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llvm-project/llvm/lib/Target/Mips/MipsFastISel.cpp

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//===-- MipsFastISel.cpp - Mips FastISel implementation --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file defines the MIPS-specific support for the FastISel class.
/// Some of the target-specific code is generated by tablegen in the file
/// MipsGenFastISel.inc, which is #included here.
///
//===----------------------------------------------------------------------===//
#include "MipsCCState.h"
#include "MipsInstrInfo.h"
#include "MipsISelLowering.h"
#include "MipsMachineFunction.h"
#include "MipsRegisterInfo.h"
#include "MipsSubtarget.h"
#include "MipsTargetMachine.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Support/Debug.h"
#define DEBUG_TYPE "mips-fastisel"
using namespace llvm;
namespace {
class MipsFastISel final : public FastISel {
// All possible address modes.
class Address {
public:
typedef enum { RegBase, FrameIndexBase } BaseKind;
private:
BaseKind Kind;
union {
unsigned Reg;
int FI;
} Base;
int64_t Offset;
const GlobalValue *GV;
public:
// Innocuous defaults for our address.
Address() : Kind(RegBase), Offset(0), GV(0) { Base.Reg = 0; }
void setKind(BaseKind K) { Kind = K; }
BaseKind getKind() const { return Kind; }
bool isRegBase() const { return Kind == RegBase; }
bool isFIBase() const { return Kind == FrameIndexBase; }
void setReg(unsigned Reg) {
assert(isRegBase() && "Invalid base register access!");
Base.Reg = Reg;
}
unsigned getReg() const {
assert(isRegBase() && "Invalid base register access!");
return Base.Reg;
}
void setFI(unsigned FI) {
assert(isFIBase() && "Invalid base frame index access!");
Base.FI = FI;
}
unsigned getFI() const {
assert(isFIBase() && "Invalid base frame index access!");
return Base.FI;
}
void setOffset(int64_t Offset_) { Offset = Offset_; }
int64_t getOffset() const { return Offset; }
void setGlobalValue(const GlobalValue *G) { GV = G; }
const GlobalValue *getGlobalValue() { return GV; }
};
/// Subtarget - Keep a pointer to the MipsSubtarget around so that we can
/// make the right decision when generating code for different targets.
const TargetMachine &TM;
const MipsSubtarget *Subtarget;
const TargetInstrInfo &TII;
const TargetLowering &TLI;
MipsFunctionInfo *MFI;
// Convenience variables to avoid some queries.
LLVMContext *Context;
bool fastLowerArguments() override;
bool fastLowerCall(CallLoweringInfo &CLI) override;
bool fastLowerIntrinsicCall(const IntrinsicInst *II) override;
bool TargetSupported;
bool UnsupportedFPMode; // To allow fast-isel to proceed and just not handle
// floating point but not reject doing fast-isel in other
// situations
private:
// Selection routines.
bool selectLogicalOp(const Instruction *I);
bool selectLoad(const Instruction *I);
bool selectStore(const Instruction *I);
bool selectBranch(const Instruction *I);
bool selectSelect(const Instruction *I);
bool selectCmp(const Instruction *I);
bool selectFPExt(const Instruction *I);
bool selectFPTrunc(const Instruction *I);
bool selectFPToInt(const Instruction *I, bool IsSigned);
bool selectRet(const Instruction *I);
bool selectTrunc(const Instruction *I);
bool selectIntExt(const Instruction *I);
bool selectShift(const Instruction *I);
bool selectDivRem(const Instruction *I, unsigned ISDOpcode);
// Utility helper routines.
bool isTypeLegal(Type *Ty, MVT &VT);
bool isTypeSupported(Type *Ty, MVT &VT);
bool isLoadTypeLegal(Type *Ty, MVT &VT);
bool computeAddress(const Value *Obj, Address &Addr);
bool computeCallAddress(const Value *V, Address &Addr);
void simplifyAddress(Address &Addr);
// Emit helper routines.
bool emitCmp(unsigned DestReg, const CmpInst *CI);
bool emitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
unsigned Alignment = 0);
bool emitStore(MVT VT, unsigned SrcReg, Address Addr,
MachineMemOperand *MMO = nullptr);
bool emitStore(MVT VT, unsigned SrcReg, Address &Addr,
unsigned Alignment = 0);
unsigned emitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, bool isZExt);
bool emitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg,
bool IsZExt);
bool emitIntZExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg);
bool emitIntSExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg);
bool emitIntSExt32r1(MVT SrcVT, unsigned SrcReg, MVT DestVT,
unsigned DestReg);
bool emitIntSExt32r2(MVT SrcVT, unsigned SrcReg, MVT DestVT,
unsigned DestReg);
unsigned getRegEnsuringSimpleIntegerWidening(const Value *, bool IsUnsigned);
unsigned emitLogicalOp(unsigned ISDOpc, MVT RetVT, const Value *LHS,
const Value *RHS);
unsigned materializeFP(const ConstantFP *CFP, MVT VT);
unsigned materializeGV(const GlobalValue *GV, MVT VT);
unsigned materializeInt(const Constant *C, MVT VT);
unsigned materialize32BitInt(int64_t Imm, const TargetRegisterClass *RC);
unsigned materializeExternalCallSym(MCSymbol *Syn);
MachineInstrBuilder emitInst(unsigned Opc) {
return BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc));
}
MachineInstrBuilder emitInst(unsigned Opc, unsigned DstReg) {
return BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc),
DstReg);
}
MachineInstrBuilder emitInstStore(unsigned Opc, unsigned SrcReg,
unsigned MemReg, int64_t MemOffset) {
return emitInst(Opc).addReg(SrcReg).addReg(MemReg).addImm(MemOffset);
}
MachineInstrBuilder emitInstLoad(unsigned Opc, unsigned DstReg,
unsigned MemReg, int64_t MemOffset) {
return emitInst(Opc, DstReg).addReg(MemReg).addImm(MemOffset);
}
unsigned fastEmitInst_rr(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill);
// for some reason, this default is not generated by tablegen
// so we explicitly generate it here.
//
unsigned fastEmitInst_riir(uint64_t inst, const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill, uint64_t imm1,
uint64_t imm2, unsigned Op3, bool Op3IsKill) {
return 0;
}
// Call handling routines.
private:
CCAssignFn *CCAssignFnForCall(CallingConv::ID CC) const;
bool processCallArgs(CallLoweringInfo &CLI, SmallVectorImpl<MVT> &ArgVTs,
unsigned &NumBytes);
bool finishCall(CallLoweringInfo &CLI, MVT RetVT, unsigned NumBytes);
const MipsABIInfo &getABI() const {
return static_cast<const MipsTargetMachine &>(TM).getABI();
}
public:
// Backend specific FastISel code.
explicit MipsFastISel(FunctionLoweringInfo &funcInfo,
const TargetLibraryInfo *libInfo)
: FastISel(funcInfo, libInfo), TM(funcInfo.MF->getTarget()),
Subtarget(&funcInfo.MF->getSubtarget<MipsSubtarget>()),
TII(*Subtarget->getInstrInfo()), TLI(*Subtarget->getTargetLowering()) {
MFI = funcInfo.MF->getInfo<MipsFunctionInfo>();
Context = &funcInfo.Fn->getContext();
bool ISASupported = !Subtarget->hasMips32r6() &&
!Subtarget->inMicroMipsMode() && Subtarget->hasMips32();
TargetSupported =
ISASupported && TM.isPositionIndependent() && getABI().IsO32();
UnsupportedFPMode = Subtarget->isFP64bit();
}
unsigned fastMaterializeAlloca(const AllocaInst *AI) override;
unsigned fastMaterializeConstant(const Constant *C) override;
bool fastSelectInstruction(const Instruction *I) override;
#include "MipsGenFastISel.inc"
};
} // end anonymous namespace.
static bool CC_Mips(unsigned ValNo, MVT ValVT, MVT LocVT,
CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
CCState &State) LLVM_ATTRIBUTE_UNUSED;
static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT, MVT LocVT,
CCValAssign::LocInfo LocInfo,
ISD::ArgFlagsTy ArgFlags, CCState &State) {
llvm_unreachable("should not be called");
}
static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT, MVT LocVT,
CCValAssign::LocInfo LocInfo,
ISD::ArgFlagsTy ArgFlags, CCState &State) {
llvm_unreachable("should not be called");
}
#include "MipsGenCallingConv.inc"
CCAssignFn *MipsFastISel::CCAssignFnForCall(CallingConv::ID CC) const {
return CC_MipsO32;
}
unsigned MipsFastISel::emitLogicalOp(unsigned ISDOpc, MVT RetVT,
const Value *LHS, const Value *RHS) {
// Canonicalize immediates to the RHS first.
