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llvm / llvm / a093ef43dd592b729da46db4ff3057fef9a46023 / . / lib / Target / AArch64 / AArch64InstrInfo.cpp
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//===- AArch64InstrInfo.cpp - AArch64 Instruction Information -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the AArch64 implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "AArch64InstrInfo.h"
#include "AArch64Subtarget.h"
#include "MCTargetDesc/AArch64AddressingModes.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
#include <algorithm>
using namespace llvm;
#define GET_INSTRINFO_CTOR_DTOR
#include "AArch64GenInstrInfo.inc"
static LLVM_CONSTEXPR MachineMemOperand::Flags MOSuppressPair =
MachineMemOperand::MOTargetFlag1;
AArch64InstrInfo::AArch64InstrInfo(const AArch64Subtarget &STI)
: AArch64GenInstrInfo(AArch64::ADJCALLSTACKDOWN, AArch64::ADJCALLSTACKUP),
RI(STI.getTargetTriple()), Subtarget(STI) {}
/// GetInstSize - Return the number of bytes of code the specified
/// instruction may be. This returns the maximum number of bytes.
unsigned AArch64InstrInfo::GetInstSizeInBytes(const MachineInstr &MI) const {
const MachineBasicBlock &MBB = *MI.getParent();
const MachineFunction *MF = MBB.getParent();
const MCAsmInfo *MAI = MF->getTarget().getMCAsmInfo();
if (MI.getOpcode() == AArch64::INLINEASM)
return getInlineAsmLength(MI.getOperand(0).getSymbolName(), *MAI);
const MCInstrDesc &Desc = MI.getDesc();
switch (Desc.getOpcode()) {
default:
// Anything not explicitly designated otherwise is a nomal 4-byte insn.
return 4;
case TargetOpcode::DBG_VALUE:
case TargetOpcode::EH_LABEL:
case TargetOpcode::IMPLICIT_DEF:
case TargetOpcode::KILL:
return 0;
}
llvm_unreachable("GetInstSizeInBytes()- Unable to determin insn size");
}
static void parseCondBranch(MachineInstr *LastInst, MachineBasicBlock *&Target,
SmallVectorImpl<MachineOperand> &Cond) {
// Block ends with fall-through condbranch.
switch (LastInst->getOpcode()) {
default:
llvm_unreachable("Unknown branch instruction?");
case AArch64::Bcc:
Target = LastInst->getOperand(1).getMBB();
Cond.push_back(LastInst->getOperand(0));
break;
case AArch64::CBZW:
case AArch64::CBZX:
case AArch64::CBNZW:
case AArch64::CBNZX:
Target = LastInst->getOperand(1).getMBB();
Cond.push_back(MachineOperand::CreateImm(-1));
Cond.push_back(MachineOperand::CreateImm(LastInst->getOpcode()));
Cond.push_back(LastInst->getOperand(0));
break;
case AArch64::TBZW:
case AArch64::TBZX:
case AArch64::TBNZW:
case AArch64::TBNZX:
Target = LastInst->getOperand(2).getMBB();
Cond.push_back(MachineOperand::CreateImm(-1));
Cond.push_back(MachineOperand::CreateImm(LastInst->getOpcode()));
Cond.push_back(LastInst->getOperand(0));
Cond.push_back(LastInst->getOperand(1));
}
}
// Branch analysis.
bool AArch64InstrInfo::analyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
if (I == MBB.end())
return false;
if (!isUnpredicatedTerminator(*I))
return false;
// Get the last instruction in the block.
MachineInstr *LastInst = &*I;
// If there is only one terminator instruction, process it.
unsigned LastOpc = LastInst->getOpcode();
if (I == MBB.begin() || !isUnpredicatedTerminator(*--I)) {
if (isUncondBranchOpcode(LastOpc)) {
TBB = LastInst->getOperand(0).getMBB();
return false;
}
if (isCondBranchOpcode(LastOpc)) {
// Block ends with fall-through condbranch.
parseCondBranch(LastInst, TBB, Cond);
return false;
}
return true; // Can't handle indirect branch.
}
// Get the instruction before it if it is a terminator.
MachineInstr *SecondLastInst = &*I;
unsigned SecondLastOpc = SecondLastInst->getOpcode();
// If AllowModify is true and the block ends with two or more unconditional
// branches, delete all but the first unconditional branch.
if (AllowModify && isUncondBranchOpcode(LastOpc)) {
while (isUncondBranchOpcode(SecondLastOpc)) {
LastInst->eraseFromParent();
LastInst = SecondLastInst;
LastOpc = LastInst->getOpcode();
if (I == MBB.begin() || !isUnpredicatedTerminator(*--I)) {
// Return now the only terminator is an unconditional branch.
TBB = LastInst->getOperand(0).getMBB();
return false;
} else {
SecondLastInst = &*I;
SecondLastOpc = SecondLastInst->getOpcode();
}
}
}
// If there are three terminators, we don't know what sort of block this is.
if (SecondLastInst && I != MBB.begin() && isUnpredicatedTerminator(*--I))
return true;
// If the block ends with a B and a Bcc, handle it.
if (isCondBranchOpcode(SecondLastOpc) && isUncondBranchOpcode(LastOpc)) {
parseCondBranch(SecondLastInst, TBB, Cond);
FBB = LastInst->getOperand(0).getMBB();
return false;
}
// If the block ends with two unconditional branches, handle it. The second
// one is not executed, so remove it.
if (isUncondBranchOpcode(SecondLastOpc) && isUncondBranchOpcode(LastOpc)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
if (AllowModify)
I->eraseFromParent();
return false;
}
// ...likewise if it ends with an indirect branch followed by an unconditional
// branch.
if (isIndirectBranchOpcode(SecondLastOpc) && isUncondBranchOpcode(LastOpc)) {
I = LastInst;
if (AllowModify)
I->eraseFromParent();
return true;
}
// Otherwise, can't handle this.
return true;
}
bool AArch64InstrInfo::ReverseBranchCondition(
SmallVectorImpl<MachineOperand> &Cond) const {
if (Cond[0].getImm() != -1) {
// Regular Bcc
AArch64CC::CondCode CC = (AArch64CC::CondCode)(int)Cond[0].getImm();
Cond[0].setImm(AArch64CC::getInvertedCondCode(CC));
} else {
// Folded compare-and-branch
switch (Cond[1].getImm()) {
default:
llvm_unreachable("Unknown conditional branch!");
case AArch64::CBZW:
Cond[1].setImm(AArch64::CBNZW);
break;
case AArch64::CBNZW:
Cond[1].setImm(AArch64::CBZW);
break;
case AArch64::CBZX:
Cond[1].setImm(AArch64::CBNZX);
break;
case AArch64::CBNZX:
Cond[1].setImm(AArch64::CBZX);
break;
case AArch64::TBZW:
Cond[1].setImm(AArch64::TBNZW);
break;
case AArch64::TBNZW:
Cond[1].setImm(AArch64::TBZW);
break;
case AArch64::TBZX:
Cond[1].setImm(AArch64::TBNZX);
break;
case AArch64::TBNZX:
Cond[1].setImm(AArch64::TBZX);
break;
}
}
return false;
}
unsigned AArch64InstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
if (I == MBB.end())
return 0;
if (!isUncondBranchOpcode(I->getOpcode()) &&
!isCondBranchOpcode(I->getOpcode()))
return 0;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin())
return 1;
--I;
if (!isCondBranchOpcode(I->getOpcode()))
return 1;
// Remove the branch.
I->eraseFromParent();
return 2;
}
void AArch64InstrInfo::instantiateCondBranch(
MachineBasicBlock &MBB, const DebugLoc &DL, MachineBasicBlock *TBB,
ArrayRef<MachineOperand> Cond) const {
if (Cond[0].getImm() != -1) {
// Regular Bcc
BuildMI(&MBB, DL, get(AArch64::Bcc)).addImm(Cond[0].getImm()).addMBB(TBB);
} else {
// Folded compare-and-branch
// Note that we use addOperand instead of addReg to keep the flags.
const MachineInstrBuilder MIB =
BuildMI(&MBB, DL, get(Cond[1].getImm())).addOperand(Cond[2]);
if (Cond.size() > 3)
MIB.addImm(Cond[3].getImm());
MIB.addMBB(TBB);
}
}
unsigned AArch64InstrInfo::InsertBranch(MachineBasicBlock &MBB,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
ArrayRef<MachineOperand> Cond,
const DebugLoc &DL) const {
// Shouldn't be a fall through.
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
if (!FBB) {
if (Cond.empty()) // Unconditional branch?
BuildMI(&MBB, DL, get(AArch64::B)).addMBB(TBB);
else
instantiateCondBranch(MBB, DL, TBB, Cond);
return 1;
}
// Two-way conditional branch.
instantiateCondBranch(MBB, DL, TBB, Cond);
BuildMI(&MBB, DL, get(AArch64::B)).addMBB(FBB);
return 2;
}
// Find the original register that VReg is copied from.
static unsigned removeCopies(const MachineRegisterInfo &MRI, unsigned VReg) {
while (TargetRegisterInfo::isVirtualRegister(VReg)) {
const MachineInstr *DefMI = MRI.getVRegDef(VReg);
if (!DefMI->isFullCopy())
return VReg;
VReg = DefMI->getOperand(1).getReg();
}
return VReg;
}
// Determine if VReg is defined by an instruction that can be folded into a
// csel instruction. If so, return the folded opcode, and the replacement
// register.
static unsigned canFoldIntoCSel(const MachineRegisterInfo &MRI, unsigned VReg,
unsigned *NewVReg = nullptr) {
VReg = removeCopies(MRI, VReg);
if (!TargetRegisterInfo::isVirtualRegister(VReg))
return 0;
bool Is64Bit = AArch64::GPR64allRegClass.hasSubClassEq(MRI.getRegClass(VReg));
const MachineInstr *DefMI = MRI.getVRegDef(VReg);
unsigned Opc = 0;
unsigned SrcOpNum = 0;
switch (DefMI->getOpcode()) {
case AArch64::ADDSXri:
case AArch64::ADDSWri:
// if NZCV is used, do not fold.
if (DefMI->findRegisterDefOperandIdx(AArch64::NZCV, true) == -1)
return 0;
// fall-through to ADDXri and ADDWri.
case AArch64::ADDXri:
case AArch64::ADDWri:
// add x, 1 -> csinc.
if (!DefMI->getOperand(2).isImm() || DefMI->getOperand(2).getImm() != 1 ||
DefMI->getOperand(3).getImm() != 0)
return 0;
SrcOpNum = 1;
Opc = Is64Bit ? AArch64::CSINCXr : AArch64::CSINCWr;
break;
case AArch64::ORNXrr:
case AArch64::ORNWrr: {
// not x -> csinv, represented as orn dst, xzr, src.
unsigned ZReg = removeCopies(MRI, DefMI->getOperand(1).getReg());
if (ZReg != AArch64::XZR && ZReg != AArch64::WZR)
return 0;
SrcOpNum = 2;
Opc = Is64Bit ? AArch64::CSINVXr : AArch64::CSINVWr;
break;
}
case AArch64::SUBSXrr:
case AArch64::SUBSWrr:
// if NZCV is used, do not fold.
if (DefMI->findRegisterDefOperandIdx(AArch64::NZCV, true) == -1)
return 0;
// fall-through to SUBXrr and SUBWrr.
case AArch64::SUBXrr:
case AArch64::SUBWrr: {
// neg x -> csneg, represented as sub dst, xzr, src.
unsigned ZReg = removeCopies(MRI, DefMI->getOperand(1).getReg());
if (ZReg != AArch64::XZR && ZReg != AArch64::WZR)
return 0;
SrcOpNum = 2;
Opc = Is64Bit ? AArch64::CSNEGXr : AArch64::CSNEGWr;
break;
}
default:
return 0;
}
assert(Opc && SrcOpNum && "Missing parameters");
if (NewVReg)
*NewVReg = DefMI->getOperand(SrcOpNum).getReg();
return Opc;
}
bool AArch64InstrInfo::canInsertSelect(
const MachineBasicBlock &MBB, ArrayRef<MachineOperand> Cond,
unsigned TrueReg, unsigned FalseReg, int &CondCycles, int &TrueCycles,
int &FalseCycles) const {
// Check register classes.
const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
const TargetRegisterClass *RC =
RI.getCommonSubClass(MRI.getRegClass(TrueReg), MRI.getRegClass(FalseReg));
if (!RC)
return false;
// Expanding cbz/tbz requires an extra cycle of latency on the condition.
unsigned ExtraCondLat = Cond.size() != 1;
// GPRs are handled by csel.
