSize0 & 31
936                                                         : SMSize0,
937                           DL, MVT::i32),
938           And0->getOperand(0));
939 
940     }
941     return SDValue();
942   }
943 }
944 
945 static SDValue performMADD_MSUBCombine(SDNode *ROOTNode, SelectionDAG &CurDAG,
946                                        const MipsSubtarget &Subtarget) {
947   // ROOTNode must have a multiplication as an operand for the match to be
948   // successful.
949   if (ROOTNode->getOperand(0).getOpcode() != ISD::MUL &&
950       ROOTNode->getOperand(1).getOpcode() != ISD::MUL)
951     return SDValue();
952 
953   // In the case where we have a multiplication as the left operand of
954   // of a subtraction, we can't combine into a MipsISD::MSub node as the
955   // the instruction definition of msub(u) places the multiplication on
956   // on the right.
957   if (ROOTNode->getOpcode() == ISD::SUB &&
958       ROOTNode->getOperand(0).getOpcode() == ISD::MUL)
959     return SDValue();
960 
961   // We don't handle vector types here.
962   if (ROOTNode->getValueType(0).isVector())
963     return SDValue();
964 
965   // For MIPS64, madd / msub instructions are inefficent to use with 64 bit
966   // arithmetic. E.g.
967   // (add (mul a b) c) =>
968   //   let res = (madd (mthi (drotr c 32))x(mtlo c) a b) in
969   //   MIPS64:   (or (dsll (mfhi res) 32) (dsrl (dsll (mflo res) 32) 32)
970   //   or
971   //   MIPS64R2: (dins (mflo res) (mfhi res) 32 32)
972   //
973   // The overhead of setting up the Hi/Lo registers and reassembling the
974   // result makes this a dubious optimzation for MIPS64. The core of the
975   // problem is that Hi/Lo contain the upper and lower 32 bits of the
976   // operand and result.
977   //
978   // It requires a chain of 4 add/mul for MIPS64R2 to get better code
979   // density than doing it naively, 5 for MIPS64. Additionally, using
980   // madd/msub on MIPS64 requires the operands actually be 32 bit sign
981   // extended operands, not true 64 bit values.
982   //
983   // FIXME: For the moment, disable this completely for MIPS64.
984   if (Subtarget.hasMips64())
985     return SDValue();
986 
987   SDValue Mult = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
988                      ? ROOTNode->getOperand(0)
989                      : ROOTNode->getOperand(1);
990 
991   SDValue AddOperand = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
992                      ? ROOTNode->getOperand(1)
993                      : ROOTNode->getOperand(0);
994 
995   // Transform this to a MADD only if the user of this node is the add.
996   // If there are other users of the mul, this function returns here.
997   if (!Mult.hasOneUse())
998     return SDValue();
999 
1000   // maddu and madd are unusual instructions in that on MIPS64 bits 63..31
1001   // must be in canonical form, i.e. sign extended. For MIPS32, the operands
1002   // of the multiply must have 32 or more sign bits, otherwise we cannot
1003   // perform this optimization. We have to check this here as we're performing
1004   // this optimization pre-legalization.
1005   SDValue MultLHS = Mult->getOperand(0);
1006   SDValue MultRHS = Mult->getOperand(1);
1007 
1008   bool IsSigned = MultLHS->getOpcode() == ISD::SIGN_EXTEND &&
1009                   MultRHS->getOpcode() == ISD::SIGN_EXTEND;
1010   bool IsUnsigned = MultLHS->getOpcode() == ISD::ZERO_EXTEND &&
1011                     MultRHS->getOpcode() == ISD::ZERO_EXTEND;
1012 
1013   if (!IsSigned && !IsUnsigned)
1014     return SDValue();
1015 
1016   // Initialize accumulator.
1017   SDLoc DL(ROOTNode);
1018   SDValue TopHalf;
1019   SDValue BottomHalf;
1020   BottomHalf = CurDAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, AddOperand,
1021                               CurDAG.getIntPtrConstant(0, DL));
1022 
1023   TopHalf = CurDAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, AddOperand,
1024                            CurDAG.getIntPtrConstant(1, DL));
1025   SDValue ACCIn = CurDAG.getNode(MipsISD::MTLOHI, DL, MVT::Untyped,
1026                                   BottomHalf,
1027                                   TopHalf);
1028 
1029   // Create MipsMAdd(u) / MipsMSub(u) node.
1030   bool IsAdd = ROOTNode->getOpcode() == ISD::ADD;
1031   unsigned Opcode = IsAdd ? (IsUnsigned ? MipsISD::MAddu : MipsISD::MAdd)
1032                           : (IsUnsigned ? MipsISD::MSubu : MipsISD::MSub);
1033   SDValue MAddOps[3] = {
1034       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(0)),
1035       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(1)), ACCIn};
1036   EVT VTs[2] = {MVT::i32, MVT::i32};
1037   SDValue MAdd = CurDAG.getNode(Opcode, DL, VTs, MAddOps);
1038 
1039   SDValue ResLo = CurDAG.getNode(MipsISD::MFLO, DL, MVT::i32, MAdd);
1040   SDValue ResHi = CurDAG.getNode(MipsISD::MFHI, DL, MVT::i32, MAdd);
1041   SDValue Combined =
1042       CurDAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, ResLo, ResHi);
1043   return Combined;
1044 }
1045 
1046 static SDValue performSUBCombine(SDNode *N, SelectionDAG &DAG,
1047                                  TargetLowering::DAGCombinerInfo &DCI,
1048                                  const MipsSubtarget &Subtarget) {
1049   // (sub v0 (mul v1, v2)) => (msub v1, v2, v0)
1050   if (DCI.isBeforeLegalizeOps()) {
1051     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1052         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1053       return performMADD_MSUBCombine(N, DAG, Subtarget);
1054 
1055     return SDValue();
1056   }
1057 
1058   return SDValue();
1059 }
1060 
1061 static SDValue performADDCombine(SDNode *N, SelectionDAG &DAG,
1062                                  TargetLowering::DAGCombinerInfo &DCI,
1063                                  const MipsSubtarget &Subtarget) {
1064   // (add v0 (mul v1, v2)) => (madd v1, v2, v0)
1065   if (DCI.isBeforeLegalizeOps()) {
1066     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1067         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1068       return performMADD_MSUBCombine(N, DAG, Subtarget);
1069 
1070     return SDValue();
1071   }
1072 
1073   // (add v0, (add v1, abs_lo(tjt))) => (add (add v0, v1), abs_lo(tjt))
1074   SDValue Add = N->getOperand(1);
1075 
1076   if (Add.getOpcode() != ISD::ADD)
1077     return SDValue();
1078 
1079   SDValue Lo = Add.getOperand(1);
1080 
1081   if ((Lo.getOpcode() != MipsISD::Lo) ||
1082       (Lo.getOperand(0).getOpcode() != ISD::TargetJumpTable))
1083     return SDValue();
1084 
1085   EVT ValTy = N->getValueType(0);
1086   SDLoc DL(N);
1087 
1088   SDValue Add1 = DAG.getNode(ISD::ADD, DL, ValTy, N->getOperand(0),
1089                              Add.getOperand(0));
1090   return DAG.getNode(ISD::ADD, DL, ValTy, Add1, Lo);
1091 }
1092 
1093 static SDValue performSHLCombine(SDNode *N, SelectionDAG &DAG,
1094                                  TargetLowering::DAGCombinerInfo &DCI,
1095                                  const MipsSubtarget &Subtarget) {
1096   // Pattern match CINS.
1097   //  $dst = shl (and $src , imm), pos
1098   //  => cins $dst, $src, pos, size
1099 
1100   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasCnMips())
1101     return SDValue();
1102 
1103   SDValue FirstOperand = N->getOperand(0);
1104   unsigned FirstOperandOpc = FirstOperand.getOpcode();
1105   SDValue SecondOperand = N->getOperand(1);
1106   EVT ValTy = N->getValueType(0);
1107   SDLoc DL(N);
1108 
1109   uint64_t Pos = 0;
1110   unsigned SMPos, SMSize;
1111   ConstantSDNode *CN;
1112   SDValue NewOperand;
1113 
1114   // The second operand of the shift must be an immediate.
1115   if (!(CN = dyn_cast<ConstantSDNode>(SecondOperand)))
1116     return SDValue();
1117 
1118   Pos = CN->getZExtValue();
1119 
1120   if (Pos >= ValTy.getSizeInBits())
1121     return SDValue();
1122 
1123   if (FirstOperandOpc != ISD::AND)
1124     return SDValue();
1125 
1126   // AND's second operand must be a shifted mask.
1127   if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))) ||
1128       !isShiftedMask_64(CN->getZExtValue(), SMPos, SMSize))
1129     return SDValue();
1130 
1131   // Return if the shifted mask does not start at bit 0 or the sum of its size
1132   // and Pos exceeds the word's size.
1133   if (SMPos != 0 || SMSize > 32 || Pos + SMSize > ValTy.getSizeInBits())
1134     return SDValue();
1135 
1136   NewOperand = FirstOperand.getOperand(0);
1137   // SMSize is 'location' (position) in this case, not size.
1138   SMSize--;
1139 
1140   return DAG.getNode(MipsISD::CIns, DL, ValTy, NewOperand,
1141                      DAG.getConstant(Pos, DL, MVT::i32),
1142                      DAG.getConstant(SMSize, DL, MVT::i32));
1143 }
1144 
1145 SDValue  MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI)
1146   const {
1147   SelectionDAG &DAG = DCI.DAG;
1148   unsigned Opc = N->getOpcode();
1149 
1150   switch (Opc) {
1151   default: break;
1152   case ISD::SDIVREM:
1153   case ISD::UDIVREM:
1154     return performDivRemCombine(N, DAG, DCI, Subtarget);
1155   case ISD::SELECT:
1156     return performSELECTCombine(N, DAG, DCI, Subtarget);
1157   case MipsISD::CMovFP_F:
1158   case MipsISD::CMovFP_T:
1159     return performCMovFPCombine(N, DAG, DCI, Subtarget);
1160   case ISD::AND:
1161     return performANDCombine(N, DAG, DCI, Subtarget);
1162   case ISD::OR:
1163     return performORCombine(N, DAG, DCI, Subtarget);
1164   case ISD::ADD:
1165     return performADDCombine(N, DAG, DCI, Subtarget);
1166   case ISD::SHL:
1167     return performSHLCombine(N, DAG, DCI, Subtarget);
1168   case ISD::SUB:
1169     return performSUBCombine(N, DAG, DCI, Subtarget);
1170   }
1171 
1172   return SDValue();
1173 }
1174 
1175 bool MipsTargetLowering::isCheapToSpeculateCttz() const {
1176   return Subtarget.hasMips32();
1177 }
1178 
1179 bool MipsTargetLowering::isCheapToSpeculateCtlz() const {
1180   return Subtarget.hasMips32();
1181 }
1182 
1183 bool MipsTargetLowering::hasBitTest(SDValue X, SDValue Y) const {
1184   // We can use ANDI+SLTIU as a bit test. Y contains the bit position.
1185   // For MIPSR2 or later, we may be able to use the `ext` instruction or its'
1186   // double-word variants.
1187   if (auto *C = dyn_cast<ConstantSDNode>(Y))
1188     return C->getAPIntValue().ule(15);
1189 
1190   return false;
1191 }
1192 
1193 bool MipsTargetLowering::shouldFoldConstantShiftPairToMask(
1194     const SDNode *N, CombineLevel Level) const {
1195   if (N->getOperand(0).getValueType().isVector())
1196     return false;
1197   return true;
1198 }
1199 
1200 void
1201 MipsTargetLowering::ReplaceNodeResults(SDNode *N,
1202                                        SmallVectorImpl<SDValue> &Results,
1203                                        SelectionDAG &DAG) const {
1204   return LowerOperationWrapper(N, Results, DAG);
1205 }
1206 
1207 SDValue MipsTargetLowering::
1208 LowerOperation(SDValue Op, SelectionDAG &DAG) const
1209 {
1210   switch (Op.getOpcode())
1211   {
1212   case ISD::BRCOND:             return lowerBRCOND(Op, DAG);
1213   case ISD::ConstantPool:       return lowerConstantPool(Op, DAG);
1214   case ISD::GlobalAddress:      return lowerGlobalAddress(Op, DAG);
1215   case ISD::BlockAddress:       return lowerBlockAddress(Op, DAG);
1216   case ISD::GlobalTLSAddress:   return lowerGlobalTLSAddress(Op, DAG);
1217   case ISD::JumpTable:          return lowerJumpTable(Op, DAG);
1218   case ISD::SELECT:             return lowerSELECT(Op, DAG);
1219   case ISD::SETCC:              return lowerSETCC(Op, DAG);
1220   case ISD::VASTART:            return lowerVASTART(Op, DAG);
1221   case ISD::VAARG:              return lowerVAARG(Op, DAG);
1222   case ISD::FCOPYSIGN:          return lowerFCOPYSIGN(Op, DAG);
1223   case ISD::FABS:               return lowerFABS(Op, DAG);
1224   case ISD::FRAMEADDR:          return lowerFRAMEADDR(Op, DAG);
1225   case ISD::RETURNADDR:         return lowerRETURNADDR(Op, DAG);
1226   case ISD::EH_RETURN:          return lowerEH_RETURN(Op, DAG);
1227   case ISD::ATOMIC_FENCE:       return lowerATOMIC_FENCE(Op, DAG);
1228   case ISD::SHL_PARTS:          return lowerShiftLeftParts(Op, DAG);
1229   case ISD::SRA_PARTS:          return lowerShiftRightParts(Op, DAG, true);
1230   case ISD::SRL_PARTS:          return lowerShiftRightParts(Op, DAG, false);
1231   case ISD::LOAD:               return lowerLOAD(Op, DAG);
1232   case ISD::STORE:              return lowerSTORE(Op, DAG);
1233   case ISD::EH_DWARF_CFA:       return lowerEH_DWARF_CFA(Op, DAG);
1234   case ISD::FP_TO_SINT:         return lowerFP_TO_SINT(Op, DAG);
1235   }
1236   return SDValue();
1237 }
1238 
1239 //===----------------------------------------------------------------------===//
1240 //  Lower helper functions
1241 //===----------------------------------------------------------------------===//
1242 
1243 // addLiveIn - This helper function adds the specified physical register to the
1244 // MachineFunction as a live in value.  It also creates a corresponding
1245 // virtual register for it.
1246 static unsigned
1247 addLiveIn(MachineFunction &MF, unsigned PReg, const TargetRegisterClass *RC)
1248 {
1249   Register VReg = MF.getRegInfo().createVirtualRegister(RC);
1250   MF.getRegInfo().addLiveIn(PReg, VReg);
1251   return VReg;
1252 }
1253 
1254 static MachineBasicBlock *insertDivByZeroTrap(MachineInstr &MI,
1255                                               MachineBasicBlock &MBB,
1256                                               const TargetInstrInfo &TII,
1257                                               bool Is64Bit, bool IsMicroMips) {
1258   if (NoZeroDivCheck)
1259     return &MBB;
1260 
1261   // Insert instruction "teq $divisor_reg, $zero, 7".
1262   MachineBasicBlock::iterator I(MI);
1263   MachineInstrBuilder MIB;
1264   MachineOperand &Divisor = MI.getOperand(2);
1265   MIB = BuildMI(MBB, std::next(I), MI.getDebugLoc(),
1266                 TII.get(IsMicroMips ? Mips::TEQ_MM : Mips::TEQ))
1267             .addReg(Divisor.getReg(), getKillRegState(Divisor.isKill()))
1268             .addReg(Mips::ZERO)
1269             .addImm(7);
1270 
1271   // Use the 32-bit sub-register if this is a 64-bit division.
1272   if (Is64Bit)
1273     MIB->getOperand(0).setSubReg(Mips::sub_32);
1274 
1275   // Clear Divisor's kill flag.
1276   Divisor.setIsKill(false);
1277 
1278   // We would normally delete the original instruction here but in this case
1279   // we only needed to inject an additional instruction rather than replace it.