if (isa<ConstantInt>(LHS) && !isa<ConstantInt>(RHS))
std::swap(LHS, RHS);
unsigned Opc;
switch (ISDOpc) {
case ISD::AND:
Opc = Mips::AND;
break;
case ISD::OR:
Opc = Mips::OR;
break;
case ISD::XOR:
Opc = Mips::XOR;
break;
default:
llvm_unreachable("unexpected opcode");
}
unsigned LHSReg = getRegForValue(LHS);
if (!LHSReg)
return 0;
unsigned RHSReg;
if (const auto *C = dyn_cast<ConstantInt>(RHS))
RHSReg = materializeInt(C, MVT::i32);
else
RHSReg = getRegForValue(RHS);
if (!RHSReg)
return 0;
unsigned ResultReg = createResultReg(&Mips::GPR32RegClass);
if (!ResultReg)
return 0;
emitInst(Opc, ResultReg).addReg(LHSReg).addReg(RHSReg);
return ResultReg;
}
unsigned MipsFastISel::fastMaterializeAlloca(const AllocaInst *AI) {
if (!TargetSupported)
return 0;
assert(TLI.getValueType(DL, AI->getType(), true) == MVT::i32 &&
"Alloca should always return a pointer.");
DenseMap<const AllocaInst *, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
unsigned ResultReg = createResultReg(&Mips::GPR32RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::LEA_ADDiu),
ResultReg)
.addFrameIndex(SI->second)
.addImm(0);
return ResultReg;
}
return 0;
}
unsigned MipsFastISel::materializeInt(const Constant *C, MVT VT) {
if (VT != MVT::i32 && VT != MVT::i16 && VT != MVT::i8 && VT != MVT::i1)
return 0;
const TargetRegisterClass *RC = &Mips::GPR32RegClass;
const ConstantInt *CI = cast<ConstantInt>(C);
return materialize32BitInt(CI->getZExtValue(), RC);
}
unsigned MipsFastISel::materialize32BitInt(int64_t Imm,
const TargetRegisterClass *RC) {
unsigned ResultReg = createResultReg(RC);
if (isInt<16>(Imm)) {
unsigned Opc = Mips::ADDiu;
emitInst(Opc, ResultReg).addReg(Mips::ZERO).addImm(Imm);
return ResultReg;
} else if (isUInt<16>(Imm)) {
emitInst(Mips::ORi, ResultReg).addReg(Mips::ZERO).addImm(Imm);
return ResultReg;
}
unsigned Lo = Imm & 0xFFFF;
unsigned Hi = (Imm >> 16) & 0xFFFF;
if (Lo) {
// Both Lo and Hi have nonzero bits.
unsigned TmpReg = createResultReg(RC);
emitInst(Mips::LUi, TmpReg).addImm(Hi);
emitInst(Mips::ORi, ResultReg).addReg(TmpReg).addImm(Lo);
} else {
emitInst(Mips::LUi, ResultReg).addImm(Hi);
}
return ResultReg;
}
unsigned MipsFastISel::materializeFP(const ConstantFP *CFP, MVT VT) {
if (UnsupportedFPMode)
return 0;
int64_t Imm = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
if (VT == MVT::f32) {
const TargetRegisterClass *RC = &Mips::FGR32RegClass;
unsigned DestReg = createResultReg(RC);
unsigned TempReg = materialize32BitInt(Imm, &Mips::GPR32RegClass);
emitInst(Mips::MTC1, DestReg).addReg(TempReg);
return DestReg;
} else if (VT == MVT::f64) {
const TargetRegisterClass *RC = &Mips::AFGR64RegClass;
unsigned DestReg = createResultReg(RC);
unsigned TempReg1 = materialize32BitInt(Imm >> 32, &Mips::GPR32RegClass);
unsigned TempReg2 =
materialize32BitInt(Imm & 0xFFFFFFFF, &Mips::GPR32RegClass);
emitInst(Mips::BuildPairF64, DestReg).addReg(TempReg2).addReg(TempReg1);
return DestReg;
}
return 0;
}
unsigned MipsFastISel::materializeGV(const GlobalValue *GV, MVT VT) {
// For now 32-bit only.
if (VT != MVT::i32)
return 0;
const TargetRegisterClass *RC = &Mips::GPR32RegClass;
unsigned DestReg = createResultReg(RC);
const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
bool IsThreadLocal = GVar && GVar->isThreadLocal();
// TLS not supported at this time.
if (IsThreadLocal)
return 0;
emitInst(Mips::LW, DestReg)
.addReg(MFI->getGlobalBaseReg())
.addGlobalAddress(GV, 0, MipsII::MO_GOT);
if ((GV->hasInternalLinkage() ||
(GV->hasLocalLinkage() && !isa<Function>(GV)))) {
unsigned TempReg = createResultReg(RC);
emitInst(Mips::ADDiu, TempReg)
.addReg(DestReg)
.addGlobalAddress(GV, 0, MipsII::MO_ABS_LO);
DestReg = TempReg;
}
return DestReg;
}
unsigned MipsFastISel::materializeExternalCallSym(MCSymbol *Sym) {
const TargetRegisterClass *RC = &Mips::GPR32RegClass;
unsigned DestReg = createResultReg(RC);
emitInst(Mips::LW, DestReg)
.addReg(MFI->getGlobalBaseReg())
.addSym(Sym, MipsII::MO_GOT);
return DestReg;
}
// Materialize a constant into a register, and return the register
// number (or zero if we failed to handle it).
unsigned MipsFastISel::fastMaterializeConstant(const Constant *C) {
if (!TargetSupported)
return 0;
EVT CEVT = TLI.getValueType(DL, C->getType(), true);
// Only handle simple types.
if (!CEVT.isSimple())
return 0;
MVT VT = CEVT.getSimpleVT();
if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C))
return (UnsupportedFPMode) ? 0 : materializeFP(CFP, VT);
else if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
return materializeGV(GV, VT);
else if (isa<ConstantInt>(C))
return materializeInt(C, VT);
return 0;
}
bool MipsFastISel::computeAddress(const Value *Obj, Address &Addr) {
const User *U = nullptr;
unsigned Opcode = Instruction::UserOp1;
if (const Instruction *I = dyn_cast<Instruction>(Obj)) {
// Don't walk into other basic blocks unless the object is an alloca from
// another block, otherwise it may not have a virtual register assigned.
if (FuncInfo.StaticAllocaMap.count(static_cast<const AllocaInst *>(Obj)) ||
FuncInfo.MBBMap[I->getParent()] == FuncInfo.MBB) {
Opcode = I->getOpcode();
U = I;
}
} else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(Obj)) {
Opcode = C->getOpcode();
U = C;
}
switch (Opcode) {
default:
break;
case Instruction::BitCast: {
// Look through bitcasts.
return computeAddress(U->getOperand(0), Addr);
}
case Instruction::GetElementPtr: {
Address SavedAddr = Addr;
uint64_t TmpOffset = Addr.getOffset();
// Iterate through the GEP folding the constants into offsets where
// we can.
gep_type_iterator GTI = gep_type_begin(U);
for (User::const_op_iterator i = U->op_begin() + 1, e = U->op_end(); i != e;
++i, ++GTI) {
const Value *Op = *i;
if (StructType *STy = dyn_cast<StructType>(*GTI)) {
const StructLayout *SL = DL.getStructLayout(STy);
unsigned Idx = cast<ConstantInt>(Op)->getZExtValue();
TmpOffset += SL->getElementOffset(Idx);
} else {
uint64_t S = DL.getTypeAllocSize(GTI.getIndexedType());
for (;;) {
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
// Constant-offset addressing.
TmpOffset += CI->getSExtValue() * S;
break;
}
if (canFoldAddIntoGEP(U, Op)) {
// A compatible add with a constant operand. Fold the constant.
ConstantInt *CI =
cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
TmpOffset += CI->getSExtValue() * S;
// Iterate on the other operand.
Op = cast<AddOperator>(Op)->getOperand(0);
continue;
}
// Unsupported
goto unsupported_gep;
}
}
}
// Try to grab the base operand now.
Addr.setOffset(TmpOffset);
if (computeAddress(U->getOperand(0), Addr))
return true;
// We failed, restore everything and try the other options.