// FIXME: Fold in x+1, -x, and ~x when applicable.
if (AArch64::GPR64allRegClass.hasSubClassEq(RC) ||
AArch64::GPR32allRegClass.hasSubClassEq(RC)) {
// Single-cycle csel, csinc, csinv, and csneg.
CondCycles = 1 + ExtraCondLat;
TrueCycles = FalseCycles = 1;
if (canFoldIntoCSel(MRI, TrueReg))
TrueCycles = 0;
else if (canFoldIntoCSel(MRI, FalseReg))
FalseCycles = 0;
return true;
}
// Scalar floating point is handled by fcsel.
// FIXME: Form fabs, fmin, and fmax when applicable.
if (AArch64::FPR64RegClass.hasSubClassEq(RC) ||
AArch64::FPR32RegClass.hasSubClassEq(RC)) {
CondCycles = 5 + ExtraCondLat;
TrueCycles = FalseCycles = 2;
return true;
}
// Can't do vectors.
return false;
}
void AArch64InstrInfo::insertSelect(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
const DebugLoc &DL, unsigned DstReg,
ArrayRef<MachineOperand> Cond,
unsigned TrueReg, unsigned FalseReg) const {
MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
// Parse the condition code, see parseCondBranch() above.
AArch64CC::CondCode CC;
switch (Cond.size()) {
default:
llvm_unreachable("Unknown condition opcode in Cond");
case 1: // b.cc
CC = AArch64CC::CondCode(Cond[0].getImm());
break;
case 3: { // cbz/cbnz
// We must insert a compare against 0.
bool Is64Bit;
switch (Cond[1].getImm()) {
default:
llvm_unreachable("Unknown branch opcode in Cond");
case AArch64::CBZW:
Is64Bit = 0;
CC = AArch64CC::EQ;
break;
case AArch64::CBZX:
Is64Bit = 1;
CC = AArch64CC::EQ;
break;
case AArch64::CBNZW:
Is64Bit = 0;
CC = AArch64CC::NE;
break;
case AArch64::CBNZX:
Is64Bit = 1;
CC = AArch64CC::NE;
break;
}
unsigned SrcReg = Cond[2].getReg();
if (Is64Bit) {
// cmp reg, #0 is actually subs xzr, reg, #0.
MRI.constrainRegClass(SrcReg, &AArch64::GPR64spRegClass);
BuildMI(MBB, I, DL, get(AArch64::SUBSXri), AArch64::XZR)
.addReg(SrcReg)
.addImm(0)
.addImm(0);
} else {
MRI.constrainRegClass(SrcReg, &AArch64::GPR32spRegClass);
BuildMI(MBB, I, DL, get(AArch64::SUBSWri), AArch64::WZR)
.addReg(SrcReg)
.addImm(0)
.addImm(0);
}
break;
}
case 4: { // tbz/tbnz
// We must insert a tst instruction.
switch (Cond[1].getImm()) {
default:
llvm_unreachable("Unknown branch opcode in Cond");
case AArch64::TBZW:
case AArch64::TBZX:
CC = AArch64CC::EQ;
break;
case AArch64::TBNZW:
case AArch64::TBNZX:
CC = AArch64CC::NE;
break;
}
// cmp reg, #foo is actually ands xzr, reg, #1<<foo.
if (Cond[1].getImm() == AArch64::TBZW || Cond[1].getImm() == AArch64::TBNZW)
BuildMI(MBB, I, DL, get(AArch64::ANDSWri), AArch64::WZR)
.addReg(Cond[2].getReg())
.addImm(
AArch64_AM::encodeLogicalImmediate(1ull << Cond[3].getImm(), 32));
else
BuildMI(MBB, I, DL, get(AArch64::ANDSXri), AArch64::XZR)
.addReg(Cond[2].getReg())
.addImm(
AArch64_AM::encodeLogicalImmediate(1ull << Cond[3].getImm(), 64));
break;
}
}
unsigned Opc = 0;
const TargetRegisterClass *RC = nullptr;
bool TryFold = false;
if (MRI.constrainRegClass(DstReg, &AArch64::GPR64RegClass)) {
RC = &AArch64::GPR64RegClass;
Opc = AArch64::CSELXr;
TryFold = true;
} else if (MRI.constrainRegClass(DstReg, &AArch64::GPR32RegClass)) {
RC = &AArch64::GPR32RegClass;
Opc = AArch64::CSELWr;
TryFold = true;
} else if (MRI.constrainRegClass(DstReg, &AArch64::FPR64RegClass)) {
RC = &AArch64::FPR64RegClass;
Opc = AArch64::FCSELDrrr;
} else if (MRI.constrainRegClass(DstReg, &AArch64::FPR32RegClass)) {
RC = &AArch64::FPR32RegClass;
Opc = AArch64::FCSELSrrr;
}
assert(RC && "Unsupported regclass");
// Try folding simple instructions into the csel.
if (TryFold) {
unsigned NewVReg = 0;
unsigned FoldedOpc = canFoldIntoCSel(MRI, TrueReg, &NewVReg);
if (FoldedOpc) {
// The folded opcodes csinc, csinc and csneg apply the operation to
// FalseReg, so we need to invert the condition.
CC = AArch64CC::getInvertedCondCode(CC);
TrueReg = FalseReg;
} else
FoldedOpc = canFoldIntoCSel(MRI, FalseReg, &NewVReg);
// Fold the operation. Leave any dead instructions for DCE to clean up.
if (FoldedOpc) {
FalseReg = NewVReg;
Opc = FoldedOpc;
// The extends the live range of NewVReg.
MRI.clearKillFlags(NewVReg);
}
}
// Pull all virtual register into the appropriate class.
MRI.constrainRegClass(TrueReg, RC);
MRI.constrainRegClass(FalseReg, RC);
// Insert the csel.
BuildMI(MBB, I, DL, get(Opc), DstReg).addReg(TrueReg).addReg(FalseReg).addImm(
CC);
}
/// Returns true if a MOVi32imm or MOVi64imm can be expanded to an ORRxx.
static bool canBeExpandedToORR(const MachineInstr &MI, unsigned BitSize) {
uint64_t Imm = MI.getOperand(1).getImm();
uint64_t UImm = Imm << (64 - BitSize) >> (64 - BitSize);
uint64_t Encoding;
return AArch64_AM::processLogicalImmediate(UImm, BitSize, Encoding);
}
// FIXME: this implementation should be micro-architecture dependent, so a
// micro-architecture target hook should be introduced here in future.
bool AArch64InstrInfo::isAsCheapAsAMove(const MachineInstr &MI) const {
if (!Subtarget.hasCustomCheapAsMoveHandling())
return MI.isAsCheapAsAMove();
unsigned Imm;
switch (MI.getOpcode()) {
default:
return false;
// add/sub on register without shift
case AArch64::ADDWri:
case AArch64::ADDXri:
case AArch64::SUBWri:
case AArch64::SUBXri:
return (Subtarget.getProcFamily() == AArch64Subtarget::ExynosM1 ||
MI.getOperand(3).getImm() == 0);
// add/sub on register with shift
case AArch64::ADDWrs:
case AArch64::ADDXrs:
case AArch64::SUBWrs:
case AArch64::SUBXrs:
Imm = MI.getOperand(3).getImm();
return (Subtarget.getProcFamily() == AArch64Subtarget::ExynosM1 &&
AArch64_AM::getArithShiftValue(Imm) < 4);
// logical ops on immediate
case AArch64::ANDWri:
case AArch64::ANDXri:
case AArch64::EORWri:
case AArch64::EORXri:
case AArch64::ORRWri:
case AArch64::ORRXri:
return true;
// logical ops on register without shift
case AArch64::ANDWrr:
case AArch64::ANDXrr:
case AArch64::BICWrr:
case AArch64::BICXrr:
case AArch64::EONWrr:
case AArch64::EONXrr:
case AArch64::EORWrr:
case AArch64::EORXrr:
case AArch64::ORNWrr:
case AArch64::ORNXrr:
case AArch64::ORRWrr:
case AArch64::ORRXrr:
return true;
// logical ops on register with shift
case AArch64::ANDWrs:
case AArch64::ANDXrs:
case AArch64::BICWrs:
case AArch64::BICXrs:
case AArch64::EONWrs:
case AArch64::EONXrs:
case AArch64::EORWrs:
case AArch64::EORXrs:
case AArch64::ORNWrs:
case AArch64::ORNXrs:
case AArch64::ORRWrs:
case AArch64::ORRXrs:
Imm = MI.getOperand(3).getImm();
return (Subtarget.getProcFamily() == AArch64Subtarget::ExynosM1 &&
AArch64_AM::getShiftValue(Imm) < 4 &&
AArch64_AM::getShiftType(Imm) == AArch64_AM::LSL);
// If MOVi32imm or MOVi64imm can be expanded into ORRWri or
// ORRXri, it is as cheap as MOV
case AArch64::MOVi32imm:
return canBeExpandedToORR(MI, 32);
case AArch64::MOVi64imm:
return canBeExpandedToORR(MI, 64);
// It is cheap to zero out registers if the subtarget has ZeroCycleZeroing
// feature.
case AArch64::FMOVS0:
case AArch64::FMOVD0:
return Subtarget.hasZeroCycleZeroing();
case TargetOpcode::COPY:
return (Subtarget.hasZeroCycleZeroing() &&
(MI.getOperand(1).getReg() == AArch64::WZR ||
MI.getOperand(1).getReg() == AArch64::XZR));
}
llvm_unreachable("Unknown opcode to check as cheap as a move!");
}
bool AArch64InstrInfo::isCoalescableExtInstr(const MachineInstr &MI,
unsigned &SrcReg, unsigned &DstReg,
unsigned &SubIdx) const {
switch (MI.getOpcode()) {
default:
return false;
case AArch64::SBFMXri: // aka sxtw
case AArch64::UBFMXri: // aka uxtw
// Check for the 32 -> 64 bit extension case, these instructions can do
// much more.
if (MI.getOperand(2).getImm() != 0 || MI.getOperand(3).getImm() != 31)
return false;
// This is a signed or unsigned 32 -> 64 bit extension.