1280 
1281   return &MBB;
1282 }
1283 
1284 MachineBasicBlock *
1285 MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
1286                                                 MachineBasicBlock *BB) const {
1287   switch (MI.getOpcode()) {
1288   default:
1289     llvm_unreachable("Unexpected instr type to insert");
1290   case Mips::ATOMIC_LOAD_ADD_I8:
1291     return emitAtomicBinaryPartword(MI, BB, 1);
1292   case Mips::ATOMIC_LOAD_ADD_I16:
1293     return emitAtomicBinaryPartword(MI, BB, 2);
1294   case Mips::ATOMIC_LOAD_ADD_I32:
1295     return emitAtomicBinary(MI, BB);
1296   case Mips::ATOMIC_LOAD_ADD_I64:
1297     return emitAtomicBinary(MI, BB);
1298 
1299   case Mips::ATOMIC_LOAD_AND_I8:
1300     return emitAtomicBinaryPartword(MI, BB, 1);
1301   case Mips::ATOMIC_LOAD_AND_I16:
1302     return emitAtomicBinaryPartword(MI, BB, 2);
1303   case Mips::ATOMIC_LOAD_AND_I32:
1304     return emitAtomicBinary(MI, BB);
1305   case Mips::ATOMIC_LOAD_AND_I64:
1306     return emitAtomicBinary(MI, BB);
1307 
1308   case Mips::ATOMIC_LOAD_OR_I8:
1309     return emitAtomicBinaryPartword(MI, BB, 1);
1310   case Mips::ATOMIC_LOAD_OR_I16:
1311     return emitAtomicBinaryPartword(MI, BB, 2);
1312   case Mips::ATOMIC_LOAD_OR_I32:
1313     return emitAtomicBinary(MI, BB);
1314   case Mips::ATOMIC_LOAD_OR_I64:
1315     return emitAtomicBinary(MI, BB);
1316 
1317   case Mips::ATOMIC_LOAD_XOR_I8:
1318     return emitAtomicBinaryPartword(MI, BB, 1);
1319   case Mips::ATOMIC_LOAD_XOR_I16:
1320     return emitAtomicBinaryPartword(MI, BB, 2);
1321   case Mips::ATOMIC_LOAD_XOR_I32:
1322     return emitAtomicBinary(MI, BB);
1323   case Mips::ATOMIC_LOAD_XOR_I64:
1324     return emitAtomicBinary(MI, BB);
1325 
1326   case Mips::ATOMIC_LOAD_NAND_I8:
1327     return emitAtomicBinaryPartword(MI, BB, 1);
1328   case Mips::ATOMIC_LOAD_NAND_I16:
1329     return emitAtomicBinaryPartword(MI, BB, 2);
1330   case Mips::ATOMIC_LOAD_NAND_I32:
1331     return emitAtomicBinary(MI, BB);
1332   case Mips::ATOMIC_LOAD_NAND_I64:
1333     return emitAtomicBinary(MI, BB);
1334 
1335   case Mips::ATOMIC_LOAD_SUB_I8:
1336     return emitAtomicBinaryPartword(MI, BB, 1);
1337   case Mips::ATOMIC_LOAD_SUB_I16:
1338     return emitAtomicBinaryPartword(MI, BB, 2);
1339   case Mips::ATOMIC_LOAD_SUB_I32:
1340     return emitAtomicBinary(MI, BB);
1341   case Mips::ATOMIC_LOAD_SUB_I64:
1342     return emitAtomicBinary(MI, BB);
1343 
1344   case Mips::ATOMIC_SWAP_I8:
1345     return emitAtomicBinaryPartword(MI, BB, 1);
1346   case Mips::ATOMIC_SWAP_I16:
1347     return emitAtomicBinaryPartword(MI, BB, 2);
1348   case Mips::ATOMIC_SWAP_I32:
1349     return emitAtomicBinary(MI, BB);
1350   case Mips::ATOMIC_SWAP_I64:
1351     return emitAtomicBinary(MI, BB);
1352 
1353   case Mips::ATOMIC_CMP_SWAP_I8:
1354     return emitAtomicCmpSwapPartword(MI, BB, 1);
1355   case Mips::ATOMIC_CMP_SWAP_I16:
1356     return emitAtomicCmpSwapPartword(MI, BB, 2);
1357   case Mips::ATOMIC_CMP_SWAP_I32:
1358     return emitAtomicCmpSwap(MI, BB);
1359   case Mips::ATOMIC_CMP_SWAP_I64:
1360     return emitAtomicCmpSwap(MI, BB);
1361 
1362   case Mips::ATOMIC_LOAD_MIN_I8:
1363     return emitAtomicBinaryPartword(MI, BB, 1);
1364   case Mips::ATOMIC_LOAD_MIN_I16:
1365     return emitAtomicBinaryPartword(MI, BB, 2);
1366   case Mips::ATOMIC_LOAD_MIN_I32:
1367     return emitAtomicBinary(MI, BB);
1368   case Mips::ATOMIC_LOAD_MIN_I64:
1369     return emitAtomicBinary(MI, BB);
1370 
1371   case Mips::ATOMIC_LOAD_MAX_I8:
1372     return emitAtomicBinaryPartword(MI, BB, 1);
1373   case Mips::ATOMIC_LOAD_MAX_I16:
1374     return emitAtomicBinaryPartword(MI, BB, 2);
1375   case Mips::ATOMIC_LOAD_MAX_I32:
1376     return emitAtomicBinary(MI, BB);
1377   case Mips::ATOMIC_LOAD_MAX_I64:
1378     return emitAtomicBinary(MI, BB);
1379 
1380   case Mips::ATOMIC_LOAD_UMIN_I8:
1381     return emitAtomicBinaryPartword(MI, BB, 1);
1382   case Mips::ATOMIC_LOAD_UMIN_I16:
1383     return emitAtomicBinaryPartword(MI, BB, 2);
1384   case Mips::ATOMIC_LOAD_UMIN_I32:
1385     return emitAtomicBinary(MI, BB);
1386   case Mips::ATOMIC_LOAD_UMIN_I64:
1387     return emitAtomicBinary(MI, BB);
1388 
1389   case Mips::ATOMIC_LOAD_UMAX_I8:
1390     return emitAtomicBinaryPartword(MI, BB, 1);
1391   case Mips::ATOMIC_LOAD_UMAX_I16:
1392     return emitAtomicBinaryPartword(MI, BB, 2);
1393   case Mips::ATOMIC_LOAD_UMAX_I32:
1394     return emitAtomicBinary(MI, BB);
1395   case Mips::ATOMIC_LOAD_UMAX_I64:
1396     return emitAtomicBinary(MI, BB);
1397 
1398   case Mips::PseudoSDIV:
1399   case Mips::PseudoUDIV:
1400   case Mips::DIV:
1401   case Mips::DIVU:
1402   case Mips::MOD:
1403   case Mips::MODU:
1404     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false,
1405                                false);
1406   case Mips::SDIV_MM_Pseudo:
1407   case Mips::UDIV_MM_Pseudo:
1408   case Mips::SDIV_MM:
1409   case Mips::UDIV_MM:
1410   case Mips::DIV_MMR6:
1411   case Mips::DIVU_MMR6:
1412   case Mips::MOD_MMR6:
1413   case Mips::MODU_MMR6:
1414     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false, true);
1415   case Mips::PseudoDSDIV:
1416   case Mips::PseudoDUDIV:
1417   case Mips::DDIV:
1418   case Mips::DDIVU:
1419   case Mips::DMOD:
1420   case Mips::DMODU:
1421     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, false);
1422 
1423   case Mips::PseudoSELECT_I:
1424   case Mips::PseudoSELECT_I64:
1425   case Mips::PseudoSELECT_S:
1426   case Mips::PseudoSELECT_D32:
1427   case Mips::PseudoSELECT_D64:
1428     return emitPseudoSELECT(MI, BB, false, Mips::BNE);
1429   case Mips::PseudoSELECTFP_F_I:
1430   case Mips::PseudoSELECTFP_F_I64:
1431   case Mips::PseudoSELECTFP_F_S:
1432   case Mips::PseudoSELECTFP_F_D32:
1433   case Mips::PseudoSELECTFP_F_D64:
1434     return emitPseudoSELECT(MI, BB, true, Mips::BC1F);
1435   case Mips::PseudoSELECTFP_T_I:
1436   case Mips::PseudoSELECTFP_T_I64:
1437   case Mips::PseudoSELECTFP_T_S:
1438   case Mips::PseudoSELECTFP_T_D32:
1439   case Mips::PseudoSELECTFP_T_D64:
1440     return emitPseudoSELECT(MI, BB, true, Mips::BC1T);
1441   case Mips::PseudoD_SELECT_I:
1442   case Mips::PseudoD_SELECT_I64:
1443     return emitPseudoD_SELECT(MI, BB);
1444   case Mips::LDR_W:
1445     return emitLDR_W(MI, BB);
1446   case Mips::LDR_D:
1447     return emitLDR_D(MI, BB);
1448   case Mips::STR_W:
1449     return emitSTR_W(MI, BB);
1450   case Mips::STR_D:
1451     return emitSTR_D(MI, BB);
1452   }
1453 }
1454 
1455 // This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and
1456 // Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true)
1457 MachineBasicBlock *
1458 MipsTargetLowering::emitAtomicBinary(MachineInstr &MI,
1459                                      MachineBasicBlock *BB) const {
1460 
1461   MachineFunction *MF = BB->getParent();
1462   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1463   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1464   DebugLoc DL = MI.getDebugLoc();
1465 
1466   unsigned AtomicOp;
1467   bool NeedsAdditionalReg = false;
1468   switch (MI.getOpcode()) {
1469   case Mips::ATOMIC_LOAD_ADD_I32:
1470     AtomicOp = Mips::ATOMIC_LOAD_ADD_I32_POSTRA;
1471     break;
1472   case Mips::ATOMIC_LOAD_SUB_I32:
1473     AtomicOp = Mips::ATOMIC_LOAD_SUB_I32_POSTRA;
1474     break;
1475   case Mips::ATOMIC_LOAD_AND_I32:
1476     AtomicOp = Mips::ATOMIC_LOAD_AND_I32_POSTRA;
1477     break;
1478   case Mips::ATOMIC_LOAD_OR_I32:
1479     AtomicOp = Mips::ATOMIC_LOAD_OR_I32_POSTRA;
1480     break;
1481   case Mips::ATOMIC_LOAD_XOR_I32:
1482     AtomicOp = Mips::ATOMIC_LOAD_XOR_I32_POSTRA;
1483     break;
1484   case Mips::ATOMIC_LOAD_NAND_I32:
1485     AtomicOp = Mips::ATOMIC_LOAD_NAND_I32_POSTRA;
1486     break;
1487   case Mips::ATOMIC_SWAP_I32:
1488     AtomicOp = Mips::ATOMIC_SWAP_I32_POSTRA;
1489     break;
1490   case Mips::ATOMIC_LOAD_ADD_I64:
1491     AtomicOp = Mips::ATOMIC_LOAD_ADD_I64_POSTRA;
1492     break;
1493   case Mips::ATOMIC_LOAD_SUB_I64:
1494     AtomicOp = Mips::ATOMIC_LOAD_SUB_I64_POSTRA;
1495     break;
1496   case Mips::ATOMIC_LOAD_AND_I64:
1497     AtomicOp = Mips::ATOMIC_LOAD_AND_I64_POSTRA;
1498     break;
1499   case Mips::ATOMIC_LOAD_OR_I64:
1500     AtomicOp = Mips::ATOMIC_LOAD_OR_I64_POSTRA;
1501     break;
1502   case Mips::ATOMIC_LOAD_XOR_I64:
1503     AtomicOp = Mips::ATOMIC_LOAD_XOR_I64_POSTRA;
1504     break;
1505   case Mips::ATOMIC_LOAD_NAND_I64:
1506     AtomicOp = Mips::ATOMIC_LOAD_NAND_I64_POSTRA;
1507     break;
1508   case Mips::ATOMIC_SWAP_I64:
1509     AtomicOp = Mips::ATOMIC_SWAP_I64_POSTRA;
1510     break;
1511   case Mips::ATOMIC_LOAD_MIN_I32:
1512     AtomicOp = Mips::ATOMIC_LOAD_MIN_I32_POSTRA;
1513     NeedsAdditionalReg = true;
1514     break;
1515   case Mips::ATOMIC_LOAD_MAX_I32:
1516     AtomicOp = Mips::ATOMIC_LOAD_MAX_I32_POSTRA;
1517     NeedsAdditionalReg = true;
1518     break;
1519   case Mips::ATOMIC_LOAD_UMIN_I32:
1520     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I32_POSTRA;
1521     NeedsAdditionalReg = true;
1522     break;
1523   case Mips::ATOMIC_LOAD_UMAX_I32:
1524     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I32_POSTRA;
1525     NeedsAdditionalReg = true;
1526     break;
1527   case Mips::ATOMIC_LOAD_MIN_I64:
1528     AtomicOp = Mips::ATOMIC_LOAD_MIN_I64_POSTRA;
1529     NeedsAdditionalReg = true;
1530     break;
1531   case Mips::ATOMIC_LOAD_MAX_I64:
1532     AtomicOp = Mips::ATOMIC_LOAD_MAX_I64_POSTRA;
1533     NeedsAdditionalReg = true;
1534     break;
1535   case Mips::ATOMIC_LOAD_UMIN_I64:
1536     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I64_POSTRA;
1537     NeedsAdditionalReg = true;
1538     break;
1539   case Mips::ATOMIC_LOAD_UMAX_I64:
1540     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I64_POSTRA;
1541     NeedsAdditionalReg = true;
1542     break;
1543   default:
1544     llvm_unreachable("Unknown pseudo atomic for replacement!");
1545   }
1546 
1547   Register OldVal = MI.getOperand(0).getReg();
1548   Register Ptr = MI.getOperand(1).getReg();
1549   Register Incr = MI.getOperand(2).getReg();
1550   Register Scratch = RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1551 
1552   MachineBasicBlock::iterator II(MI);
1553 
1554   // The scratch registers here with the EarlyClobber | Define | Implicit
1555   // flags is used to persuade the register allocator and the machine
1556   // verifier to accept the usage of this register. This has to be a real
1557   // register which has an UNDEF value but is dead after the instruction which
1558   // is unique among the registers chosen for the instruction.
1559 
1560   // The EarlyClobber flag has the semantic properties that the operand it is
1561   // attached to is clobbered before the rest of the inputs are read. Hence it
1562   // must be unique among the operands to the instruction.
1563   // The Define flag is needed to coerce the machine verifier that an Undef
1564   // value isn't a problem.
1565   // The Dead flag is needed as the value in scratch isn't used by any other
1566   // instruction. Kill isn't used as Dead is more precise.
1567   // The implicit flag is here due to the interaction between the other flags
1568   // and the machine verifier.
1569 
1570   // For correctness purpose, a new pseudo is introduced here. We need this
1571   // new pseudo, so that FastRegisterAllocator does not see an ll/sc sequence
1572   // that is spread over >1 basic blocks. A register allocator which
1573   // introduces (or any codegen infact) a store, can violate the expectations
1574   // of the hardware.
1575   //
1576   // An atomic read-modify-write sequence starts with a linked load
1577   // instruction and ends with a store conditional instruction. The atomic
1578   // read-modify-write sequence fails if any of the following conditions
1579   // occur between the execution of ll and sc:
1580   //   * A coherent store is completed by another process or coherent I/O
1581   //     module into the block of synchronizable physical memory containing
1582   //     the word. The size and alignment of the block is
1583   //     implementation-dependent.
1584   //   * A coherent store is executed between an LL and SC sequence on the
1585   //     same processor to the block of synchornizable physical memory
1586   //     containing the word.
1587   //
1588 
1589   Register PtrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Ptr));
1590   Register IncrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Incr));
1591 
1592   BuildMI(*BB, II, DL, TII->get(Mips::COPY), IncrCopy).addReg(Incr);
1593   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1594 
1595   MachineInstrBuilder MIB =
1596       BuildMI(*BB, II, DL, TII->get(AtomicOp))
1597           .addReg(OldVal, RegState::Define | RegState::EarlyClobber)
1598           .addReg(PtrCopy)
1599           .addReg(IncrCopy)
1600           .addReg(Scratch, RegState::Define | RegState::EarlyClobber |
1601                                RegState::Implicit | RegState::Dead);
1602   if (NeedsAdditionalReg) {
1603     Register Scratch2 =
1604         RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1605     MIB.addReg(Scratch2, RegState::Define | RegState::EarlyClobber |
1606                              RegState::Implicit | RegState::Dead);
1607   }
1608 
1609   MI.eraseFromParent();
1610 
1611   return BB;
1612 }
1613 
1614 MachineBasicBlock *MipsTargetLowering::emitSignExtendToI32InReg(
1615     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned DstReg,
1616     unsigned SrcReg) const {
1617   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1618   const DebugLoc &DL = MI.getDebugLoc();
1619 
1620   if (Subtarget.hasMips32r2() && Size == 1) {
1621     BuildMI(BB, DL, TII->get(Mips::SEB), DstReg).addReg(SrcReg);
1622     return BB;
1623   }
1624 
1625   if (Subtarget.hasMips32r2() && Size == 2) {
1626     BuildMI(BB, DL, TII->get(Mips::SEH), DstReg).addReg(SrcReg);
1627     return BB;
1628   }
1629 
1630   MachineFunction *MF = BB->getParent();
1631   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1632   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1633   Register ScrReg = RegInfo.createVirtualRegister(RC);
1634 
1635   assert(Size < 32);
1636   int64_t ShiftImm = 32 - (Size * 8);
1637 
1638   BuildMI(BB, DL, TII->get(Mips::SLL), ScrReg).addReg(SrcReg).addImm(ShiftImm);
1639   BuildMI(BB, DL, TII->get(Mips::SRA), DstReg).addReg(ScrReg).addImm(ShiftImm);
1640 
1641   return BB;
1642 }
1643 
1644 MachineBasicBlock *MipsTargetLowering::emitAtomicBinaryPartword(
1645     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1646   assert((Size == 1 || Size == 2) &&
1647          "Unsupported size for EmitAtomicBinaryPartial.");
1648 
1649   MachineFunction *MF = BB->getParent();
1650   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1651   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1652   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1653   const TargetRegisterClass *RCp =
1654     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1655   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1656   DebugLoc DL = MI.getDebugLoc();
1657 
1658   Register Dest = MI.getOperand(0).getReg();
1659   Register Ptr = MI.getOperand(1).getReg();
1660   Register Incr = MI.getOperand(2).getReg();
1661 
1662   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1663   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1664   Register Mask = RegInfo.createVirtualRegister(RC);
1665   Register Mask2 = RegInfo.createVirtualRegister(RC);
1666   Register Incr2 = RegInfo.createVirtualRegister(RC);
1667   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1668   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1669   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1670   Register Scratch = RegInfo.createVirtualRegister(RC);
1671   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1672   Register Scratch3 = RegInfo.createVirtualRegister(RC);
1673 
1674   unsigned AtomicOp = 0;
1675   bool NeedsAdditionalReg = false;
1676   switch (MI.getOpcode()) {
1677   case Mips::ATOMIC_LOAD_NAND_I8:
1678     AtomicOp = Mips::ATOMIC_LOAD_NAND_I8_POSTRA;
1679     break;
1680   case Mips::ATOMIC_LOAD_NAND_I16:
1681     AtomicOp = Mips::ATOMIC_LOAD_NAND_I16_POSTRA;
1682     break;
1683   case Mips::ATOMIC_SWAP_I8:
1684     AtomicOp = Mips::ATOMIC_SWAP_I8_POSTRA;
1685     break;
1686   case Mips::ATOMIC_SWAP_I16:
1687     AtomicOp = Mips::ATOMIC_SWAP_I16_POSTRA;
1688     break;
1689   case Mips::ATOMIC_LOAD_ADD_I8:
1690     AtomicOp = Mips::ATOMIC_LOAD_ADD_I8_POSTRA;
1691     break;
1692   case Mips::ATOMIC_LOAD_ADD_I16:
1693     AtomicOp = Mips::ATOMIC_LOAD_ADD_I16_POSTRA;
1694     break;
1695   case Mips::ATOMIC_LOAD_SUB_I8:
1696     AtomicOp = Mips::ATOMIC_LOAD_SUB_I8_POSTRA;
1697     break;
1698   case Mips::ATOMIC_LOAD_SUB_I16:
1699     AtomicOp = Mips::ATOMIC_LOAD_SUB_I16_POSTRA;
1700     break;
1701   case Mips::ATOMIC_LOAD_AND_I8:
1702     AtomicOp = Mips::ATOMIC_LOAD_AND_I8_POSTRA;
1703     break;
1704   case Mips::ATOMIC_LOAD_AND_I16:
1705     AtomicOp = Mips::ATOMIC_LOAD_AND_I16_POSTRA;
1706     break;
1707   case Mips::ATOMIC_LOAD_OR_I8:
1708     AtomicOp = Mips::ATOMIC_LOAD_OR_I8_POSTRA;
1709     break;
1710   case Mips::ATOMIC_LOAD_OR_I16:
1711     AtomicOp = Mips::ATOMIC_LOAD_OR_I16_POSTRA;
1712     break;
1713   case Mips::ATOMIC_LOAD_XOR_I8:
1714     AtomicOp = Mips::ATOMIC_LOAD_XOR_I8_POSTRA;
1715     break;
1716   case Mips::ATOMIC_LOAD_XOR_I16:
1717     AtomicOp = Mips::ATOMIC_LOAD_XOR_I16_POSTRA;
1718     break;
1719   case Mips::ATOMIC_LOAD_MIN_I8:
1720     AtomicOp = Mips::ATOMIC_LOAD_MIN_I8_POSTRA;
1721     NeedsAdditionalReg = true;
1722     break;
1723   case Mips::ATOMIC_LOAD_MIN_I16:
1724     AtomicOp = Mips::ATOMIC_LOAD_MIN_I16_POSTRA;
1725     NeedsAdditionalReg = true;
1726     break;
1727   case Mips::ATOMIC_LOAD_MAX_I8:
1728     AtomicOp = Mips::ATOMIC_LOAD_MAX_I8_POSTRA;
1729     NeedsAdditionalReg = true;
1730     break;
1731   case Mips::ATOMIC_LOAD_MAX_I16:
1732     AtomicOp = Mips::ATOMIC_LOAD_MAX_I16_POSTRA;
1733     NeedsAdditionalReg = true;
1734     break;
1735   case Mips::ATOMIC_LOAD_UMIN_I8:
1736     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I8_POSTRA;
1737     NeedsAdditionalReg = true;
1738     break;
1739   case Mips::ATOMIC_LOAD_UMIN_I16:
1740     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I16_POSTRA;
1741     NeedsAdditionalReg = true;
1742     break;
1743   case Mips::ATOMIC_LOAD_UMAX_I8:
1744     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I8_POSTRA;
1745     NeedsAdditionalReg = true;
1746     break;
1747   case Mips::ATOMIC_LOAD_UMAX_I16:
1748     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I16_POSTRA;
1749     NeedsAdditionalReg = true;
1750     break;
1751   default:
1752     llvm_unreachable("Unknown subword atomic pseudo for expansion!");
1753   }
1754 
1755   // insert new blocks after the current block
1756   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1757   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1758   MachineFunction::iterator It = ++BB->getIterator();
1759   MF->insert(It, exitMBB);
1760 
1761   // Transfer the remainder of BB and its successor edges to exitMBB.
1762   exitMBB->splice(exitMBB->begin(), BB,
1763                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1764   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1765 
1766   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1767 
1768   //  thisMBB:
1769   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1770   //    and     alignedaddr,ptr,masklsb2
1771   //    andi    ptrlsb2,ptr,3
1772   //    sll     shiftamt,ptrlsb2,3
1773   //    ori     maskupper,$0,255               # 0xff
1774   //    sll     mask,maskupper,shiftamt
1775   //    nor     mask2,$0,mask
1776   //    sll     incr2,incr,shiftamt
1777 
1778   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1779   BuildMI(BB, DL, TII->get(ABI.GetPtrAddiuOp()), MaskLSB2)
1780     .addReg(ABI.GetNullPtr()).addImm(-4);
1781   BuildMI(BB, DL, TII->get(ABI.GetPtrAndOp()), AlignedAddr)
1782     .addReg(Ptr).addReg(MaskLSB2);
1783   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1784       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1785   if (Subtarget.isLittle()) {
1786     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1787   } else {
1788     Register Off = RegInfo.createVirtualRegister(RC);
1789     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1790       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1791     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1792   }
1793   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1794     .addReg(Mips::ZERO).addImm(MaskImm);
1795   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1796     .addReg(MaskUpper).addReg(ShiftAmt);
1797   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1798   BuildMI(BB, DL, TII->get(Mips::SLLV), Incr2).addReg(Incr).addReg(ShiftAmt);
1799 
1800 
1801   // The purposes of the flags on the scratch registers is explained in
1802   // emitAtomicBinary. In summary, we need a scratch register which is going to
1803   // be undef, that is unique among registers chosen for the instruction.
1804 
1805   MachineInstrBuilder MIB =
1806       BuildMI(BB, DL, TII->get(AtomicOp))
1807           .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1808           .addReg(AlignedAddr)
1809           .addReg(Incr2)
1810           .addReg(Mask)
1811           .addReg(Mask2)
1812           .addReg(ShiftAmt)
1813           .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1814                                RegState::Dead | RegState::Implicit)
1815           .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
1816                                 RegState::Dead | RegState::Implicit)
1817           .addReg(Scratch3, RegState::EarlyClobber | RegState::Define |
1818                                 RegState::Dead | RegState::Implicit);
1819   if (NeedsAdditionalReg) {
1820     Register Scratch4 = RegInfo.createVirtualRegister(RC);
1821     MIB.addReg(Scratch4, RegState::EarlyClobber | RegState::Define |
1822                              RegState::Dead | RegState::Implicit);
1823   }
1824 
1825   MI.eraseFromParent(); // The instruction is gone now.
1826 
1827   return exitMBB;
1828 }
1829 
1830 // Lower atomic compare and swap to a pseudo instruction, taking care to
1831 // define a scratch register for the pseudo instruction's expansion. The
1832 // instruction is expanded after the register allocator as to prevent
1833 // the insertion of stores between the linked load and the store conditional.
1834 
1835 MachineBasicBlock *
1836 MipsTargetLowering::emitAtomicCmpSwap(MachineInstr &MI,
1837                                       MachineBasicBlock *BB) const {
1838 
1839   assert((MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ||
1840           MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I64) &&
1841          "Unsupported atomic pseudo for EmitAtomicCmpSwap.");
1842 
1843   const unsigned Size = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ? 4 : 8;
1844 
1845   MachineFunction *MF = BB->getParent();
1846   MachineRegisterInfo &MRI = MF->getRegInfo();
1847   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1848   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1849   DebugLoc DL = MI.getDebugLoc();
1850 
1851   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32
1852                           ? Mips::ATOMIC_CMP_SWAP_I32_POSTRA
1853                           : Mips::ATOMIC_CMP_SWAP_I64_POSTRA;
1854   Register Dest = MI.getOperand(0).getReg();
1855   Register Ptr = MI.getOperand(1).getReg();
1856   Register OldVal = MI.getOperand(2).getReg();
1857   Register NewVal = MI.getOperand(3).getReg();
1858 
1859   Register Scratch = MRI.createVirtualRegister(RC);
1860   MachineBasicBlock::iterator II(MI);
1861 
1862   // We need to create copies of the various registers and kill them at the
1863   // atomic pseudo. If the copies are not made, when the atomic is expanded
1864   // after fast register allocation, the spills will end up outside of the
1865   // blocks that their values are defined in, causing livein errors.
1866 
1867   Register PtrCopy = MRI.createVirtualRegister(MRI.getRegClass(Ptr));
1868   Register OldValCopy = MRI.createVirtualRegister(MRI.getRegClass(OldVal));
1869   Register NewValCopy = MRI.createVirtualRegister(MRI.getRegClass(NewVal));
1870 
1871   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1872   BuildMI(*BB, II, DL, TII->get(Mips::COPY), OldValCopy).addReg(OldVal);
1873   BuildMI(*BB, II, DL, TII->get(Mips::COPY), NewValCopy).addReg(NewVal);
1874 
1875   // The purposes of the flags on the scratch registers is explained in
1876   // emitAtomicBinary. In summary, we need a scratch register which is going to
1877   // be undef, that is unique among registers chosen for the instruction.