Addr = SavedAddr;
unsupported_gep:
break;
}
case Instruction::Alloca: {
const AllocaInst *AI = cast<AllocaInst>(Obj);
DenseMap<const AllocaInst *, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
Addr.setKind(Address::FrameIndexBase);
Addr.setFI(SI->second);
return true;
}
break;
}
}
Addr.setReg(getRegForValue(Obj));
return Addr.getReg() != 0;
}
bool MipsFastISel::computeCallAddress(const Value *V, Address &Addr) {
const User *U = nullptr;
unsigned Opcode = Instruction::UserOp1;
if (const auto *I = dyn_cast<Instruction>(V)) {
// Check if the value is defined in the same basic block. This information
// is crucial to know whether or not folding an operand is valid.
if (I->getParent() == FuncInfo.MBB->getBasicBlock()) {
Opcode = I->getOpcode();
U = I;
}
} else if (const auto *C = dyn_cast<ConstantExpr>(V)) {
Opcode = C->getOpcode();
U = C;
}
switch (Opcode) {
default:
break;
case Instruction::BitCast:
// Look past bitcasts if its operand is in the same BB.
return computeCallAddress(U->getOperand(0), Addr);
break;
case Instruction::IntToPtr:
// Look past no-op inttoptrs if its operand is in the same BB.
if (TLI.getValueType(DL, U->getOperand(0)->getType()) ==
TLI.getPointerTy(DL))
return computeCallAddress(U->getOperand(0), Addr);
break;
case Instruction::PtrToInt:
// Look past no-op ptrtoints if its operand is in the same BB.
if (TLI.getValueType(DL, U->getType()) == TLI.getPointerTy(DL))
return computeCallAddress(U->getOperand(0), Addr);
break;
}
if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
Addr.setGlobalValue(GV);
return true;
}
// If all else fails, try to materialize the value in a register.
if (!Addr.getGlobalValue()) {
Addr.setReg(getRegForValue(V));
return Addr.getReg() != 0;
}
return false;
}
bool MipsFastISel::isTypeLegal(Type *Ty, MVT &VT) {
EVT evt = TLI.getValueType(DL, Ty, true);
// Only handle simple types.
if (evt == MVT::Other || !evt.isSimple())
return false;
VT = evt.getSimpleVT();
// Handle all legal types, i.e. a register that will directly hold this
// value.
return TLI.isTypeLegal(VT);
}
bool MipsFastISel::isTypeSupported(Type *Ty, MVT &VT) {
if (Ty->isVectorTy())
return false;
if (isTypeLegal(Ty, VT))
return true;
// If this is a type than can be sign or zero-extended to a basic operation
// go ahead and accept it now.
if (VT == MVT::i1 || VT == MVT::i8 || VT == MVT::i16)
return true;
return false;
}
bool MipsFastISel::isLoadTypeLegal(Type *Ty, MVT &VT) {
if (isTypeLegal(Ty, VT))
return true;
// We will extend this in a later patch:
// If this is a type than can be sign or zero-extended to a basic operation
// go ahead and accept it now.
if (VT == MVT::i8 || VT == MVT::i16)
return true;
return false;
}
// Because of how EmitCmp is called with fast-isel, you can
// end up with redundant "andi" instructions after the sequences emitted below.
// We should try and solve this issue in the future.
//
bool MipsFastISel::emitCmp(unsigned ResultReg, const CmpInst *CI) {
const Value *Left = CI->getOperand(0), *Right = CI->getOperand(1);
bool IsUnsigned = CI->isUnsigned();
unsigned LeftReg = getRegEnsuringSimpleIntegerWidening(Left, IsUnsigned);
if (LeftReg == 0)
return false;
unsigned RightReg = getRegEnsuringSimpleIntegerWidening(Right, IsUnsigned);
if (RightReg == 0)
return false;
CmpInst::Predicate P = CI->getPredicate();
switch (P) {
default:
return false;
case CmpInst::ICMP_EQ: {
unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
emitInst(Mips::XOR, TempReg).addReg(LeftReg).addReg(RightReg);
emitInst(Mips::SLTiu, ResultReg).addReg(TempReg).addImm(1);
break;
}
case CmpInst::ICMP_NE: {
unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
emitInst(Mips::XOR, TempReg).addReg(LeftReg).addReg(RightReg);
emitInst(Mips::SLTu, ResultReg).addReg(Mips::ZERO).addReg(TempReg);
break;
}
case CmpInst::ICMP_UGT: {
emitInst(Mips::SLTu, ResultReg).addReg(RightReg).addReg(LeftReg);
break;
}
case CmpInst::ICMP_ULT: {
emitInst(Mips::SLTu, ResultReg).addReg(LeftReg).addReg(RightReg);
break;
}
case CmpInst::ICMP_UGE: {
unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
emitInst(Mips::SLTu, TempReg).addReg(LeftReg).addReg(RightReg);
emitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1);
break;
}
case CmpInst::ICMP_ULE: {
unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
emitInst(Mips::SLTu, TempReg).addReg(RightReg).addReg(LeftReg);
emitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1);
break;
}
case CmpInst::ICMP_SGT: {
emitInst(Mips::SLT, ResultReg).addReg(RightReg).addReg(LeftReg);
break;
}
case CmpInst::ICMP_SLT: {
emitInst(Mips::SLT, ResultReg).addReg(LeftReg).addReg(RightReg);
break;
}
case CmpInst::ICMP_SGE: {
unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
emitInst(Mips::SLT, TempReg).addReg(LeftReg).addReg(RightReg);
emitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1);
break;
}
case CmpInst::ICMP_SLE: {
unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
emitInst(Mips::SLT, TempReg).addReg(RightReg).addReg(LeftReg);
emitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1);
break;
}
case CmpInst::FCMP_OEQ:
case CmpInst::FCMP_UNE:
case CmpInst::FCMP_OLT:
case CmpInst::FCMP_OLE:
case CmpInst::FCMP_OGT:
case CmpInst::FCMP_OGE: {
if (UnsupportedFPMode)
return false;
bool IsFloat = Left->getType()->isFloatTy();
bool IsDouble = Left->getType()->isDoubleTy();
if (!IsFloat && !IsDouble)
return false;
unsigned Opc, CondMovOpc;
switch (P) {
case CmpInst::FCMP_OEQ:
Opc = IsFloat ? Mips::C_EQ_S : Mips::C_EQ_D32;
CondMovOpc = Mips::MOVT_I;
break;
case CmpInst::FCMP_UNE:
Opc = IsFloat ? Mips::C_EQ_S : Mips::C_EQ_D32;
CondMovOpc = Mips::MOVF_I;
break;
case CmpInst::FCMP_OLT:
Opc = IsFloat ? Mips::C_OLT_S : Mips::C_OLT_D32;
CondMovOpc = Mips::MOVT_I;
break;
case CmpInst::FCMP_OLE:
Opc = IsFloat ? Mips::C_OLE_S : Mips::C_OLE_D32;
CondMovOpc = Mips::MOVT_I;
break;
case CmpInst::FCMP_OGT:
Opc = IsFloat ? Mips::C_ULE_S : Mips::C_ULE_D32;
CondMovOpc = Mips::MOVF_I;
break;
case CmpInst::FCMP_OGE:
Opc = IsFloat ? Mips::C_ULT_S : Mips::C_ULT_D32;
CondMovOpc = Mips::MOVF_I;
break;
default:
llvm_unreachable("Only switching of a subset of CCs.");
}
unsigned RegWithZero = createResultReg(&Mips::GPR32RegClass);
unsigned RegWithOne = createResultReg(&Mips::GPR32RegClass);
emitInst(Mips::ADDiu, RegWithZero).addReg(Mips::ZERO).addImm(0);
emitInst(Mips::ADDiu, RegWithOne).addReg(Mips::ZERO).addImm(1);
emitInst(Opc).addReg(LeftReg).addReg(RightReg).addReg(
Mips::FCC0, RegState::ImplicitDefine);
emitInst(CondMovOpc, ResultReg)
.addReg(RegWithOne)
.addReg(Mips::FCC0)
.addReg(RegWithZero);
break;
}
}
return true;
}
bool MipsFastISel::emitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
unsigned Alignment) {
//
// more cases will be handled here in following patches.
//
unsigned Opc;
switch (VT.SimpleTy) {
case MVT::i32: {
ResultReg = createResultReg(&Mips::GPR32RegClass);
Opc = Mips::LW;
break;
}
case MVT::i16: {
ResultReg = createResultReg(&Mips::GPR32RegClass);
Opc = Mips::LHu;
break;
}
case MVT::i8: {
ResultReg = createResultReg(&Mips::GPR32RegClass);
Opc = Mips::LBu;
break;
}
case MVT::f32: {
if (UnsupportedFPMode)
return false;
ResultReg = createResultReg(&Mips::FGR32RegClass);
Opc = Mips::LWC1;
break;
}
case MVT::f64: {
if (UnsupportedFPMode)
return false;
ResultReg = createResultReg(&Mips::AFGR64RegClass);
Opc = Mips::LDC1;
break;
}
default:
return false;
}
if (Addr.isRegBase()) {
simplifyAddress(Addr);
emitInstLoad(Opc, ResultReg, Addr.getReg(), Addr.getOffset());
return true;
}
if (Addr.isFIBase()) {
unsigned FI = Addr.getFI();
unsigned Align = 4;
unsigned Offset = Addr.getOffset();
MachineFrameInfo &MFI = MF->getFrameInfo();
MachineMemOperand *MMO = MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*MF, FI), MachineMemOperand::MOLoad,
MFI.getObjectSize(FI), Align);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg)
.addFrameIndex(FI)
.addImm(Offset)
.addMemOperand(MMO);
return true;
}
return false;
}
bool MipsFastISel::emitStore(MVT VT, unsigned SrcReg, Address &Addr,
unsigned Alignment) {
//
// more cases will be handled here in following patches.
