LLVM  15.0.0git
X86RegisterBankInfo.cpp
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1 //===- X86RegisterBankInfo.cpp -----------------------------------*- C++ -*-==//
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 /// \file
9 /// This file implements the targeting of the RegisterBankInfo class for X86.
10 /// \todo This should be generated by TableGen.
11 //===----------------------------------------------------------------------===//
12 
13 #include "X86RegisterBankInfo.h"
14 #include "X86InstrInfo.h"
19 
20 #define GET_TARGET_REGBANK_IMPL
21 #include "X86GenRegisterBank.inc"
22 
23 using namespace llvm;
24 // This file will be TableGen'ed at some point.
25 #define GET_TARGET_REGBANK_INFO_IMPL
26 #include "X86GenRegisterBankInfo.def"
27 
29 
30  // validate RegBank initialization.
31  const RegisterBank &RBGPR = getRegBank(X86::GPRRegBankID);
32  (void)RBGPR;
33  assert(&X86::GPRRegBank == &RBGPR && "Incorrect RegBanks inizalization.");
34 
35  // The GPR register bank is fully defined by all the registers in
36  // GR64 + its subclasses.
37  assert(RBGPR.covers(*TRI.getRegClass(X86::GR64RegClassID)) &&
38  "Subclass not added?");
39  assert(RBGPR.getSize() == 64 && "GPRs should hold up to 64-bit");
40 }
41 
42 const RegisterBank &
44  LLT) const {
45 
46  if (X86::GR8RegClass.hasSubClassEq(&RC) ||
47  X86::GR16RegClass.hasSubClassEq(&RC) ||
48  X86::GR32RegClass.hasSubClassEq(&RC) ||
49  X86::GR64RegClass.hasSubClassEq(&RC) ||
50  X86::LOW32_ADDR_ACCESSRegClass.hasSubClassEq(&RC) ||
51  X86::LOW32_ADDR_ACCESS_RBPRegClass.hasSubClassEq(&RC))
52  return getRegBank(X86::GPRRegBankID);
53 
54  if (X86::FR32XRegClass.hasSubClassEq(&RC) ||
55  X86::FR64XRegClass.hasSubClassEq(&RC) ||
56  X86::VR128XRegClass.hasSubClassEq(&RC) ||
57  X86::VR256XRegClass.hasSubClassEq(&RC) ||
58  X86::VR512RegClass.hasSubClassEq(&RC))
59  return getRegBank(X86::VECRRegBankID);
60 
61  llvm_unreachable("Unsupported register kind yet.");
62 }
63 
66  if ((Ty.isScalar() && !isFP) || Ty.isPointer()) {
67  switch (Ty.getSizeInBits()) {
68  case 1:
69  case 8:
70  return PMI_GPR8;
71  case 16:
72  return PMI_GPR16;
73  case 32:
74  return PMI_GPR32;
75  case 64:
76  return PMI_GPR64;
77  case 128:
78  return PMI_VEC128;
79  break;
80  default:
81  llvm_unreachable("Unsupported register size.");
82  }
83  } else if (Ty.isScalar()) {
84  switch (Ty.getSizeInBits()) {
85  case 32:
86  return PMI_FP32;
87  case 64:
88  return PMI_FP64;
89  case 128:
90  return PMI_VEC128;
91  default:
92  llvm_unreachable("Unsupported register size.");
93  }
94  } else {
95  switch (Ty.getSizeInBits()) {
96  case 128:
97  return PMI_VEC128;
98  case 256:
99  return PMI_VEC256;
100  case 512:
101  return PMI_VEC512;
102  default:
103  llvm_unreachable("Unsupported register size.");
104  }
105  }
106 
107  return PMI_None;
108 }
109 
110 void X86RegisterBankInfo::getInstrPartialMappingIdxs(
111  const MachineInstr &MI, const MachineRegisterInfo &MRI, const bool isFP,
112  SmallVectorImpl<PartialMappingIdx> &OpRegBankIdx) {
113 
114  unsigned NumOperands = MI.getNumOperands();
115  for (unsigned Idx = 0; Idx < NumOperands; ++Idx) {
116  auto &MO = MI.getOperand(Idx);