SrcReg = MI.getOperand(1).getReg();
DstReg = MI.getOperand(0).getReg();
SubIdx = AArch64::sub_32;
return true;
}
}
bool AArch64InstrInfo::areMemAccessesTriviallyDisjoint(
MachineInstr &MIa, MachineInstr &MIb, AliasAnalysis *AA) const {
const TargetRegisterInfo *TRI = &getRegisterInfo();
unsigned BaseRegA = 0, BaseRegB = 0;
int64_t OffsetA = 0, OffsetB = 0;
unsigned WidthA = 0, WidthB = 0;
assert(MIa.mayLoadOrStore() && "MIa must be a load or store.");
assert(MIb.mayLoadOrStore() && "MIb must be a load or store.");
if (MIa.hasUnmodeledSideEffects() || MIb.hasUnmodeledSideEffects() ||
MIa.hasOrderedMemoryRef() || MIb.hasOrderedMemoryRef())
return false;
// Retrieve the base register, offset from the base register and width. Width
// is the size of memory that is being loaded/stored (e.g. 1, 2, 4, 8). If
// base registers are identical, and the offset of a lower memory access +
// the width doesn't overlap the offset of a higher memory access,
// then the memory accesses are different.
if (getMemOpBaseRegImmOfsWidth(MIa, BaseRegA, OffsetA, WidthA, TRI) &&
getMemOpBaseRegImmOfsWidth(MIb, BaseRegB, OffsetB, WidthB, TRI)) {
if (BaseRegA == BaseRegB) {
int LowOffset = OffsetA < OffsetB ? OffsetA : OffsetB;
int HighOffset = OffsetA < OffsetB ? OffsetB : OffsetA;
int LowWidth = (LowOffset == OffsetA) ? WidthA : WidthB;
if (LowOffset + LowWidth <= HighOffset)
return true;
}
}
return false;
}
/// analyzeCompare - For a comparison instruction, return the source registers
/// in SrcReg and SrcReg2, and the value it compares against in CmpValue.
/// Return true if the comparison instruction can be analyzed.
bool AArch64InstrInfo::analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
unsigned &SrcReg2, int &CmpMask,
int &CmpValue) const {
switch (MI.getOpcode()) {
default:
break;
case AArch64::SUBSWrr:
case AArch64::SUBSWrs:
case AArch64::SUBSWrx:
case AArch64::SUBSXrr:
case AArch64::SUBSXrs:
case AArch64::SUBSXrx:
case AArch64::ADDSWrr:
case AArch64::ADDSWrs:
case AArch64::ADDSWrx:
case AArch64::ADDSXrr:
case AArch64::ADDSXrs:
case AArch64::ADDSXrx:
// Replace SUBSWrr with SUBWrr if NZCV is not used.
SrcReg = MI.getOperand(1).getReg();
SrcReg2 = MI.getOperand(2).getReg();
CmpMask = ~0;
CmpValue = 0;
return true;
case AArch64::SUBSWri:
case AArch64::ADDSWri:
case AArch64::SUBSXri:
case AArch64::ADDSXri:
SrcReg = MI.getOperand(1).getReg();
SrcReg2 = 0;
CmpMask = ~0;
// FIXME: In order to convert CmpValue to 0 or 1
CmpValue = MI.getOperand(2).getImm() != 0;
return true;
case AArch64::ANDSWri:
case AArch64::ANDSXri:
// ANDS does not use the same encoding scheme as the others xxxS
// instructions.
SrcReg = MI.getOperand(1).getReg();
SrcReg2 = 0;
CmpMask = ~0;
// FIXME:The return val type of decodeLogicalImmediate is uint64_t,
// while the type of CmpValue is int. When converting uint64_t to int,
// the high 32 bits of uint64_t will be lost.
// In fact it causes a bug in spec2006-483.xalancbmk
// CmpValue is only used to compare with zero in OptimizeCompareInstr
CmpValue = AArch64_AM::decodeLogicalImmediate(
MI.getOperand(2).getImm(),
MI.getOpcode() == AArch64::ANDSWri ? 32 : 64) != 0;
return true;
}
return false;
}
static bool UpdateOperandRegClass(MachineInstr &Instr) {
MachineBasicBlock *MBB = Instr.getParent();
assert(MBB && "Can't get MachineBasicBlock here");
MachineFunction *MF = MBB->getParent();
assert(MF && "Can't get MachineFunction here");
const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
MachineRegisterInfo *MRI = &MF->getRegInfo();
for (unsigned OpIdx = 0, EndIdx = Instr.getNumOperands(); OpIdx < EndIdx;
++OpIdx) {
MachineOperand &MO = Instr.getOperand(OpIdx);
const TargetRegisterClass *OpRegCstraints =
Instr.getRegClassConstraint(OpIdx, TII, TRI);
// If there's no constraint, there's nothing to do.
if (!OpRegCstraints)
continue;
// If the operand is a frame index, there's nothing to do here.
// A frame index operand will resolve correctly during PEI.
if (MO.isFI())
continue;
assert(MO.isReg() &&
"Operand has register constraints without being a register!");
unsigned Reg = MO.getReg();
if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
if (!OpRegCstraints->contains(Reg))
return false;
} else if (!OpRegCstraints->hasSubClassEq(MRI->getRegClass(Reg)) &&
!MRI->constrainRegClass(Reg, OpRegCstraints))
return false;
}
return true;
}
/// \brief Return the opcode that does not set flags when possible - otherwise
/// return the original opcode. The caller is responsible to do the actual
/// substitution and legality checking.
static unsigned convertFlagSettingOpcode(const MachineInstr &MI) {
// Don't convert all compare instructions, because for some the zero register
// encoding becomes the sp register.
bool MIDefinesZeroReg = false;
if (MI.definesRegister(AArch64::WZR) || MI.definesRegister(AArch64::XZR))
MIDefinesZeroReg = true;
switch (MI.getOpcode()) {
default:
return MI.getOpcode();
case AArch64::ADDSWrr:
return AArch64::ADDWrr;
case AArch64::ADDSWri:
return MIDefinesZeroReg ? AArch64::ADDSWri : AArch64::ADDWri;
case AArch64::ADDSWrs:
return MIDefinesZeroReg ? AArch64::ADDSWrs : AArch64::ADDWrs;
case AArch64::ADDSWrx:
return AArch64::ADDWrx;
case AArch64::ADDSXrr:
return AArch64::ADDXrr;
case AArch64::ADDSXri:
return MIDefinesZeroReg ? AArch64::ADDSXri : AArch64::ADDXri;
case AArch64::ADDSXrs:
return MIDefinesZeroReg ? AArch64::ADDSXrs : AArch64::ADDXrs;
case AArch64::ADDSXrx:
return AArch64::ADDXrx;
case AArch64::SUBSWrr:
return AArch64::SUBWrr;
case AArch64::SUBSWri:
return MIDefinesZeroReg ? AArch64::SUBSWri : AArch64::SUBWri;
case AArch64::SUBSWrs:
return MIDefinesZeroReg ? AArch64::SUBSWrs : AArch64::SUBWrs;
case AArch64::SUBSWrx:
return AArch64::SUBWrx;
case AArch64::SUBSXrr:
return AArch64::SUBXrr;
case AArch64::SUBSXri:
return MIDefinesZeroReg ? AArch64::SUBSXri : AArch64::SUBXri;
case AArch64::SUBSXrs:
return MIDefinesZeroReg ? AArch64::SUBSXrs : AArch64::SUBXrs;
case AArch64::SUBSXrx:
return AArch64::SUBXrx;
}
}
enum AccessKind {
AK_Write = 0x01,
AK_Read = 0x10,
AK_All = 0x11
};
/// True when condition flags are accessed (either by writing or reading)
/// on the instruction trace starting at From and ending at To.
///
/// Note: If From and To are from different blocks it's assumed CC are accessed
/// on the path.
static bool areCFlagsAccessedBetweenInstrs(
MachineBasicBlock::iterator From, MachineBasicBlock::iterator To,
const TargetRegisterInfo *TRI, const AccessKind AccessToCheck = AK_All) {
// Early exit if To is at the beginning of the BB.
if (To == To->getParent()->begin())
return true;
// Check whether the instructions are in the same basic block
// If not, assume the condition flags might get modified somewhere.
if (To->getParent() != From->getParent())
return true;
// From must be above To.
assert(std::find_if(MachineBasicBlock::reverse_iterator(To),
To->getParent()->rend(), [From](MachineInstr &MI) {
return MachineBasicBlock::iterator(MI) == From;
}) != To->getParent()->rend());
// We iterate backward starting \p To until we hit \p From.
for (--To; To != From; --To) {
const MachineInstr &Instr = *To;
if ( ((AccessToCheck & AK_Write) && Instr.modifiesRegister(AArch64::NZCV, TRI)) ||
((AccessToCheck & AK_Read) && Instr.readsRegister(AArch64::NZCV, TRI)))
return true;
}
return false;
}
/// Try to optimize a compare instruction. A compare instruction is an
/// instruction which produces AArch64::NZCV. It can be truly compare instruction
/// when there are no uses of its destination register.
///
/// The following steps are tried in order:
/// 1. Convert CmpInstr into an unconditional version.
/// 2. Remove CmpInstr if above there is an instruction producing a needed
/// condition code or an instruction which can be converted into such an instruction.
/// Only comparison with zero is supported.
bool AArch64InstrInfo::optimizeCompareInstr(
MachineInstr &CmpInstr, unsigned SrcReg, unsigned SrcReg2, int CmpMask,
int CmpValue, const MachineRegisterInfo *MRI) const {
assert(CmpInstr.getParent());
assert(MRI);
// Replace SUBSWrr with SUBWrr if NZCV is not used.
int DeadNZCVIdx = CmpInstr.findRegisterDefOperandIdx(AArch64::NZCV, true);
if (DeadNZCVIdx != -1) {
if (CmpInstr.definesRegister(AArch64::WZR) ||
CmpInstr.definesRegister(AArch64::XZR)) {
CmpInstr.eraseFromParent();
return true;
}
unsigned Opc = CmpInstr.getOpcode();
unsigned NewOpc = convertFlagSettingOpcode(CmpInstr);
if (NewOpc == Opc)
return false;
const MCInstrDesc &MCID = get(NewOpc);
CmpInstr.setDesc(MCID);
CmpInstr.RemoveOperand(DeadNZCVIdx);
bool succeeded = UpdateOperandRegClass(CmpInstr);
(void)succeeded;
assert(succeeded && "Some operands reg class are incompatible!");
return true;
}
// Continue only if we have a "ri" where immediate is zero.
// FIXME:CmpValue has already been converted to 0 or 1 in analyzeCompare
// function.
assert((CmpValue == 0 || CmpValue == 1) && "CmpValue must be 0 or 1!");
if (CmpValue != 0 || SrcReg2 != 0)
return false;
// CmpInstr is a Compare instruction if destination register is not used.
if (!MRI->use_nodbg_empty(CmpInstr.getOperand(0).getReg()))
return false;
return substituteCmpToZero(CmpInstr, SrcReg, MRI);
}
/// Get opcode of S version of Instr.
/// If Instr is S version its opcode is returned.