//
unsigned Opc;
switch (VT.SimpleTy) {
case MVT::i8:
Opc = Mips::SB;
break;
case MVT::i16:
Opc = Mips::SH;
break;
case MVT::i32:
Opc = Mips::SW;
break;
case MVT::f32:
if (UnsupportedFPMode)
return false;
Opc = Mips::SWC1;
break;
case MVT::f64:
if (UnsupportedFPMode)
return false;
Opc = Mips::SDC1;
break;
default:
return false;
}
if (Addr.isRegBase()) {
simplifyAddress(Addr);
emitInstStore(Opc, SrcReg, Addr.getReg(), Addr.getOffset());
return true;
}
if (Addr.isFIBase()) {
unsigned FI = Addr.getFI();
unsigned Align = 4;
unsigned Offset = Addr.getOffset();
MachineFrameInfo &MFI = MF->getFrameInfo();
MachineMemOperand *MMO = MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*MF, FI), MachineMemOperand::MOStore,
MFI.getObjectSize(FI), Align);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc))
.addReg(SrcReg)
.addFrameIndex(FI)
.addImm(Offset)
.addMemOperand(MMO);
return true;
}
return false;
}
bool MipsFastISel::selectLogicalOp(const Instruction *I) {
MVT VT;
if (!isTypeSupported(I->getType(), VT))
return false;
unsigned ResultReg;
switch (I->getOpcode()) {
default:
llvm_unreachable("Unexpected instruction.");
case Instruction::And:
ResultReg = emitLogicalOp(ISD::AND, VT, I->getOperand(0), I->getOperand(1));
break;
case Instruction::Or:
ResultReg = emitLogicalOp(ISD::OR, VT, I->getOperand(0), I->getOperand(1));
break;
case Instruction::Xor:
ResultReg = emitLogicalOp(ISD::XOR, VT, I->getOperand(0), I->getOperand(1));
break;
}
if (!ResultReg)
return false;
updateValueMap(I, ResultReg);
return true;
}
bool MipsFastISel::selectLoad(const Instruction *I) {
// Atomic loads need special handling.
if (cast<LoadInst>(I)->isAtomic())
return false;
// Verify we have a legal type before going any further.
MVT VT;
if (!isLoadTypeLegal(I->getType(), VT))
return false;
// See if we can handle this address.
Address Addr;
if (!computeAddress(I->getOperand(0), Addr))
return false;
unsigned ResultReg;
if (!emitLoad(VT, ResultReg, Addr, cast<LoadInst>(I)->getAlignment()))
return false;
updateValueMap(I, ResultReg);
return true;
}
bool MipsFastISel::selectStore(const Instruction *I) {
Value *Op0 = I->getOperand(0);
unsigned SrcReg = 0;
// Atomic stores need special handling.
if (cast<StoreInst>(I)->isAtomic())
return false;
// Verify we have a legal type before going any further.
MVT VT;
if (!isLoadTypeLegal(I->getOperand(0)->getType(), VT))
return false;
// Get the value to be stored into a register.
SrcReg = getRegForValue(Op0);
if (SrcReg == 0)
return false;
// See if we can handle this address.
Address Addr;
if (!computeAddress(I->getOperand(1), Addr))
return false;
if (!emitStore(VT, SrcReg, Addr, cast<StoreInst>(I)->getAlignment()))
return false;
return true;
}
//
// This can cause a redundant sltiu to be generated.
// FIXME: try and eliminate this in a future patch.
//
bool MipsFastISel::selectBranch(const Instruction *I) {
const BranchInst *BI = cast<BranchInst>(I);
MachineBasicBlock *BrBB = FuncInfo.MBB;
//
// TBB is the basic block for the case where the comparison is true.
// FBB is the basic block for the case where the comparison is false.
// if (cond) goto TBB
// goto FBB
// TBB:
//
MachineBasicBlock *TBB = FuncInfo.MBBMap[BI->getSuccessor(0)];
MachineBasicBlock *FBB = FuncInfo.MBBMap[BI->getSuccessor(1)];
BI->getCondition();
// For now, just try the simplest case where it's fed by a compare.
if (const CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition())) {
unsigned CondReg = createResultReg(&Mips::GPR32RegClass);
if (!emitCmp(CondReg, CI))
return false;
BuildMI(*BrBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::BGTZ))
.addReg(CondReg)
.addMBB(TBB);
finishCondBranch(BI->getParent(), TBB, FBB);
return true;
}
return false;
}
bool MipsFastISel::selectCmp(const Instruction *I) {
const CmpInst *CI = cast<CmpInst>(I);
unsigned ResultReg = createResultReg(&Mips::GPR32RegClass);
if (!emitCmp(ResultReg, CI))
return false;
updateValueMap(I, ResultReg);
return true;
}
// Attempt to fast-select a floating-point extend instruction.
bool MipsFastISel::selectFPExt(const Instruction *I) {
if (UnsupportedFPMode)
return false;
Value *Src = I->getOperand(0);
EVT SrcVT = TLI.getValueType(DL, Src->getType(), true);
EVT DestVT = TLI.getValueType(DL, I->getType(), true);
if (SrcVT != MVT::f32 || DestVT != MVT::f64)
return false;
unsigned SrcReg =
getRegForValue(Src); // this must be a 32bit floating point register class
// maybe we should handle this differently
if (!SrcReg)
return false;
unsigned DestReg = createResultReg(&Mips::AFGR64RegClass);
emitInst(Mips::CVT_D32_S, DestReg).addReg(SrcReg);
updateValueMap(I, DestReg);
return true;
}
bool MipsFastISel::selectSelect(const Instruction *I) {
assert(isa<SelectInst>(I) && "Expected a select instruction.");
DEBUG(dbgs() << "selectSelect\n");
MVT VT;
if (!isTypeSupported(I->getType(), VT) || UnsupportedFPMode) {
DEBUG(dbgs() << ".. .. gave up (!isTypeSupported || UnsupportedFPMode)\n");
return false;
}
unsigned CondMovOpc;
const TargetRegisterClass *RC;
if (VT.isInteger() && !VT.isVector() && VT.getSizeInBits() <= 32) {
CondMovOpc = Mips::MOVN_I_I;
RC = &Mips::GPR32RegClass;
} else if (VT == MVT::f32) {
CondMovOpc = Mips::MOVN_I_S;
RC = &Mips::FGR32RegClass;
} else if (VT == MVT::f64) {
CondMovOpc = Mips::MOVN_I_D32;
RC = &Mips::AFGR64RegClass;
} else
return false;
const SelectInst *SI = cast<SelectInst>(I);
const Value *Cond = SI->getCondition();
unsigned Src1Reg = getRegForValue(SI->getTrueValue());
unsigned Src2Reg = getRegForValue(SI->getFalseValue());
unsigned CondReg = getRegForValue(Cond);
if (!Src1Reg || !Src2Reg || !CondReg)
return false;
unsigned ZExtCondReg = createResultReg(&Mips::GPR32RegClass);
if (!ZExtCondReg)
return false;
if (!emitIntExt(MVT::i1, CondReg, MVT::i32, ZExtCondReg, true))
return false;
unsigned ResultReg = createResultReg(RC);
unsigned TempReg = createResultReg(RC);
if (!ResultReg || !TempReg)
return false;
emitInst(TargetOpcode::COPY, TempReg).addReg(Src2Reg);
emitInst(CondMovOpc, ResultReg)
.addReg(Src1Reg).addReg(ZExtCondReg).addReg(TempReg);
updateValueMap(I, ResultReg);
return true;
}
// Attempt to fast-select a floating-point truncate instruction.
bool MipsFastISel::selectFPTrunc(const Instruction *I) {
if (UnsupportedFPMode)
return false;
Value *Src = I->getOperand(0);
EVT SrcVT = TLI.getValueType(DL, Src->getType(), true);
EVT DestVT = TLI.getValueType(DL, I->getType(), true);
if (SrcVT != MVT::f64 || DestVT != MVT::f32)
return false;
unsigned SrcReg = getRegForValue(Src);
if (!SrcReg)
return false;
unsigned DestReg = createResultReg(&Mips::FGR32RegClass);
if (!DestReg)
return false;
emitInst(Mips::CVT_S_D32, DestReg).addReg(SrcReg);
updateValueMap(I, DestReg);
return true;
}
// Attempt to fast-select a floating-point-to-integer conversion.
bool MipsFastISel::selectFPToInt(const Instruction *I, bool IsSigned) {
if (UnsupportedFPMode)
return false;
MVT DstVT, SrcVT;
if (!IsSigned)
return false; // We don't handle this case yet. There is no native
// instruction for this but it can be synthesized.