117  if (!MO.isReg())
118  OpRegBankIdx[Idx] = PMI_None;
119  else
120  OpRegBankIdx[Idx] = getPartialMappingIdx(MRI.getType(MO.getReg()), isFP);
121  }
122 }
123 
124 bool X86RegisterBankInfo::getInstrValueMapping(
125  const MachineInstr &MI,
126  const SmallVectorImpl<PartialMappingIdx> &OpRegBankIdx,
128 
129  unsigned NumOperands = MI.getNumOperands();
130  for (unsigned Idx = 0; Idx < NumOperands; ++Idx) {
131  if (!MI.getOperand(Idx).isReg())
132  continue;
133 
134  auto Mapping = getValueMapping(OpRegBankIdx[Idx], 1);
135  if (!Mapping->isValid())
136  return false;
137 
138  OpdsMapping[Idx] = Mapping;
139  }
140  return true;
141 }
142 
144 X86RegisterBankInfo::getSameOperandsMapping(const MachineInstr &MI,
145  bool isFP) const {
146  const MachineFunction &MF = *MI.getParent()->getParent();
147  const MachineRegisterInfo &MRI = MF.getRegInfo();
148 
149  unsigned NumOperands = MI.getNumOperands();
150  LLT Ty = MRI.getType(MI.getOperand(0).getReg());
151 
152  if (NumOperands != 3 || (Ty != MRI.getType(MI.getOperand(1).getReg())) ||
153  (Ty != MRI.getType(MI.getOperand(2).getReg())))
154  llvm_unreachable("Unsupported operand mapping yet.");
155 
156  auto Mapping = getValueMapping(getPartialMappingIdx(Ty, isFP), 3);
157  return getInstructionMapping(DefaultMappingID, 1, Mapping, NumOperands);
158 }
159 
162  const MachineFunction &MF = *MI.getParent()->getParent();
163  const MachineRegisterInfo &MRI = MF.getRegInfo();
164  unsigned Opc = MI.getOpcode();
165 
166  // Try the default logic for non-generic instructions that are either copies
167  // or already have some operands assigned to banks.
168  if (!isPreISelGenericOpcode(Opc) || Opc == TargetOpcode::G_PHI) {
169  const InstructionMapping &Mapping = getInstrMappingImpl(MI);
170  if (Mapping.isValid())
171  return Mapping;
172  }
173 
174  switch (Opc) {
175  case TargetOpcode::G_ADD:
176  case TargetOpcode::G_SUB:
177  case TargetOpcode::G_MUL:
178  return getSameOperandsMapping(MI, false);
179  case TargetOpcode::G_FADD:
180  case TargetOpcode::G_FSUB:
181  case TargetOpcode::G_FMUL:
182  case TargetOpcode::G_FDIV:
183  return getSameOperandsMapping(MI, true);
184  case TargetOpcode::G_SHL:
185  case TargetOpcode::G_LSHR:
186  case TargetOpcode::G_ASHR: {
187  unsigned NumOperands = MI.getNumOperands();
188  LLT Ty = MRI.getType(MI.getOperand(0).getReg());
189 
190  auto Mapping = getValueMapping(getPartialMappingIdx(Ty, false), 3);
191  return getInstructionMapping(DefaultMappingID, 1, Mapping, NumOperands);
192 
193  }
194  default:
195  break;
196  }
197 
198  unsigned NumOperands = MI.getNumOperands();
199  SmallVector<PartialMappingIdx, 4> OpRegBankIdx(NumOperands);
200 
201  switch (Opc) {
202  case TargetOpcode::G_FPEXT:
203  case TargetOpcode::G_FPTRUNC:
204  case TargetOpcode::G_FCONSTANT:
205  // Instruction having only floating-point operands (all scalars in VECRReg)
206  getInstrPartialMappingIdxs(MI, MRI, /* isFP */ true, OpRegBankIdx);
207  break;
208  case TargetOpcode::G_SITOFP:
209  case TargetOpcode::G_FPTOSI: {
210  // Some of the floating-point instructions have mixed GPR and FP operands:
211  // fine-tune the computed mapping.