/// AArch64::INSTRUCTION_LIST_END is returned if Instr does not have S version
/// or we are not interested in it.
static unsigned sForm(MachineInstr &Instr) {
switch (Instr.getOpcode()) {
default:
return AArch64::INSTRUCTION_LIST_END;
case AArch64::ADDSWrr:
case AArch64::ADDSWri:
case AArch64::ADDSXrr:
case AArch64::ADDSXri:
case AArch64::SUBSWrr:
case AArch64::SUBSWri:
case AArch64::SUBSXrr:
case AArch64::SUBSXri:
return Instr.getOpcode();;
case AArch64::ADDWrr: return AArch64::ADDSWrr;
case AArch64::ADDWri: return AArch64::ADDSWri;
case AArch64::ADDXrr: return AArch64::ADDSXrr;
case AArch64::ADDXri: return AArch64::ADDSXri;
case AArch64::ADCWr: return AArch64::ADCSWr;
case AArch64::ADCXr: return AArch64::ADCSXr;
case AArch64::SUBWrr: return AArch64::SUBSWrr;
case AArch64::SUBWri: return AArch64::SUBSWri;
case AArch64::SUBXrr: return AArch64::SUBSXrr;
case AArch64::SUBXri: return AArch64::SUBSXri;
case AArch64::SBCWr: return AArch64::SBCSWr;
case AArch64::SBCXr: return AArch64::SBCSXr;
case AArch64::ANDWri: return AArch64::ANDSWri;
case AArch64::ANDXri: return AArch64::ANDSXri;
}
}
/// Check if AArch64::NZCV should be alive in successors of MBB.
static bool areCFlagsAliveInSuccessors(MachineBasicBlock *MBB) {
for (auto *BB : MBB->successors())
if (BB->isLiveIn(AArch64::NZCV))
return true;
return false;
}
struct UsedNZCV {
bool N;
bool Z;
bool C;
bool V;
UsedNZCV(): N(false), Z(false), C(false), V(false) {}
UsedNZCV& operator |=(const UsedNZCV& UsedFlags) {
this->N |= UsedFlags.N;
this->Z |= UsedFlags.Z;
this->C |= UsedFlags.C;
this->V |= UsedFlags.V;
return *this;
}
};
/// Find a condition code used by the instruction.
/// Returns AArch64CC::Invalid if either the instruction does not use condition
/// codes or we don't optimize CmpInstr in the presence of such instructions.
static AArch64CC::CondCode findCondCodeUsedByInstr(const MachineInstr &Instr) {
switch (Instr.getOpcode()) {
default:
return AArch64CC::Invalid;
case AArch64::Bcc: {
int Idx = Instr.findRegisterUseOperandIdx(AArch64::NZCV);
assert(Idx >= 2);
return static_cast<AArch64CC::CondCode>(Instr.getOperand(Idx - 2).getImm());
}
case AArch64::CSINVWr:
case AArch64::CSINVXr:
case AArch64::CSINCWr:
case AArch64::CSINCXr:
case AArch64::CSELWr:
case AArch64::CSELXr:
case AArch64::CSNEGWr:
case AArch64::CSNEGXr:
case AArch64::FCSELSrrr:
case AArch64::FCSELDrrr: {
int Idx = Instr.findRegisterUseOperandIdx(AArch64::NZCV);
assert(Idx >= 1);
return static_cast<AArch64CC::CondCode>(Instr.getOperand(Idx - 1).getImm());
}
}
}
static UsedNZCV getUsedNZCV(AArch64CC::CondCode CC) {
assert(CC != AArch64CC::Invalid);
UsedNZCV UsedFlags;
switch (CC) {
default:
break;
case AArch64CC::EQ: // Z set
case AArch64CC::NE: // Z clear
UsedFlags.Z = true;
break;
case AArch64CC::HI: // Z clear and C set
case AArch64CC::LS: // Z set or C clear
UsedFlags.Z = true;
case AArch64CC::HS: // C set
case AArch64CC::LO: // C clear
UsedFlags.C = true;
break;
case AArch64CC::MI: // N set
case AArch64CC::PL: // N clear
UsedFlags.N = true;
break;
case AArch64CC::VS: // V set
case AArch64CC::VC: // V clear
UsedFlags.V = true;
break;
case AArch64CC::GT: // Z clear, N and V the same
case AArch64CC::LE: // Z set, N and V differ
UsedFlags.Z = true;
case AArch64CC::GE: // N and V the same
case AArch64CC::LT: // N and V differ
UsedFlags.N = true;
UsedFlags.V = true;
break;
}
return UsedFlags;
}
static bool isADDSRegImm(unsigned Opcode) {
return Opcode == AArch64::ADDSWri || Opcode == AArch64::ADDSXri;
}
static bool isSUBSRegImm(unsigned Opcode) {
return Opcode == AArch64::SUBSWri || Opcode == AArch64::SUBSXri;
}
/// Check if CmpInstr can be substituted by MI.
///
/// CmpInstr can be substituted:
/// - CmpInstr is either 'ADDS %vreg, 0' or 'SUBS %vreg, 0'
/// - and, MI and CmpInstr are from the same MachineBB
/// - and, condition flags are not alive in successors of the CmpInstr parent
/// - and, if MI opcode is the S form there must be no defs of flags between
/// MI and CmpInstr
/// or if MI opcode is not the S form there must be neither defs of flags
/// nor uses of flags between MI and CmpInstr.
/// - and C/V flags are not used after CmpInstr
static bool canInstrSubstituteCmpInstr(MachineInstr *MI, MachineInstr *CmpInstr,
const TargetRegisterInfo *TRI) {
assert(MI);
assert(sForm(*MI) != AArch64::INSTRUCTION_LIST_END);
assert(CmpInstr);
const unsigned CmpOpcode = CmpInstr->getOpcode();
if (!isADDSRegImm(CmpOpcode) && !isSUBSRegImm(CmpOpcode))
return false;
if (MI->getParent() != CmpInstr->getParent())
return false;
if (areCFlagsAliveInSuccessors(CmpInstr->getParent()))
return false;
AccessKind AccessToCheck = AK_Write;
if (sForm(*MI) != MI->getOpcode())
AccessToCheck = AK_All;
if (areCFlagsAccessedBetweenInstrs(MI, CmpInstr, TRI, AccessToCheck))
return false;
UsedNZCV NZCVUsedAfterCmp;
for (auto I = std::next(CmpInstr->getIterator()), E = CmpInstr->getParent()->instr_end();
I != E; ++I) {
const MachineInstr &Instr = *I;
if (Instr.readsRegister(AArch64::NZCV, TRI)) {
AArch64CC::CondCode CC = findCondCodeUsedByInstr(Instr);
if (CC == AArch64CC::Invalid) // Unsupported conditional instruction
return false;
NZCVUsedAfterCmp |= getUsedNZCV(CC);
}
if (Instr.modifiesRegister(AArch64::NZCV, TRI))
break;
}
return !NZCVUsedAfterCmp.C && !NZCVUsedAfterCmp.V;
}
/// Substitute an instruction comparing to zero with another instruction
/// which produces needed condition flags.
///
/// Return true on success.
bool AArch64InstrInfo::substituteCmpToZero(
MachineInstr &CmpInstr, unsigned SrcReg,
const MachineRegisterInfo *MRI) const {
assert(MRI);
// Get the unique definition of SrcReg.
MachineInstr *MI = MRI->getUniqueVRegDef(SrcReg);
if (!MI)
return false;
const TargetRegisterInfo *TRI = &getRegisterInfo();
unsigned NewOpc = sForm(*MI);
if (NewOpc == AArch64::INSTRUCTION_LIST_END)
return false;
if (!canInstrSubstituteCmpInstr(MI, &CmpInstr, TRI))
return false;
// Update the instruction to set NZCV.
MI->setDesc(get(NewOpc));
CmpInstr.eraseFromParent();
bool succeeded = UpdateOperandRegClass(*MI);
(void)succeeded;
assert(succeeded && "Some operands reg class are incompatible!");
MI->addRegisterDefined(AArch64::NZCV, TRI);
return true;
}
bool AArch64InstrInfo::expandPostRAPseudo(MachineInstr &MI) const {
if (MI.getOpcode() != TargetOpcode::LOAD_STACK_GUARD)
return false;
MachineBasicBlock &MBB = *MI.getParent();
DebugLoc DL = MI.getDebugLoc();
unsigned Reg = MI.getOperand(0).getReg();
const GlobalValue *GV =
cast<GlobalValue>((*MI.memoperands_begin())->getValue());
const TargetMachine &TM = MBB.getParent()->getTarget();
unsigned char OpFlags = Subtarget.ClassifyGlobalReference(GV, TM);
const unsigned char MO_NC = AArch64II::MO_NC;
if ((OpFlags & AArch64II::MO_GOT) != 0) {
BuildMI(MBB, MI, DL, get(AArch64::LOADgot), Reg)
.addGlobalAddress(GV, 0, AArch64II::MO_GOT);
BuildMI(MBB, MI, DL, get(AArch64::LDRXui), Reg)
.addReg(Reg, RegState::Kill)
.addImm(0)
.addMemOperand(*MI.memoperands_begin());
} else if (TM.getCodeModel() == CodeModel::Large) {
BuildMI(MBB, MI, DL, get(AArch64::MOVZXi), Reg)
.addGlobalAddress(GV, 0, AArch64II::MO_G3).addImm(48);
BuildMI(MBB, MI, DL, get(AArch64::MOVKXi), Reg)
.addReg(Reg, RegState::Kill)
.addGlobalAddress(GV, 0, AArch64II::MO_G2 | MO_NC).addImm(32);
BuildMI(MBB, MI, DL, get(AArch64::MOVKXi), Reg)
.addReg(Reg, RegState::Kill)
.addGlobalAddress(GV, 0, AArch64II::MO_G1 | MO_NC).addImm(16);
BuildMI(MBB, MI, DL, get(AArch64::MOVKXi), Reg)
.addReg(Reg, RegState::Kill)
.addGlobalAddress(GV, 0, AArch64II::MO_G0 | MO_NC).addImm(0);
BuildMI(MBB, MI, DL, get(AArch64::LDRXui), Reg)
.addReg(Reg, RegState::Kill)
.addImm(0)
.addMemOperand(*MI.memoperands_begin());
} else {
BuildMI(MBB, MI, DL, get(AArch64::ADRP), Reg)
.addGlobalAddress(GV, 0, OpFlags | AArch64II::MO_PAGE);
unsigned char LoFlags = OpFlags | AArch64II::MO_PAGEOFF | MO_NC;
BuildMI(MBB, MI, DL, get(AArch64::LDRXui), Reg)
.addReg(Reg, RegState::Kill)
.addGlobalAddress(GV, 0, LoFlags)
.addMemOperand(*MI.memoperands_begin());
}
MBB.erase(MI);
return true;
}
/// Return true if this is this instruction has a non-zero immediate
bool AArch64InstrInfo::hasShiftedReg(const MachineInstr &MI) const {
switch (MI.getOpcode()) {
default:
break;
case AArch64::ADDSWrs:
case AArch64::ADDSXrs:
case AArch64::ADDWrs:
case AArch64::ADDXrs:
case AArch64::ANDSWrs:
case AArch64::ANDSXrs:
case AArch64::ANDWrs:
case AArch64::ANDXrs:
case AArch64::BICSWrs:
case AArch64::BICSXrs:
case AArch64::BICWrs:
case AArch64::BICXrs:
case AArch64::CRC32Brr:
case AArch64::CRC32CBrr:
case AArch64::CRC32CHrr:
case AArch64::CRC32CWrr:
case AArch64::CRC32CXrr:
case AArch64::CRC32Hrr:
case AArch64::CRC32Wrr:
case AArch64::CRC32Xrr:
case AArch64::EONWrs:
case AArch64::EONXrs:
case AArch64::EORWrs:
case AArch64::EORXrs:
case AArch64::ORNWrs:
case AArch64::ORNXrs:
case AArch64::ORRWrs:
case AArch64::ORRXrs:
case AArch64::SUBSWrs:
case AArch64::SUBSXrs:
case AArch64::SUBWrs:
case AArch64::SUBXrs:
if (MI.getOperand(3).isImm()) {
unsigned val = MI.getOperand(3).getImm();
return (val != 0);
}
break;
}
return false;
}
/// Return true if this is this instruction has a non-zero immediate
bool AArch64InstrInfo::hasExtendedReg(const MachineInstr &MI) const {
switch (MI.getOpcode()) {
default:
break;
case AArch64::ADDSWrx:
case AArch64::ADDSXrx:
case AArch64::ADDSXrx64:
case AArch64::ADDWrx:
case AArch64::ADDXrx:
case AArch64::ADDXrx64:
case AArch64::SUBSWrx:
case AArch64::SUBSXrx:
case AArch64::SUBSXrx64:
case AArch64::SUBWrx:
case AArch64::SUBXrx:
case AArch64::SUBXrx64:
if (MI.getOperand(3).isImm()) {
unsigned val = MI.getOperand(3).getImm();
return (val != 0);
}
break;
}
return false;
}
// Return true if this instruction simply sets its single destination register
// to zero. This is equivalent to a register rename of the zero-register.