Type *DstTy = I->getType();
if (!isTypeLegal(DstTy, DstVT))
return false;
if (DstVT != MVT::i32)
return false;
Value *Src = I->getOperand(0);
Type *SrcTy = Src->getType();
if (!isTypeLegal(SrcTy, SrcVT))
return false;
if (SrcVT != MVT::f32 && SrcVT != MVT::f64)
return false;
unsigned SrcReg = getRegForValue(Src);
if (SrcReg == 0)
return false;
// Determine the opcode for the conversion, which takes place
// entirely within FPRs.
unsigned DestReg = createResultReg(&Mips::GPR32RegClass);
unsigned TempReg = createResultReg(&Mips::FGR32RegClass);
unsigned Opc = (SrcVT == MVT::f32) ? Mips::TRUNC_W_S : Mips::TRUNC_W_D32;
// Generate the convert.
emitInst(Opc, TempReg).addReg(SrcReg);
emitInst(Mips::MFC1, DestReg).addReg(TempReg);
updateValueMap(I, DestReg);
return true;
}
bool MipsFastISel::processCallArgs(CallLoweringInfo &CLI,
SmallVectorImpl<MVT> &OutVTs,
unsigned &NumBytes) {
CallingConv::ID CC = CLI.CallConv;
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CC, false, *FuncInfo.MF, ArgLocs, *Context);
CCInfo.AnalyzeCallOperands(OutVTs, CLI.OutFlags, CCAssignFnForCall(CC));
// Get a count of how many bytes are to be pushed on the stack.
NumBytes = CCInfo.getNextStackOffset();
// This is the minimum argument area used for A0-A3.
if (NumBytes < 16)
NumBytes = 16;
emitInst(Mips::ADJCALLSTACKDOWN).addImm(16);
// Process the args.
MVT firstMVT;
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
const Value *ArgVal = CLI.OutVals[VA.getValNo()];
MVT ArgVT = OutVTs[VA.getValNo()];
if (i == 0) {
firstMVT = ArgVT;
if (ArgVT == MVT::f32) {
VA.convertToReg(Mips::F12);
} else if (ArgVT == MVT::f64) {
VA.convertToReg(Mips::D6);
}
} else if (i == 1) {
if ((firstMVT == MVT::f32) || (firstMVT == MVT::f64)) {
if (ArgVT == MVT::f32) {
VA.convertToReg(Mips::F14);
} else if (ArgVT == MVT::f64) {
VA.convertToReg(Mips::D7);
}
}
}
if (((ArgVT == MVT::i32) || (ArgVT == MVT::f32) || (ArgVT == MVT::i16) ||
(ArgVT == MVT::i8)) &&
VA.isMemLoc()) {
switch (VA.getLocMemOffset()) {
case 0:
VA.convertToReg(Mips::A0);
break;
case 4:
VA.convertToReg(Mips::A1);
break;
case 8:
VA.convertToReg(Mips::A2);
break;
case 12:
VA.convertToReg(Mips::A3);
break;
default:
break;
}
}
unsigned ArgReg = getRegForValue(ArgVal);
if (!ArgReg)
return false;
// Handle arg promotion: SExt, ZExt, AExt.
switch (VA.getLocInfo()) {
case CCValAssign::Full:
break;
case CCValAssign::AExt:
case CCValAssign::SExt: {
MVT DestVT = VA.getLocVT();
MVT SrcVT = ArgVT;
ArgReg = emitIntExt(SrcVT, ArgReg, DestVT, /*isZExt=*/false);
if (!ArgReg)
return false;
break;
}
case CCValAssign::ZExt: {
MVT DestVT = VA.getLocVT();
MVT SrcVT = ArgVT;
ArgReg = emitIntExt(SrcVT, ArgReg, DestVT, /*isZExt=*/true);
if (!ArgReg)
return false;
break;
}
default:
llvm_unreachable("Unknown arg promotion!");
}
// Now copy/store arg to correct locations.
if (VA.isRegLoc() && !VA.needsCustom()) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), VA.getLocReg()).addReg(ArgReg);
CLI.OutRegs.push_back(VA.getLocReg());
} else if (VA.needsCustom()) {
llvm_unreachable("Mips does not use custom args.");
return false;
} else {
//
// FIXME: This path will currently return false. It was copied
// from the AArch64 port and should be essentially fine for Mips too.
// The work to finish up this path will be done in a follow-on patch.
//
assert(VA.isMemLoc() && "Assuming store on stack.");
// Don't emit stores for undef values.
if (isa<UndefValue>(ArgVal))
continue;
// Need to store on the stack.
// FIXME: This alignment is incorrect but this path is disabled
// for now (will return false). We need to determine the right alignment
// based on the normal alignment for the underlying machine type.
//
unsigned ArgSize = alignTo(ArgVT.getSizeInBits(), 4);
unsigned BEAlign = 0;
if (ArgSize < 8 && !Subtarget->isLittle())
BEAlign = 8 - ArgSize;
Address Addr;
Addr.setKind(Address::RegBase);
Addr.setReg(Mips::SP);
Addr.setOffset(VA.getLocMemOffset() + BEAlign);
unsigned Alignment = DL.getABITypeAlignment(ArgVal->getType());
MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand(
MachinePointerInfo::getStack(*FuncInfo.MF, Addr.getOffset()),
MachineMemOperand::MOStore, ArgVT.getStoreSize(), Alignment);
(void)(MMO);
// if (!emitStore(ArgVT, ArgReg, Addr, MMO))
return false; // can't store on the stack yet.
}
}
return true;
}
bool MipsFastISel::finishCall(CallLoweringInfo &CLI, MVT RetVT,
unsigned NumBytes) {
CallingConv::ID CC = CLI.CallConv;
emitInst(Mips::ADJCALLSTACKUP).addImm(16).addImm(0);
if (RetVT != MVT::isVoid) {
SmallVector<CCValAssign, 16> RVLocs;
CCState CCInfo(CC, false, *FuncInfo.MF, RVLocs, *Context);
CCInfo.AnalyzeCallResult(RetVT, RetCC_Mips);
// Only handle a single return value.
if (RVLocs.size() != 1)
return false;
// Copy all of the result registers out of their specified physreg.
MVT CopyVT = RVLocs[0].getValVT();
// Special handling for extended integers.
if (RetVT == MVT::i1 || RetVT == MVT::i8 || RetVT == MVT::i16)
CopyVT = MVT::i32;
unsigned ResultReg = createResultReg(TLI.getRegClassFor(CopyVT));
if (!ResultReg)
return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY),
ResultReg).addReg(RVLocs[0].getLocReg());
CLI.InRegs.push_back(RVLocs[0].getLocReg());
CLI.ResultReg = ResultReg;
CLI.NumResultRegs = 1;
}
return true;
}
bool MipsFastISel::fastLowerArguments() {
DEBUG(dbgs() << "fastLowerArguments\n");
if (!FuncInfo.CanLowerReturn) {
DEBUG(dbgs() << ".. gave up (!CanLowerReturn)\n");
return false;
}
const Function *F = FuncInfo.Fn;
if (F->isVarArg()) {
DEBUG(dbgs() << ".. gave up (varargs)\n");
return false;
}
CallingConv::ID CC = F->getCallingConv();
if (CC != CallingConv::C) {
DEBUG(dbgs() << ".. gave up (calling convention is not C)\n");
return false;
}
const ArrayRef<MCPhysReg> GPR32ArgRegs = {Mips::A0, Mips::A1, Mips::A2,
Mips::A3};
const ArrayRef<MCPhysReg> FGR32ArgRegs = {Mips::F12, Mips::F14};
const ArrayRef<MCPhysReg> AFGR64ArgRegs = {Mips::D6, Mips::D7};
ArrayRef<MCPhysReg>::iterator NextGPR32 = GPR32ArgRegs.begin();
ArrayRef<MCPhysReg>::iterator NextFGR32 = FGR32ArgRegs.begin();
ArrayRef<MCPhysReg>::iterator NextAFGR64 = AFGR64ArgRegs.begin();
struct AllocatedReg {
const TargetRegisterClass *RC;
unsigned Reg;
AllocatedReg(const TargetRegisterClass *RC, unsigned Reg)
: RC(RC), Reg(Reg) {}
};
// Only handle simple cases. i.e. All arguments are directly mapped to
// registers of the appropriate type.
SmallVector<AllocatedReg, 4> Allocation;
unsigned Idx = 1;
for (const auto &FormalArg : F->args()) {
if (F->getAttributes().hasAttribute(Idx, Attribute::InReg) ||
F->getAttributes().hasAttribute(Idx, Attribute::StructRet) ||
F->getAttributes().hasAttribute(Idx, Attribute::ByVal)) {
DEBUG(dbgs() << ".. gave up (inreg, structret, byval)\n");
return false;
}
Type *ArgTy = FormalArg.getType();
if (ArgTy->isStructTy() || ArgTy->isArrayTy() || ArgTy->isVectorTy()) {
DEBUG(dbgs() << ".. gave up (struct, array, or vector)\n");
return false;
}
EVT ArgVT = TLI.getValueType(DL, ArgTy);
DEBUG(dbgs() << ".. " << (Idx - 1) << ": " << ArgVT.getEVTString() << "\n");
if (!ArgVT.isSimple()) {
DEBUG(dbgs() << ".. .. gave up (not a simple type)\n");
return false;
}
switch (ArgVT.getSimpleVT().SimpleTy) {
case MVT::i1:
case MVT::i8:
case MVT::i16:
if (!F->getAttributes().hasAttribute(Idx, Attribute::SExt) &&
!F->getAttributes().hasAttribute(Idx, Attribute::ZExt)) {
// It must be any extend, this shouldn't happen for clang-generated IR
// so just fall back on SelectionDAG.