1878 
1879   BuildMI(*BB, II, DL, TII->get(AtomicOp))
1880       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1881       .addReg(PtrCopy, RegState::Kill)
1882       .addReg(OldValCopy, RegState::Kill)
1883       .addReg(NewValCopy, RegState::Kill)
1884       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1885                            RegState::Dead | RegState::Implicit);
1886 
1887   MI.eraseFromParent(); // The instruction is gone now.
1888 
1889   return BB;
1890 }
1891 
1892 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwapPartword(
1893     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1894   assert((Size == 1 || Size == 2) &&
1895       "Unsupported size for EmitAtomicCmpSwapPartial.");
1896 
1897   MachineFunction *MF = BB->getParent();
1898   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1899   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1900   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1901   const TargetRegisterClass *RCp =
1902     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1903   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1904   DebugLoc DL = MI.getDebugLoc();
1905 
1906   Register Dest = MI.getOperand(0).getReg();
1907   Register Ptr = MI.getOperand(1).getReg();
1908   Register CmpVal = MI.getOperand(2).getReg();
1909   Register NewVal = MI.getOperand(3).getReg();
1910 
1911   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1912   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1913   Register Mask = RegInfo.createVirtualRegister(RC);
1914   Register Mask2 = RegInfo.createVirtualRegister(RC);
1915   Register ShiftedCmpVal = RegInfo.createVirtualRegister(RC);
1916   Register ShiftedNewVal = RegInfo.createVirtualRegister(RC);
1917   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1918   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1919   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1920   Register MaskedCmpVal = RegInfo.createVirtualRegister(RC);
1921   Register MaskedNewVal = RegInfo.createVirtualRegister(RC);
1922   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I8
1923                           ? Mips::ATOMIC_CMP_SWAP_I8_POSTRA
1924                           : Mips::ATOMIC_CMP_SWAP_I16_POSTRA;
1925 
1926   // The scratch registers here with the EarlyClobber | Define | Dead | Implicit
1927   // flags are used to coerce the register allocator and the machine verifier to
1928   // accept the usage of these registers.
1929   // The EarlyClobber flag has the semantic properties that the operand it is
1930   // attached to is clobbered before the rest of the inputs are read. Hence it
1931   // must be unique among the operands to the instruction.
1932   // The Define flag is needed to coerce the machine verifier that an Undef
1933   // value isn't a problem.
1934   // The Dead flag is needed as the value in scratch isn't used by any other
1935   // instruction. Kill isn't used as Dead is more precise.
1936   Register Scratch = RegInfo.createVirtualRegister(RC);
1937   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1938 
1939   // insert new blocks after the current block
1940   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1941   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1942   MachineFunction::iterator It = ++BB->getIterator();
1943   MF->insert(It, exitMBB);
1944 
1945   // Transfer the remainder of BB and its successor edges to exitMBB.
1946   exitMBB->splice(exitMBB->begin(), BB,
1947                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1948   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1949 
1950   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1951 
1952   //  thisMBB:
1953   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1954   //    and     alignedaddr,ptr,masklsb2
1955   //    andi    ptrlsb2,ptr,3
1956   //    xori    ptrlsb2,ptrlsb2,3              # Only for BE
1957   //    sll     shiftamt,ptrlsb2,3
1958   //    ori     maskupper,$0,255               # 0xff
1959   //    sll     mask,maskupper,shiftamt
1960   //    nor     mask2,$0,mask
1961   //    andi    maskedcmpval,cmpval,255
1962   //    sll     shiftedcmpval,maskedcmpval,shiftamt
1963   //    andi    maskednewval,newval,255
1964   //    sll     shiftednewval,maskednewval,shiftamt
1965   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1966   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::DADDiu : Mips::ADDiu), MaskLSB2)
1967     .addReg(ABI.GetNullPtr()).addImm(-4);
1968   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::AND64 : Mips::AND), AlignedAddr)
1969     .addReg(Ptr).addReg(MaskLSB2);
1970   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1971       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1972   if (Subtarget.isLittle()) {
1973     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1974   } else {
1975     Register Off = RegInfo.createVirtualRegister(RC);
1976     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1977       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1978     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1979   }
1980   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1981     .addReg(Mips::ZERO).addImm(MaskImm);
1982   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1983     .addReg(MaskUpper).addReg(ShiftAmt);
1984   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1985   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedCmpVal)
1986     .addReg(CmpVal).addImm(MaskImm);
1987   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedCmpVal)
1988     .addReg(MaskedCmpVal).addReg(ShiftAmt);
1989   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedNewVal)
1990     .addReg(NewVal).addImm(MaskImm);
1991   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedNewVal)
1992     .addReg(MaskedNewVal).addReg(ShiftAmt);
1993 
1994   // The purposes of the flags on the scratch registers are explained in
1995   // emitAtomicBinary. In summary, we need a scratch register which is going to
1996   // be undef, that is unique among the register chosen for the instruction.
1997 
1998   BuildMI(BB, DL, TII->get(AtomicOp))
1999       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
2000       .addReg(AlignedAddr)
2001       .addReg(Mask)
2002       .addReg(ShiftedCmpVal)
2003       .addReg(Mask2)
2004       .addReg(ShiftedNewVal)
2005       .addReg(ShiftAmt)
2006       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
2007                            RegState::Dead | RegState::Implicit)
2008       .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
2009                             RegState::Dead | RegState::Implicit);
2010 
2011   MI.eraseFromParent(); // The instruction is gone now.
2012 
2013   return exitMBB;
2014 }
2015 
2016 SDValue MipsTargetLowering::lowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
2017   // The first operand is the chain, the second is the condition, the third is
2018   // the block to branch to if the condition is true.
2019   SDValue Chain = Op.getOperand(0);
2020   SDValue Dest = Op.getOperand(2);
2021   SDLoc DL(Op);
2022 
2023   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2024   SDValue CondRes = createFPCmp(DAG, Op.getOperand(1));
2025 
2026   // Return if flag is not set by a floating point comparison.
2027   if (CondRes.getOpcode() != MipsISD::FPCmp)
2028     return Op;
2029 
2030   SDValue CCNode  = CondRes.getOperand(2);
2031   Mips::CondCode CC =
2032     (Mips::CondCode)cast<ConstantSDNode>(CCNode)->getZExtValue();
2033   unsigned Opc = invertFPCondCodeUser(CC) ? Mips::BRANCH_F : Mips::BRANCH_T;
2034   SDValue BrCode = DAG.getConstant(Opc, DL, MVT::i32);
2035   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
2036   return DAG.getNode(MipsISD::FPBrcond, DL, Op.getValueType(), Chain, BrCode,
2037                      FCC0, Dest, CondRes);
2038 }
2039 
2040 SDValue MipsTargetLowering::
2041 lowerSELECT(SDValue Op, SelectionDAG &DAG) const
2042 {
2043   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2044   SDValue Cond = createFPCmp(DAG, Op.getOperand(0));
2045 
2046   // Return if flag is not set by a floating point comparison.
2047   if (Cond.getOpcode() != MipsISD::FPCmp)
2048     return Op;
2049 
2050   return createCMovFP(DAG, Cond, Op.getOperand(1), Op.getOperand(2),
2051                       SDLoc(Op));
2052 }
2053 
2054 SDValue MipsTargetLowering::lowerSETCC(SDValue Op, SelectionDAG &DAG) const {
2055   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2056   SDValue Cond = createFPCmp(DAG, Op);
2057 
2058   assert(Cond.getOpcode() == MipsISD::FPCmp &&
2059          "Floating point operand expected.");
2060 
2061   SDLoc DL(Op);
2062   SDValue True  = DAG.getConstant(1, DL, MVT::i32);
2063   SDValue False = DAG.getConstant(0, DL, MVT::i32);
2064 
2065   return createCMovFP(DAG, Cond, True, False, DL);
2066 }
2067 
2068 SDValue MipsTargetLowering::lowerGlobalAddress(SDValue Op,
2069                                                SelectionDAG &DAG) const {
2070   EVT Ty = Op.getValueType();
2071   GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
2072   const GlobalValue *GV = N->getGlobal();
2073 
2074   if (!isPositionIndependent()) {
2075     const MipsTargetObjectFile *TLOF =
2076         static_cast<const MipsTargetObjectFile *>(
2077             getTargetMachine().getObjFileLowering());
2078     const GlobalObject *GO = GV->getAliaseeObject();
2079     if (GO && TLOF->IsGlobalInSmallSection(GO, getTargetMachine()))
2080       // %gp_rel relocation
2081       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2082 
2083                                 // %hi/%lo relocation
2084     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2085                                 // %highest/%higher/%hi/%lo relocation
2086                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2087   }
2088 
2089   // Every other architecture would use shouldAssumeDSOLocal in here, but
2090   // mips is special.
2091   // * In PIC code mips requires got loads even for local statics!
2092   // * To save on got entries, for local statics the got entry contains the
2093   //   page and an additional add instruction takes care of the low bits.
2094   // * It is legal to access a hidden symbol with a non hidden undefined,
2095   //   so one cannot guarantee that all access to a hidden symbol will know
2096   //   it is hidden.
2097   // * Mips linkers don't support creating a page and a full got entry for
2098   //   the same symbol.
2099   // * Given all that, we have to use a full got entry for hidden symbols :-(
2100   if (GV->hasLocalLinkage())
2101     return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2102 
2103   if (Subtarget.useXGOT())
2104     return getAddrGlobalLargeGOT(
2105         N, SDLoc(N), Ty, DAG, MipsII::MO_GOT_HI16, MipsII::MO_GOT_LO16,
2106         DAG.getEntryNode(),
2107         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2108 
2109   return getAddrGlobal(
2110       N, SDLoc(N), Ty, DAG,
2111       (ABI.IsN32() || ABI.IsN64()) ? MipsII::MO_GOT_DISP : MipsII::MO_GOT,
2112       DAG.getEntryNode(), MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2113 }
2114 
2115 SDValue MipsTargetLowering::lowerBlockAddress(SDValue Op,
2116                                               SelectionDAG &DAG) const {
2117   BlockAddressSDNode *N = cast<BlockAddressSDNode>(Op);
2118   EVT Ty = Op.getValueType();
2119 
2120   if (!isPositionIndependent())
2121     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2122                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2123 
2124   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2125 }
2126 
2127 SDValue MipsTargetLowering::
2128 lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
2129 {
2130   // If the relocation model is PIC, use the General Dynamic TLS Model or
2131   // Local Dynamic TLS model, otherwise use the Initial Exec or
2132   // Local Exec TLS Model.
2133 
2134   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
2135   if (DAG.getTarget().useEmulatedTLS())
2136     return LowerToTLSEmulatedModel(GA, DAG);
2137 
2138   SDLoc DL(GA);
2139   const GlobalValue *GV = GA->getGlobal();
2140   EVT PtrVT = getPointerTy(DAG.getDataLayout());
2141 
2142   TLSModel::Model model = getTargetMachine().getTLSModel(GV);
2143 
2144   if (model == TLSModel::GeneralDynamic || model == TLSModel::LocalDynamic) {
2145     // General Dynamic and Local Dynamic TLS Model.
2146     unsigned Flag = (model == TLSModel::LocalDynamic) ? MipsII::MO_TLSLDM
2147                                                       : MipsII::MO_TLSGD;
2148 
2149     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, Flag);
2150     SDValue Argument = DAG.getNode(MipsISD::Wrapper, DL, PtrVT,
2151                                    getGlobalReg(DAG, PtrVT), TGA);
2152     unsigned PtrSize = PtrVT.getSizeInBits();
2153     IntegerType *PtrTy = Type::getIntNTy(*DAG.getContext(), PtrSize);
2154 
2155     SDValue TlsGetAddr = DAG.getExternalSymbol("__tls_get_addr", PtrVT);
2156 
2157     ArgListTy Args;
2158     ArgListEntry Entry;
2159     Entry.Node = Argument;
2160     Entry.Ty = PtrTy;
2161     Args.push_back(Entry);
2162 
2163     TargetLowering::CallLoweringInfo CLI(DAG);
2164     CLI.setDebugLoc(DL)
2165         .setChain(DAG.getEntryNode())
2166         .setLibCallee(CallingConv::C, PtrTy, TlsGetAddr, std::move(Args));
2167     std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
2168 
2169     SDValue Ret = CallResult.first;
2170 
2171     if (model != TLSModel::LocalDynamic)
2172       return Ret;
2173 
2174     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2175                                                MipsII::MO_DTPREL_HI);
2176     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2177     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2178                                                MipsII::MO_DTPREL_LO);
2179     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2180     SDValue Add = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Ret);
2181     return DAG.getNode(ISD::ADD, DL, PtrVT, Add, Lo);
2182   }
2183 
2184   SDValue Offset;
2185   if (model == TLSModel::InitialExec) {
2186     // Initial Exec TLS Model
2187     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2188                                              MipsII::MO_GOTTPREL);
2189     TGA = DAG.getNode(MipsISD::Wrapper, DL, PtrVT, getGlobalReg(DAG, PtrVT),
2190                       TGA);
2191     Offset =
2192         DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), TGA, MachinePointerInfo());
2193   } else {
2194     // Local Exec TLS Model
2195     assert(model == TLSModel::LocalExec);
2196     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2197                                                MipsII::MO_TPREL_HI);
2198     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2199                                                MipsII::MO_TPREL_LO);
2200     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2201     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2202     Offset = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Lo);
2203   }
2204 
2205   SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, DL, PtrVT);
2206   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadPointer, Offset);
2207 }
2208 
2209 SDValue MipsTargetLowering::
2210 lowerJumpTable(SDValue Op, SelectionDAG &DAG) const
2211 {
2212   JumpTableSDNode *N = cast<JumpTableSDNode>(Op);
2213   EVT Ty = Op.getValueType();
2214 
2215   if (!isPositionIndependent())
2216     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2217                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2218 
2219   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2220 }
2221 
2222 SDValue MipsTargetLowering::
2223 lowerConstantPool(SDValue Op, SelectionDAG &DAG) const
2224 {
2225   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
2226   EVT Ty = Op.getValueType();
2227 
2228   if (!isPositionIndependent()) {
2229     const MipsTargetObjectFile *TLOF =
2230         static_cast<const MipsTargetObjectFile *>(
2231             getTargetMachine().getObjFileLowering());
2232 
2233     if (TLOF->IsConstantInSmallSection(DAG.getDataLayout(), N->getConstVal(),
2234                                        getTargetMachine()))
2235       // %gp_rel relocation
2236       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2237 
2238     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2239                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2240   }
2241 
2242  return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2243 }
2244 
2245 SDValue MipsTargetLowering::lowerVASTART(SDValue Op, SelectionDAG &DAG) const {
2246   MachineFunction &MF = DAG.getMachineFunction();
2247   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
2248 
2249   SDLoc DL(Op);
2250   SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
2251                                  getPointerTy(MF.getDataLayout()));
2252 
2253   // vastart just stores the address of the VarArgsFrameIndex slot into the
2254   // memory location argument.
2255   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
2256   return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
2257                       MachinePointerInfo(SV));
2258 }
2259 
2260 SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
2261   SDNode *Node = Op.getNode();
2262   EVT VT = Node->getValueType(0);
2263   SDValue Chain = Node->getOperand(0);
2264   SDValue VAListPtr = Node->getOperand(1);
2265   const Align Align =
2266       llvm::MaybeAlign(Node->getConstantOperandVal(3)).valueOrOne();
2267   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
2268   SDLoc DL(Node);
2269   unsigned ArgSlotSizeInBytes = (ABI.IsN32() || ABI.IsN64()) ? 8 : 4;
2270 
2271   SDValue VAListLoad = DAG.getLoad(getPointerTy(DAG.getDataLayout()), DL, Chain,
2272                                    VAListPtr, MachinePointerInfo(SV));
2273   SDValue VAList = VAListLoad;
2274 
2275   // Re-align the pointer if necessary.
2276   // It should only ever be necessary for 64-bit types on O32 since the minimum
2277   // argument alignment is the same as the maximum type alignment for N32/N64.
2278   //
2279   // FIXME: We currently align too often. The code generator doesn't notice
2280   //        when the pointer is still aligned from the last va_arg (or pair of
2281   //        va_args for the i64 on O32 case).
2282   if (Align > getMinStackArgumentAlignment()) {
2283     VAList = DAG.getNode(
2284         ISD::ADD, DL, VAList.getValueType(), VAList,
2285         DAG.getConstant(Align.value() - 1, DL, VAList.getValueType()));
2286 
2287     VAList = DAG.getNode(
2288         ISD::AND, DL, VAList.getValueType(), VAList,
2289         DAG.getConstant(-(int64_t)Align.value(), DL, VAList.getValueType()));
2290   }
2291 
2292   // Increment the pointer, VAList, to the next vaarg.
2293   auto &TD = DAG.getDataLayout();
2294   unsigned ArgSizeInBytes =
2295       TD.getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext()));
2296   SDValue Tmp3 =
2297       DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
2298                   DAG.getConstant(alignTo(ArgSizeInBytes, ArgSlotSizeInBytes),
2299                                   DL, VAList.getValueType()));
2300   // Store the incremented VAList to the legalized pointer
2301   Chain = DAG.getStore(VAListLoad.getValue(1), DL, Tmp3, VAListPtr,
2302                        MachinePointerInfo(SV));
2303 
2304   // In big-endian mode we must adjust the pointer when the load size is smaller
2305   // than the argument slot size. We must also reduce the known alignment to
2306   // match. For example in the N64 ABI, we must add 4 bytes to the offset to get
2307   // the correct half of the slot, and reduce the alignment from 8 (slot
2308   // alignment) down to 4 (type alignment).
2309   if (!Subtarget.isLittle() && ArgSizeInBytes < ArgSlotSizeInBytes) {
2310     unsigned Adjustment = ArgSlotSizeInBytes - ArgSizeInBytes;
2311     VAList = DAG.getNode(ISD::ADD, DL, VAListPtr.getValueType(), VAList,
2312                          DAG.getIntPtrConstant(Adjustment, DL));
2313   }
2314   // Load the actual argument out of the pointer VAList
2315   return DAG.getLoad(VT, DL, Chain, VAList, MachinePointerInfo());
2316 }
2317 
2318 static SDValue lowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG,
2319                                 bool HasExtractInsert) {
2320   EVT TyX = Op.getOperand(0).getValueType();
2321   EVT TyY = Op.getOperand(1).getValueType();
2322   SDLoc DL(Op);
2323   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2324   SDValue Const31 = DAG.getConstant(31, DL, MVT::i32);
2325   SDValue Res;
2326 
2327   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2328   // to i32.
2329   SDValue X = (TyX == MVT::f32) ?
2330     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0)) :
2331     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2332                 Const1);
2333   SDValue Y = (TyY == MVT::f32) ?
2334     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(1)) :
2335     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(1),
2336                 Const1);
2337 
2338   if (HasExtractInsert) {
2339     // ext  E, Y, 31, 1  ; extract bit31 of Y
2340     // ins  X, E, 31, 1  ; insert extracted bit at bit31 of X
2341     SDValue E = DAG.getNode(MipsISD::Ext, DL, MVT::i32, Y, Const31, Const1);
2342     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32, E, Const31, Const1, X);
2343   } else {
2344     // sll SllX, X, 1
2345     // srl SrlX, SllX, 1
2346     // srl SrlY, Y, 31
2347     // sll SllY, SrlX, 31
2348     // or  Or, SrlX, SllY
2349     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2350     SDValue SrlX = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2351     SDValue SrlY = DAG.getNode(ISD::SRL, DL, MVT::i32, Y, Const31);
2352     SDValue SllY = DAG.getNode(ISD::SHL, DL, MVT::i32, SrlY, Const31);
2353     Res = DAG.getNode(ISD::OR, DL, MVT::i32, SrlX, SllY);
2354   }
2355 
2356   if (TyX == MVT::f32)
2357     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Res);
2358 
2359   SDValue LowX = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2360                              Op.getOperand(0),
2361                              DAG.getConstant(0, DL, MVT::i32));
2362   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2363 }
2364 
2365 static SDValue lowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG,
2366                                 bool HasExtractInsert) {
2367   unsigned WidthX = Op.getOperand(0).getValueSizeInBits();
2368   unsigned WidthY = Op.getOperand(1).getValueSizeInBits();
2369   EVT TyX = MVT::getIntegerVT(WidthX), TyY = MVT::getIntegerVT(WidthY);
2370   SDLoc DL(Op);
2371   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2372 
2373   // Bitcast to integer nodes.