212  auto &Op0 = MI.getOperand(0);
213  auto &Op1 = MI.getOperand(1);
214  const LLT Ty0 = MRI.getType(Op0.getReg());
215  const LLT Ty1 = MRI.getType(Op1.getReg());
216 
217  bool FirstArgIsFP = Opc == TargetOpcode::G_SITOFP;
218  bool SecondArgIsFP = Opc == TargetOpcode::G_FPTOSI;
219  OpRegBankIdx[0] = getPartialMappingIdx(Ty0, /* isFP */ FirstArgIsFP);
220  OpRegBankIdx[1] = getPartialMappingIdx(Ty1, /* isFP */ SecondArgIsFP);
221  break;
222  }
223  case TargetOpcode::G_FCMP: {
224  LLT Ty1 = MRI.getType(MI.getOperand(2).getReg());
225  LLT Ty2 = MRI.getType(MI.getOperand(3).getReg());
226  (void)Ty2;
227  assert(Ty1.getSizeInBits() == Ty2.getSizeInBits() &&
228  "Mismatched operand sizes for G_FCMP");
229 
230  unsigned Size = Ty1.getSizeInBits();
231  (void)Size;
232  assert((Size == 32 || Size == 64) && "Unsupported size for G_FCMP");
233 
234  auto FpRegBank = getPartialMappingIdx(Ty1, /* isFP */ true);
235  OpRegBankIdx = {PMI_GPR8,
236  /* Predicate */ PMI_None, FpRegBank, FpRegBank};
237  break;
238  }
239  case TargetOpcode::G_TRUNC:
240  case TargetOpcode::G_ANYEXT: {
241  auto &Op0 = MI.getOperand(0);
242  auto &Op1 = MI.getOperand(1);
243  const LLT Ty0 = MRI.getType(Op0.getReg());
244  const LLT Ty1 = MRI.getType(Op1.getReg());
245 
246  bool isFPTrunc = (Ty0.getSizeInBits() == 32 || Ty0.getSizeInBits() == 64) &&
247  Ty1.getSizeInBits() == 128 && Opc == TargetOpcode::G_TRUNC;
248  bool isFPAnyExt =
249  Ty0.getSizeInBits() == 128 &&
250  (Ty1.getSizeInBits() == 32 || Ty1.getSizeInBits() == 64) &&
251  Opc == TargetOpcode::G_ANYEXT;
252 
253  getInstrPartialMappingIdxs(MI, MRI, /* isFP */ isFPTrunc || isFPAnyExt,
254  OpRegBankIdx);
255  } break;
256  default:
257  // Track the bank of each register, use NotFP mapping (all scalars in GPRs)
258  getInstrPartialMappingIdxs(MI, MRI, /* isFP */ false, OpRegBankIdx);
259  break;
260  }
261 
262  // Finally construct the computed mapping.
263  SmallVector<const ValueMapping *, 8> OpdsMapping(NumOperands);
264  if (!getInstrValueMapping(MI, OpRegBankIdx, OpdsMapping))
266 
267  return getInstructionMapping(DefaultMappingID, /* Cost */ 1,
268  getOperandsMapping(OpdsMapping), NumOperands);
269 }
270 
272  const OperandsMapper &OpdMapper) const {
273  return applyDefaultMapping(OpdMapper);
274 }
275 
278 
279  const MachineFunction &MF = *MI.getParent()->getParent();
280  const TargetSubtargetInfo &STI = MF.getSubtarget();
281  const TargetRegisterInfo &TRI = *STI.getRegisterInfo();
282  const MachineRegisterInfo &MRI = MF.getRegInfo();
283 
284  switch (MI.getOpcode()) {
285  case TargetOpcode::G_LOAD:
286  case TargetOpcode::G_STORE:
287  case TargetOpcode::G_IMPLICIT_DEF: {
288  // we going to try to map 32/64 bit to PMI_FP32/PMI_FP64
289  unsigned Size = getSizeInBits(MI.getOperand(0).getReg(), MRI, TRI);
290  if (Size != 32 && Size != 64)
291  break;
292 
293  unsigned NumOperands = MI.getNumOperands();
294 
295  // Track the bank of each register, use FP mapping (all scalars in VEC)
296  SmallVector<PartialMappingIdx, 4> OpRegBankIdx(NumOperands);
297  getInstrPartialMappingIdxs(MI, MRI, /* isFP */ true, OpRegBankIdx);
298 
299  // Finally construct the computed mapping.
