xref: /llvm-project/llvm/lib/Target/Hexagon/HexagonRegisterInfo.cpp (revision 22a21d4c5d16c6acf5ff9b628df15df0e06dbdff)
1 //===-- HexagonRegisterInfo.cpp - Hexagon Register Information ------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains the Hexagon implementation of the TargetRegisterInfo
11 // class.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "HexagonRegisterInfo.h"
16 #include "Hexagon.h"
17 #include "HexagonMachineFunctionInfo.h"
18 #include "HexagonSubtarget.h"
19 #include "HexagonTargetMachine.h"
20 #include "llvm/ADT/BitVector.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/CodeGen/MachineFrameInfo.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineFunctionPass.h"
25 #include "llvm/CodeGen/MachineInstrBuilder.h"
26 #include "llvm/CodeGen/MachineRegisterInfo.h"
27 #include "llvm/CodeGen/PseudoSourceValue.h"
28 #include "llvm/CodeGen/RegisterScavenging.h"
29 #include "llvm/CodeGen/TargetInstrInfo.h"
30 #include "llvm/IR/Function.h"
31 #include "llvm/IR/Type.h"
32 #include "llvm/MC/MachineLocation.h"
33 #include "llvm/Support/Debug.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/raw_ostream.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetOptions.h"
38 
39 #define GET_REGINFO_TARGET_DESC
40 #include "HexagonGenRegisterInfo.inc"
41 
42 using namespace llvm;
43 
44 HexagonRegisterInfo::HexagonRegisterInfo(unsigned HwMode)
45     : HexagonGenRegisterInfo(Hexagon::R31, 0/*DwarfFlavor*/, 0/*EHFlavor*/,
46                              0/*PC*/, HwMode) {}
47 
48 
49 bool HexagonRegisterInfo::isEHReturnCalleeSaveReg(unsigned R) const {
50   return R == Hexagon::R0 || R == Hexagon::R1 || R == Hexagon::R2 ||
51          R == Hexagon::R3 || R == Hexagon::D0 || R == Hexagon::D1;
52 }
53 
54 const MCPhysReg *
55 HexagonRegisterInfo::getCallerSavedRegs(const MachineFunction *MF,
56       const TargetRegisterClass *RC) const {
57   using namespace Hexagon;
58 
59   static const MCPhysReg Int32[] = {
60     R0, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, 0
61   };
62   static const MCPhysReg Int64[] = {
63     D0, D1, D2, D3, D4, D5, D6, D7, 0
64   };
65   static const MCPhysReg Pred[] = {
66     P0, P1, P2, P3, 0
67   };
68   static const MCPhysReg VecSgl[] = {
69      V0,  V1,  V2,  V3,  V4,  V5,  V6,  V7,  V8,  V9, V10, V11, V12, V13,
70     V14, V15, V16, V17, V18, V19, V20, V21, V22, V23, V24, V25, V26, V27,
71     V28, V29, V30, V31,   0
72   };
73   static const MCPhysReg VecDbl[] = {
74     W0, W1, W2, W3, W4, W5, W6, W7, W8, W9, W10, W11, W12, W13, W14, W15, 0
75   };
76 
77   switch (RC->getID()) {
78     case IntRegsRegClassID:
79       return Int32;
80     case DoubleRegsRegClassID:
81       return Int64;
82     case PredRegsRegClassID:
83       return Pred;
84     case HvxVRRegClassID:
85       return VecSgl;
86     case HvxWRRegClassID:
87       return VecDbl;
88     default:
89       break;
90   }
91 
92   static const MCPhysReg Empty[] = { 0 };
93 #ifndef NDEBUG
94   dbgs() << "Register class: " << getRegClassName(RC) << "\n";
95 #endif
96   llvm_unreachable("Unexpected register class");
97   return Empty;
98 }
99 
100 
101 const MCPhysReg *
102 HexagonRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
103   static const MCPhysReg CalleeSavedRegsV3[] = {
104     Hexagon::R16,   Hexagon::R17,   Hexagon::R18,   Hexagon::R19,
105     Hexagon::R20,   Hexagon::R21,   Hexagon::R22,   Hexagon::R23,
106     Hexagon::R24,   Hexagon::R25,   Hexagon::R26,   Hexagon::R27, 0
107   };
108 
109   // Functions that contain a call to __builtin_eh_return also save the first 4
110   // parameter registers.