2374   SDValue X = DAG.getNode(ISD::BITCAST, DL, TyX, Op.getOperand(0));
2375   SDValue Y = DAG.getNode(ISD::BITCAST, DL, TyY, Op.getOperand(1));
2376 
2377   if (HasExtractInsert) {
2378     // ext  E, Y, width(Y) - 1, 1  ; extract bit width(Y)-1 of Y
2379     // ins  X, E, width(X) - 1, 1  ; insert extracted bit at bit width(X)-1 of X
2380     SDValue E = DAG.getNode(MipsISD::Ext, DL, TyY, Y,
2381                             DAG.getConstant(WidthY - 1, DL, MVT::i32), Const1);
2382 
2383     if (WidthX > WidthY)
2384       E = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, E);
2385     else if (WidthY > WidthX)
2386       E = DAG.getNode(ISD::TRUNCATE, DL, TyX, E);
2387 
2388     SDValue I = DAG.getNode(MipsISD::Ins, DL, TyX, E,
2389                             DAG.getConstant(WidthX - 1, DL, MVT::i32), Const1,
2390                             X);
2391     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), I);
2392   }
2393 
2394   // (d)sll SllX, X, 1
2395   // (d)srl SrlX, SllX, 1
2396   // (d)srl SrlY, Y, width(Y)-1
2397   // (d)sll SllY, SrlX, width(Y)-1
2398   // or     Or, SrlX, SllY
2399   SDValue SllX = DAG.getNode(ISD::SHL, DL, TyX, X, Const1);
2400   SDValue SrlX = DAG.getNode(ISD::SRL, DL, TyX, SllX, Const1);
2401   SDValue SrlY = DAG.getNode(ISD::SRL, DL, TyY, Y,
2402                              DAG.getConstant(WidthY - 1, DL, MVT::i32));
2403 
2404   if (WidthX > WidthY)
2405     SrlY = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, SrlY);
2406   else if (WidthY > WidthX)
2407     SrlY = DAG.getNode(ISD::TRUNCATE, DL, TyX, SrlY);
2408 
2409   SDValue SllY = DAG.getNode(ISD::SHL, DL, TyX, SrlY,
2410                              DAG.getConstant(WidthX - 1, DL, MVT::i32));
2411   SDValue Or = DAG.getNode(ISD::OR, DL, TyX, SrlX, SllY);
2412   return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Or);
2413 }
2414 
2415 SDValue
2416 MipsTargetLowering::lowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
2417   if (Subtarget.isGP64bit())
2418     return lowerFCOPYSIGN64(Op, DAG, Subtarget.hasExtractInsert());
2419 
2420   return lowerFCOPYSIGN32(Op, DAG, Subtarget.hasExtractInsert());
2421 }
2422 
2423 SDValue MipsTargetLowering::lowerFABS32(SDValue Op, SelectionDAG &DAG,
2424                                         bool HasExtractInsert) const {
2425   SDLoc DL(Op);
2426   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2427 
2428   if (DAG.getTarget().Options.NoNaNsFPMath || Subtarget.inAbs2008Mode())
2429     return DAG.getNode(MipsISD::FAbs, DL, Op.getValueType(), Op.getOperand(0));
2430 
2431   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2432   // to i32.
2433   SDValue X = (Op.getValueType() == MVT::f32)
2434                   ? DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0))
2435                   : DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2436                                 Op.getOperand(0), Const1);
2437 
2438   // Clear MSB.
2439   if (HasExtractInsert)
2440     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32,
2441                       DAG.getRegister(Mips::ZERO, MVT::i32),
2442                       DAG.getConstant(31, DL, MVT::i32), Const1, X);
2443   else {
2444     // TODO: Provide DAG patterns which transform (and x, cst)
2445     // back to a (shl (srl x (clz cst)) (clz cst)) sequence.
2446     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2447     Res = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2448   }
2449 
2450   if (Op.getValueType() == MVT::f32)
2451     return DAG.getNode(ISD::BITCAST, DL, MVT::f32, Res);
2452 
2453   // FIXME: For mips32r2, the sequence of (BuildPairF64 (ins (ExtractElementF64
2454   // Op 1), $zero, 31 1) (ExtractElementF64 Op 0)) and the Op has one use, we
2455   // should be able to drop the usage of mfc1/mtc1 and rewrite the register in
2456   // place.
2457   SDValue LowX =
2458       DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2459                   DAG.getConstant(0, DL, MVT::i32));
2460   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2461 }
2462 
2463 SDValue MipsTargetLowering::lowerFABS64(SDValue Op, SelectionDAG &DAG,
2464                                         bool HasExtractInsert) const {
2465   SDLoc DL(Op);
2466   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2467 
2468   if (DAG.getTarget().Options.NoNaNsFPMath || Subtarget.inAbs2008Mode())
2469     return DAG.getNode(MipsISD::FAbs, DL, Op.getValueType(), Op.getOperand(0));
2470 
2471   // Bitcast to integer node.
2472   SDValue X = DAG.getNode(ISD::BITCAST, DL, MVT::i64, Op.getOperand(0));
2473 
2474   // Clear MSB.
2475   if (HasExtractInsert)
2476     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i64,
2477                       DAG.getRegister(Mips::ZERO_64, MVT::i64),
2478                       DAG.getConstant(63, DL, MVT::i32), Const1, X);
2479   else {
2480     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i64, X, Const1);
2481     Res = DAG.getNode(ISD::SRL, DL, MVT::i64, SllX, Const1);
2482   }
2483 
2484   return DAG.getNode(ISD::BITCAST, DL, MVT::f64, Res);
2485 }
2486 
2487 SDValue MipsTargetLowering::lowerFABS(SDValue Op, SelectionDAG &DAG) const {
2488   if ((ABI.IsN32() || ABI.IsN64()) && (Op.getValueType() == MVT::f64))
2489     return lowerFABS64(Op, DAG, Subtarget.hasExtractInsert());
2490 
2491   return lowerFABS32(Op, DAG, Subtarget.hasExtractInsert());
2492 }
2493 
2494 SDValue MipsTargetLowering::
2495 lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2496   // check the depth
2497   if (cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() != 0) {
2498     DAG.getContext()->emitError(
2499         "return address can be determined only for current frame");
2500     return SDValue();
2501   }
2502 
2503   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2504   MFI.setFrameAddressIsTaken(true);
2505   EVT VT = Op.getValueType();
2506   SDLoc DL(Op);
2507   SDValue FrameAddr = DAG.getCopyFromReg(
2508       DAG.getEntryNode(), DL, ABI.IsN64() ? Mips::FP_64 : Mips::FP, VT);
2509   return FrameAddr;
2510 }
2511 
2512 SDValue MipsTargetLowering::lowerRETURNADDR(SDValue Op,
2513                                             SelectionDAG &DAG) const {
2514   if (verifyReturnAddressArgumentIsConstant(Op, DAG))
2515     return SDValue();
2516 
2517   // check the depth
2518   if (cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() != 0) {
2519     DAG.getContext()->emitError(
2520         "return address can be determined only for current frame");
2521     return SDValue();
2522   }
2523 
2524   MachineFunction &MF = DAG.getMachineFunction();
2525   MachineFrameInfo &MFI = MF.getFrameInfo();
2526   MVT VT = Op.getSimpleValueType();
2527   unsigned RA = ABI.IsN64() ? Mips::RA_64 : Mips::RA;
2528   MFI.setReturnAddressIsTaken(true);
2529 
2530   // Return RA, which contains the return address. Mark it an implicit live-in.
2531   Register Reg = MF.addLiveIn(RA, getRegClassFor(VT));
2532   return DAG.getCopyFromReg(DAG.getEntryNode(), SDLoc(Op), Reg, VT);
2533 }
2534 
2535 // An EH_RETURN is the result of lowering llvm.eh.return which in turn is
2536 // generated from __builtin_eh_return (offset, handler)
2537 // The effect of this is to adjust the stack pointer by "offset"
2538 // and then branch to "handler".
2539 SDValue MipsTargetLowering::lowerEH_RETURN(SDValue Op, SelectionDAG &DAG)
2540                                                                      const {
2541   MachineFunction &MF = DAG.getMachineFunction();
2542   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
2543 
2544   MipsFI->setCallsEhReturn();
2545   SDValue Chain     = Op.getOperand(0);
2546   SDValue Offset    = Op.getOperand(1);
2547   SDValue Handler   = Op.getOperand(2);
2548   SDLoc DL(Op);
2549   EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2550 
2551   // Store stack offset in V1, store jump target in V0. Glue CopyToReg and
2552   // EH_RETURN nodes, so that instructions are emitted back-to-back.
2553   unsigned OffsetReg = ABI.IsN64() ? Mips::V1_64 : Mips::V1;
2554   unsigned AddrReg = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
2555   Chain = DAG.getCopyToReg(Chain, DL, OffsetReg, Offset, SDValue());
2556   Chain = DAG.getCopyToReg(Chain, DL, AddrReg, Handler, Chain.getValue(1));
2557   return DAG.getNode(MipsISD::EH_RETURN, DL, MVT::Other, Chain,
2558                      DAG.getRegister(OffsetReg, Ty),
2559                      DAG.getRegister(AddrReg, getPointerTy(MF.getDataLayout())),
2560                      Chain.getValue(1));
2561 }
2562 
2563 SDValue MipsTargetLowering::lowerATOMIC_FENCE(SDValue Op,
2564                                               SelectionDAG &DAG) const {
2565   // FIXME: Need pseudo-fence for 'singlethread' fences
2566   // FIXME: Set SType for weaker fences where supported/appropriate.
2567   unsigned SType = 0;
2568   SDLoc DL(Op);
2569   return DAG.getNode(MipsISD::Sync, DL, MVT::Other, Op.getOperand(0),
2570                      DAG.getConstant(SType, DL, MVT::i32));
2571 }
2572 
2573 SDValue MipsTargetLowering::lowerShiftLeftParts(SDValue Op,
2574                                                 SelectionDAG &DAG) const {
2575   SDLoc DL(Op);
2576   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2577 
2578   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2579   SDValue Shamt = Op.getOperand(2);
2580   // if shamt < (VT.bits):
2581   //  lo = (shl lo, shamt)
2582   //  hi = (or (shl hi, shamt) (srl (srl lo, 1), ~shamt))
2583   // else:
2584   //  lo = 0
2585   //  hi = (shl lo, shamt[4:0])
2586   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2587                             DAG.getConstant(-1, DL, MVT::i32));
2588   SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo,
2589                                       DAG.getConstant(1, DL, VT));
2590   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, Not);
2591   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
2592   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2593   SDValue ShiftLeftLo = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
2594   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2595                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2596   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2597                    DAG.getConstant(0, DL, VT), ShiftLeftLo);
2598   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftLeftLo, Or);
2599 
2600   SDValue Ops[2] = {Lo, Hi};
2601   return DAG.getMergeValues(Ops, DL);
2602 }
2603 
2604 SDValue MipsTargetLowering::lowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
2605                                                  bool IsSRA) const {
2606   SDLoc DL(Op);
2607   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2608   SDValue Shamt = Op.getOperand(2);
2609   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2610 
2611   // if shamt < (VT.bits):
2612   //  lo = (or (shl (shl hi, 1), ~shamt) (srl lo, shamt))
2613   //  if isSRA:
2614   //    hi = (sra hi, shamt)
2615   //  else:
2616   //    hi = (srl hi, shamt)
2617   // else:
2618   //  if isSRA:
2619   //   lo = (sra hi, shamt[4:0])
2620   //   hi = (sra hi, 31)
2621   //  else:
2622   //   lo = (srl hi, shamt[4:0])
2623   //   hi = 0
2624   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2625                             DAG.getConstant(-1, DL, MVT::i32));
2626   SDValue ShiftLeft1Hi = DAG.getNode(ISD::SHL, DL, VT, Hi,
2627                                      DAG.getConstant(1, DL, VT));
2628   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, ShiftLeft1Hi, Not);
2629   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
2630   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2631   SDValue ShiftRightHi = DAG.getNode(IsSRA ? ISD::SRA : ISD::SRL,
2632                                      DL, VT, Hi, Shamt);
2633   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2634                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2635   SDValue Ext = DAG.getNode(ISD::SRA, DL, VT, Hi,
2636                             DAG.getConstant(VT.getSizeInBits() - 1, DL, VT));
2637 
2638   if (!(Subtarget.hasMips4() || Subtarget.hasMips32())) {
2639     SDVTList VTList = DAG.getVTList(VT, VT);
2640     return DAG.getNode(Subtarget.isGP64bit() ? Mips::PseudoD_SELECT_I64
2641                                              : Mips::PseudoD_SELECT_I,
2642                        DL, VTList, Cond, ShiftRightHi,
2643                        IsSRA ? Ext : DAG.getConstant(0, DL, VT), Or,
2644                        ShiftRightHi);
2645   }
2646 
2647   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftRightHi, Or);
2648   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2649                    IsSRA ? Ext : DAG.getConstant(0, DL, VT), ShiftRightHi);
2650 
2651   SDValue Ops[2] = {Lo, Hi};
2652   return DAG.getMergeValues(Ops, DL);
2653 }
2654 
2655 static SDValue createLoadLR(unsigned Opc, SelectionDAG &DAG, LoadSDNode *LD,
2656                             SDValue Chain, SDValue Src, unsigned Offset) {
2657   SDValue Ptr = LD->getBasePtr();
2658   EVT VT = LD->getValueType(0), MemVT = LD->getMemoryVT();
2659   EVT BasePtrVT = Ptr.getValueType();
2660   SDLoc DL(LD);
2661   SDVTList VTList = DAG.getVTList(VT, MVT::Other);
2662 
2663   if (Offset)
2664     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2665                       DAG.getConstant(Offset, DL, BasePtrVT));
2666 
2667   SDValue Ops[] = { Chain, Ptr, Src };
2668   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2669                                  LD->getMemOperand());
2670 }
2671 
2672 // Expand an unaligned 32 or 64-bit integer load node.
2673 SDValue MipsTargetLowering::lowerLOAD(SDValue Op, SelectionDAG &DAG) const {
2674   LoadSDNode *LD = cast<LoadSDNode>(Op);
2675   EVT MemVT = LD->getMemoryVT();
2676 
2677   if (Subtarget.systemSupportsUnalignedAccess())
2678     return Op;
2679 
2680   // Return if load is aligned or if MemVT is neither i32 nor i64.
2681   if ((LD->getAlign().value() >= (MemVT.getSizeInBits() / 8)) ||
2682       ((MemVT != MVT::i32) && (MemVT != MVT::i64)))
2683     return SDValue();
2684 
2685   bool IsLittle = Subtarget.isLittle();
2686   EVT VT = Op.getValueType();
2687   ISD::LoadExtType ExtType = LD->getExtensionType();
2688   SDValue Chain = LD->getChain(), Undef = DAG.getUNDEF(VT);
2689 
2690   assert((VT == MVT::i32) || (VT == MVT::i64));
2691 
2692   // Expand
2693   //  (set dst, (i64 (load baseptr)))
2694   // to
2695   //  (set tmp, (ldl (add baseptr, 7), undef))
2696   //  (set dst, (ldr baseptr, tmp))
2697   if ((VT == MVT::i64) && (ExtType == ISD::NON_EXTLOAD)) {
2698     SDValue LDL = createLoadLR(MipsISD::LDL, DAG, LD, Chain, Undef,
2699                                IsLittle ? 7 : 0);
2700     return createLoadLR(MipsISD::LDR, DAG, LD, LDL.getValue(1), LDL,
2701                         IsLittle ? 0 : 7);
2702   }
2703 
2704   SDValue LWL = createLoadLR(MipsISD::LWL, DAG, LD, Chain, Undef,
2705                              IsLittle ? 3 : 0);
2706   SDValue LWR = createLoadLR(MipsISD::LWR, DAG, LD, LWL.getValue(1), LWL,
2707                              IsLittle ? 0 : 3);
2708 
2709   // Expand
2710   //  (set dst, (i32 (load baseptr))) or
2711   //  (set dst, (i64 (sextload baseptr))) or
2712   //  (set dst, (i64 (extload baseptr)))
2713   // to
2714   //  (set tmp, (lwl (add baseptr, 3), undef))
2715   //  (set dst, (lwr baseptr, tmp))
2716   if ((VT == MVT::i32) || (ExtType == ISD::SEXTLOAD) ||
2717       (ExtType == ISD::EXTLOAD))
2718     return LWR;
2719 
2720   assert((VT == MVT::i64) && (ExtType == ISD::ZEXTLOAD));
2721 
2722   // Expand
2723   //  (set dst, (i64 (zextload baseptr)))
2724   // to
2725   //  (set tmp0, (lwl (add baseptr, 3), undef))
2726   //  (set tmp1, (lwr baseptr, tmp0))
2727   //  (set tmp2, (shl tmp1, 32))
2728   //  (set dst, (srl tmp2, 32))
2729   SDLoc DL(LD);
2730   SDValue Const32 = DAG.getConstant(32, DL, MVT::i32);
2731   SDValue SLL = DAG.getNode(ISD::SHL, DL, MVT::i64, LWR, Const32);
2732   SDValue SRL = DAG.getNode(ISD::SRL, DL, MVT::i64, SLL, Const32);
2733   SDValue Ops[] = { SRL, LWR.getValue(1) };
2734   return DAG.getMergeValues(Ops, DL);
2735 }
2736 
2737 static SDValue createStoreLR(unsigned Opc, SelectionDAG &DAG, StoreSDNode *SD,
2738                              SDValue Chain, unsigned Offset) {
2739   SDValue Ptr = SD->getBasePtr(), Value = SD->getValue();
2740   EVT MemVT = SD->getMemoryVT(), BasePtrVT = Ptr.getValueType();
2741   SDLoc DL(SD);
2742   SDVTList VTList = DAG.getVTList(MVT::Other);
2743 
2744   if (Offset)
2745     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2746                       DAG.getConstant(Offset, DL, BasePtrVT));
2747 
2748   SDValue Ops[] = { Chain, Value, Ptr };
2749   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2750                                  SD->getMemOperand());
2751 }
2752 
2753 // Expand an unaligned 32 or 64-bit integer store node.
2754 static SDValue lowerUnalignedIntStore(StoreSDNode *SD, SelectionDAG &DAG,
2755                                       bool IsLittle) {
2756   SDValue Value = SD->getValue(), Chain = SD->getChain();
2757   EVT VT = Value.getValueType();
2758 
2759   // Expand
2760   //  (store val, baseptr) or
2761   //  (truncstore val, baseptr)
2762   // to
2763   //  (swl val, (add baseptr, 3))
2764   //  (swr val, baseptr)
2765   if ((VT == MVT::i32) || SD->isTruncatingStore()) {
2766     SDValue SWL = createStoreLR(MipsISD::SWL, DAG, SD, Chain,
2767                                 IsLittle ? 3 : 0);
2768     return createStoreLR(MipsISD::SWR, DAG, SD, SWL, IsLittle ? 0 : 3);
2769   }
2770 
2771   assert(VT == MVT::i64);
2772 
2773   // Expand
2774   //  (store val, baseptr)
2775   // to
2776   //  (sdl val, (add baseptr, 7))
2777   //  (sdr val, baseptr)
2778   SDValue SDL = createStoreLR(MipsISD::SDL, DAG, SD, Chain, IsLittle ? 7 : 0);
2779   return createStoreLR(MipsISD::SDR, DAG, SD, SDL, IsLittle ? 0 : 7);
2780 }
2781 
2782 // Lower (store (fp_to_sint $fp) $ptr) to (store (TruncIntFP $fp), $ptr).
2783 static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG,
2784                                      bool SingleFloat) {
2785   SDValue Val = SD->getValue();
2786 
2787   if (Val.getOpcode() != ISD::FP_TO_SINT ||
2788       (Val.getValueSizeInBits() > 32 && SingleFloat))
2789     return SDValue();
2790 
2791   EVT FPTy = EVT::getFloatingPointVT(Val.getValueSizeInBits());
2792   SDValue Tr = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Val), FPTy,
2793                            Val.getOperand(0));
2794   return DAG.getStore(SD->getChain(), SDLoc(SD), Tr, SD->getBasePtr(),
2795                       SD->getPointerInfo(), SD->getAlign(),
2796                       SD->getMemOperand()->getFlags());
2797 }
2798 
2799 SDValue MipsTargetLowering::lowerSTORE(SDValue Op, SelectionDAG &DAG) const {
2800   StoreSDNode *SD = cast<StoreSDNode>(Op);
2801   EVT MemVT = SD->getMemoryVT();
2802 
2803   // Lower unaligned integer stores.
2804   if (!Subtarget.systemSupportsUnalignedAccess() &&
2805       (SD->getAlign().value() < (MemVT.getSizeInBits() / 8)) &&
2806       ((MemVT == MVT::i32) || (MemVT == MVT::i64)))
2807     return lowerUnalignedIntStore(SD, DAG, Subtarget.isLittle());
2808 
2809   return lowerFP_TO_SINT_STORE(SD, DAG, Subtarget.isSingleFloat());
2810 }
2811 
2812 SDValue MipsTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
2813                                               SelectionDAG &DAG) const {
2814 
2815   // Return a fixed StackObject with offset 0 which points to the old stack
2816   // pointer.
2817   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2818   EVT ValTy = Op->getValueType(0);
2819   int FI = MFI.CreateFixedObject(Op.getValueSizeInBits() / 8, 0, false);
2820   return DAG.getFrameIndex(FI, ValTy);
2821 }
2822 
2823 SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op,
2824                                             SelectionDAG &DAG) const {
2825   if (Op.getValueSizeInBits() > 32 && Subtarget.isSingleFloat())
2826     return SDValue();
2827 
2828   EVT FPTy = EVT::getFloatingPointVT(Op.getValueSizeInBits());
2829   SDValue Trunc = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Op), FPTy,
2830                               Op.getOperand(0));
2831   return DAG.getNode(ISD::BITCAST, SDLoc(Op), Op.getValueType(), Trunc);
2832 }
2833 
2834 //===----------------------------------------------------------------------===//
2835 //                      Calling Convention Implementation
2836 //===----------------------------------------------------------------------===//
2837 
2838 //===----------------------------------------------------------------------===//
2839 // TODO: Implement a generic logic using tblgen that can support this.
2840 // Mips O32 ABI rules:
2841 // ---
2842 // i32 - Passed in A0, A1, A2, A3 and stack
2843 // f32 - Only passed in f32 registers if no int reg has been used yet to hold
2844 //       an argument. Otherwise, passed in A1, A2, A3 and stack.
2845 // f64 - Only passed in two aliased f32 registers if no int reg has been used
2846 //       yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is
2847 //       not used, it must be shadowed. If only A3 is available, shadow it and
2848 //       go to stack.
2849 // vXiX - Received as scalarized i32s, passed in A0 - A3 and the stack.
2850 // vXf32 - Passed in either a pair of registers {A0, A1}, {A2, A3} or {A0 - A3}
2851 //         with the remainder spilled to the stack.
2852 // vXf64 - Passed in either {A0, A1, A2, A3} or {A2, A3} and in both cases
2853 //         spilling the remainder to the stack.
2854 //
2855 //  For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack.