bool AArch64InstrInfo::isGPRZero(const MachineInstr &MI) const {
switch (MI.getOpcode()) {
default:
break;
case AArch64::MOVZWi:
case AArch64::MOVZXi: // movz Rd, #0 (LSL #0)
if (MI.getOperand(1).isImm() && MI.getOperand(1).getImm() == 0) {
assert(MI.getDesc().getNumOperands() == 3 &&
MI.getOperand(2).getImm() == 0 && "invalid MOVZi operands");
return true;
}
break;
case AArch64::ANDWri: // and Rd, Rzr, #imm
return MI.getOperand(1).getReg() == AArch64::WZR;
case AArch64::ANDXri:
return MI.getOperand(1).getReg() == AArch64::XZR;
case TargetOpcode::COPY:
return MI.getOperand(1).getReg() == AArch64::WZR;
}
return false;
}
// Return true if this instruction simply renames a general register without
// modifying bits.
bool AArch64InstrInfo::isGPRCopy(const MachineInstr &MI) const {
switch (MI.getOpcode()) {
default:
break;
case TargetOpcode::COPY: {
// GPR32 copies will by lowered to ORRXrs
unsigned DstReg = MI.getOperand(0).getReg();
return (AArch64::GPR32RegClass.contains(DstReg) ||
AArch64::GPR64RegClass.contains(DstReg));
}
case AArch64::ORRXrs: // orr Xd, Xzr, Xm (LSL #0)
if (MI.getOperand(1).getReg() == AArch64::XZR) {
assert(MI.getDesc().getNumOperands() == 4 &&
MI.getOperand(3).getImm() == 0 && "invalid ORRrs operands");
return true;
}
break;
case AArch64::ADDXri: // add Xd, Xn, #0 (LSL #0)
if (MI.getOperand(2).getImm() == 0) {
assert(MI.getDesc().getNumOperands() == 4 &&
MI.getOperand(3).getImm() == 0 && "invalid ADDXri operands");
return true;
}
break;
}
return false;
}
// Return true if this instruction simply renames a general register without
// modifying bits.
bool AArch64InstrInfo::isFPRCopy(const MachineInstr &MI) const {
switch (MI.getOpcode()) {
default:
break;
case TargetOpcode::COPY: {
// FPR64 copies will by lowered to ORR.16b
unsigned DstReg = MI.getOperand(0).getReg();
return (AArch64::FPR64RegClass.contains(DstReg) ||
AArch64::FPR128RegClass.contains(DstReg));
}
case AArch64::ORRv16i8:
if (MI.getOperand(1).getReg() == MI.getOperand(2).getReg()) {
assert(MI.getDesc().getNumOperands() == 3 && MI.getOperand(0).isReg() &&
"invalid ORRv16i8 operands");
return true;
}
break;
}
return false;
}
unsigned AArch64InstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
int &FrameIndex) const {
switch (MI.getOpcode()) {
default:
break;
case AArch64::LDRWui:
case AArch64::LDRXui:
case AArch64::LDRBui:
case AArch64::LDRHui:
case AArch64::LDRSui:
case AArch64::LDRDui:
case AArch64::LDRQui:
if (MI.getOperand(0).getSubReg() == 0 && MI.getOperand(1).isFI() &&
MI.getOperand(2).isImm() && MI.getOperand(2).getImm() == 0) {
FrameIndex = MI.getOperand(1).getIndex();
return MI.getOperand(0).getReg();
}
break;
}
return 0;
}
unsigned AArch64InstrInfo::isStoreToStackSlot(const MachineInstr &MI,
int &FrameIndex) const {
switch (MI.getOpcode()) {
default:
break;
case AArch64::STRWui:
case AArch64::STRXui:
case AArch64::STRBui:
case AArch64::STRHui:
case AArch64::STRSui:
case AArch64::STRDui:
case AArch64::STRQui:
if (MI.getOperand(0).getSubReg() == 0 && MI.getOperand(1).isFI() &&
MI.getOperand(2).isImm() && MI.getOperand(2).getImm() == 0) {
FrameIndex = MI.getOperand(1).getIndex();
return MI.getOperand(0).getReg();
}
break;
}
return 0;
}
/// Return true if this is load/store scales or extends its register offset.
/// This refers to scaling a dynamic index as opposed to scaled immediates.
/// MI should be a memory op that allows scaled addressing.
bool AArch64InstrInfo::isScaledAddr(const MachineInstr &MI) const {
switch (MI.getOpcode()) {
default:
break;
case AArch64::LDRBBroW:
case AArch64::LDRBroW:
case AArch64::LDRDroW:
case AArch64::LDRHHroW:
case AArch64::LDRHroW:
case AArch64::LDRQroW:
case AArch64::LDRSBWroW:
case AArch64::LDRSBXroW:
case AArch64::LDRSHWroW:
case AArch64::LDRSHXroW:
case AArch64::LDRSWroW:
case AArch64::LDRSroW:
case AArch64::LDRWroW:
case AArch64::LDRXroW:
case AArch64::STRBBroW:
case AArch64::STRBroW:
case AArch64::STRDroW:
case AArch64::STRHHroW:
case AArch64::STRHroW:
case AArch64::STRQroW:
case AArch64::STRSroW:
case AArch64::STRWroW:
case AArch64::STRXroW:
case AArch64::LDRBBroX:
case AArch64::LDRBroX:
case AArch64::LDRDroX:
case AArch64::LDRHHroX:
case AArch64::LDRHroX:
case AArch64::LDRQroX:
case AArch64::LDRSBWroX:
case AArch64::LDRSBXroX:
case AArch64::LDRSHWroX:
case AArch64::LDRSHXroX:
case AArch64::LDRSWroX:
case AArch64::LDRSroX:
case AArch64::LDRWroX:
case AArch64::LDRXroX:
case AArch64::STRBBroX:
case AArch64::STRBroX:
case AArch64::STRDroX:
case AArch64::STRHHroX:
case AArch64::STRHroX:
case AArch64::STRQroX:
case AArch64::STRSroX:
case AArch64::STRWroX:
case AArch64::STRXroX:
unsigned Val = MI.getOperand(3).getImm();
AArch64_AM::ShiftExtendType ExtType = AArch64_AM::getMemExtendType(Val);
return (ExtType != AArch64_AM::UXTX) || AArch64_AM::getMemDoShift(Val);
}
return false;
}
/// Check all MachineMemOperands for a hint to suppress pairing.
bool AArch64InstrInfo::isLdStPairSuppressed(const MachineInstr &MI) const {
return any_of(MI.memoperands(), [](MachineMemOperand *MMO) {
return MMO->getFlags() & MOSuppressPair;
});
}
/// Set a flag on the first MachineMemOperand to suppress pairing.
void AArch64InstrInfo::suppressLdStPair(MachineInstr &MI) const {
if (MI.memoperands_empty())
return;
(*MI.memoperands_begin())->setFlags(MOSuppressPair);
}
bool AArch64InstrInfo::isUnscaledLdSt(unsigned Opc) const {
switch (Opc) {
default:
return false;
case AArch64::STURSi:
case AArch64::STURDi:
case AArch64::STURQi:
case AArch64::STURBBi:
case AArch64::STURHHi:
case AArch64::STURWi:
case AArch64::STURXi:
case AArch64::LDURSi:
case AArch64::LDURDi:
case AArch64::LDURQi:
case AArch64::LDURWi:
case AArch64::LDURXi:
case AArch64::LDURSWi:
case AArch64::LDURHHi:
case AArch64::LDURBBi:
case AArch64::LDURSBWi:
case AArch64::LDURSHWi:
return true;
}
}
bool AArch64InstrInfo::isUnscaledLdSt(MachineInstr &MI) const {
return isUnscaledLdSt(MI.getOpcode());
}
// Is this a candidate for ld/st merging or pairing? For example, we don't
// touch volatiles or load/stores that have a hint to avoid pair formation.
bool AArch64InstrInfo::isCandidateToMergeOrPair(MachineInstr &MI) const {
// If this is a volatile load/store, don't mess with it.
if (MI.hasOrderedMemoryRef())
return false;
// Make sure this is a reg+imm (as opposed to an address reloc).
assert(MI.getOperand(1).isReg() && "Expected a reg operand.");
if (!MI.getOperand(2).isImm())
return false;
// Can't merge/pair if the instruction modifies the base register.
// e.g., ldr x0, [x0]
unsigned BaseReg = MI.getOperand(1).getReg();
const TargetRegisterInfo *TRI = &getRegisterInfo();
if (MI.modifiesRegister(BaseReg, TRI))
return false;
// Check if this load/store has a hint to avoid pair formation.
// MachineMemOperands hints are set by the AArch64StorePairSuppress pass.
if (isLdStPairSuppressed(MI))
return false;
// On some CPUs quad load/store pairs are slower than two single load/stores.
if (Subtarget.avoidQuadLdStPairs()) {
switch (MI.getOpcode()) {
default:
break;
case AArch64::LDURQi:
case AArch64::STURQi:
case AArch64::LDRQui:
case AArch64::STRQui:
return false;
}
}
return true;
}
bool AArch64InstrInfo::getMemOpBaseRegImmOfs(
MachineInstr &LdSt, unsigned &BaseReg, int64_t &Offset,
const TargetRegisterInfo *TRI) const {
switch (LdSt.getOpcode()) {
default:
return false;
// Scaled instructions.
case AArch64::STRSui:
case AArch64::STRDui:
case AArch64::STRQui:
case AArch64::STRXui:
case AArch64::STRWui:
case AArch64::LDRSui:
case AArch64::LDRDui:
case AArch64::LDRQui:
case AArch64::LDRXui:
case AArch64::LDRWui:
case AArch64::LDRSWui:
// Unscaled instructions.
case AArch64::STURSi:
case AArch64::STURDi:
case AArch64::STURQi:
case AArch64::STURXi:
case AArch64::STURWi:
case AArch64::LDURSi:
case AArch64::LDURDi:
case AArch64::LDURQi:
case AArch64::LDURWi:
case AArch64::LDURXi:
case AArch64::LDURSWi:
unsigned Width;
return getMemOpBaseRegImmOfsWidth(LdSt, BaseReg, Offset, Width, TRI);
};
}
bool AArch64InstrInfo::getMemOpBaseRegImmOfsWidth(
MachineInstr &LdSt, unsigned &BaseReg, int64_t &Offset, unsigned &Width,
const TargetRegisterInfo *TRI) const {
assert(LdSt.mayLoadOrStore() && "Expected a memory operation.");
// Handle only loads/stores with base register followed by immediate offset.
if (LdSt.getNumExplicitOperands() == 3) {
// Non-paired instruction (e.g., ldr x1, [x0, #8]).
if (!LdSt.getOperand(1).isReg() || !LdSt.getOperand(2).isImm())
return false;
} else if (LdSt.getNumExplicitOperands() == 4) {
// Paired instruction (e.g., ldp x1, x2, [x0, #8]).
if (!LdSt.getOperand(1).isReg() || !LdSt.getOperand(2).isReg() ||
!LdSt.getOperand(3).isImm())
return false;
} else
return false;
// Offset is calculated as the immediate operand multiplied by the scaling factor.