300  SmallVector<const ValueMapping *, 8> OpdsMapping(NumOperands);
301  if (!getInstrValueMapping(MI, OpRegBankIdx, OpdsMapping))
302  break;
303 
305  /*ID*/ 1, /*Cost*/ 1, getOperandsMapping(OpdsMapping), NumOperands);
306  InstructionMappings AltMappings;
307  AltMappings.push_back(&Mapping);
308  return AltMappings;
309  }
310  default:
311  break;
312  }
314 }
MI
IRTranslator LLVM IR MI
Definition: IRTranslator.cpp:104
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:17
llvm::X86RegisterBankInfo::applyMappingImpl
void applyMappingImpl(const OperandsMapper &OpdMapper) const override
See RegisterBankInfo::applyMapping.
Definition: X86RegisterBankInfo.cpp:271
llvm::RegisterBankInfo::getInstrMappingImpl
const InstructionMapping & getInstrMappingImpl(const MachineInstr &MI) const
Try to get the mapping of MI.
Definition: RegisterBankInfo.cpp:159
llvm::MachineRegisterInfo
MachineRegisterInfo - Keep track of information for virtual and physical registers,...
Definition: MachineRegisterInfo.h:50
llvm::SmallVector
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1185
llvm::isPreISelGenericOpcode
bool isPreISelGenericOpcode(unsigned Opcode)
Check whether the given Opcode is a generic opcode that is not supposed to appear after ISel.
Definition: TargetOpcodes.h:30
llvm::RegisterBankInfo::getRegBank
RegisterBank & getRegBank(unsigned ID)
Get the register bank identified by ID.
Definition: RegisterBankInfo.h:431
RegisterBankInfo.h
llvm::RegisterBankInfo::applyDefaultMapping
static void applyDefaultMapping(const OperandsMapper &OpdMapper)
Helper method to apply something that is like the default mapping.
Definition: RegisterBankInfo.cpp:435
llvm::TargetSubtargetInfo::getRegisterInfo
virtual const TargetRegisterInfo * getRegisterInfo() const
getRegisterInfo - If register information is available, return it.
Definition: TargetSubtargetInfo.h:125
llvm::TargetRegisterInfo
TargetRegisterInfo base class - We assume that the target defines a static array of TargetRegisterDes...
Definition: TargetRegisterInfo.h:234
llvm::RegisterBankInfo::InstructionMapping::isValid
bool isValid() const
Check whether this object is valid.
Definition: RegisterBankInfo.h:253
llvm::X86RegisterBankInfo::getInstrMapping
const InstructionMapping & getInstrMapping(const MachineInstr &MI) const override
Get the mapping of the different operands of MI on the register bank.
Definition: X86RegisterBankInfo.cpp:161
TRI
unsigned const TargetRegisterInfo * TRI
Definition: MachineSink.cpp:1628
llvm::X86GenRegisterBankInfo::getPartialMappingIdx
static PartialMappingIdx getPartialMappingIdx(const LLT &Ty, bool isFP)
Definition: X86RegisterBankInfo.cpp:65
MachineRegisterInfo.h
llvm::MachineFunction::getRegInfo
MachineRegisterInfo & getRegInfo()
getRegInfo - Return information about the registers currently in use.
Definition: MachineFunction.h:666
llvm::RegisterBank
This class implements the register bank concept.
Definition: RegisterBank.h:28
llvm::LLT::getSizeInBits
TypeSize getSizeInBits() const
Returns the total size of the type. Must only be called on sized types.
Definition: LowLevelTypeImpl.h:152
llvm::TargetRegisterClass
Definition: TargetRegisterInfo.h:45
llvm::X86RegisterBankInfo::X86RegisterBankInfo
X86RegisterBankInfo(const TargetRegisterInfo &TRI)
Definition: X86RegisterBankInfo.cpp:28
llvm::RegisterBankInfo::getInstrAlternativeMappings
virtual InstructionMappings getInstrAlternativeMappings(const MachineInstr &MI) const
Get the alternative mappings for MI.
Definition: RegisterBankInfo.cpp:430
llvm::RegisterBankInfo::getSizeInBits
unsigned getSizeInBits(Register Reg, const MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI) const
Get the size in bits of Reg.