2856 //===----------------------------------------------------------------------===//
2857 
2858 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2859                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2860                        CCState &State, ArrayRef<MCPhysReg> F64Regs) {
2861   const MipsSubtarget &Subtarget = static_cast<const MipsSubtarget &>(
2862       State.getMachineFunction().getSubtarget());
2863 
2864   static const MCPhysReg IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 };
2865 
2866   const MipsCCState * MipsState = static_cast<MipsCCState *>(&State);
2867 
2868   static const MCPhysReg F32Regs[] = { Mips::F12, Mips::F14 };
2869 
2870   static const MCPhysReg FloatVectorIntRegs[] = { Mips::A0, Mips::A2 };
2871 
2872   // Do not process byval args here.
2873   if (ArgFlags.isByVal())
2874     return true;
2875 
2876   // Promote i8 and i16
2877   if (ArgFlags.isInReg() && !Subtarget.isLittle()) {
2878     if (LocVT == MVT::i8 || LocVT == MVT::i16 || LocVT == MVT::i32) {
2879       LocVT = MVT::i32;
2880       if (ArgFlags.isSExt())
2881         LocInfo = CCValAssign::SExtUpper;
2882       else if (ArgFlags.isZExt())
2883         LocInfo = CCValAssign::ZExtUpper;
2884       else
2885         LocInfo = CCValAssign::AExtUpper;
2886     }
2887   }
2888 
2889   // Promote i8 and i16
2890   if (LocVT == MVT::i8 || LocVT == MVT::i16) {
2891     LocVT = MVT::i32;
2892     if (ArgFlags.isSExt())
2893       LocInfo = CCValAssign::SExt;
2894     else if (ArgFlags.isZExt())
2895       LocInfo = CCValAssign::ZExt;
2896     else
2897       LocInfo = CCValAssign::AExt;
2898   }
2899 
2900   unsigned Reg;
2901 
2902   // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following
2903   // is true: function is vararg, argument is 3rd or higher, there is previous
2904   // argument which is not f32 or f64.
2905   bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1 ||
2906                                 State.getFirstUnallocated(F32Regs) != ValNo;
2907   Align OrigAlign = ArgFlags.getNonZeroOrigAlign();
2908   bool isI64 = (ValVT == MVT::i32 && OrigAlign == Align(8));
2909   bool isVectorFloat = MipsState->WasOriginalArgVectorFloat(ValNo);
2910 
2911   // The MIPS vector ABI for floats passes them in a pair of registers
2912   if (ValVT == MVT::i32 && isVectorFloat) {
2913     // This is the start of an vector that was scalarized into an unknown number
2914     // of components. It doesn't matter how many there are. Allocate one of the
2915     // notional 8 byte aligned registers which map onto the argument stack, and
2916     // shadow the register lost to alignment requirements.
2917     if (ArgFlags.isSplit()) {
2918       Reg = State.AllocateReg(FloatVectorIntRegs);
2919       if (Reg == Mips::A2)
2920         State.AllocateReg(Mips::A1);
2921       else if (Reg == 0)
2922         State.AllocateReg(Mips::A3);
2923     } else {
2924       // If we're an intermediate component of the split, we can just attempt to
2925       // allocate a register directly.
2926       Reg = State.AllocateReg(IntRegs);
2927     }
2928   } else if (ValVT == MVT::i32 ||
2929              (ValVT == MVT::f32 && AllocateFloatsInIntReg)) {
2930     Reg = State.AllocateReg(IntRegs);
2931     // If this is the first part of an i64 arg,
2932     // the allocated register must be either A0 or A2.
2933     if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3))
2934       Reg = State.AllocateReg(IntRegs);
2935     LocVT = MVT::i32;
2936   } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) {
2937     LocVT = MVT::i32;
2938 
2939     // Allocate int register and shadow next int register. If first
2940     // available register is Mips::A1 or Mips::A3, shadow it too.
2941     Reg = State.AllocateReg(IntRegs);
2942     if (Reg == Mips::A1 || Reg == Mips::A3)
2943       Reg = State.AllocateReg(IntRegs);
2944 
2945     if (Reg) {
2946       State.addLoc(
2947           CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2948       MCRegister HiReg = State.AllocateReg(IntRegs);
2949       assert(HiReg);
2950       State.addLoc(
2951           CCValAssign::getCustomReg(ValNo, ValVT, HiReg, LocVT, LocInfo));
2952       return false;
2953     }
2954   } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) {
2955     // we are guaranteed to find an available float register
2956     if (ValVT == MVT::f32) {
2957       Reg = State.AllocateReg(F32Regs);
2958       // Shadow int register
2959       State.AllocateReg(IntRegs);
2960     } else {
2961       Reg = State.AllocateReg(F64Regs);
2962       // Shadow int registers
2963       unsigned Reg2 = State.AllocateReg(IntRegs);
2964       if (Reg2 == Mips::A1 || Reg2 == Mips::A3)
2965         State.AllocateReg(IntRegs);
2966       State.AllocateReg(IntRegs);
2967     }
2968   } else
2969     llvm_unreachable("Cannot handle this ValVT.");
2970 
2971   if (!Reg) {
2972     unsigned Offset = State.AllocateStack(ValVT.getStoreSize(), OrigAlign);
2973     State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
2974   } else
2975     State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2976 
2977   return false;
2978 }
2979 
2980 static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT,
2981                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2982                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2983   static const MCPhysReg F64Regs[] = { Mips::D6, Mips::D7 };
2984 
2985   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2986 }
2987 
2988 static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT,
2989                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2990                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2991   static const MCPhysReg F64Regs[] = { Mips::D12_64, Mips::D14_64 };
2992 
2993   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2994 }
2995 
2996 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2997                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2998                        CCState &State) LLVM_ATTRIBUTE_UNUSED;
2999 
3000 #include "MipsGenCallingConv.inc"
3001 
3002  CCAssignFn *MipsTargetLowering::CCAssignFnForCall() const{
3003    return CC_Mips_FixedArg;
3004  }
3005 
3006  CCAssignFn *MipsTargetLowering::CCAssignFnForReturn() const{
3007    return RetCC_Mips;
3008  }
3009 //===----------------------------------------------------------------------===//
3010 //                  Call Calling Convention Implementation
3011 //===----------------------------------------------------------------------===//
3012 
3013 SDValue MipsTargetLowering::passArgOnStack(SDValue StackPtr, unsigned Offset,
3014                                            SDValue Chain, SDValue Arg,
3015                                            const SDLoc &DL, bool IsTailCall,
3016                                            SelectionDAG &DAG) const {
3017   if (!IsTailCall) {
3018     SDValue PtrOff =
3019         DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr,
3020                     DAG.getIntPtrConstant(Offset, DL));
3021     return DAG.getStore(Chain, DL, Arg, PtrOff, MachinePointerInfo());
3022   }
3023 
3024   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
3025   int FI = MFI.CreateFixedObject(Arg.getValueSizeInBits() / 8, Offset, false);
3026   SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3027   return DAG.getStore(Chain, DL, Arg, FIN, MachinePointerInfo(), MaybeAlign(),
3028                       MachineMemOperand::MOVolatile);
3029 }
3030 
3031 void MipsTargetLowering::
3032 getOpndList(SmallVectorImpl<SDValue> &Ops,
3033             std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
3034             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
3035             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
3036             SDValue Chain) const {
3037   // Insert node "GP copy globalreg" before call to function.
3038   //
3039   // R_MIPS_CALL* operators (emitted when non-internal functions are called
3040   // in PIC mode) allow symbols to be resolved via lazy binding.
3041   // The lazy binding stub requires GP to point to the GOT.
3042   // Note that we don't need GP to point to the GOT for indirect calls
3043   // (when R_MIPS_CALL* is not used for the call) because Mips linker generates
3044   // lazy binding stub for a function only when R_MIPS_CALL* are the only relocs
3045   // used for the function (that is, Mips linker doesn't generate lazy binding
3046   // stub for a function whose address is taken in the program).
3047   if (IsPICCall && !InternalLinkage && IsCallReloc) {
3048     unsigned GPReg = ABI.IsN64() ? Mips::GP_64 : Mips::GP;
3049     EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
3050     RegsToPass.push_back(std::make_pair(GPReg, getGlobalReg(CLI.DAG, Ty)));
3051   }
3052 
3053   // Build a sequence of copy-to-reg nodes chained together with token
3054   // chain and flag operands which copy the outgoing args into registers.
3055   // The InFlag in necessary since all emitted instructions must be
3056   // stuck together.
3057   SDValue InFlag;
3058 
3059   for (auto &R : RegsToPass) {
3060     Chain = CLI.DAG.getCopyToReg(Chain, CLI.DL, R.first, R.second, InFlag);
3061     InFlag = Chain.getValue(1);
3062   }
3063 
3064   // Add argument registers to the end of the list so that they are
3065   // known live into the call.
3066   for (auto &R : RegsToPass)
3067     Ops.push_back(CLI.DAG.getRegister(R.first, R.second.getValueType()));
3068 
3069   // Add a register mask operand representing the call-preserved registers.
3070   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
3071   const uint32_t *Mask =
3072       TRI->getCallPreservedMask(CLI.DAG.getMachineFunction(), CLI.CallConv);
3073   assert(Mask && "Missing call preserved mask for calling convention");
3074   if (Subtarget.inMips16HardFloat()) {
3075     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
3076       StringRef Sym = G->getGlobal()->getName();
3077       Function *F = G->getGlobal()->getParent()->getFunction(Sym);
3078       if (F && F->hasFnAttribute("__Mips16RetHelper")) {
3079         Mask = MipsRegisterInfo::getMips16RetHelperMask();
3080       }
3081     }
3082   }
3083   Ops.push_back(CLI.DAG.getRegisterMask(Mask));
3084 
3085   if (InFlag.getNode())
3086     Ops.push_back(InFlag);
3087 }
3088 
3089 void MipsTargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
3090                                                        SDNode *Node) const {
3091   switch (MI.getOpcode()) {
3092     default:
3093       return;
3094     case Mips::JALR:
3095     case Mips::JALRPseudo:
3096     case Mips::JALR64:
3097     case Mips::JALR64Pseudo:
3098     case Mips::JALR16_MM:
3099     case Mips::JALRC16_MMR6:
3100     case Mips::TAILCALLREG:
3101     case Mips::TAILCALLREG64:
3102     case Mips::TAILCALLR6REG:
3103     case Mips::TAILCALL64R6REG:
3104     case Mips::TAILCALLREG_MM:
3105     case Mips::TAILCALLREG_MMR6: {
3106       if (!EmitJalrReloc ||
3107           Subtarget.inMips16Mode() ||
3108           !isPositionIndependent() ||
3109           Node->getNumOperands() < 1 ||
3110           Node->getOperand(0).getNumOperands() < 2) {
3111         return;
3112       }
3113       // We are after the callee address, set by LowerCall().
3114       // If added to MI, asm printer will emit .reloc R_MIPS_JALR for the
3115       // symbol.
3116       const SDValue TargetAddr = Node->getOperand(0).getOperand(1);
3117       StringRef Sym;
3118       if (const GlobalAddressSDNode *G =
3119               dyn_cast_or_null<const GlobalAddressSDNode>(TargetAddr)) {
3120         // We must not emit the R_MIPS_JALR relocation against data symbols
3121         // since this will cause run-time crashes if the linker replaces the
3122         // call instruction with a relative branch to the data symbol.
3123         if (!isa<Function>(G->getGlobal())) {
3124           LLVM_DEBUG(dbgs() << "Not adding R_MIPS_JALR against data symbol "
3125                             << G->getGlobal()->getName() << "\n");
3126           return;
3127         }
3128         Sym = G->getGlobal()->getName();
3129       }
3130       else if (const ExternalSymbolSDNode *ES =
3131                    dyn_cast_or_null<const ExternalSymbolSDNode>(TargetAddr)) {
3132         Sym = ES->getSymbol();
3133       }
3134 
3135       if (Sym.empty())
3136         return;
3137 
3138       MachineFunction *MF = MI.getParent()->getParent();
3139       MCSymbol *S = MF->getContext().getOrCreateSymbol(Sym);
3140       LLVM_DEBUG(dbgs() << "Adding R_MIPS_JALR against " << Sym << "\n");
3141       MI.addOperand(MachineOperand::CreateMCSymbol(S, MipsII::MO_JALR));
3142     }
3143   }
3144 }
3145 
3146 /// LowerCall - functions arguments are copied from virtual regs to
3147 /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
3148 SDValue
3149 MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
3150                               SmallVectorImpl<SDValue> &InVals) const {
3151   SelectionDAG &DAG                     = CLI.DAG;
3152   SDLoc DL                              = CLI.DL;
3153   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
3154   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
3155   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
3156   SDValue Chain                         = CLI.Chain;
3157   SDValue Callee                        = CLI.Callee;
3158   bool &IsTailCall                      = CLI.IsTailCall;
3159   CallingConv::ID CallConv              = CLI.CallConv;
3160   bool IsVarArg                         = CLI.IsVarArg;
3161 
3162   MachineFunction &MF = DAG.getMachineFunction();
3163   MachineFrameInfo &MFI = MF.getFrameInfo();
3164   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
3165   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
3166   bool IsPIC = isPositionIndependent();
3167 
3168   // Analyze operands of the call, assigning locations to each operand.
3169   SmallVector<CCValAssign, 16> ArgLocs;
3170   MipsCCState CCInfo(
3171       CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext(),
3172       MipsCCState::getSpecialCallingConvForCallee(Callee.getNode(), Subtarget));
3173 
3174   const ExternalSymbolSDNode *ES =
3175       dyn_cast_or_null<const ExternalSymbolSDNode>(Callee.getNode());
3176 
3177   // There is one case where CALLSEQ_START..CALLSEQ_END can be nested, which
3178   // is during the lowering of a call with a byval argument which produces
3179   // a call to memcpy. For the O32 case, this causes the caller to allocate
3180   // stack space for the reserved argument area for the callee, then recursively
3181   // again for the memcpy call. In the NEWABI case, this doesn't occur as those
3182   // ABIs mandate that the callee allocates the reserved argument area. We do
3183   // still produce nested CALLSEQ_START..CALLSEQ_END with zero space though.
3184   //
3185   // If the callee has a byval argument and memcpy is used, we are mandated
3186   // to already have produced a reserved argument area for the callee for O32.
3187   // Therefore, the reserved argument area can be reused for both calls.
3188   //
3189   // Other cases of calling memcpy cannot have a chain with a CALLSEQ_START
3190   // present, as we have yet to hook that node onto the chain.
3191   //
3192   // Hence, the CALLSEQ_START and CALLSEQ_END nodes can be eliminated in this
3193   // case. GCC does a similar trick, in that wherever possible, it calculates
3194   // the maximum out going argument area (including the reserved area), and
3195   // preallocates the stack space on entrance to the caller.
3196   //
3197   // FIXME: We should do the same for efficiency and space.
3198 
3199   // Note: The check on the calling convention below must match
3200   //       MipsABIInfo::GetCalleeAllocdArgSizeInBytes().
3201   bool MemcpyInByVal = ES &&
3202                        StringRef(ES->getSymbol()) == StringRef("memcpy") &&
3203                        CallConv != CallingConv::Fast &&
3204                        Chain.getOpcode() == ISD::CALLSEQ_START;
3205 
3206   // Allocate the reserved argument area. It seems strange to do this from the
3207   // caller side but removing it breaks the frame size calculation.
3208   unsigned ReservedArgArea =
3209       MemcpyInByVal ? 0 : ABI.GetCalleeAllocdArgSizeInBytes(CallConv);
3210   CCInfo.AllocateStack(ReservedArgArea, Align(1));
3211 
3212   CCInfo.AnalyzeCallOperands(Outs, CC_Mips, CLI.getArgs(),
3213                              ES ? ES->getSymbol() : nullptr);
3214 
3215   // Get a count of how many bytes are to be pushed on the stack.
3216   unsigned NextStackOffset = CCInfo.getNextStackOffset();
3217 
3218   // Call site info for function parameters tracking.
3219   MachineFunction::CallSiteInfo CSInfo;
3220 
3221   // Check if it's really possible to do a tail call. Restrict it to functions
3222   // that are part of this compilation unit.
3223   bool InternalLinkage = false;
3224   if (IsTailCall) {
3225     IsTailCall = isEligibleForTailCallOptimization(
3226         CCInfo, NextStackOffset, *MF.getInfo<MipsFunctionInfo>());
3227      if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3228       InternalLinkage = G->getGlobal()->hasInternalLinkage();
3229       IsTailCall &= (InternalLinkage || G->getGlobal()->hasLocalLinkage() ||
3230                      G->getGlobal()->hasPrivateLinkage() ||
3231                      G->getGlobal()->hasHiddenVisibility() ||
3232                      G->getGlobal()->hasProtectedVisibility());
3233      }
3234   }
3235   if (!IsTailCall && CLI.CB && CLI.CB->isMustTailCall())
3236     report_fatal_error("failed to perform tail call elimination on a call "
3237                        "site marked musttail");
3238 
3239   if (IsTailCall)
3240     ++NumTailCalls;
3241 
3242   // Chain is the output chain of the last Load/Store or CopyToReg node.
3243   // ByValChain is the output chain of the last Memcpy node created for copying
3244   // byval arguments to the stack.
3245   unsigned StackAlignment = TFL->getStackAlignment();
3246   NextStackOffset = alignTo(NextStackOffset, StackAlignment);
3247   SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, DL, true);
3248 
3249   if (!(IsTailCall || MemcpyInByVal))
3250     Chain = DAG.getCALLSEQ_START(Chain, NextStackOffset, 0, DL);
3251 
3252   SDValue StackPtr =
3253       DAG.getCopyFromReg(Chain, DL, ABI.IsN64() ? Mips::SP_64 : Mips::SP,
3254                          getPointerTy(DAG.getDataLayout()));
3255 
3256   std::deque<std::pair<unsigned, SDValue>> RegsToPass;
3257   SmallVector<SDValue, 8> MemOpChains;
3258 
3259   CCInfo.rewindByValRegsInfo();
3260 
3261   // Walk the register/memloc assignments, inserting copies/loads.
3262   for (unsigned i = 0, e = ArgLocs.size(), OutIdx = 0; i != e; ++i, ++OutIdx) {
3263     SDValue Arg = OutVals[OutIdx];
3264     CCValAssign &VA = ArgLocs[i];
3265     MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
3266     ISD::ArgFlagsTy Flags = Outs[OutIdx].Flags;
3267     bool UseUpperBits = false;
3268 
3269     // ByVal Arg.
3270     if (Flags.isByVal()) {
3271       unsigned FirstByValReg, LastByValReg;
3272       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3273       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3274 
3275       assert(Flags.getByValSize() &&
3276              "ByVal args of size 0 should have been ignored by front-end.");
3277       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3278       assert(!IsTailCall &&
3279              "Do not tail-call optimize if there is a byval argument.");
3280       passByValArg(Chain, DL, RegsToPass, MemOpChains, StackPtr, MFI, DAG, Arg,
3281                    FirstByValReg, LastByValReg, Flags, Subtarget.isLittle(),
3282                    VA);
3283       CCInfo.nextInRegsParam();
3284       continue;
3285     }
3286 
3287     // Promote the value if needed.
3288     switch (VA.getLocInfo()) {
3289     default:
3290       llvm_unreachable("Unknown loc info!");
3291     case CCValAssign::Full:
3292       if (VA.isRegLoc()) {
3293         if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
3294             (ValVT == MVT::f64 && LocVT == MVT::i64) ||
3295             (ValVT == MVT::i64 && LocVT == MVT::f64))
3296           Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3297         else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
3298           SDValue Lo = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3299                                    Arg, DAG.getConstant(0, DL, MVT::i32));
3300           SDValue Hi = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3301                                    Arg, DAG.getConstant(1, DL, MVT::i32));
3302           if (!Subtarget.isLittle())
3303             std::swap(Lo, Hi);
3304 
3305           assert(VA.needsCustom());
3306 
3307           Register LocRegLo = VA.getLocReg();
3308           Register LocRegHigh = ArgLocs[++i].getLocReg();
3309           RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
3310           RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
3311           continue;
3312         }
3313       }
3314       break;
3315     case CCValAssign::BCvt:
3316       Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3317       break;
3318     case CCValAssign::SExtUpper:
3319       UseUpperBits = true;
3320       LLVM_FALLTHROUGH;
3321     case CCValAssign::SExt:
3322       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, LocVT, Arg);
3323       break;
3324     case CCValAssign::ZExtUpper:
3325       UseUpperBits = true;
3326       LLVM_FALLTHROUGH;
3327     case CCValAssign::ZExt:
3328       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, LocVT, Arg);
3329       break;
3330     case CCValAssign::AExtUpper:
3331       UseUpperBits = true;
3332       LLVM_FALLTHROUGH;
3333     case CCValAssign::AExt:
3334       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, LocVT, Arg);
3335       break;
3336     }
3337 
3338     if (UseUpperBits) {
3339       unsigned ValSizeInBits = Outs[OutIdx].ArgVT.getSizeInBits();
3340       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3341       Arg = DAG.getNode(
3342           ISD::SHL, DL, VA.getLocVT(), Arg,
3343           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3344     }
3345 
3346     // Arguments that can be passed on register must be kept at
3347     // RegsToPass vector
3348     if (VA.isRegLoc()) {
3349       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
3350 
3351       // If the parameter is passed through reg $D, which splits into
3352       // two physical registers, avoid creating call site info.
3353       if (Mips::AFGR64RegClass.contains(VA.getLocReg()))
3354         continue;
3355 
3356       // Collect CSInfo about which register passes which parameter.
3357       const TargetOptions &Options = DAG.getTarget().Options;
3358       if (Options.SupportsDebugEntryValues)
3359         CSInfo.emplace_back(VA.getLocReg(), i);
3360 
3361       continue;
3362     }
3363 
3364     // Register can't get to this point...
3365     assert(VA.isMemLoc());
3366 
3367     // emit ISD::STORE whichs stores the
3368     // parameter value to a stack Location
3369     MemOpChains.push_back(passArgOnStack(StackPtr, VA.getLocMemOffset(),
3370                                          Chain, Arg, DL, IsTailCall, DAG));
3371   }
3372 
3373   // Transform all store nodes into one single node because all store
3374   // nodes are independent of each other.