111   static const MCPhysReg CalleeSavedRegsV3EHReturn[] = {
112     Hexagon::R0,    Hexagon::R1,    Hexagon::R2,    Hexagon::R3,
113     Hexagon::R16,   Hexagon::R17,   Hexagon::R18,   Hexagon::R19,
114     Hexagon::R20,   Hexagon::R21,   Hexagon::R22,   Hexagon::R23,
115     Hexagon::R24,   Hexagon::R25,   Hexagon::R26,   Hexagon::R27, 0
116   };
117 
118   bool HasEHReturn = MF->getInfo<HexagonMachineFunctionInfo>()->hasEHReturn();
119 
120   switch (MF->getSubtarget<HexagonSubtarget>().getHexagonArchVersion()) {
121   case Hexagon::ArchEnum::V4:
122   case Hexagon::ArchEnum::V5:
123   case Hexagon::ArchEnum::V55:
124   case Hexagon::ArchEnum::V60:
125   case Hexagon::ArchEnum::V62:
126   case Hexagon::ArchEnum::V65:
127     return HasEHReturn ? CalleeSavedRegsV3EHReturn : CalleeSavedRegsV3;
128   }
129 
130   llvm_unreachable("Callee saved registers requested for unknown architecture "
131                    "version");
132 }
133 
134 
135 const uint32_t *HexagonRegisterInfo::getCallPreservedMask(
136       const MachineFunction &MF, CallingConv::ID) const {
137   return HexagonCSR_RegMask;
138 }
139 
140 
141 BitVector HexagonRegisterInfo::getReservedRegs(const MachineFunction &MF)
142   const {
143   BitVector Reserved(getNumRegs());
144   Reserved.set(Hexagon::R29);
145   Reserved.set(Hexagon::R30);
146   Reserved.set(Hexagon::R31);
147   Reserved.set(Hexagon::VTMP);
148 
149   // Guest registers.
150   Reserved.set(Hexagon::GELR);        // G0
151   Reserved.set(Hexagon::GSR);         // G1
152   Reserved.set(Hexagon::GOSP);        // G2
153   Reserved.set(Hexagon::G3);          // G3
154 
155   // Control registers.
156   Reserved.set(Hexagon::SA0);         // C0
157   Reserved.set(Hexagon::LC0);         // C1
158   Reserved.set(Hexagon::SA1);         // C2
159   Reserved.set(Hexagon::LC1);         // C3
160   Reserved.set(Hexagon::P3_0);        // C4
161   Reserved.set(Hexagon::USR);         // C8
162   Reserved.set(Hexagon::PC);          // C9
163   Reserved.set(Hexagon::UGP);         // C10
164   Reserved.set(Hexagon::GP);          // C11
165   Reserved.set(Hexagon::CS0);         // C12
166   Reserved.set(Hexagon::CS1);         // C13
167   Reserved.set(Hexagon::UPCYCLELO);   // C14
168   Reserved.set(Hexagon::UPCYCLEHI);   // C15
169   Reserved.set(Hexagon::FRAMELIMIT);  // C16
170   Reserved.set(Hexagon::FRAMEKEY);    // C17
171   Reserved.set(Hexagon::PKTCOUNTLO);  // C18
172   Reserved.set(Hexagon::PKTCOUNTHI);  // C19
173   Reserved.set(Hexagon::UTIMERLO);    // C30
174   Reserved.set(Hexagon::UTIMERHI);    // C31
175   // Out of the control registers, only C8 is explicitly defined in
176   // HexagonRegisterInfo.td. If others are defined, make sure to add
177   // them here as well.
178   Reserved.set(Hexagon::C8);
179   Reserved.set(Hexagon::USR_OVF);
180 
181   if (MF.getSubtarget<HexagonSubtarget>().hasReservedR19())
182     Reserved.set(Hexagon::R19);
183 
184   for (int x = Reserved.find_first(); x >= 0; x = Reserved.find_next(x))
185     markSuperRegs(Reserved, x);
186 
187   return Reserved;
188 }
189 
190 
191 void HexagonRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
192                                               int SPAdj, unsigned FIOp,
193                                               RegScavenger *RS) const {
194   //
195   // Hexagon_TODO: Do we need to enforce this for Hexagon?