Definition: RegisterBankInfo.cpp:490
llvm::RegisterBankInfo::OperandsMapper
Helper class used to get/create the virtual registers that will be used to replace the MachineOperand...
Definition: RegisterBankInfo.h:279
llvm::MachineFunction::getSubtarget
const TargetSubtargetInfo & getSubtarget() const
getSubtarget - Return the subtarget for which this machine code is being compiled.
Definition: MachineFunction.h:656
llvm::TargetRegisterInfo::getRegClass
const TargetRegisterClass * getRegClass(unsigned i) const
Returns the register class associated with the enumeration value.
Definition: TargetRegisterInfo.h:750
llvm::X86RegisterBankInfo::getRegBankFromRegClass
const RegisterBank & getRegBankFromRegClass(const TargetRegisterClass &RC, LLT) const override
Get a register bank that covers RC.
Definition: X86RegisterBankInfo.cpp:43
llvm::MachineInstr
Representation of each machine instruction.
Definition: MachineInstr.h:66
llvm::RegisterBankInfo::InstructionMapping
Helper class that represents how the value of an instruction may be mapped and what is the related co...
Definition: RegisterBankInfo.h:189
X86RegisterBankInfo.h
llvm::RegisterBankInfo::DefaultMappingID
static const unsigned DefaultMappingID
Identifier used when the related instruction mapping instance is generated by target independent code...
Definition: RegisterBankInfo.h:652
llvm::RegisterBankInfo::getOperandsMapping
const ValueMapping * getOperandsMapping(Iterator Begin, Iterator End) const
Get the uniquely generated array of ValueMapping for the elements of between Begin and End.
Definition: RegisterBankInfo.cpp:329
llvm::RegisterBank::covers
bool covers(const TargetRegisterClass &RC) const
Check whether this register bank covers RC.
Definition: RegisterBank.cpp:61
assert
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
llvm::LLT::isPointer
bool isPointer() const
Definition: LowLevelTypeImpl.h:120
llvm::X86GenRegisterBankInfo::getValueMapping
static const RegisterBankInfo::ValueMapping * getValueMapping(PartialMappingIdx Idx, unsigned NumOperands)
llvm::LLT::isScalar
bool isScalar() const
Definition: LowLevelTypeImpl.h:118
llvm::MachineFunction
Definition: MachineFunction.h:257
llvm::RegisterBankInfo::getInstructionMapping
const InstructionMapping & getInstructionMapping(unsigned ID, unsigned Cost, const ValueMapping *OperandsMapping, unsigned NumOperands) const
Method to get a uniquely generated InstructionMapping.
Definition: RegisterBankInfo.h:525
llvm_unreachable
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Definition: ErrorHandling.h:143
llvm::TargetSubtargetInfo
TargetSubtargetInfo - Generic base class for all target subtargets.
Definition: TargetSubtargetInfo.h:60
MRI
unsigned const MachineRegisterInfo * MRI
Definition: AArch64AdvSIMDScalarPass.cpp:105
llvm::X86RegisterBankInfo::getInstrAlternativeMappings
InstructionMappings getInstrAlternativeMappings(const MachineInstr &MI) const override
Get the alternative mappings for MI.
Definition: X86RegisterBankInfo.cpp:277
llvm::RegisterBank::getSize
unsigned getSize() const
Get the maximal size in bits that fits in this register bank.
Definition: RegisterBank.h:54
llvm::RegisterBankInfo::getInvalidInstructionMapping
const InstructionMapping & getInvalidInstructionMapping() const
Method to get a uniquely generated invalid InstructionMapping.
Definition: RegisterBankInfo.h:533
llvm::MachineRegisterInfo::getType
LLT getType(Register Reg) const
Get the low-level type of Reg or LLT{} if Reg is not a generic (target independent) virtual register.
Definition: MachineRegisterInfo.h:740
RegisterBank.h
llvm::ARM::PartialMappingIdx
PartialMappingIdx
Definition: ARMRegisterBankInfo.cpp:31
llvm::SmallVectorImpl
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:42
X86InstrInfo.h
TargetRegisterInfo.h
llvm::LLT
Definition: LowLevelTypeImpl.h:39