3375   if (!MemOpChains.empty())
3376     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
3377 
3378   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
3379   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
3380   // node so that legalize doesn't hack it.
3381 
3382   EVT Ty = Callee.getValueType();
3383   bool GlobalOrExternal = false, IsCallReloc = false;
3384 
3385   // The long-calls feature is ignored in case of PIC.
3386   // While we do not support -mshared / -mno-shared properly,
3387   // ignore long-calls in case of -mabicalls too.
3388   if (!Subtarget.isABICalls() && !IsPIC) {
3389     // If the function should be called using "long call",
3390     // get its address into a register to prevent using
3391     // of the `jal` instruction for the direct call.
3392     if (auto *N = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3393       if (Subtarget.useLongCalls())
3394         Callee = Subtarget.hasSym32()
3395                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3396                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3397     } else if (auto *N = dyn_cast<GlobalAddressSDNode>(Callee)) {
3398       bool UseLongCalls = Subtarget.useLongCalls();
3399       // If the function has long-call/far/near attribute
3400       // it overrides command line switch pased to the backend.
3401       if (auto *F = dyn_cast<Function>(N->getGlobal())) {
3402         if (F->hasFnAttribute("long-call"))
3403           UseLongCalls = true;
3404         else if (F->hasFnAttribute("short-call"))
3405           UseLongCalls = false;
3406       }
3407       if (UseLongCalls)
3408         Callee = Subtarget.hasSym32()
3409                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3410                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3411     }
3412   }
3413 
3414   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3415     if (IsPIC) {
3416       const GlobalValue *Val = G->getGlobal();
3417       InternalLinkage = Val->hasInternalLinkage();
3418 
3419       if (InternalLinkage)
3420         Callee = getAddrLocal(G, DL, Ty, DAG, ABI.IsN32() || ABI.IsN64());
3421       else if (Subtarget.useXGOT()) {
3422         Callee = getAddrGlobalLargeGOT(G, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3423                                        MipsII::MO_CALL_LO16, Chain,
3424                                        FuncInfo->callPtrInfo(MF, Val));
3425         IsCallReloc = true;
3426       } else {
3427         Callee = getAddrGlobal(G, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3428                                FuncInfo->callPtrInfo(MF, Val));
3429         IsCallReloc = true;
3430       }
3431     } else
3432       Callee = DAG.getTargetGlobalAddress(G->getGlobal(), DL,
3433                                           getPointerTy(DAG.getDataLayout()), 0,
3434                                           MipsII::MO_NO_FLAG);
3435     GlobalOrExternal = true;
3436   }
3437   else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3438     const char *Sym = S->getSymbol();
3439 
3440     if (!IsPIC) // static
3441       Callee = DAG.getTargetExternalSymbol(
3442           Sym, getPointerTy(DAG.getDataLayout()), MipsII::MO_NO_FLAG);
3443     else if (Subtarget.useXGOT()) {
3444       Callee = getAddrGlobalLargeGOT(S, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3445                                      MipsII::MO_CALL_LO16, Chain,
3446                                      FuncInfo->callPtrInfo(MF, Sym));
3447       IsCallReloc = true;
3448     } else { // PIC
3449       Callee = getAddrGlobal(S, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3450                              FuncInfo->callPtrInfo(MF, Sym));
3451       IsCallReloc = true;
3452     }
3453 
3454     GlobalOrExternal = true;
3455   }
3456 
3457   SmallVector<SDValue, 8> Ops(1, Chain);
3458   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
3459 
3460   getOpndList(Ops, RegsToPass, IsPIC, GlobalOrExternal, InternalLinkage,
3461               IsCallReloc, CLI, Callee, Chain);
3462 
3463   if (IsTailCall) {
3464     MF.getFrameInfo().setHasTailCall();
3465     SDValue Ret = DAG.getNode(MipsISD::TailCall, DL, MVT::Other, Ops);
3466     DAG.addCallSiteInfo(Ret.getNode(), std::move(CSInfo));
3467     return Ret;
3468   }
3469 
3470   Chain = DAG.getNode(MipsISD::JmpLink, DL, NodeTys, Ops);
3471   SDValue InFlag = Chain.getValue(1);
3472 
3473   DAG.addCallSiteInfo(Chain.getNode(), std::move(CSInfo));
3474 
3475   // Create the CALLSEQ_END node in the case of where it is not a call to
3476   // memcpy.
3477   if (!(MemcpyInByVal)) {
3478     Chain = DAG.getCALLSEQ_END(Chain, NextStackOffsetVal,
3479                                DAG.getIntPtrConstant(0, DL, true), InFlag, DL);
3480     InFlag = Chain.getValue(1);
3481   }
3482 
3483   // Handle result values, copying them out of physregs into vregs that we
3484   // return.
3485   return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG,
3486                          InVals, CLI);
3487 }
3488 
3489 /// LowerCallResult - Lower the result values of a call into the
3490 /// appropriate copies out of appropriate physical registers.
3491 SDValue MipsTargetLowering::LowerCallResult(
3492     SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool IsVarArg,
3493     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3494     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
3495     TargetLowering::CallLoweringInfo &CLI) const {
3496   // Assign locations to each value returned by this call.
3497   SmallVector<CCValAssign, 16> RVLocs;
3498   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
3499                      *DAG.getContext());
3500 
3501   const ExternalSymbolSDNode *ES =
3502       dyn_cast_or_null<const ExternalSymbolSDNode>(CLI.Callee.getNode());
3503   CCInfo.AnalyzeCallResult(Ins, RetCC_Mips, CLI.RetTy,
3504                            ES ? ES->getSymbol() : nullptr);
3505 
3506   // Copy all of the result registers out of their specified physreg.
3507   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3508     CCValAssign &VA = RVLocs[i];
3509     assert(VA.isRegLoc() && "Can only return in registers!");
3510 
3511     SDValue Val = DAG.getCopyFromReg(Chain, DL, RVLocs[i].getLocReg(),
3512                                      RVLocs[i].getLocVT(), InFlag);
3513     Chain = Val.getValue(1);
3514     InFlag = Val.getValue(2);
3515 
3516     if (VA.isUpperBitsInLoc()) {
3517       unsigned ValSizeInBits = Ins[i].ArgVT.getSizeInBits();
3518       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3519       unsigned Shift =
3520           VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3521       Val = DAG.getNode(
3522           Shift, DL, VA.getLocVT(), Val,
3523           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3524     }
3525 
3526     switch (VA.getLocInfo()) {
3527     default:
3528       llvm_unreachable("Unknown loc info!");
3529     case CCValAssign::Full:
3530       break;
3531     case CCValAssign::BCvt:
3532       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
3533       break;
3534     case CCValAssign::AExt:
3535     case CCValAssign::AExtUpper:
3536       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3537       break;
3538     case CCValAssign::ZExt:
3539     case CCValAssign::ZExtUpper:
3540       Val = DAG.getNode(ISD::AssertZext, DL, VA.getLocVT(), Val,
3541                         DAG.getValueType(VA.getValVT()));
3542       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3543       break;
3544     case CCValAssign::SExt:
3545     case CCValAssign::SExtUpper:
3546       Val = DAG.getNode(ISD::AssertSext, DL, VA.getLocVT(), Val,
3547                         DAG.getValueType(VA.getValVT()));
3548       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3549       break;
3550     }
3551 
3552     InVals.push_back(Val);
3553   }
3554 
3555   return Chain;
3556 }
3557 
3558 static SDValue UnpackFromArgumentSlot(SDValue Val, const CCValAssign &VA,
3559                                       EVT ArgVT, const SDLoc &DL,
3560                                       SelectionDAG &DAG) {
3561   MVT LocVT = VA.getLocVT();
3562   EVT ValVT = VA.getValVT();
3563 
3564   // Shift into the upper bits if necessary.
3565   switch (VA.getLocInfo()) {
3566   default:
3567     break;
3568   case CCValAssign::AExtUpper:
3569   case CCValAssign::SExtUpper:
3570   case CCValAssign::ZExtUpper: {
3571     unsigned ValSizeInBits = ArgVT.getSizeInBits();
3572     unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3573     unsigned Opcode =
3574         VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3575     Val = DAG.getNode(
3576         Opcode, DL, VA.getLocVT(), Val,
3577         DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3578     break;
3579   }
3580   }
3581 
3582   // If this is an value smaller than the argument slot size (32-bit for O32,
3583   // 64-bit for N32/N64), it has been promoted in some way to the argument slot
3584   // size. Extract the value and insert any appropriate assertions regarding
3585   // sign/zero extension.
3586   switch (VA.getLocInfo()) {
3587   default:
3588     llvm_unreachable("Unknown loc info!");
3589   case CCValAssign::Full:
3590     break;
3591   case CCValAssign::AExtUpper:
3592   case CCValAssign::AExt:
3593     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3594     break;
3595   case CCValAssign::SExtUpper:
3596   case CCValAssign::SExt:
3597     Val = DAG.getNode(ISD::AssertSext, DL, LocVT, Val, DAG.getValueType(ValVT));
3598     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3599     break;
3600   case CCValAssign::ZExtUpper:
3601   case CCValAssign::ZExt:
3602     Val = DAG.getNode(ISD::AssertZext, DL, LocVT, Val, DAG.getValueType(ValVT));
3603     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3604     break;
3605   case CCValAssign::BCvt:
3606     Val = DAG.getNode(ISD::BITCAST, DL, ValVT, Val);
3607     break;
3608   }
3609 
3610   return Val;
3611 }
3612 
3613 //===----------------------------------------------------------------------===//
3614 //             Formal Arguments Calling Convention Implementation
3615 //===----------------------------------------------------------------------===//
3616 /// LowerFormalArguments - transform physical registers into virtual registers
3617 /// and generate load operations for arguments places on the stack.
3618 SDValue MipsTargetLowering::LowerFormalArguments(
3619     SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
3620     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3621     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
3622   MachineFunction &MF = DAG.getMachineFunction();
3623   MachineFrameInfo &MFI = MF.getFrameInfo();
3624   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3625 
3626   MipsFI->setVarArgsFrameIndex(0);
3627 
3628   // Used with vargs to acumulate store chains.
3629   std::vector<SDValue> OutChains;
3630 
3631   // Assign locations to all of the incoming arguments.
3632   SmallVector<CCValAssign, 16> ArgLocs;
3633   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
3634                      *DAG.getContext());
3635   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), Align(1));
3636   const Function &Func = DAG.getMachineFunction().getFunction();
3637   Function::const_arg_iterator FuncArg = Func.arg_begin();
3638 
3639   if (Func.hasFnAttribute("interrupt") && !Func.arg_empty())
3640     report_fatal_error(
3641         "Functions with the interrupt attribute cannot have arguments!");
3642 
3643   CCInfo.AnalyzeFormalArguments(Ins, CC_Mips_FixedArg);
3644   MipsFI->setFormalArgInfo(CCInfo.getNextStackOffset(),
3645                            CCInfo.getInRegsParamsCount() > 0);
3646 
3647   unsigned CurArgIdx = 0;
3648   CCInfo.rewindByValRegsInfo();
3649 
3650   for (unsigned i = 0, e = ArgLocs.size(), InsIdx = 0; i != e; ++i, ++InsIdx) {
3651     CCValAssign &VA = ArgLocs[i];
3652     if (Ins[InsIdx].isOrigArg()) {
3653       std::advance(FuncArg, Ins[InsIdx].getOrigArgIndex() - CurArgIdx);
3654       CurArgIdx = Ins[InsIdx].getOrigArgIndex();
3655     }
3656     EVT ValVT = VA.getValVT();
3657     ISD::ArgFlagsTy Flags = Ins[InsIdx].Flags;
3658     bool IsRegLoc = VA.isRegLoc();
3659 
3660     if (Flags.isByVal()) {
3661       assert(Ins[InsIdx].isOrigArg() && "Byval arguments cannot be implicit");
3662       unsigned FirstByValReg, LastByValReg;
3663       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3664       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3665 
3666       assert(Flags.getByValSize() &&
3667              "ByVal args of size 0 should have been ignored by front-end.");
3668       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3669       copyByValRegs(Chain, DL, OutChains, DAG, Flags, InVals, &*FuncArg,
3670                     FirstByValReg, LastByValReg, VA, CCInfo);
3671       CCInfo.nextInRegsParam();
3672       continue;
3673     }
3674 
3675     // Arguments stored on registers
3676     if (IsRegLoc) {
3677       MVT RegVT = VA.getLocVT();
3678       Register ArgReg = VA.getLocReg();
3679       const TargetRegisterClass *RC = getRegClassFor(RegVT);
3680 
3681       // Transform the arguments stored on
3682       // physical registers into virtual ones
3683       unsigned Reg = addLiveIn(DAG.getMachineFunction(), ArgReg, RC);
3684       SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
3685 
3686       ArgValue =
3687           UnpackFromArgumentSlot(ArgValue, VA, Ins[InsIdx].ArgVT, DL, DAG);
3688 
3689       // Handle floating point arguments passed in integer registers and
3690       // long double arguments passed in floating point registers.
3691       if ((RegVT == MVT::i32 && ValVT == MVT::f32) ||
3692           (RegVT == MVT::i64 && ValVT == MVT::f64) ||
3693           (RegVT == MVT::f64 && ValVT == MVT::i64))
3694         ArgValue = DAG.getNode(ISD::BITCAST, DL, ValVT, ArgValue);
3695       else if (ABI.IsO32() && RegVT == MVT::i32 &&
3696                ValVT == MVT::f64) {
3697         assert(VA.needsCustom() && "Expected custom argument for f64 split");
3698         CCValAssign &NextVA = ArgLocs[++i];
3699         unsigned Reg2 =
3700             addLiveIn(DAG.getMachineFunction(), NextVA.getLocReg(), RC);
3701         SDValue ArgValue2 = DAG.getCopyFromReg(Chain, DL, Reg2, RegVT);
3702         if (!Subtarget.isLittle())
3703           std::swap(ArgValue, ArgValue2);
3704         ArgValue = DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64,
3705                                ArgValue, ArgValue2);
3706       }
3707 
3708       InVals.push_back(ArgValue);
3709     } else { // VA.isRegLoc()
3710       MVT LocVT = VA.getLocVT();
3711 
3712       assert(!VA.needsCustom() && "unexpected custom memory argument");
3713 
3714       if (ABI.IsO32()) {
3715         // We ought to be able to use LocVT directly but O32 sets it to i32
3716         // when allocating floating point values to integer registers.
3717         // This shouldn't influence how we load the value into registers unless
3718         // we are targeting softfloat.
3719         if (VA.getValVT().isFloatingPoint() && !Subtarget.useSoftFloat())
3720           LocVT = VA.getValVT();
3721       }
3722 
3723       // Only arguments pased on the stack should make it here.
3724       assert(VA.isMemLoc());
3725 
3726       // The stack pointer offset is relative to the caller stack frame.
3727       int FI = MFI.CreateFixedObject(LocVT.getSizeInBits() / 8,
3728                                      VA.getLocMemOffset(), true);
3729 
3730       // Create load nodes to retrieve arguments from the stack
3731       SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3732       SDValue ArgValue = DAG.getLoad(
3733           LocVT, DL, Chain, FIN,
3734           MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI));
3735       OutChains.push_back(ArgValue.getValue(1));
3736 
3737       ArgValue =
3738           UnpackFromArgumentSlot(ArgValue, VA, Ins[InsIdx].ArgVT, DL, DAG);
3739 
3740       InVals.push_back(ArgValue);
3741     }
3742   }
3743 
3744   for (unsigned i = 0, e = ArgLocs.size(), InsIdx = 0; i != e; ++i, ++InsIdx) {
3745 
3746     if (ArgLocs[i].needsCustom()) {
3747       ++i;
3748       continue;
3749     }
3750 
3751     // The mips ABIs for returning structs by value requires that we copy
3752     // the sret argument into $v0 for the return. Save the argument into
3753     // a virtual register so that we can access it from the return points.
3754     if (Ins[InsIdx].Flags.isSRet()) {
3755       unsigned Reg = MipsFI->getSRetReturnReg();
3756       if (!Reg) {
3757         Reg = MF.getRegInfo().createVirtualRegister(
3758             getRegClassFor(ABI.IsN64() ? MVT::i64 : MVT::i32));
3759         MipsFI->setSRetReturnReg(Reg);
3760       }
3761       SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), DL, Reg, InVals[i]);
3762       Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Copy, Chain);
3763       break;
3764     }
3765   }
3766 
3767   if (IsVarArg)
3768     writeVarArgRegs(OutChains, Chain, DL, DAG, CCInfo);
3769 
3770   // All stores are grouped in one node to allow the matching between
3771   // the size of Ins and InVals. This only happens when on varg functions
3772   if (!OutChains.empty()) {
3773     OutChains.push_back(Chain);
3774     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
3775   }
3776 
3777   return Chain;
3778 }
3779 
3780 //===----------------------------------------------------------------------===//
3781 //               Return Value Calling Convention Implementation
3782 //===----------------------------------------------------------------------===//
3783 
3784 bool
3785 MipsTargetLowering::CanLowerReturn(CallingConv::ID CallConv,
3786                                    MachineFunction &MF, bool IsVarArg,
3787                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
3788                                    LLVMContext &Context) const {
3789   SmallVector<CCValAssign, 16> RVLocs;
3790   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context);
3791   return CCInfo.CheckReturn(Outs, RetCC_Mips);
3792 }
3793 
3794 bool MipsTargetLowering::shouldSignExtendTypeInLibCall(EVT Type,
3795                                                        bool IsSigned) const {
3796   if ((ABI.IsN32() || ABI.IsN64()) && Type == MVT::i32)
3797       return true;
3798 
3799   return IsSigned;
3800 }
3801 
3802 SDValue
3803 MipsTargetLowering::LowerInterruptReturn(SmallVectorImpl<SDValue> &RetOps,
3804                                          const SDLoc &DL,
3805                                          SelectionDAG &DAG) const {
3806   MachineFunction &MF = DAG.getMachineFunction();
3807   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3808 
3809   MipsFI->setISR();
3810 
3811   return DAG.getNode(MipsISD::ERet, DL, MVT::Other, RetOps);
3812 }
3813 
3814 SDValue
3815 MipsTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
3816                                 bool IsVarArg,
3817                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
3818                                 const SmallVectorImpl<SDValue> &OutVals,
3819                                 const SDLoc &DL, SelectionDAG &DAG) const {
3820   // CCValAssign - represent the assignment of
3821   // the return value to a location
3822   SmallVector<CCValAssign, 16> RVLocs;
3823   MachineFunction &MF = DAG.getMachineFunction();
3824 
3825   // CCState - Info about the registers and stack slot.
3826   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, *DAG.getContext());
3827 
3828   // Analyze return values.
3829   CCInfo.AnalyzeReturn(Outs, RetCC_Mips);
3830 
3831   SDValue Flag;
3832   SmallVector<SDValue, 4> RetOps(1, Chain);
3833 
3834   // Copy the result values into the output registers.
3835   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3836     SDValue Val = OutVals[i];
3837     CCValAssign &VA = RVLocs[i];
3838     assert(VA.isRegLoc() && "Can only return in registers!");
3839     bool UseUpperBits = false;
3840 
3841     switch (VA.getLocInfo()) {
3842     default:
3843       llvm_unreachable("Unknown loc info!");
3844     case CCValAssign::Full:
3845       break;
3846     case CCValAssign::BCvt:
3847       Val = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Val);
3848       break;
3849     case CCValAssign::AExtUpper:
3850       UseUpperBits = true;
3851       LLVM_FALLTHROUGH;
3852     case CCValAssign::AExt:
3853       Val = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Val);
3854       break;
3855     case CCValAssign::ZExtUpper:
3856       UseUpperBits = true;
3857       LLVM_FALLTHROUGH;
3858     case CCValAssign::ZExt:
3859       Val = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Val);
3860       break;
3861     case CCValAssign::SExtUpper:
3862       UseUpperBits = true;
3863       LLVM_FALLTHROUGH;
3864     case CCValAssign::SExt:
3865       Val = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Val);
3866       break;
3867     }
3868 
3869     if (UseUpperBits) {
3870       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
3871       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3872       Val = DAG.getNode(
3873           ISD::SHL, DL, VA.getLocVT(), Val,
3874           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3875     }
3876 
3877     Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Val, Flag);
3878 
3879     // Guarantee that all emitted copies are stuck together with flags.
3880     Flag = Chain.getValue(1);
3881     RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3882   }
3883 
3884   // The mips ABIs for returning structs by value requires that we copy
3885   // the sret argument into $v0 for the return. We saved the argument into
3886   // a virtual register in the entry block, so now we copy the value out
3887   // and into $v0.
3888   if (MF.getFunction().hasStructRetAttr()) {
3889     MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3890     unsigned Reg = MipsFI->getSRetReturnReg();
3891 
3892     if (!Reg)
3893       llvm_unreachable("sret virtual register not created in the entry block");
3894     SDValue Val =
3895         DAG.getCopyFromReg(Chain, DL, Reg, getPointerTy(DAG.getDataLayout()));
3896     unsigned V0 = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
3897 
3898     Chain = DAG.getCopyToReg(Chain, DL, V0, Val, Flag);
3899     Flag = Chain.getValue(1);
3900     RetOps.push_back(DAG.getRegister(V0, getPointerTy(DAG.getDataLayout())));
3901   }
3902 
3903   RetOps[0] = Chain;  // Update chain.
3904 
3905   // Add the flag if we have it.
3906   if (Flag.getNode())
3907     RetOps.push_back(Flag);
3908 
3909   // ISRs must use "eret".
3910   if (DAG.getMachineFunction().getFunction().hasFnAttribute("interrupt"))
3911     return LowerInterruptReturn(RetOps, DL, DAG);
3912 
3913   // Standard return on Mips is a "jr $ra"
3914   return DAG.getNode(MipsISD::Ret, DL, MVT::Other, RetOps);
3915 }
3916 
3917 //===----------------------------------------------------------------------===//
3918 //                           Mips Inline Assembly Support
3919 //===----------------------------------------------------------------------===//
3920 
3921 /// getConstraintType - Given a constraint letter, return the type of
3922 /// constraint it is for this target.