// Unscaled instructions have scaling factor set to 1.
unsigned Scale = 0;
switch (LdSt.getOpcode()) {
default:
return false;
case AArch64::LDURQi:
case AArch64::STURQi:
Width = 16;
Scale = 1;
break;
case AArch64::LDURXi:
case AArch64::LDURDi:
case AArch64::STURXi:
case AArch64::STURDi:
Width = 8;
Scale = 1;
break;
case AArch64::LDURWi:
case AArch64::LDURSi:
case AArch64::LDURSWi:
case AArch64::STURWi:
case AArch64::STURSi:
Width = 4;
Scale = 1;
break;
case AArch64::LDURHi:
case AArch64::LDURHHi:
case AArch64::LDURSHXi:
case AArch64::LDURSHWi:
case AArch64::STURHi:
case AArch64::STURHHi:
Width = 2;
Scale = 1;
break;
case AArch64::LDURBi:
case AArch64::LDURBBi:
case AArch64::LDURSBXi:
case AArch64::LDURSBWi:
case AArch64::STURBi:
case AArch64::STURBBi:
Width = 1;
Scale = 1;
break;
case AArch64::LDPQi:
case AArch64::LDNPQi:
case AArch64::STPQi:
case AArch64::STNPQi:
Scale = 16;
Width = 32;
break;
case AArch64::LDRQui:
case AArch64::STRQui:
Scale = Width = 16;
break;
case AArch64::LDPXi:
case AArch64::LDPDi:
case AArch64::LDNPXi:
case AArch64::LDNPDi:
case AArch64::STPXi:
case AArch64::STPDi:
case AArch64::STNPXi:
case AArch64::STNPDi:
Scale = 8;
Width = 16;
break;
case AArch64::LDRXui:
case AArch64::LDRDui:
case AArch64::STRXui:
case AArch64::STRDui:
Scale = Width = 8;
break;
case AArch64::LDPWi:
case AArch64::LDPSi:
case AArch64::LDNPWi:
case AArch64::LDNPSi:
case AArch64::STPWi:
case AArch64::STPSi:
case AArch64::STNPWi:
case AArch64::STNPSi:
Scale = 4;
Width = 8;
break;
case AArch64::LDRWui:
case AArch64::LDRSui:
case AArch64::LDRSWui:
case AArch64::STRWui:
case AArch64::STRSui:
Scale = Width = 4;
break;
case AArch64::LDRHui:
case AArch64::LDRHHui:
case AArch64::STRHui:
case AArch64::STRHHui:
Scale = Width = 2;
break;
case AArch64::LDRBui:
case AArch64::LDRBBui:
case AArch64::STRBui:
case AArch64::STRBBui:
Scale = Width = 1;
break;
}
if (LdSt.getNumExplicitOperands() == 3) {
BaseReg = LdSt.getOperand(1).getReg();
Offset = LdSt.getOperand(2).getImm() * Scale;
} else {
assert(LdSt.getNumExplicitOperands() == 4 && "invalid number of operands");
BaseReg = LdSt.getOperand(2).getReg();
Offset = LdSt.getOperand(3).getImm() * Scale;
}
return true;
}
// Scale the unscaled offsets. Returns false if the unscaled offset can't be
// scaled.
static bool scaleOffset(unsigned Opc, int64_t &Offset) {
unsigned OffsetStride = 1;
switch (Opc) {
default:
return false;
case AArch64::LDURQi:
case AArch64::STURQi:
OffsetStride = 16;
break;
case AArch64::LDURXi:
case AArch64::LDURDi:
case AArch64::STURXi:
case AArch64::STURDi:
OffsetStride = 8;
break;
case AArch64::LDURWi:
case AArch64::LDURSi:
case AArch64::LDURSWi:
case AArch64::STURWi:
case AArch64::STURSi:
OffsetStride = 4;
break;
}
// If the byte-offset isn't a multiple of the stride, we can't scale this
// offset.
if (Offset % OffsetStride != 0)
return false;
// Convert the byte-offset used by unscaled into an "element" offset used
// by the scaled pair load/store instructions.
Offset /= OffsetStride;
return true;
}
static bool canPairLdStOpc(unsigned FirstOpc, unsigned SecondOpc) {
if (FirstOpc == SecondOpc)
return true;
// We can also pair sign-ext and zero-ext instructions.
switch (FirstOpc) {
default:
return false;
case AArch64::LDRWui:
case AArch64::LDURWi:
return SecondOpc == AArch64::LDRSWui || SecondOpc == AArch64::LDURSWi;
case AArch64::LDRSWui:
case AArch64::LDURSWi:
return SecondOpc == AArch64::LDRWui || SecondOpc == AArch64::LDURWi;
}
// These instructions can't be paired based on their opcodes.
return false;
}
/// Detect opportunities for ldp/stp formation.
///
/// Only called for LdSt for which getMemOpBaseRegImmOfs returns true.
bool AArch64InstrInfo::shouldClusterMemOps(MachineInstr &FirstLdSt,
MachineInstr &SecondLdSt,
unsigned NumLoads) const {
// Only cluster up to a single pair.
if (NumLoads > 1)
return false;
// Can we pair these instructions based on their opcodes?
unsigned FirstOpc = FirstLdSt.getOpcode();
unsigned SecondOpc = SecondLdSt.getOpcode();
if (!canPairLdStOpc(FirstOpc, SecondOpc))
return false;
// Can't merge volatiles or load/stores that have a hint to avoid pair
// formation, for example.
if (!isCandidateToMergeOrPair(FirstLdSt) ||
!isCandidateToMergeOrPair(SecondLdSt))
return false;
// isCandidateToMergeOrPair guarantees that operand 2 is an immediate.
int64_t Offset1 = FirstLdSt.getOperand(2).getImm();
if (isUnscaledLdSt(FirstOpc) && !scaleOffset(FirstOpc, Offset1))
return false;
int64_t Offset2 = SecondLdSt.getOperand(2).getImm();
if (isUnscaledLdSt(SecondOpc) && !scaleOffset(SecondOpc, Offset2))
return false;
// Pairwise instructions have a 7-bit signed offset field.
if (Offset1 > 63 || Offset1 < -64)
return false;
// The caller should already have ordered First/SecondLdSt by offset.
assert(Offset1 <= Offset2 && "Caller should have ordered offsets.");
return Offset1 + 1 == Offset2;
}
bool AArch64InstrInfo::shouldScheduleAdjacent(MachineInstr &First,
MachineInstr &Second) const {
if (Subtarget.hasMacroOpFusion()) {
// Fuse CMN, CMP, TST followed by Bcc.
unsigned SecondOpcode = Second.getOpcode();
if (SecondOpcode == AArch64::Bcc) {
switch (First.getOpcode()) {
default:
return false;
case AArch64::SUBSWri:
case AArch64::ADDSWri:
case AArch64::ANDSWri:
case AArch64::SUBSXri:
case AArch64::ADDSXri:
case AArch64::ANDSXri:
return true;
}
}
// Fuse ALU operations followed by CBZ/CBNZ.
if (SecondOpcode == AArch64::CBNZW || SecondOpcode == AArch64::CBNZX ||
SecondOpcode == AArch64::CBZW || SecondOpcode == AArch64::CBZX) {
switch (First.getOpcode()) {
default:
return false;
case AArch64::ADDWri:
case AArch64::ADDXri:
case AArch64::ANDWri:
case AArch64::ANDXri:
case AArch64::EORWri:
case AArch64::EORXri:
case AArch64::ORRWri:
case AArch64::ORRXri:
case AArch64::SUBWri:
case AArch64::SUBXri:
return true;
}
}
}
return false;
}
MachineInstr *AArch64InstrInfo::emitFrameIndexDebugValue(
MachineFunction &MF, int FrameIx, uint64_t Offset, const MDNode *Var,
const MDNode *Expr, const DebugLoc &DL) const {
MachineInstrBuilder MIB = BuildMI(MF, DL, get(AArch64::DBG_VALUE))
.addFrameIndex(FrameIx)
.addImm(0)
.addImm(Offset)
.addMetadata(Var)
.addMetadata(Expr);
return &*MIB;
}
static const MachineInstrBuilder &AddSubReg(const MachineInstrBuilder &MIB,
unsigned Reg, unsigned SubIdx,
unsigned State,
const TargetRegisterInfo *TRI) {
if (!SubIdx)
return MIB.addReg(Reg, State);
if (TargetRegisterInfo::isPhysicalRegister(Reg))
return MIB.addReg(TRI->getSubReg(Reg, SubIdx), State);
return MIB.addReg(Reg, State, SubIdx);
}
static bool forwardCopyWillClobberTuple(unsigned DestReg, unsigned SrcReg,
unsigned NumRegs) {
// We really want the positive remainder mod 32 here, that happens to be
// easily obtainable with a mask.
return ((DestReg - SrcReg) & 0x1f) < NumRegs;
}
void AArch64InstrInfo::copyPhysRegTuple(
MachineBasicBlock &MBB, MachineBasicBlock::iterator I, const DebugLoc &DL,
unsigned DestReg, unsigned SrcReg, bool KillSrc, unsigned Opcode,
llvm::ArrayRef<unsigned> Indices) const {
assert(Subtarget.hasNEON() &&
"Unexpected register copy without NEON");
const TargetRegisterInfo *TRI = &getRegisterInfo();
uint16_t DestEncoding = TRI->getEncodingValue(DestReg);
uint16_t SrcEncoding = TRI->getEncodingValue(SrcReg);
unsigned NumRegs = Indices.size();
int SubReg = 0, End = NumRegs, Incr = 1;
if (forwardCopyWillClobberTuple(DestEncoding, SrcEncoding, NumRegs)) {
SubReg = NumRegs - 1;
End = -1;
Incr = -1;
}
for (; SubReg != End; SubReg += Incr) {
const MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(Opcode));
AddSubReg(MIB, DestReg, Indices[SubReg], RegState::Define, TRI);
AddSubReg(MIB, SrcReg, Indices[SubReg], 0, TRI);
AddSubReg(MIB, SrcReg, Indices[SubReg], getKillRegState(KillSrc), TRI);
}
}
void AArch64InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
const DebugLoc &DL, unsigned DestReg,
unsigned SrcReg, bool KillSrc) const {
if (AArch64::GPR32spRegClass.contains(DestReg) &&
(AArch64::GPR32spRegClass.contains(SrcReg) || SrcReg == AArch64::WZR)) {
const TargetRegisterInfo *TRI = &getRegisterInfo();
if (DestReg == AArch64::WSP || SrcReg == AArch64::WSP) {
// If either operand is WSP, expand to ADD #0.
if (Subtarget.hasZeroCycleRegMove()) {
// Cyclone recognizes "ADD Xd, Xn, #0" as a zero-cycle register move.
unsigned DestRegX = TRI->getMatchingSuperReg(DestReg, AArch64::sub_32,
&AArch64::GPR64spRegClass);
unsigned SrcRegX = TRI->getMatchingSuperReg(SrcReg, AArch64::sub_32,
&AArch64::GPR64spRegClass);
// This instruction is reading and writing X registers. This may upset
// the register scavenger and machine verifier, so we need to indicate
// that we are reading an undefined value from SrcRegX, but a proper
// value from SrcReg.