DEBUG(dbgs() << ".. .. gave up (i8/i16 arg is not extended)\n");
return false;
}
if (NextGPR32 == GPR32ArgRegs.end()) {
DEBUG(dbgs() << ".. .. gave up (ran out of GPR32 arguments)\n");
return false;
}
DEBUG(dbgs() << ".. .. GPR32(" << *NextGPR32 << ")\n");
Allocation.emplace_back(&Mips::GPR32RegClass, *NextGPR32++);
// Allocating any GPR32 prohibits further use of floating point arguments.
NextFGR32 = FGR32ArgRegs.end();
NextAFGR64 = AFGR64ArgRegs.end();
break;
case MVT::i32:
if (F->getAttributes().hasAttribute(Idx, Attribute::ZExt)) {
// The O32 ABI does not permit a zero-extended i32.
DEBUG(dbgs() << ".. .. gave up (i32 arg is zero extended)\n");
return false;
}
if (NextGPR32 == GPR32ArgRegs.end()) {
DEBUG(dbgs() << ".. .. gave up (ran out of GPR32 arguments)\n");
return false;
}
DEBUG(dbgs() << ".. .. GPR32(" << *NextGPR32 << ")\n");
Allocation.emplace_back(&Mips::GPR32RegClass, *NextGPR32++);
// Allocating any GPR32 prohibits further use of floating point arguments.
NextFGR32 = FGR32ArgRegs.end();
NextAFGR64 = AFGR64ArgRegs.end();
break;
case MVT::f32:
if (NextFGR32 == FGR32ArgRegs.end()) {
DEBUG(dbgs() << ".. .. gave up (ran out of FGR32 arguments)\n");
return false;
}
DEBUG(dbgs() << ".. .. FGR32(" << *NextFGR32 << ")\n");
Allocation.emplace_back(&Mips::FGR32RegClass, *NextFGR32++);
// Allocating an FGR32 also allocates the super-register AFGR64, and
// ABI rules require us to skip the corresponding GPR32.
if (NextGPR32 != GPR32ArgRegs.end())
NextGPR32++;
if (NextAFGR64 != AFGR64ArgRegs.end())
NextAFGR64++;
break;
case MVT::f64:
if (UnsupportedFPMode) {
DEBUG(dbgs() << ".. .. gave up (UnsupportedFPMode\n");
return false;
}
if (NextAFGR64 == AFGR64ArgRegs.end()) {
DEBUG(dbgs() << ".. .. gave up (ran out of AFGR64 arguments)\n");
return false;
}
DEBUG(dbgs() << ".. .. AFGR64(" << *NextAFGR64 << ")\n");
Allocation.emplace_back(&Mips::AFGR64RegClass, *NextAFGR64++);
// Allocating an FGR32 also allocates the super-register AFGR64, and
// ABI rules require us to skip the corresponding GPR32 pair.
if (NextGPR32 != GPR32ArgRegs.end())
NextGPR32++;
if (NextGPR32 != GPR32ArgRegs.end())
NextGPR32++;
if (NextFGR32 != FGR32ArgRegs.end())
NextFGR32++;
break;
default:
DEBUG(dbgs() << ".. .. gave up (unknown type)\n");
return false;
}
++Idx;
}
Idx = 0;
for (const auto &FormalArg : F->args()) {
unsigned SrcReg = Allocation[Idx].Reg;
unsigned DstReg = FuncInfo.MF->addLiveIn(SrcReg, Allocation[Idx].RC);
// FIXME: Unfortunately it's necessary to emit a copy from the livein copy.
// Without this, EmitLiveInCopies may eliminate the livein if its only
// use is a bitcast (which isn't turned into an instruction).
unsigned ResultReg = createResultReg(Allocation[Idx].RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(DstReg, getKillRegState(true));
updateValueMap(&FormalArg, ResultReg);
++Idx;
}
// Calculate the size of the incoming arguments area.
// We currently reject all the cases where this would be non-zero.
unsigned IncomingArgSizeInBytes = 0;
// Account for the reserved argument area on ABI's that have one (O32).
// It seems strange to do this on the caller side but it's necessary in
// SelectionDAG's implementation.
IncomingArgSizeInBytes = std::min(getABI().GetCalleeAllocdArgSizeInBytes(CC),
IncomingArgSizeInBytes);
MF->getInfo<MipsFunctionInfo>()->setFormalArgInfo(IncomingArgSizeInBytes,
false);
return true;
}
bool MipsFastISel::fastLowerCall(CallLoweringInfo &CLI) {
if (!TargetSupported)
return false;
CallingConv::ID CC = CLI.CallConv;
bool IsTailCall = CLI.IsTailCall;
bool IsVarArg = CLI.IsVarArg;
const Value *Callee = CLI.Callee;
MCSymbol *Symbol = CLI.Symbol;
// Do not handle FastCC.
if (CC == CallingConv::Fast)
return false;
// Allow SelectionDAG isel to handle tail calls.
if (IsTailCall)
return false;
// Let SDISel handle vararg functions.
if (IsVarArg)
return false;
// FIXME: Only handle *simple* calls for now.
MVT RetVT;
if (CLI.RetTy->isVoidTy())
RetVT = MVT::isVoid;
else if (!isTypeSupported(CLI.RetTy, RetVT))
return false;
for (auto Flag : CLI.OutFlags)
if (Flag.isInReg() || Flag.isSRet() || Flag.isNest() || Flag.isByVal())
return false;
// Set up the argument vectors.
SmallVector<MVT, 16> OutVTs;
OutVTs.reserve(CLI.OutVals.size());
for (auto *Val : CLI.OutVals) {
MVT VT;
if (!isTypeLegal(Val->getType(), VT) &&
!(VT == MVT::i1 || VT == MVT::i8 || VT == MVT::i16))
return false;
// We don't handle vector parameters yet.
if (VT.isVector() || VT.getSizeInBits() > 64)
return false;
OutVTs.push_back(VT);
}
Address Addr;
if (!computeCallAddress(Callee, Addr))
return false;
// Handle the arguments now that we've gotten them.
unsigned NumBytes;
if (!processCallArgs(CLI, OutVTs, NumBytes))
return false;
if (!Addr.getGlobalValue())
return false;
// Issue the call.
unsigned DestAddress;
if (Symbol)
DestAddress = materializeExternalCallSym(Symbol);
else
DestAddress = materializeGV(Addr.getGlobalValue(), MVT::i32);
emitInst(TargetOpcode::COPY, Mips::T9).addReg(DestAddress);
MachineInstrBuilder MIB =
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::JALR),
Mips::RA).addReg(Mips::T9);
// Add implicit physical register uses to the call.
for (auto Reg : CLI.OutRegs)
MIB.addReg(Reg, RegState::Implicit);
// Add a register mask with the call-preserved registers.
// Proper defs for return values will be added by setPhysRegsDeadExcept().
MIB.addRegMask(TRI.getCallPreservedMask(*FuncInfo.MF, CC));
CLI.Call = MIB;
// Finish off the call including any return values.