3923 MipsTargetLowering::ConstraintType
3924 MipsTargetLowering::getConstraintType(StringRef Constraint) const {
3925   // Mips specific constraints
3926   // GCC config/mips/constraints.md
3927   //
3928   // 'd' : An address register. Equivalent to r
3929   //       unless generating MIPS16 code.
3930   // 'y' : Equivalent to r; retained for
3931   //       backwards compatibility.
3932   // 'c' : A register suitable for use in an indirect
3933   //       jump. This will always be $25 for -mabicalls.
3934   // 'l' : The lo register. 1 word storage.
3935   // 'x' : The hilo register pair. Double word storage.
3936   if (Constraint.size() == 1) {
3937     switch (Constraint[0]) {
3938       default : break;
3939       case 'd':
3940       case 'y':
3941       case 'f':
3942       case 'c':
3943       case 'l':
3944       case 'x':
3945         return C_RegisterClass;
3946       case 'R':
3947         return C_Memory;
3948     }
3949   }
3950 
3951   if (Constraint == "ZC")
3952     return C_Memory;
3953 
3954   return TargetLowering::getConstraintType(Constraint);
3955 }
3956 
3957 /// Examine constraint type and operand type and determine a weight value.
3958 /// This object must already have been set up with the operand type
3959 /// and the current alternative constraint selected.
3960 TargetLowering::ConstraintWeight
3961 MipsTargetLowering::getSingleConstraintMatchWeight(
3962     AsmOperandInfo &info, const char *constraint) const {
3963   ConstraintWeight weight = CW_Invalid;
3964   Value *CallOperandVal = info.CallOperandVal;
3965     // If we don't have a value, we can't do a match,
3966     // but allow it at the lowest weight.
3967   if (!CallOperandVal)
3968     return CW_Default;
3969   Type *type = CallOperandVal->getType();
3970   // Look at the constraint type.
3971   switch (*constraint) {
3972   default:
3973     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
3974     break;
3975   case 'd':
3976   case 'y':
3977     if (type->isIntegerTy())
3978       weight = CW_Register;
3979     break;
3980   case 'f': // FPU or MSA register
3981     if (Subtarget.hasMSA() && type->isVectorTy() &&
3982         type->getPrimitiveSizeInBits().getFixedSize() == 128)
3983       weight = CW_Register;
3984     else if (type->isFloatTy())
3985       weight = CW_Register;
3986     break;
3987   case 'c': // $25 for indirect jumps
3988   case 'l': // lo register
3989   case 'x': // hilo register pair
3990     if (type->isIntegerTy())
3991       weight = CW_SpecificReg;
3992     break;
3993   case 'I': // signed 16 bit immediate
3994   case 'J': // integer zero
3995   case 'K': // unsigned 16 bit immediate
3996   case 'L': // signed 32 bit immediate where lower 16 bits are 0
3997   case 'N': // immediate in the range of -65535 to -1 (inclusive)
3998   case 'O': // signed 15 bit immediate (+- 16383)
3999   case 'P': // immediate in the range of 65535 to 1 (inclusive)
4000     if (isa<ConstantInt>(CallOperandVal))
4001       weight = CW_Constant;
4002     break;
4003   case 'R':
4004     weight = CW_Memory;
4005     break;
4006   }
4007   return weight;
4008 }
4009 
4010 /// This is a helper function to parse a physical register string and split it
4011 /// into non-numeric and numeric parts (Prefix and Reg). The first boolean flag
4012 /// that is returned indicates whether parsing was successful. The second flag
4013 /// is true if the numeric part exists.
4014 static std::pair<bool, bool> parsePhysicalReg(StringRef C, StringRef &Prefix,
4015                                               unsigned long long &Reg) {
4016   if (C.front() != '{' || C.back() != '}')
4017     return std::make_pair(false, false);
4018 
4019   // Search for the first numeric character.
4020   StringRef::const_iterator I, B = C.begin() + 1, E = C.end() - 1;
4021   I = std::find_if(B, E, isdigit);
4022 
4023   Prefix = StringRef(B, I - B);
4024 
4025   // The second flag is set to false if no numeric characters were found.
4026   if (I == E)
4027     return std::make_pair(true, false);
4028 
4029   // Parse the numeric characters.
4030   return std::make_pair(!getAsUnsignedInteger(StringRef(I, E - I), 10, Reg),
4031                         true);
4032 }
4033 
4034 EVT MipsTargetLowering::getTypeForExtReturn(LLVMContext &Context, EVT VT,
4035                                             ISD::NodeType) const {
4036   bool Cond = !Subtarget.isABI_O32() && VT.getSizeInBits() == 32;
4037   EVT MinVT = getRegisterType(Context, Cond ? MVT::i64 : MVT::i32);
4038   return VT.bitsLT(MinVT) ? MinVT : VT;
4039 }
4040 
4041 std::pair<unsigned, const TargetRegisterClass *> MipsTargetLowering::
4042 parseRegForInlineAsmConstraint(StringRef C, MVT VT) const {
4043   const TargetRegisterInfo *TRI =
4044       Subtarget.getRegisterInfo();
4045   const TargetRegisterClass *RC;
4046   StringRef Prefix;
4047   unsigned long long Reg;
4048 
4049   std::pair<bool, bool> R = parsePhysicalReg(C, Prefix, Reg);
4050 
4051   if (!R.first)
4052     return std::make_pair(0U, nullptr);
4053 
4054   if ((Prefix == "hi" || Prefix == "lo")) { // Parse hi/lo.
4055     // No numeric characters follow "hi" or "lo".
4056     if (R.second)
4057       return std::make_pair(0U, nullptr);
4058 
4059     RC = TRI->getRegClass(Prefix == "hi" ?
4060                           Mips::HI32RegClassID : Mips::LO32RegClassID);
4061     return std::make_pair(*(RC->begin()), RC);
4062   } else if (Prefix.startswith("$msa")) {
4063     // Parse $msa(ir|csr|access|save|modify|request|map|unmap)
4064 
4065     // No numeric characters follow the name.
4066     if (R.second)
4067       return std::make_pair(0U, nullptr);
4068 
4069     Reg = StringSwitch<unsigned long long>(Prefix)
4070               .Case("$msair", Mips::MSAIR)
4071               .Case("$msacsr", Mips::MSACSR)
4072               .Case("$msaaccess", Mips::MSAAccess)
4073               .Case("$msasave", Mips::MSASave)
4074               .Case("$msamodify", Mips::MSAModify)
4075               .Case("$msarequest", Mips::MSARequest)
4076               .Case("$msamap", Mips::MSAMap)
4077               .Case("$msaunmap", Mips::MSAUnmap)
4078               .Default(0);
4079 
4080     if (!Reg)
4081       return std::make_pair(0U, nullptr);
4082 
4083     RC = TRI->getRegClass(Mips::MSACtrlRegClassID);
4084     return std::make_pair(Reg, RC);
4085   }
4086 
4087   if (!R.second)
4088     return std::make_pair(0U, nullptr);
4089 
4090   if (Prefix == "$f") { // Parse $f0-$f31.
4091     // If the size of FP registers is 64-bit or Reg is an even number, select
4092     // the 64-bit register class. Otherwise, select the 32-bit register class.
4093     if (VT == MVT::Other)
4094       VT = (Subtarget.isFP64bit() || !(Reg % 2)) ? MVT::f64 : MVT::f32;
4095 
4096     RC = getRegClassFor(VT);
4097 
4098     if (RC == &Mips::AFGR64RegClass) {
4099       assert(Reg % 2 == 0);
4100       Reg >>= 1;
4101     }
4102   } else if (Prefix == "$fcc") // Parse $fcc0-$fcc7.
4103     RC = TRI->getRegClass(Mips::FCCRegClassID);
4104   else if (Prefix == "$w") { // Parse $w0-$w31.
4105     RC = getRegClassFor((VT == MVT::Other) ? MVT::v16i8 : VT);
4106   } else { // Parse $0-$31.
4107     assert(Prefix == "$");
4108     RC = getRegClassFor((VT == MVT::Other) ? MVT::i32 : VT);
4109   }
4110 
4111   assert(Reg < RC->getNumRegs());
4112   return std::make_pair(*(RC->begin() + Reg), RC);
4113 }
4114 
4115 /// Given a register class constraint, like 'r', if this corresponds directly
4116 /// to an LLVM register class, return a register of 0 and the register class
4117 /// pointer.
4118 std::pair<unsigned, const TargetRegisterClass *>
4119 MipsTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
4120                                                  StringRef Constraint,
4121                                                  MVT VT) const {
4122   if (Constraint.size() == 1) {
4123     switch (Constraint[0]) {
4124     case 'd': // Address register. Same as 'r' unless generating MIPS16 code.
4125     case 'y': // Same as 'r'. Exists for compatibility.
4126     case 'r':
4127       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8 || VT == MVT::i1) {
4128         if (Subtarget.inMips16Mode())
4129           return std::make_pair(0U, &Mips::CPU16RegsRegClass);
4130         return std::make_pair(0U, &Mips::GPR32RegClass);
4131       }
4132       if (VT == MVT::i64 && !Subtarget.isGP64bit())
4133         return std::make_pair(0U, &Mips::GPR32RegClass);
4134       if (VT == MVT::i64 && Subtarget.isGP64bit())
4135         return std::make_pair(0U, &Mips::GPR64RegClass);
4136       // This will generate an error message
4137       return std::make_pair(0U, nullptr);
4138     case 'f': // FPU or MSA register
4139       if (VT == MVT::v16i8)
4140         return std::make_pair(0U, &Mips::MSA128BRegClass);
4141       else if (VT == MVT::v8i16 || VT == MVT::v8f16)
4142         return std::make_pair(0U, &Mips::MSA128HRegClass);
4143       else if (VT == MVT::v4i32 || VT == MVT::v4f32)
4144         return std::make_pair(0U, &Mips::MSA128WRegClass);
4145       else if (VT == MVT::v2i64 || VT == MVT::v2f64)
4146         return std::make_pair(0U, &Mips::MSA128DRegClass);
4147       else if (VT == MVT::f32)
4148         return std::make_pair(0U, &Mips::FGR32RegClass);
4149       else if ((VT == MVT::f64) && (!Subtarget.isSingleFloat())) {
4150         if (Subtarget.isFP64bit())
4151           return std::make_pair(0U, &Mips::FGR64RegClass);
4152         return std::make_pair(0U, &Mips::AFGR64RegClass);
4153       }
4154       break;
4155     case 'c': // register suitable for indirect jump
4156       if (VT == MVT::i32)
4157         return std::make_pair((unsigned)Mips::T9, &Mips::GPR32RegClass);
4158       if (VT == MVT::i64)
4159         return std::make_pair((unsigned)Mips::T9_64, &Mips::GPR64RegClass);
4160       // This will generate an error message
4161       return std::make_pair(0U, nullptr);
4162     case 'l': // use the `lo` register to store values
4163               // that are no bigger than a word
4164       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8)
4165         return std::make_pair((unsigned)Mips::LO0, &Mips::LO32RegClass);
4166       return std::make_pair((unsigned)Mips::LO0_64, &Mips::LO64RegClass);
4167     case 'x': // use the concatenated `hi` and `lo` registers
4168               // to store doubleword values
4169       // Fixme: Not triggering the use of both hi and low
4170       // This will generate an error message
4171       return std::make_pair(0U, nullptr);
4172     }
4173   }
4174 
4175   if (!Constraint.empty()) {
4176     std::pair<unsigned, const TargetRegisterClass *> R;
4177     R = parseRegForInlineAsmConstraint(Constraint, VT);
4178 
4179     if (R.second)
4180       return R;
4181   }
4182 
4183   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
4184 }
4185 
4186 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
4187 /// vector.  If it is invalid, don't add anything to Ops.
4188 void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
4189                                                      std::string &Constraint,
4190                                                      std::vector<SDValue>&Ops,
4191                                                      SelectionDAG &DAG) const {
4192   SDLoc DL(Op);
4193   SDValue Result;
4194 
4195   // Only support length 1 constraints for now.
4196   if (Constraint.length() > 1) return;
4197 
4198   char ConstraintLetter = Constraint[0];
4199   switch (ConstraintLetter) {
4200   default: break; // This will fall through to the generic implementation
4201   case 'I': // Signed 16 bit constant
4202     // If this fails, the parent routine will give an error
4203     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4204       EVT Type = Op.getValueType();
4205       int64_t Val = C->getSExtValue();
4206       if (isInt<16>(Val)) {
4207         Result = DAG.getTargetConstant(Val, DL, Type);
4208         break;
4209       }
4210     }
4211     return;
4212   case 'J': // integer zero
4213     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4214       EVT Type = Op.getValueType();
4215       int64_t Val = C->getZExtValue();
4216       if (Val == 0) {
4217         Result = DAG.getTargetConstant(0, DL, Type);
4218         break;
4219       }
4220     }
4221     return;
4222   case 'K': // unsigned 16 bit immediate
4223     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4224       EVT Type = Op.getValueType();
4225       uint64_t Val = (uint64_t)C->getZExtValue();
4226       if (isUInt<16>(Val)) {
4227         Result = DAG.getTargetConstant(Val, DL, Type);
4228         break;
4229       }
4230     }
4231     return;
4232   case 'L': // signed 32 bit immediate where lower 16 bits are 0
4233     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4234       EVT Type = Op.getValueType();
4235       int64_t Val = C->getSExtValue();
4236       if ((isInt<32>(Val)) && ((Val & 0xffff) == 0)){
4237         Result = DAG.getTargetConstant(Val, DL, Type);
4238         break;
4239       }
4240     }
4241     return;
4242   case 'N': // immediate in the range of -65535 to -1 (inclusive)
4243     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4244       EVT Type = Op.getValueType();
4245       int64_t Val = C->getSExtValue();
4246       if ((Val >= -65535) && (Val <= -1)) {
4247         Result = DAG.getTargetConstant(Val, DL, Type);
4248         break;
4249       }
4250     }
4251     return;
4252   case 'O': // signed 15 bit immediate
4253     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4254       EVT Type = Op.getValueType();
4255       int64_t Val = C->getSExtValue();
4256       if ((isInt<15>(Val))) {
4257         Result = DAG.getTargetConstant(Val, DL, Type);
4258         break;
4259       }
4260     }
4261     return;
4262   case 'P': // immediate in the range of 1 to 65535 (inclusive)
4263     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4264       EVT Type = Op.getValueType();
4265       int64_t Val = C->getSExtValue();
4266       if ((Val <= 65535) && (Val >= 1)) {
4267         Result = DAG.getTargetConstant(Val, DL, Type);
4268         break;
4269       }
4270     }
4271     return;
4272   }
4273 
4274   if (Result.getNode()) {
4275     Ops.push_back(Result);
4276     return;
4277   }
4278 
4279   TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
4280 }
4281 
4282 bool MipsTargetLowering::isLegalAddressingMode(const DataLayout &DL,
4283                                                const AddrMode &AM, Type *Ty,
4284                                                unsigned AS,
4285                                                Instruction *I) const {
4286   // No global is ever allowed as a base.
4287   if (AM.BaseGV)
4288     return false;
4289 
4290   switch (AM.Scale) {
4291   case 0: // "r+i" or just "i", depending on HasBaseReg.
4292     break;
4293   case 1:
4294     if (!AM.HasBaseReg) // allow "r+i".
4295       break;
4296     return false; // disallow "r+r" or "r+r+i".
4297   default:
4298     return false;
4299   }
4300 
4301   return true;
4302 }
4303 
4304 bool
4305 MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
4306   // The Mips target isn't yet aware of offsets.
4307   return false;
4308 }
4309 
4310 EVT MipsTargetLowering::getOptimalMemOpType(
4311     const MemOp &Op, const AttributeList &FuncAttributes) const {
4312   if (Subtarget.hasMips64())
4313     return MVT::i64;
4314 
4315   return MVT::i32;
4316 }
4317 
4318 bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
4319                                       bool ForCodeSize) const {
4320   if (VT != MVT::f32 && VT != MVT::f64)
4321     return false;
4322   if (Imm.isNegZero())
4323     return false;
4324   return Imm.isZero();
4325 }
4326 
4327 unsigned MipsTargetLowering::getJumpTableEncoding() const {
4328 
4329   // FIXME: For space reasons this should be: EK_GPRel32BlockAddress.
4330   if (ABI.IsN64() && isPositionIndependent())
4331     return MachineJumpTableInfo::EK_GPRel64BlockAddress;
4332 
4333   return TargetLowering::getJumpTableEncoding();
4334 }
4335 
4336 bool MipsTargetLowering::useSoftFloat() const {
4337   return Subtarget.useSoftFloat();
4338 }
4339 
4340 void MipsTargetLowering::copyByValRegs(
4341     SDValue Chain, const SDLoc &DL, std::vector<SDValue> &OutChains,
4342     SelectionDAG &DAG, const ISD::ArgFlagsTy &Flags,
4343     SmallVectorImpl<SDValue> &InVals, const Argument *FuncArg,
4344     unsigned FirstReg, unsigned LastReg, const CCValAssign &VA,
4345     MipsCCState &State) const {
4346   MachineFunction &MF = DAG.getMachineFunction();
4347   MachineFrameInfo &MFI = MF.getFrameInfo();
4348   unsigned GPRSizeInBytes = Subtarget.getGPRSizeInBytes();
4349   unsigned NumRegs = LastReg - FirstReg;
4350   unsigned RegAreaSize = NumRegs * GPRSizeInBytes;
4351   unsigned FrameObjSize = std::max(Flags.getByValSize(), RegAreaSize);
4352   int FrameObjOffset;
4353   ArrayRef<MCPhysReg> ByValArgRegs = ABI.GetByValArgRegs();
4354 
4355   if (RegAreaSize)
4356     FrameObjOffset =
4357         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4358         (int)((ByValArgRegs.size() - FirstReg) * GPRSizeInBytes);
4359   else
4360     FrameObjOffset = VA.getLocMemOffset();
4361 
4362   // Create frame object.
4363   EVT PtrTy = getPointerTy(DAG.getDataLayout());
4364   // Make the fixed object stored to mutable so that the load instructions
4365   // referencing it have their memory dependencies added.
4366   // Set the frame object as isAliased which clears the underlying objects
4367   // vector in ScheduleDAGInstrs::buildSchedGraph() resulting in addition of all
4368   // stores as dependencies for loads referencing this fixed object.
4369   int FI = MFI.CreateFixedObject(FrameObjSize, FrameObjOffset, false, true);
4370   SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
4371   InVals.push_back(FIN);
4372 
4373   if (!NumRegs)
4374     return;
4375 
4376   // Copy arg registers.
4377   MVT RegTy = MVT::getIntegerVT(GPRSizeInBytes * 8);
4378   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4379 
4380   for (unsigned I = 0; I < NumRegs; ++I) {
4381     unsigned ArgReg = ByValArgRegs[FirstReg + I];
4382     unsigned VReg = addLiveIn(MF, ArgReg, RC);
4383     unsigned Offset = I * GPRSizeInBytes;
4384     SDValue StorePtr = DAG.getNode(ISD::ADD, DL, PtrTy, FIN,
4385                                    DAG.getConstant(Offset, DL, PtrTy));
4386     SDValue Store = DAG.getStore(Chain, DL, DAG.getRegister(VReg, RegTy),
4387                                  StorePtr, MachinePointerInfo(FuncArg, Offset));
4388     OutChains.push_back(Store);
4389   }
4390 }
4391 
4392 // Copy byVal arg to registers and stack.
4393 void MipsTargetLowering::passByValArg(
4394     SDValue Chain, const SDLoc &DL,
4395     std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
4396     SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
4397     MachineFrameInfo &MFI, SelectionDAG &DAG, SDValue Arg, unsigned FirstReg,
4398     unsigned LastReg, const ISD::ArgFlagsTy &Flags, bool isLittle,
4399     const CCValAssign &VA) const {
4400   unsigned ByValSizeInBytes = Flags.getByValSize();
4401   unsigned OffsetInBytes = 0; // From beginning of struct
4402   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4403   Align Alignment =
4404       std::min(Flags.getNonZeroByValAlign(), Align(RegSizeInBytes));
4405   EVT PtrTy = getPointerTy(DAG.getDataLayout()),
4406       RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4407   unsigned NumRegs = LastReg - FirstReg;
4408 
4409   if (NumRegs) {
4410     ArrayRef<MCPhysReg> ArgRegs = ABI.GetByValArgRegs();
4411     bool LeftoverBytes = (NumRegs * RegSizeInBytes > ByValSizeInBytes);
4412     unsigned I = 0;
4413 
4414     // Copy words to registers.
4415     for (; I < NumRegs - LeftoverBytes; ++I, OffsetInBytes += RegSizeInBytes) {
4416       SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4417                                     DAG.getConstant(OffsetInBytes, DL, PtrTy));
4418       SDValue LoadVal = DAG.getLoad(RegTy, DL, Chain, LoadPtr,
4419                                     MachinePointerInfo(), Alignment);
4420       MemOpChains.push_back(LoadVal.getValue(1));
4421       unsigned ArgReg = ArgRegs[FirstReg + I];
4422       RegsToPass.push_back(std::make_pair(ArgReg, LoadVal));
4423     }
4424 
4425     // Return if the struct has been fully copied.
4426     if (ByValSizeInBytes == OffsetInBytes)
4427       return;
4428 
4429     // Copy the remainder of the byval argument with sub-word loads and shifts.
4430     if (LeftoverBytes) {
4431       SDValue Val;
4432 
4433       for (unsigned LoadSizeInBytes = RegSizeInBytes / 2, TotalBytesLoaded = 0;
4434            OffsetInBytes < ByValSizeInBytes; LoadSizeInBytes /= 2) {
4435         unsigned RemainingSizeInBytes = ByValSizeInBytes - OffsetInBytes;
4436 
4437         if (RemainingSizeInBytes < LoadSizeInBytes)
4438           continue;
4439 
4440         // Load subword.