BuildMI(MBB, I, DL, get(AArch64::ADDXri), DestRegX)
.addReg(SrcRegX, RegState::Undef)
.addImm(0)
.addImm(AArch64_AM::getShifterImm(AArch64_AM::LSL, 0))
.addReg(SrcReg, RegState::Implicit | getKillRegState(KillSrc));
} else {
BuildMI(MBB, I, DL, get(AArch64::ADDWri), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc))
.addImm(0)
.addImm(AArch64_AM::getShifterImm(AArch64_AM::LSL, 0));
}
} else if (SrcReg == AArch64::WZR && Subtarget.hasZeroCycleZeroing()) {
BuildMI(MBB, I, DL, get(AArch64::MOVZWi), DestReg).addImm(0).addImm(
AArch64_AM::getShifterImm(AArch64_AM::LSL, 0));
} else {
if (Subtarget.hasZeroCycleRegMove()) {
// Cyclone recognizes "ORR Xd, XZR, Xm" as a zero-cycle register move.
unsigned DestRegX = TRI->getMatchingSuperReg(DestReg, AArch64::sub_32,
&AArch64::GPR64spRegClass);
unsigned SrcRegX = TRI->getMatchingSuperReg(SrcReg, AArch64::sub_32,
&AArch64::GPR64spRegClass);
// This instruction is reading and writing X registers. This may upset
// the register scavenger and machine verifier, so we need to indicate
// that we are reading an undefined value from SrcRegX, but a proper
// value from SrcReg.
BuildMI(MBB, I, DL, get(AArch64::ORRXrr), DestRegX)
.addReg(AArch64::XZR)
.addReg(SrcRegX, RegState::Undef)
.addReg(SrcReg, RegState::Implicit | getKillRegState(KillSrc));
} else {
// Otherwise, expand to ORR WZR.
BuildMI(MBB, I, DL, get(AArch64::ORRWrr), DestReg)
.addReg(AArch64::WZR)
.addReg(SrcReg, getKillRegState(KillSrc));
}
}
return;
}
if (AArch64::GPR64spRegClass.contains(DestReg) &&
(AArch64::GPR64spRegClass.contains(SrcReg) || SrcReg == AArch64::XZR)) {
if (DestReg == AArch64::SP || SrcReg == AArch64::SP) {
// If either operand is SP, expand to ADD #0.
BuildMI(MBB, I, DL, get(AArch64::ADDXri), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc))
.addImm(0)
.addImm(AArch64_AM::getShifterImm(AArch64_AM::LSL, 0));
} else if (SrcReg == AArch64::XZR && Subtarget.hasZeroCycleZeroing()) {
BuildMI(MBB, I, DL, get(AArch64::MOVZXi), DestReg).addImm(0).addImm(
AArch64_AM::getShifterImm(AArch64_AM::LSL, 0));
} else {
// Otherwise, expand to ORR XZR.
BuildMI(MBB, I, DL, get(AArch64::ORRXrr), DestReg)
.addReg(AArch64::XZR)
.addReg(SrcReg, getKillRegState(KillSrc));
}
return;
}
// Copy a DDDD register quad by copying the individual sub-registers.
if (AArch64::DDDDRegClass.contains(DestReg) &&
AArch64::DDDDRegClass.contains(SrcReg)) {
static const unsigned Indices[] = { AArch64::dsub0, AArch64::dsub1,
AArch64::dsub2, AArch64::dsub3 };
copyPhysRegTuple(MBB, I, DL, DestReg, SrcReg, KillSrc, AArch64::ORRv8i8,
Indices);
return;
}
// Copy a DDD register triple by copying the individual sub-registers.
if (AArch64::DDDRegClass.contains(DestReg) &&
AArch64::DDDRegClass.contains(SrcReg)) {
static const unsigned Indices[] = { AArch64::dsub0, AArch64::dsub1,
AArch64::dsub2 };
copyPhysRegTuple(MBB, I, DL, DestReg, SrcReg, KillSrc, AArch64::ORRv8i8,
Indices);
return;
}
// Copy a DD register pair by copying the individual sub-registers.
if (AArch64::DDRegClass.contains(DestReg) &&
AArch64::DDRegClass.contains(SrcReg)) {
static const unsigned Indices[] = { AArch64::dsub0, AArch64::dsub1 };
copyPhysRegTuple(MBB, I, DL, DestReg, SrcReg, KillSrc, AArch64::ORRv8i8,
Indices);
return;
}
// Copy a QQQQ register quad by copying the individual sub-registers.
if (AArch64::QQQQRegClass.contains(DestReg) &&
AArch64::QQQQRegClass.contains(SrcReg)) {
static const unsigned Indices[] = { AArch64::qsub0, AArch64::qsub1,
AArch64::qsub2, AArch64::qsub3 };
copyPhysRegTuple(MBB, I, DL, DestReg, SrcReg, KillSrc, AArch64::ORRv16i8,
Indices);
return;
}
// Copy a QQQ register triple by copying the individual sub-registers.
if (AArch64::QQQRegClass.contains(DestReg) &&
AArch64::QQQRegClass.contains(SrcReg)) {
static const unsigned Indices[] = { AArch64::qsub0, AArch64::qsub1,
AArch64::qsub2 };
copyPhysRegTuple(MBB, I, DL, DestReg, SrcReg, KillSrc, AArch64::ORRv16i8,
Indices);
return;
}
// Copy a QQ register pair by copying the individual sub-registers.
if (AArch64::QQRegClass.contains(DestReg) &&
AArch64::QQRegClass.contains(SrcReg)) {
static const unsigned Indices[] = { AArch64::qsub0, AArch64::qsub1 };
copyPhysRegTuple(MBB, I, DL, DestReg, SrcReg, KillSrc, AArch64::ORRv16i8,
Indices);
return;
}
if (AArch64::FPR128RegClass.contains(DestReg) &&
AArch64::FPR128RegClass.contains(SrcReg)) {
if(Subtarget.hasNEON()) {
BuildMI(MBB, I, DL, get(AArch64::ORRv16i8), DestReg)
.addReg(SrcReg)
.addReg(SrcReg, getKillRegState(KillSrc));
} else {
BuildMI(MBB, I, DL, get(AArch64::STRQpre))
.addReg(AArch64::SP, RegState::Define)
.addReg(SrcReg, getKillRegState(KillSrc))
.addReg(AArch64::SP)
.addImm(-16);
BuildMI(MBB, I, DL, get(AArch64::LDRQpre))
.addReg(AArch64::SP, RegState::Define)
.addReg(DestReg, RegState::Define)
.addReg(AArch64::SP)
.addImm(16);
}
return;
}
if (AArch64::FPR64RegClass.contains(DestReg) &&
AArch64::FPR64RegClass.contains(SrcReg)) {
if(Subtarget.hasNEON()) {
DestReg = RI.getMatchingSuperReg(DestReg, AArch64::dsub,
&AArch64::FPR128RegClass);
SrcReg = RI.getMatchingSuperReg(SrcReg, AArch64::dsub,
&AArch64::FPR128RegClass);
BuildMI(MBB, I, DL, get(AArch64::ORRv16i8), DestReg)
.addReg(SrcReg)
.addReg(SrcReg, getKillRegState(KillSrc));
} else {
BuildMI(MBB, I, DL, get(AArch64::FMOVDr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
}
return;
}
if (AArch64::FPR32RegClass.contains(DestReg) &&
AArch64::FPR32RegClass.contains(SrcReg)) {
if(Subtarget.hasNEON()) {
DestReg = RI.getMatchingSuperReg(DestReg, AArch64::ssub,
&AArch64::FPR128RegClass);
SrcReg = RI.getMatchingSuperReg(SrcReg, AArch64::ssub,
&AArch64::FPR128RegClass);
BuildMI(MBB, I, DL, get(AArch64::ORRv16i8), DestReg)
.addReg(SrcReg)
.addReg(SrcReg, getKillRegState(KillSrc));
} else {
BuildMI(MBB, I, DL, get(AArch64::FMOVSr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
}
return;
}
if (AArch64::FPR16RegClass.contains(DestReg) &&
AArch64::FPR16RegClass.contains(SrcReg)) {
if(Subtarget.hasNEON()) {
DestReg = RI.getMatchingSuperReg(DestReg, AArch64::hsub,
&AArch64::FPR128RegClass);
SrcReg = RI.getMatchingSuperReg(SrcReg, AArch64::hsub,
&AArch64::FPR128RegClass);
BuildMI(MBB, I, DL, get(AArch64::ORRv16i8), DestReg)
.addReg(SrcReg)
.addReg(SrcReg, getKillRegState(KillSrc));
} else {
DestReg = RI.getMatchingSuperReg(DestReg, AArch64::hsub,
&AArch64::FPR32RegClass);
SrcReg = RI.getMatchingSuperReg(SrcReg, AArch64::hsub,
&AArch64::FPR32RegClass);
BuildMI(MBB, I, DL, get(AArch64::FMOVSr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
}
return;
}
if (AArch64::FPR8RegClass.contains(DestReg) &&
AArch64::FPR8RegClass.contains(SrcReg)) {
if(Subtarget.hasNEON()) {
DestReg = RI.getMatchingSuperReg(DestReg, AArch64::bsub,
&AArch64::FPR128RegClass);
SrcReg = RI.getMatchingSuperReg(SrcReg, AArch64::bsub,
&AArch64::FPR128RegClass);
BuildMI(MBB, I, DL, get(AArch64::ORRv16i8), DestReg)
.addReg(SrcReg)
.addReg(SrcReg, getKillRegState(KillSrc));
} else {
DestReg = RI.getMatchingSuperReg(DestReg, AArch64::bsub,
&AArch64::FPR32RegClass);
SrcReg = RI.getMatchingSuperReg(SrcReg, AArch64::bsub,
&AArch64::FPR32RegClass);
BuildMI(MBB, I, DL, get(AArch64::FMOVSr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
}
return;
}
// Copies between GPR64 and FPR64.
if (AArch64::FPR64RegClass.contains(DestReg) &&
AArch64::GPR64RegClass.contains(SrcReg)) {
BuildMI(MBB, I, DL, get(AArch64::FMOVXDr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
return;
}
if (AArch64::GPR64RegClass.contains(DestReg) &&
AArch64::FPR64RegClass.contains(SrcReg)) {
BuildMI(MBB, I, DL, get(AArch64::FMOVDXr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
return;
}
// Copies between GPR32 and FPR32.