return finishCall(CLI, RetVT, NumBytes);
}
bool MipsFastISel::fastLowerIntrinsicCall(const IntrinsicInst *II) {
if (!TargetSupported)
return false;
switch (II->getIntrinsicID()) {
default:
return false;
case Intrinsic::bswap: {
Type *RetTy = II->getCalledFunction()->getReturnType();
MVT VT;
if (!isTypeSupported(RetTy, VT))
return false;
unsigned SrcReg = getRegForValue(II->getOperand(0));
if (SrcReg == 0)
return false;
unsigned DestReg = createResultReg(&Mips::GPR32RegClass);
if (DestReg == 0)
return false;
if (VT == MVT::i16) {
if (Subtarget->hasMips32r2()) {
emitInst(Mips::WSBH, DestReg).addReg(SrcReg);
updateValueMap(II, DestReg);
return true;
} else {
unsigned TempReg[3];
for (int i = 0; i < 3; i++) {
TempReg[i] = createResultReg(&Mips::GPR32RegClass);
if (TempReg[i] == 0)
return false;
}
emitInst(Mips::SLL, TempReg[0]).addReg(SrcReg).addImm(8);
emitInst(Mips::SRL, TempReg[1]).addReg(SrcReg).addImm(8);
emitInst(Mips::OR, TempReg[2]).addReg(TempReg[0]).addReg(TempReg[1]);
emitInst(Mips::ANDi, DestReg).addReg(TempReg[2]).addImm(0xFFFF);
updateValueMap(II, DestReg);
return true;
}
} else if (VT == MVT::i32) {
if (Subtarget->hasMips32r2()) {
unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
emitInst(Mips::WSBH, TempReg).addReg(SrcReg);
emitInst(Mips::ROTR, DestReg).addReg(TempReg).addImm(16);
updateValueMap(II, DestReg);
return true;
} else {
unsigned TempReg[8];
for (int i = 0; i < 8; i++) {
TempReg[i] = createResultReg(&Mips::GPR32RegClass);
if (TempReg[i] == 0)
return false;
}
emitInst(Mips::SRL, TempReg[0]).addReg(SrcReg).addImm(8);
emitInst(Mips::SRL, TempReg[1]).addReg(SrcReg).addImm(24);
emitInst(Mips::ANDi, TempReg[2]).addReg(TempReg[0]).addImm(0xFF00);
emitInst(Mips::OR, TempReg[3]).addReg(TempReg[1]).addReg(TempReg[2]);
emitInst(Mips::ANDi, TempReg[4]).addReg(SrcReg).addImm(0xFF00);
emitInst(Mips::SLL, TempReg[5]).addReg(TempReg[4]).addImm(8);
emitInst(Mips::SLL, TempReg[6]).addReg(SrcReg).addImm(24);
emitInst(Mips::OR, TempReg[7]).addReg(TempReg[3]).addReg(TempReg[5]);
emitInst(Mips::OR, DestReg).addReg(TempReg[6]).addReg(TempReg[7]);
updateValueMap(II, DestReg);
return true;
}
}
return false;
}
case Intrinsic::memcpy:
case Intrinsic::memmove: {
const auto *MTI = cast<MemTransferInst>(II);
// Don't handle volatile.
if (MTI->isVolatile())
return false;
if (!MTI->getLength()->getType()->isIntegerTy(32))
return false;
const char *IntrMemName = isa<MemCpyInst>(II) ? "memcpy" : "memmove";
return lowerCallTo(II, IntrMemName, II->getNumArgOperands() - 2);
}
case Intrinsic::memset: {
const MemSetInst *MSI = cast<MemSetInst>(II);
// Don't handle volatile.
if (MSI->isVolatile())
return false;
if (!MSI->getLength()->getType()->isIntegerTy(32))
return false;
return lowerCallTo(II, "memset", II->getNumArgOperands() - 2);
}
}
return false;
}
bool MipsFastISel::selectRet(const Instruction *I) {
const Function &F = *I->getParent()->getParent();
const ReturnInst *Ret = cast<ReturnInst>(I);
DEBUG(dbgs() << "selectRet\n");
if (!FuncInfo.CanLowerReturn)
return false;
// Build a list of return value registers.
SmallVector<unsigned, 4> RetRegs;
if (Ret->getNumOperands() > 0) {
CallingConv::ID CC = F.getCallingConv();
// Do not handle FastCC.
if (CC == CallingConv::Fast)
return false;
SmallVector<ISD::OutputArg, 4> Outs;
GetReturnInfo(F.getReturnType(), F.getAttributes(), Outs, TLI, DL);
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ValLocs;
MipsCCState CCInfo(CC, F.isVarArg(), *FuncInfo.MF, ValLocs,
I->getContext());
CCAssignFn *RetCC = RetCC_Mips;
CCInfo.AnalyzeReturn(Outs, RetCC);
// Only handle a single return value for now.
if (ValLocs.size() != 1)
return false;
CCValAssign &VA = ValLocs[0];
const Value *RV = Ret->getOperand(0);
// Don't bother handling odd stuff for now.
if ((VA.getLocInfo() != CCValAssign::Full) &&
(VA.getLocInfo() != CCValAssign::BCvt))
return false;
// Only handle register returns for now.
if (!VA.isRegLoc())
return false;
unsigned Reg = getRegForValue(RV);
if (Reg == 0)
return false;
unsigned SrcReg = Reg + VA.getValNo();
unsigned DestReg = VA.getLocReg();
// Avoid a cross-class copy. This is very unlikely.
if (!MRI.getRegClass(SrcReg)->contains(DestReg))
return false;
EVT RVEVT = TLI.getValueType(DL, RV->getType());
if (!RVEVT.isSimple())
return false;
if (RVEVT.isVector())
return false;
MVT RVVT = RVEVT.getSimpleVT();
if (RVVT == MVT::f128)
return false;
// Do not handle FGR64 returns for now.
if (RVVT == MVT::f64 && UnsupportedFPMode) {
DEBUG(dbgs() << ".. .. gave up (UnsupportedFPMode\n");
return false;
}
MVT DestVT = VA.getValVT();
// Special handling for extended integers.
if (RVVT != DestVT) {
if (RVVT != MVT::i1 && RVVT != MVT::i8 && RVVT != MVT::i16)
return false;
if (Outs[0].Flags.isZExt() || Outs[0].Flags.isSExt()) {
bool IsZExt = Outs[0].Flags.isZExt();
SrcReg = emitIntExt(RVVT, SrcReg, DestVT, IsZExt);
if (SrcReg == 0)
return false;
}
}
// Make the copy.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), DestReg).addReg(SrcReg);
// Add register to return instruction.
RetRegs.push_back(VA.getLocReg());
}
MachineInstrBuilder MIB = emitInst(Mips::RetRA);
for (unsigned i = 0, e = RetRegs.size(); i != e; ++i)
MIB.addReg(RetRegs[i], RegState::Implicit);
return true;
}
bool MipsFastISel::selectTrunc(const Instruction *I) {
// The high bits for a type smaller than the register size are assumed to be
// undefined.
Value *Op = I->getOperand(0);
EVT SrcVT, DestVT;
SrcVT = TLI.getValueType(DL, Op->getType(), true);
DestVT = TLI.getValueType(DL, I->getType(), true);
if (SrcVT != MVT::i32 && SrcVT != MVT::i16 && SrcVT != MVT::i8)
return false;
if (DestVT != MVT::i16 && DestVT != MVT::i8 && DestVT != MVT::i1)
return false;
unsigned SrcReg = getRegForValue(Op);
if (!SrcReg)
return false;
// Because the high bits are undefined, a truncate doesn't generate
// any code.
updateValueMap(I, SrcReg);
return true;
}
bool MipsFastISel::selectIntExt(const Instruction *I) {
Type *DestTy = I->getType();
Value *Src = I->getOperand(0);
Type *SrcTy = Src->getType();
bool isZExt = isa<ZExtInst>(I);
unsigned SrcReg = getRegForValue(Src);
if (!SrcReg)
return false;
EVT SrcEVT, DestEVT;
SrcEVT = TLI.getValueType(DL, SrcTy, true);
DestEVT = TLI.getValueType(DL, DestTy, true);
if (!SrcEVT.isSimple())
return false;
if (!DestEVT.isSimple())
return false;
MVT SrcVT = SrcEVT.getSimpleVT();
MVT DestVT = DestEVT.getSimpleVT();
unsigned ResultReg = createResultReg(&Mips::GPR32RegClass);
if (!emitIntExt(SrcVT, SrcReg, DestVT, ResultReg, isZExt))
return false;
updateValueMap(I, ResultReg);
return true;
}
bool MipsFastISel::emitIntSExt32r1(MVT SrcVT, unsigned SrcReg, MVT DestVT,
unsigned DestReg) {
unsigned ShiftAmt;
switch (SrcVT.SimpleTy) {
default:
return false;
case MVT::i8:
ShiftAmt = 24;
break;
case MVT::i16:
ShiftAmt = 16;
break;
}
unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
emitInst(Mips::SLL, TempReg).addReg(SrcReg).addImm(ShiftAmt);
emitInst(Mips::SRA, DestReg).addReg(TempReg).addImm(ShiftAmt);
return true;
}
bool MipsFastISel::emitIntSExt32r2(MVT SrcVT, unsigned SrcReg, MVT DestVT,
unsigned DestReg) {
switch (SrcVT.SimpleTy) {
default:
return false;
case MVT::i8:
emitInst(Mips::SEB, DestReg).addReg(SrcReg);
break;
case MVT::i16:
emitInst(Mips::SEH, DestReg).addReg(SrcReg);
break;
}
return true;
}
bool MipsFastISel::emitIntSExt(MVT SrcVT, unsigned SrcReg, MVT DestVT,
unsigned DestReg) {
if ((DestVT != MVT::i32) && (DestVT != MVT::i16))
return false;
if (Subtarget->hasMips32r2())
return emitIntSExt32r2(SrcVT, SrcReg, DestVT, DestReg);
return emitIntSExt32r1(SrcVT, SrcReg, DestVT, DestReg);
}
bool MipsFastISel::emitIntZExt(MVT SrcVT, unsigned SrcReg, MVT DestVT,
unsigned DestReg) {
int64_t Imm;
switch (SrcVT.SimpleTy) {
default:
return false;
case MVT::i1:
Imm = 1;
break;
case MVT::i8:
Imm = 0xff;
break;
case MVT::i16:
Imm = 0xffff;
break;
}
emitInst(Mips::ANDi, DestReg).addReg(SrcReg).addImm(Imm);
return true;
}
bool MipsFastISel::emitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT,
unsigned DestReg, bool IsZExt) {
// FastISel does not have plumbing to deal with extensions where the SrcVT or
// DestVT are odd things, so test to make sure that they are both types we can
// handle (i1/i8/i16/i32 for SrcVT and i8/i16/i32/i64 for DestVT), otherwise
// bail out to SelectionDAG.