4441         SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4442                                       DAG.getConstant(OffsetInBytes, DL,
4443                                                       PtrTy));
4444         SDValue LoadVal = DAG.getExtLoad(
4445             ISD::ZEXTLOAD, DL, RegTy, Chain, LoadPtr, MachinePointerInfo(),
4446             MVT::getIntegerVT(LoadSizeInBytes * 8), Alignment);
4447         MemOpChains.push_back(LoadVal.getValue(1));
4448 
4449         // Shift the loaded value.
4450         unsigned Shamt;
4451 
4452         if (isLittle)
4453           Shamt = TotalBytesLoaded * 8;
4454         else
4455           Shamt = (RegSizeInBytes - (TotalBytesLoaded + LoadSizeInBytes)) * 8;
4456 
4457         SDValue Shift = DAG.getNode(ISD::SHL, DL, RegTy, LoadVal,
4458                                     DAG.getConstant(Shamt, DL, MVT::i32));
4459 
4460         if (Val.getNode())
4461           Val = DAG.getNode(ISD::OR, DL, RegTy, Val, Shift);
4462         else
4463           Val = Shift;
4464 
4465         OffsetInBytes += LoadSizeInBytes;
4466         TotalBytesLoaded += LoadSizeInBytes;
4467         Alignment = std::min(Alignment, Align(LoadSizeInBytes));
4468       }
4469 
4470       unsigned ArgReg = ArgRegs[FirstReg + I];
4471       RegsToPass.push_back(std::make_pair(ArgReg, Val));
4472       return;
4473     }
4474   }
4475 
4476   // Copy remainder of byval arg to it with memcpy.
4477   unsigned MemCpySize = ByValSizeInBytes - OffsetInBytes;
4478   SDValue Src = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4479                             DAG.getConstant(OffsetInBytes, DL, PtrTy));
4480   SDValue Dst = DAG.getNode(ISD::ADD, DL, PtrTy, StackPtr,
4481                             DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
4482   Chain = DAG.getMemcpy(
4483       Chain, DL, Dst, Src, DAG.getConstant(MemCpySize, DL, PtrTy),
4484       Align(Alignment), /*isVolatile=*/false, /*AlwaysInline=*/false,
4485       /*isTailCall=*/false, MachinePointerInfo(), MachinePointerInfo());
4486   MemOpChains.push_back(Chain);
4487 }
4488 
4489 void MipsTargetLowering::writeVarArgRegs(std::vector<SDValue> &OutChains,
4490                                          SDValue Chain, const SDLoc &DL,
4491                                          SelectionDAG &DAG,
4492                                          CCState &State) const {
4493   ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();
4494   unsigned Idx = State.getFirstUnallocated(ArgRegs);
4495   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4496   MVT RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4497   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4498   MachineFunction &MF = DAG.getMachineFunction();
4499   MachineFrameInfo &MFI = MF.getFrameInfo();
4500   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
4501 
4502   // Offset of the first variable argument from stack pointer.
4503   int VaArgOffset;
4504 
4505   if (ArgRegs.size() == Idx)
4506     VaArgOffset = alignTo(State.getNextStackOffset(), RegSizeInBytes);
4507   else {
4508     VaArgOffset =
4509         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4510         (int)(RegSizeInBytes * (ArgRegs.size() - Idx));
4511   }
4512 
4513   // Record the frame index of the first variable argument
4514   // which is a value necessary to VASTART.
4515   int FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4516   MipsFI->setVarArgsFrameIndex(FI);
4517 
4518   // Copy the integer registers that have not been used for argument passing
4519   // to the argument register save area. For O32, the save area is allocated
4520   // in the caller's stack frame, while for N32/64, it is allocated in the
4521   // callee's stack frame.
4522   for (unsigned I = Idx; I < ArgRegs.size();
4523        ++I, VaArgOffset += RegSizeInBytes) {
4524     unsigned Reg = addLiveIn(MF, ArgRegs[I], RC);
4525     SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegTy);
4526     FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4527     SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
4528     SDValue Store =
4529         DAG.getStore(Chain, DL, ArgValue, PtrOff, MachinePointerInfo());
4530     cast<StoreSDNode>(Store.getNode())->getMemOperand()->setValue(
4531         (Value *)nullptr);
4532     OutChains.push_back(Store);
4533   }
4534 }
4535 
4536 void MipsTargetLowering::HandleByVal(CCState *State, unsigned &Size,
4537                                      Align Alignment) const {
4538   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
4539 
4540   assert(Size && "Byval argument's size shouldn't be 0.");
4541 
4542   Alignment = std::min(Alignment, TFL->getStackAlign());
4543 
4544   unsigned FirstReg = 0;
4545   unsigned NumRegs = 0;
4546 
4547   if (State->getCallingConv() != CallingConv::Fast) {
4548     unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4549     ArrayRef<MCPhysReg> IntArgRegs = ABI.GetByValArgRegs();
4550     // FIXME: The O32 case actually describes no shadow registers.
4551     const MCPhysReg *ShadowRegs =
4552         ABI.IsO32() ? IntArgRegs.data() : Mips64DPRegs;
4553 
4554     // We used to check the size as well but we can't do that anymore since
4555     // CCState::HandleByVal() rounds up the size after calling this function.
4556     assert(
4557         Alignment >= Align(RegSizeInBytes) &&
4558         "Byval argument's alignment should be a multiple of RegSizeInBytes.");
4559 
4560     FirstReg = State->getFirstUnallocated(IntArgRegs);
4561 
4562     // If Alignment > RegSizeInBytes, the first arg register must be even.
4563     // FIXME: This condition happens to do the right thing but it's not the
4564     //        right way to test it. We want to check that the stack frame offset
4565     //        of the register is aligned.
4566     if ((Alignment > RegSizeInBytes) && (FirstReg % 2)) {
4567       State->AllocateReg(IntArgRegs[FirstReg], ShadowRegs[FirstReg]);
4568       ++FirstReg;
4569     }
4570 
4571     // Mark the registers allocated.
4572     Size = alignTo(Size, RegSizeInBytes);
4573     for (unsigned I = FirstReg; Size > 0 && (I < IntArgRegs.size());
4574          Size -= RegSizeInBytes, ++I, ++NumRegs)
4575       State->AllocateReg(IntArgRegs[I], ShadowRegs[I]);
4576   }
4577 
4578   State->addInRegsParamInfo(FirstReg, FirstReg + NumRegs);
4579 }
4580 
4581 MachineBasicBlock *MipsTargetLowering::emitPseudoSELECT(MachineInstr &MI,
4582                                                         MachineBasicBlock *BB,
4583                                                         bool isFPCmp,
4584                                                         unsigned Opc) const {
4585   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4586          "Subtarget already supports SELECT nodes with the use of"
4587          "conditional-move instructions.");
4588 
4589   const TargetInstrInfo *TII =
4590       Subtarget.getInstrInfo();
4591   DebugLoc DL = MI.getDebugLoc();
4592 
4593   // To "insert" a SELECT instruction, we actually have to insert the
4594   // diamond control-flow pattern.  The incoming instruction knows the
4595   // destination vreg to set, the condition code register to branch on, the
4596   // true/false values to select between, and a branch opcode to use.
4597   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4598   MachineFunction::iterator It = ++BB->getIterator();
4599 
4600   //  thisMBB:
4601   //  ...
4602   //   TrueVal = ...
4603   //   setcc r1, r2, r3
4604   //   bNE   r1, r0, copy1MBB
4605   //   fallthrough --> copy0MBB
4606   MachineBasicBlock *thisMBB  = BB;
4607   MachineFunction *F = BB->getParent();
4608   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4609   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
4610   F->insert(It, copy0MBB);
4611   F->insert(It, sinkMBB);
4612 
4613   // Transfer the remainder of BB and its successor edges to sinkMBB.
4614   sinkMBB->splice(sinkMBB->begin(), BB,
4615                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4616   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4617 
4618   // Next, add the true and fallthrough blocks as its successors.
4619   BB->addSuccessor(copy0MBB);
4620   BB->addSuccessor(sinkMBB);
4621 
4622   if (isFPCmp) {
4623     // bc1[tf] cc, sinkMBB
4624     BuildMI(BB, DL, TII->get(Opc))
4625         .addReg(MI.getOperand(1).getReg())
4626         .addMBB(sinkMBB);
4627   } else {
4628     // bne rs, $0, sinkMBB
4629     BuildMI(BB, DL, TII->get(Opc))
4630         .addReg(MI.getOperand(1).getReg())
4631         .addReg(Mips::ZERO)
4632         .addMBB(sinkMBB);
4633   }
4634 
4635   //  copy0MBB:
4636   //   %FalseValue = ...
4637   //   # fallthrough to sinkMBB
4638   BB = copy0MBB;
4639 
4640   // Update machine-CFG edges
4641   BB->addSuccessor(sinkMBB);
4642 
4643   //  sinkMBB:
4644   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4645   //  ...
4646   BB = sinkMBB;
4647 
4648   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4649       .addReg(MI.getOperand(2).getReg())
4650       .addMBB(thisMBB)
4651       .addReg(MI.getOperand(3).getReg())
4652       .addMBB(copy0MBB);
4653 
4654   MI.eraseFromParent(); // The pseudo instruction is gone now.
4655 
4656   return BB;
4657 }
4658 
4659 MachineBasicBlock *
4660 MipsTargetLowering::emitPseudoD_SELECT(MachineInstr &MI,
4661                                        MachineBasicBlock *BB) const {
4662   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4663          "Subtarget already supports SELECT nodes with the use of"
4664          "conditional-move instructions.");
4665 
4666   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4667   DebugLoc DL = MI.getDebugLoc();
4668 
4669   // D_SELECT substitutes two SELECT nodes that goes one after another and
4670   // have the same condition operand. On machines which don't have
4671   // conditional-move instruction, it reduces unnecessary branch instructions
4672   // which are result of using two diamond patterns that are result of two
4673   // SELECT pseudo instructions.
4674   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4675   MachineFunction::iterator It = ++BB->getIterator();
4676 
4677   //  thisMBB:
4678   //  ...
4679   //   TrueVal = ...
4680   //   setcc r1, r2, r3
4681   //   bNE   r1, r0, copy1MBB
4682   //   fallthrough --> copy0MBB
4683   MachineBasicBlock *thisMBB = BB;
4684   MachineFunction *F = BB->getParent();
4685   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4686   MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
4687   F->insert(It, copy0MBB);
4688   F->insert(It, sinkMBB);
4689 
4690   // Transfer the remainder of BB and its successor edges to sinkMBB.
4691   sinkMBB->splice(sinkMBB->begin(), BB,
4692                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4693   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4694 
4695   // Next, add the true and fallthrough blocks as its successors.
4696   BB->addSuccessor(copy0MBB);
4697   BB->addSuccessor(sinkMBB);
4698 
4699   // bne rs, $0, sinkMBB
4700   BuildMI(BB, DL, TII->get(Mips::BNE))
4701       .addReg(MI.getOperand(2).getReg())
4702       .addReg(Mips::ZERO)
4703       .addMBB(sinkMBB);
4704 
4705   //  copy0MBB:
4706   //   %FalseValue = ...
4707   //   # fallthrough to sinkMBB
4708   BB = copy0MBB;
4709 
4710   // Update machine-CFG edges
4711   BB->addSuccessor(sinkMBB);
4712 
4713   //  sinkMBB:
4714   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4715   //  ...
4716   BB = sinkMBB;
4717 
4718   // Use two PHI nodes to select two reults
4719   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4720       .addReg(MI.getOperand(3).getReg())
4721       .addMBB(thisMBB)
4722       .addReg(MI.getOperand(5).getReg())
4723       .addMBB(copy0MBB);
4724   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(1).getReg())
4725       .addReg(MI.getOperand(4).getReg())
4726       .addMBB(thisMBB)
4727       .addReg(MI.getOperand(6).getReg())
4728       .addMBB(copy0MBB);
4729 
4730   MI.eraseFromParent(); // The pseudo instruction is gone now.
4731 
4732   return BB;
4733 }
4734 
4735 // FIXME? Maybe this could be a TableGen attribute on some registers and
4736 // this table could be generated automatically from RegInfo.
4737 Register
4738 MipsTargetLowering::getRegisterByName(const char *RegName, LLT VT,
4739                                       const MachineFunction &MF) const {
4740   // The Linux kernel uses $28 and sp.
4741   if (Subtarget.isGP64bit()) {
4742     Register Reg = StringSwitch<Register>(RegName)
4743                        .Case("$28", Mips::GP_64)
4744                        .Case("sp", Mips::SP_64)
4745                        .Default(Register());
4746     if (Reg)
4747       return Reg;
4748   } else {
4749     Register Reg = StringSwitch<Register>(RegName)
4750                        .Case("$28", Mips::GP)
4751                        .Case("sp", Mips::SP)
4752                        .Default(Register());
4753     if (Reg)
4754       return Reg;
4755   }
4756   report_fatal_error("Invalid register name global variable");
4757 }
4758 
4759 MachineBasicBlock *MipsTargetLowering::emitLDR_W(MachineInstr &MI,
4760                                                  MachineBasicBlock *BB) const {
4761   MachineFunction *MF = BB->getParent();
4762   MachineRegisterInfo &MRI = MF->getRegInfo();
4763   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4764   const bool IsLittle = Subtarget.isLittle();
4765   DebugLoc DL = MI.getDebugLoc();
4766 
4767   Register Dest = MI.getOperand(0).getReg();
4768   Register Address = MI.getOperand(1).getReg();
4769   unsigned Imm = MI.getOperand(2).getImm();
4770 
4771   MachineBasicBlock::iterator I(MI);
4772 
4773   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4774     // Mips release 6 can load from adress that is not naturally-aligned.
4775     Register Temp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4776     BuildMI(*BB, I, DL, TII->get(Mips::LW))
4777         .addDef(Temp)
4778         .addUse(Address)
4779         .addImm(Imm);
4780     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(Temp);
4781   } else {
4782     // Mips release 5 needs to use instructions that can load from an unaligned
4783     // memory address.
4784     Register LoadHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4785     Register LoadFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4786     Register Undef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4787     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(Undef);
4788     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4789         .addDef(LoadHalf)
4790         .addUse(Address)
4791         .addImm(Imm + (IsLittle ? 0 : 3))
4792         .addUse(Undef);
4793     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4794         .addDef(LoadFull)
4795         .addUse(Address)
4796         .addImm(Imm + (IsLittle ? 3 : 0))
4797         .addUse(LoadHalf);
4798     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(LoadFull);
4799   }
4800 
4801   MI.eraseFromParent();
4802   return BB;
4803 }
4804 
4805 MachineBasicBlock *MipsTargetLowering::emitLDR_D(MachineInstr &MI,
4806                                                  MachineBasicBlock *BB) const {
4807   MachineFunction *MF = BB->getParent();
4808   MachineRegisterInfo &MRI = MF->getRegInfo();
4809   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4810   const bool IsLittle = Subtarget.isLittle();
4811   DebugLoc DL = MI.getDebugLoc();
4812 
4813   Register Dest = MI.getOperand(0).getReg();
4814   Register Address = MI.getOperand(1).getReg();
4815   unsigned Imm = MI.getOperand(2).getImm();
4816 
4817   MachineBasicBlock::iterator I(MI);
4818 
4819   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4820     // Mips release 6 can load from adress that is not naturally-aligned.
4821     if (Subtarget.isGP64bit()) {
4822       Register Temp = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4823       BuildMI(*BB, I, DL, TII->get(Mips::LD))
4824           .addDef(Temp)
4825           .addUse(Address)
4826           .addImm(Imm);
4827       BuildMI(*BB, I, DL, TII->get(Mips::FILL_D)).addDef(Dest).addUse(Temp);
4828     } else {
4829       Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4830       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4831       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4832       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4833           .addDef(Lo)
4834           .addUse(Address)
4835           .addImm(Imm + (IsLittle ? 0 : 4));
4836       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4837           .addDef(Hi)
4838           .addUse(Address)
4839           .addImm(Imm + (IsLittle ? 4 : 0));
4840       BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(Lo);
4841       BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4842           .addUse(Wtemp)
4843           .addUse(Hi)
4844           .addImm(1);
4845     }
4846   } else {
4847     // Mips release 5 needs to use instructions that can load from an unaligned
4848     // memory address.
4849     Register LoHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4850     Register LoFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4851     Register LoUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4852     Register HiHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4853     Register HiFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4854     Register HiUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4855     Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4856     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(LoUndef);
4857     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4858         .addDef(LoHalf)
4859         .addUse(Address)
4860         .addImm(Imm + (IsLittle ? 0 : 7))
4861         .addUse(LoUndef);
4862     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4863         .addDef(LoFull)
4864         .addUse(Address)
4865         .addImm(Imm + (IsLittle ? 3 : 4))
4866         .addUse(LoHalf);
4867     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(HiUndef);
4868     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4869         .addDef(HiHalf)
4870         .addUse(Address)
4871         .addImm(Imm + (IsLittle ? 4 : 3))
4872         .addUse(HiUndef);
4873     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4874         .addDef(HiFull)
4875         .addUse(Address)
4876         .addImm(Imm + (IsLittle ? 7 : 0))
4877         .addUse(HiHalf);
4878     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(LoFull);
4879     BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4880         .addUse(Wtemp)
4881         .addUse(HiFull)
4882         .addImm(1);
4883   }
4884 
4885   MI.eraseFromParent();
4886   return BB;
4887 }
4888 
4889 MachineBasicBlock *MipsTargetLowering::emitSTR_W(MachineInstr &MI,
4890                                                  MachineBasicBlock *BB) const {
4891   MachineFunction *MF = BB->getParent();
4892   MachineRegisterInfo &MRI = MF->getRegInfo();
4893   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4894   const bool IsLittle = Subtarget.isLittle();
4895   DebugLoc DL = MI.getDebugLoc();
4896 
4897   Register StoreVal = MI.getOperand(0).getReg();
4898   Register Address = MI.getOperand(1).getReg();
4899   unsigned Imm = MI.getOperand(2).getImm();
4900 
4901   MachineBasicBlock::iterator I(MI);
4902 
4903   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4904     // Mips release 6 can store to adress that is not naturally-aligned.
4905     Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4906     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4907     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(BitcastW).addUse(StoreVal);
4908     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4909         .addDef(Tmp)
4910         .addUse(BitcastW)
4911         .addImm(0);
4912     BuildMI(*BB, I, DL, TII->get(Mips::SW))
4913         .addUse(Tmp)
4914         .addUse(Address)
4915         .addImm(Imm);
4916   } else {
4917     // Mips release 5 needs to use instructions that can store to an unaligned
4918     // memory address.
4919     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4920     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4921         .addDef(Tmp)
4922         .addUse(StoreVal)
4923         .addImm(0);
4924     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
4925         .addUse(Tmp)
4926         .addUse(Address)
4927         .addImm(Imm + (IsLittle ? 0 : 3));
4928     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
4929         .addUse(Tmp)
4930         .addUse(Address)
4931         .addImm(Imm + (IsLittle ? 3 : 0));
4932   }
4933 
4934   MI.eraseFromParent();
4935 
4936   return BB;
4937 }
4938 
4939 MachineBasicBlock *MipsTargetLowering::emitSTR_D(MachineInstr &MI,
4940                                                  MachineBasicBlock *BB) const {
4941   MachineFunction *MF = BB->getParent();
4942   MachineRegisterInfo &MRI = MF->getRegInfo();
4943   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4944   const bool IsLittle = Subtarget.isLittle();
4945   DebugLoc DL = MI.getDebugLoc();
4946 
4947   Register StoreVal = MI.getOperand(0).getReg();
4948   Register Address = MI.getOperand(1).getReg();
4949   unsigned Imm = MI.getOperand(2).getImm();
4950 
4951   MachineBasicBlock::iterator I(MI);
4952 
4953   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4954     // Mips release 6 can store to adress that is not naturally-aligned.
4955     if (Subtarget.isGP64bit()) {
4956       Register BitcastD = MRI.createVirtualRegister(&Mips::MSA128DRegClass);
4957       Register Lo = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4958       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
4959           .addDef(BitcastD)
4960           .addUse(StoreVal);
4961       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_D))
4962           .addDef(Lo)
4963           .addUse(BitcastD)
4964           .addImm(0);
4965       BuildMI(*BB, I, DL, TII->get(Mips::SD))
4966           .addUse(Lo)
4967           .addUse(Address)
4968           .addImm(Imm);
4969     } else {
4970       Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4971       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4972       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4973       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
4974           .addDef(BitcastW)
4975           .addUse(StoreVal);
4976       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4977           .addDef(Lo)
4978           .addUse(BitcastW)
4979           .addImm(0);
4980       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4981           .addDef(Hi)
4982           .addUse(BitcastW)
4983           .addImm(1);
4984       BuildMI(*BB, I, DL, TII->get(Mips::SW))
4985           .addUse(Lo)
4986           .addUse(Address)
4987           .addImm(Imm + (IsLittle ? 0 : 4));
4988       BuildMI(*BB, I, DL, TII->get(Mips::SW))
4989           .addUse(Hi)
4990           .addUse(Address)
4991           .addImm(Imm + (IsLittle ? 4 : 0));
4992     }
4993   } else {
4994     // Mips release 5 needs to use instructions that can store to an unaligned
4995     // memory address.
4996     Register Bitcast = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4997     Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4998     Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4999     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(Bitcast).addUse(StoreVal);
5000     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5001         .addDef(Lo)
5002         .addUse(Bitcast)
5003         .addImm(0);
5004     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5005         .addDef(Hi)
5006         .addUse(Bitcast)
5007         .addImm(1);
5008     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5009         .addUse(Lo)
5010         .addUse(Address)
5011         .addImm(Imm + (IsLittle ? 0 : 3));
5012     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5013         .addUse(Lo)
5014         .addUse(Address)
5015         .addImm(Imm + (IsLittle ? 3 : 0));
5016     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5017         .addUse(Hi)
5018         .addUse(Address)
5019         .addImm(Imm + (IsLittle ? 4 : 7));
5020     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5021         .addUse(Hi)
5022         .addUse(Address)
5023         .addImm(Imm + (IsLittle ? 7 : 4));
5024   }
5025 
5026   MI.eraseFromParent();
5027   return BB;
5028 }
5029