196   assert(SPAdj == 0 && "Unexpected");
197 
198   MachineInstr &MI = *II;
199   MachineBasicBlock &MB = *MI.getParent();
200   MachineFunction &MF = *MB.getParent();
201   auto &HST = MF.getSubtarget<HexagonSubtarget>();
202   auto &HII = *HST.getInstrInfo();
203   auto &HFI = *HST.getFrameLowering();
204 
205   unsigned BP = 0;
206   int FI = MI.getOperand(FIOp).getIndex();
207   // Select the base pointer (BP) and calculate the actual offset from BP
208   // to the beginning of the object at index FI.
209   int Offset = HFI.getFrameIndexReference(MF, FI, BP);
210   // Add the offset from the instruction.
211   int RealOffset = Offset + MI.getOperand(FIOp+1).getImm();
212   bool IsKill = false;
213 
214   unsigned Opc = MI.getOpcode();
215   switch (Opc) {
216     case Hexagon::PS_fia:
217       MI.setDesc(HII.get(Hexagon::A2_addi));
218       MI.getOperand(FIOp).ChangeToImmediate(RealOffset);
219       MI.RemoveOperand(FIOp+1);
220       return;
221     case Hexagon::PS_fi:
222       // Set up the instruction for updating below.
223       MI.setDesc(HII.get(Hexagon::A2_addi));
224       break;
225   }
226 
227   if (!HII.isValidOffset(Opc, RealOffset, this)) {
228     // If the offset is not valid, calculate the address in a temporary
229     // register and use it with offset 0.
230     auto &MRI = MF.getRegInfo();
231     unsigned TmpR = MRI.createVirtualRegister(&Hexagon::IntRegsRegClass);
232     const DebugLoc &DL = MI.getDebugLoc();
233     BuildMI(MB, II, DL, HII.get(Hexagon::A2_addi), TmpR)
234       .addReg(BP)
235       .addImm(RealOffset);
236     BP = TmpR;
237     RealOffset = 0;
238     IsKill = true;
239   }
240 
241   MI.getOperand(FIOp).ChangeToRegister(BP, false, false, IsKill);
242   MI.getOperand(FIOp+1).ChangeToImmediate(RealOffset);
243 }
244 
245 
246 unsigned HexagonRegisterInfo::getRARegister() const {
247   return Hexagon::R31;
248 }
249 
250 
251 unsigned HexagonRegisterInfo::getFrameRegister(const MachineFunction
252                                                &MF) const {
253   const HexagonFrameLowering *TFI = getFrameLowering(MF);
254   if (TFI->hasFP(MF))
255     return getFrameRegister();
256   return getStackRegister();
257 }
258 
259 
260 unsigned HexagonRegisterInfo::getFrameRegister() const {
261   return Hexagon::R30;
262 }
263 
264 
265 unsigned HexagonRegisterInfo::getStackRegister() const {
266   return Hexagon::R29;
267 }
268 
269 
270 unsigned HexagonRegisterInfo::getHexagonSubRegIndex(
271       const TargetRegisterClass &RC, unsigned GenIdx) const {
272   assert(GenIdx == Hexagon::ps_sub_lo || GenIdx == Hexagon::ps_sub_hi);
273 
274   static const unsigned ISub[] = { Hexagon::isub_lo, Hexagon::isub_hi };
275   static const unsigned VSub[] = { Hexagon::vsub_lo, Hexagon::vsub_hi };
276 
277   switch (RC.getID()) {
278     case Hexagon::CtrRegs64RegClassID:
279     case Hexagon::DoubleRegsRegClassID:
280       return ISub[GenIdx];
281     case Hexagon::HvxWRRegClassID:
282       return VSub[GenIdx];
283   }
284 
285   if (const TargetRegisterClass *SuperRC = *RC.getSuperClasses())
286     return getHexagonSubRegIndex(*SuperRC, GenIdx);
287 
288   llvm_unreachable("Invalid register class");
289 }
290 
291 bool HexagonRegisterInfo::useFPForScavengingIndex(const MachineFunction &MF)
292       const {
293   return MF.getSubtarget<HexagonSubtarget>().getFrameLowering()->hasFP(MF);
294 }
295 
296 const TargetRegisterClass *
297 HexagonRegisterInfo::getPointerRegClass(const MachineFunction &MF,
298                                         unsigned Kind) const {
299   return &Hexagon::IntRegsRegClass;
300 }
301 
302 unsigned HexagonRegisterInfo::getFirstCallerSavedNonParamReg() const {
303   return Hexagon::R6;
304 }
305 
306