if (((DestVT != MVT::i8) && (DestVT != MVT::i16) && (DestVT != MVT::i32)) ||
((SrcVT != MVT::i1) && (SrcVT != MVT::i8) && (SrcVT != MVT::i16)))
return false;
if (IsZExt)
return emitIntZExt(SrcVT, SrcReg, DestVT, DestReg);
return emitIntSExt(SrcVT, SrcReg, DestVT, DestReg);
}
unsigned MipsFastISel::emitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT,
bool isZExt) {
unsigned DestReg = createResultReg(&Mips::GPR32RegClass);
bool Success = emitIntExt(SrcVT, SrcReg, DestVT, DestReg, isZExt);
return Success ? DestReg : 0;
}
bool MipsFastISel::selectDivRem(const Instruction *I, unsigned ISDOpcode) {
EVT DestEVT = TLI.getValueType(DL, I->getType(), true);
if (!DestEVT.isSimple())
return false;
MVT DestVT = DestEVT.getSimpleVT();
if (DestVT != MVT::i32)
return false;
unsigned DivOpc;
switch (ISDOpcode) {
default:
return false;
case ISD::SDIV:
case ISD::SREM:
DivOpc = Mips::SDIV;
break;
case ISD::UDIV:
case ISD::UREM:
DivOpc = Mips::UDIV;
break;
}
unsigned Src0Reg = getRegForValue(I->getOperand(0));
unsigned Src1Reg = getRegForValue(I->getOperand(1));
if (!Src0Reg || !Src1Reg)
return false;
emitInst(DivOpc).addReg(Src0Reg).addReg(Src1Reg);
emitInst(Mips::TEQ).addReg(Src1Reg).addReg(Mips::ZERO).addImm(7);
unsigned ResultReg = createResultReg(&Mips::GPR32RegClass);
if (!ResultReg)
return false;
unsigned MFOpc = (ISDOpcode == ISD::SREM || ISDOpcode == ISD::UREM)
? Mips::MFHI
: Mips::MFLO;
emitInst(MFOpc, ResultReg);
updateValueMap(I, ResultReg);
return true;
}
bool MipsFastISel::selectShift(const Instruction *I) {
MVT RetVT;
if (!isTypeSupported(I->getType(), RetVT))
return false;
unsigned ResultReg = createResultReg(&Mips::GPR32RegClass);
if (!ResultReg)
return false;
unsigned Opcode = I->getOpcode();
const Value *Op0 = I->getOperand(0);
unsigned Op0Reg = getRegForValue(Op0);
if (!Op0Reg)
return false;
// If AShr or LShr, then we need to make sure the operand0 is sign extended.
if (Opcode == Instruction::AShr || Opcode == Instruction::LShr) {
unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
if (!TempReg)
return false;
MVT Op0MVT = TLI.getValueType(DL, Op0->getType(), true).getSimpleVT();
bool IsZExt = Opcode == Instruction::LShr;
if (!emitIntExt(Op0MVT, Op0Reg, MVT::i32, TempReg, IsZExt))
return false;
Op0Reg = TempReg;
}
if (const auto *C = dyn_cast<ConstantInt>(I->getOperand(1))) {
uint64_t ShiftVal = C->getZExtValue();
switch (Opcode) {
default:
llvm_unreachable("Unexpected instruction.");
case Instruction::Shl:
Opcode = Mips::SLL;
break;
case Instruction::AShr:
Opcode = Mips::SRA;
break;
case Instruction::LShr:
Opcode = Mips::SRL;
break;
}
emitInst(Opcode, ResultReg).addReg(Op0Reg).addImm(ShiftVal);
updateValueMap(I, ResultReg);
return true;
}
unsigned Op1Reg = getRegForValue(I->getOperand(1));
if (!Op1Reg)
return false;
switch (Opcode) {
default:
llvm_unreachable("Unexpected instruction.");
case Instruction::Shl:
Opcode = Mips::SLLV;
break;
case Instruction::AShr:
Opcode = Mips::SRAV;
break;
case Instruction::LShr:
Opcode = Mips::SRLV;
break;
}
emitInst(Opcode, ResultReg).addReg(Op0Reg).addReg(Op1Reg);
updateValueMap(I, ResultReg);
return true;
}
bool MipsFastISel::fastSelectInstruction(const Instruction *I) {
if (!TargetSupported)
return false;
switch (I->getOpcode()) {
default:
break;
case Instruction::Load:
return selectLoad(I);
case Instruction::Store:
return selectStore(I);
case Instruction::SDiv:
if (!selectBinaryOp(I, ISD::SDIV))
return selectDivRem(I, ISD::SDIV);
return true;
case Instruction::UDiv:
if (!selectBinaryOp(I, ISD::UDIV))
return selectDivRem(I, ISD::UDIV);
return true;
case Instruction::SRem:
if (!selectBinaryOp(I, ISD::SREM))
return selectDivRem(I, ISD::SREM);
return true;
case Instruction::URem:
if (!selectBinaryOp(I, ISD::UREM))
return selectDivRem(I, ISD::UREM);
return true;
case Instruction::Shl:
case Instruction::LShr:
case Instruction::AShr:
return selectShift(I);
case Instruction::And:
case Instruction::Or:
case Instruction::Xor:
return selectLogicalOp(I);
case Instruction::Br:
return selectBranch(I);
case Instruction::Ret:
return selectRet(I);
case Instruction::Trunc:
return selectTrunc(I);
case Instruction::ZExt:
case Instruction::SExt:
return selectIntExt(I);
case Instruction::FPTrunc:
return selectFPTrunc(I);
case Instruction::FPExt:
return selectFPExt(I);
case Instruction::FPToSI:
return selectFPToInt(I, /*isSigned*/ true);
case Instruction::FPToUI:
return selectFPToInt(I, /*isSigned*/ false);
case Instruction::ICmp:
case Instruction::FCmp:
return selectCmp(I);
case Instruction::Select:
return selectSelect(I);
}
return false;
}
unsigned MipsFastISel::getRegEnsuringSimpleIntegerWidening(const Value *V,
bool IsUnsigned) {
unsigned VReg = getRegForValue(V);
if (VReg == 0)
return 0;
MVT VMVT = TLI.getValueType(DL, V->getType(), true).getSimpleVT();
if ((VMVT == MVT::i8) || (VMVT == MVT::i16)) {
unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
if (!emitIntExt(VMVT, VReg, MVT::i32, TempReg, IsUnsigned))
return 0;
VReg = TempReg;
}
return VReg;
}
void MipsFastISel::simplifyAddress(Address &Addr) {
if (!isInt<16>(Addr.getOffset())) {
unsigned TempReg =
materialize32BitInt(Addr.getOffset(), &Mips::GPR32RegClass);
unsigned DestReg = createResultReg(&Mips::GPR32RegClass);
emitInst(Mips::ADDu, DestReg).addReg(TempReg).addReg(Addr.getReg());
Addr.setReg(DestReg);
Addr.setOffset(0);
}
}
unsigned MipsFastISel::fastEmitInst_rr(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill) {
// We treat the MUL instruction in a special way because it clobbers
// the HI0 & LO0 registers. The TableGen definition of this instruction can
// mark these registers only as implicitly defined. As a result, the
// register allocator runs out of registers when this instruction is
// followed by another instruction that defines the same registers too.
// We can fix this by explicitly marking those registers as dead.
if (MachineInstOpcode == Mips::MUL) {
unsigned ResultReg = createResultReg(RC);
const MCInstrDesc &II = TII.get(MachineInstOpcode);
Op0 = constrainOperandRegClass(II, Op0, II.getNumDefs());
Op1 = constrainOperandRegClass(II, Op1, II.getNumDefs() + 1);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II, ResultReg)
.addReg(Op0, getKillRegState(Op0IsKill))
.addReg(Op1, getKillRegState(Op1IsKill))
.addReg(Mips::HI0, RegState::ImplicitDefine | RegState::Dead)
.addReg(Mips::LO0, RegState::ImplicitDefine | RegState::Dead);
return ResultReg;
}
return FastISel::fastEmitInst_rr(MachineInstOpcode, RC, Op0, Op0IsKill, Op1,
Op1IsKill);
}
namespace llvm {
FastISel *Mips::createFastISel(FunctionLoweringInfo &funcInfo,
const TargetLibraryInfo *libInfo) {
return new MipsFastISel(funcInfo, libInfo);
}
}
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