if (AArch64::FPR32RegClass.contains(DestReg) &&
AArch64::GPR32RegClass.contains(SrcReg)) {
BuildMI(MBB, I, DL, get(AArch64::FMOVWSr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
return;
}
if (AArch64::GPR32RegClass.contains(DestReg) &&
AArch64::FPR32RegClass.contains(SrcReg)) {
BuildMI(MBB, I, DL, get(AArch64::FMOVSWr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
return;
}
if (DestReg == AArch64::NZCV) {
assert(AArch64::GPR64RegClass.contains(SrcReg) && "Invalid NZCV copy");
BuildMI(MBB, I, DL, get(AArch64::MSR))
.addImm(AArch64SysReg::NZCV)
.addReg(SrcReg, getKillRegState(KillSrc))
.addReg(AArch64::NZCV, RegState::Implicit | RegState::Define);
return;
}
if (SrcReg == AArch64::NZCV) {
assert(AArch64::GPR64RegClass.contains(DestReg) && "Invalid NZCV copy");
BuildMI(MBB, I, DL, get(AArch64::MRS), DestReg)
.addImm(AArch64SysReg::NZCV)
.addReg(AArch64::NZCV, RegState::Implicit | getKillRegState(KillSrc));
return;
}
llvm_unreachable("unimplemented reg-to-reg copy");
}
void AArch64InstrInfo::storeRegToStackSlot(
MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, unsigned SrcReg,
bool isKill, int FI, const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
DebugLoc DL;
if (MBBI != MBB.end())
DL = MBBI->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = *MF.getFrameInfo();
unsigned Align = MFI.getObjectAlignment(FI);
MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(MF, FI);
MachineMemOperand *MMO = MF.getMachineMemOperand(
PtrInfo, MachineMemOperand::MOStore, MFI.getObjectSize(FI), Align);
unsigned Opc = 0;
bool Offset = true;
switch (RC->getSize()) {
case 1:
if (AArch64::FPR8RegClass.hasSubClassEq(RC))
Opc = AArch64::STRBui;
break;
case 2:
if (AArch64::FPR16RegClass.hasSubClassEq(RC))
Opc = AArch64::STRHui;
break;
case 4:
if (AArch64::GPR32allRegClass.hasSubClassEq(RC)) {
Opc = AArch64::STRWui;
if (TargetRegisterInfo::isVirtualRegister(SrcReg))
MF.getRegInfo().constrainRegClass(SrcReg, &AArch64::GPR32RegClass);
else
assert(SrcReg != AArch64::WSP);
} else if (AArch64::FPR32RegClass.hasSubClassEq(RC))
Opc = AArch64::STRSui;
break;
case 8:
if (AArch64::GPR64allRegClass.hasSubClassEq(RC)) {
Opc = AArch64::STRXui;
if (TargetRegisterInfo::isVirtualRegister(SrcReg))
MF.getRegInfo().constrainRegClass(SrcReg, &AArch64::GPR64RegClass);
else
assert(SrcReg != AArch64::SP);
} else if (AArch64::FPR64RegClass.hasSubClassEq(RC))
Opc = AArch64::STRDui;
break;
case 16:
if (AArch64::FPR128RegClass.hasSubClassEq(RC))
Opc = AArch64::STRQui;
else if (AArch64::DDRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register store without NEON");
Opc = AArch64::ST1Twov1d;
Offset = false;
}
break;
case 24:
if (AArch64::DDDRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register store without NEON");
Opc = AArch64::ST1Threev1d;
Offset = false;
}
break;
case 32:
if (AArch64::DDDDRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register store without NEON");
Opc = AArch64::ST1Fourv1d;
Offset = false;
} else if (AArch64::QQRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register store without NEON");
Opc = AArch64::ST1Twov2d;
Offset = false;
}
break;
case 48:
if (AArch64::QQQRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register store without NEON");
Opc = AArch64::ST1Threev2d;
Offset = false;
}
break;
case 64:
if (AArch64::QQQQRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register store without NEON");
Opc = AArch64::ST1Fourv2d;
Offset = false;
}
break;
}
assert(Opc && "Unknown register class");
const MachineInstrBuilder MI = BuildMI(MBB, MBBI, DL, get(Opc))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI);
if (Offset)
MI.addImm(0);
MI.addMemOperand(MMO);
}
void AArch64InstrInfo::loadRegFromStackSlot(
MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, unsigned DestReg,
int FI, const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
DebugLoc DL;
if (MBBI != MBB.end())
DL = MBBI->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = *MF.getFrameInfo();
unsigned Align = MFI.getObjectAlignment(FI);
MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(MF, FI);
MachineMemOperand *MMO = MF.getMachineMemOperand(
PtrInfo, MachineMemOperand::MOLoad, MFI.getObjectSize(FI), Align);
unsigned Opc = 0;
bool Offset = true;
switch (RC->getSize()) {
case 1:
if (AArch64::FPR8RegClass.hasSubClassEq(RC))
Opc = AArch64::LDRBui;
break;
case 2:
if (AArch64::FPR16RegClass.hasSubClassEq(RC))
Opc = AArch64::LDRHui;
break;
case 4:
if (AArch64::GPR32allRegClass.hasSubClassEq(RC)) {
Opc = AArch64::LDRWui;
if (TargetRegisterInfo::isVirtualRegister(DestReg))
MF.getRegInfo().constrainRegClass(DestReg, &AArch64::GPR32RegClass);
else
assert(DestReg != AArch64::WSP);
} else if (AArch64::FPR32RegClass.hasSubClassEq(RC))
Opc = AArch64::LDRSui;
break;
case 8:
if (AArch64::GPR64allRegClass.hasSubClassEq(RC)) {
Opc = AArch64::LDRXui;
if (TargetRegisterInfo::isVirtualRegister(DestReg))
MF.getRegInfo().constrainRegClass(DestReg, &AArch64::GPR64RegClass);
else
assert(DestReg != AArch64::SP);
} else if (AArch64::FPR64RegClass.hasSubClassEq(RC))
Opc = AArch64::LDRDui;
break;
case 16:
if (AArch64::FPR128RegClass.hasSubClassEq(RC))
Opc = AArch64::LDRQui;
else if (AArch64::DDRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register load without NEON");
Opc = AArch64::LD1Twov1d;
Offset = false;
}
break;
case 24:
if (AArch64::DDDRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register load without NEON");
Opc = AArch64::LD1Threev1d;
Offset = false;
}
break;
case 32:
if (AArch64::DDDDRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register load without NEON");
Opc = AArch64::LD1Fourv1d;
Offset = false;
} else if (AArch64::QQRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register load without NEON");
Opc = AArch64::LD1Twov2d;
Offset = false;
}
break;
case 48:
if (AArch64::QQQRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register load without NEON");
Opc = AArch64::LD1Threev2d;
Offset = false;
}
break;
case 64:
if (AArch64::QQQQRegClass.hasSubClassEq(RC)) {
assert(Subtarget.hasNEON() &&
"Unexpected register load without NEON");
Opc = AArch64::LD1Fourv2d;
Offset = false;
}
break;
}
assert(Opc && "Unknown register class");
const MachineInstrBuilder MI = BuildMI(MBB, MBBI, DL, get(Opc))
.addReg(DestReg, getDefRegState(true))
.addFrameIndex(FI);
if (Offset)
MI.addImm(0);
MI.addMemOperand(MMO);
}
void llvm::emitFrameOffset(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI, const DebugLoc &DL,
unsigned DestReg, unsigned SrcReg, int Offset,
const TargetInstrInfo *TII,
MachineInstr::MIFlag Flag, bool SetNZCV) {
if (DestReg == SrcReg && Offset == 0)
return;
assert((DestReg != AArch64::SP || Offset % 16 == 0) &&
"SP increment/decrement not 16-byte aligned");
bool isSub = Offset < 0;
if (isSub)
Offset = -Offset;
// FIXME: If the offset won't fit in 24-bits, compute the offset into a
// scratch register. If DestReg is a virtual register, use it as the
// scratch register; otherwise, create a new virtual register (to be
// replaced by the scavenger at the end of PEI). That case can be optimized
// slightly if DestReg is SP which is always 16-byte aligned, so the scratch
// register can be loaded with offset%8 and the add/sub can use an extending
// instruction with LSL#3.
// Currently the function handles any offsets but generates a poor sequence
// of code.
// assert(Offset < (1 << 24) && "unimplemented reg plus immediate");
unsigned Opc;
if (SetNZCV)
Opc = isSub ? AArch64::SUBSXri : AArch64::ADDSXri;
else
Opc = isSub ? AArch64::SUBXri : AArch64::ADDXri;
const unsigned MaxEncoding = 0xfff;
const unsigned ShiftSize = 12;
const unsigned MaxEncodableValue = MaxEncoding << ShiftSize;
while (((unsigned)Offset) >= (1 << ShiftSize)) {
unsigned ThisVal;
if (((unsigned)Offset) > MaxEncodableValue) {
ThisVal = MaxEncodableValue;
} else {
ThisVal = Offset & MaxEncodableValue;
}
assert((ThisVal >> ShiftSize) <= MaxEncoding &&
"Encoding cannot handle value that big");
BuildMI(MBB, MBBI, DL, TII->get(Opc), DestReg)
.addReg(SrcReg)
.addImm(ThisVal >> ShiftSize)
.addImm(AArch64_AM::getShifterImm(AArch64_AM::LSL, ShiftSize))
.setMIFlag(Flag);
SrcReg = DestReg;
Offset -= ThisVal;
if (Offset == 0)
return;
}
BuildMI(MBB, MBBI, DL, TII->get(Opc), DestReg)
.addReg(SrcReg)
.addImm(Offset)
.addImm(AArch64_AM::getShifterImm(AArch64_AM::LSL, 0))
.setMIFlag(Flag);
}
MachineInstr *AArch64InstrInfo::foldMemoryOperandImpl(
MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
MachineBasicBlock::iterator InsertPt, int FrameIndex,
LiveIntervals *LIS) const {
// This is a bit of a hack. Consider this instruction:
//
// %vreg0<def> = COPY %SP; GPR64all:%vreg0
//
// We explicitly chose GPR64all for the virtual register so such a copy might
// be eliminated by RegisterCoalescer. However, that may not be possible, and
// %vreg0 may even spill. We can't spill %SP, and since it is in the GPR64all
// register class, TargetInstrInfo::foldMemoryOperand() is going to try.
//
// To prevent that, we are going to constrain the %vreg0 register class here.
//
// <rdar://problem/11522048>
//
if (MI.isCopy()) {
unsigned DstReg = MI.getOperand(0).getReg();
unsigned SrcReg = MI.getOperand(1).getReg();
if (SrcReg == AArch64::SP &&
TargetRegisterInfo::isVirtualRegister(DstReg)) {
MF.getRegInfo().constrainRegClass(DstReg, &AArch64::GPR64RegClass);
return nullptr;
}
if (DstReg == AArch64::SP &&
TargetRegisterInfo::isVirtualRegister(SrcReg)) {
MF.getRegInfo().constrainRegClass(SrcReg, &AArch64::GPR64RegClass);
return nullptr;
}
}
// Cannot fold.
return nullptr;
}
int llvm::isAArch64FrameOffsetLegal(const MachineInstr &MI, int &Offset,
bool *OutUseUnscaledOp,
unsigned *OutUnscaledOp,
int *EmittableOffset) {
int Scale = 1;
bool IsSigned = false;
// The ImmIdx should be changed case by case if it is not 2.
unsigned ImmIdx = 2;
unsigned UnscaledOp = 0;
// Set output values in case of early exit.
if (EmittableOffset)
*EmittableOffset = 0;
if (OutUseUnscaledOp)
*OutUseUnscaledOp = false;
if (OutUnscaledOp)
*OutUnscaledOp = 0;
switch (MI.getOpcode()) {
default:
llvm_unreachable("unhandled opcode in rewriteAArch64FrameIndex");
// Vector spills/fills can't take an immediate offset.
case AArch64::LD1Twov2d:
case AArch64::LD1Threev2d:
case AArch64::LD1Fourv2d:
case AArch64::LD1Twov1d:
case AArch64::LD1Threev1d:
case AArch64::LD1Fourv1d:
case AArch64::ST1Twov2d:
case AArch64::ST1Threev2d:
case AArch64::ST1Fourv2d:
case AArch64::ST1Twov1d:
case AArch64::ST1Threev1d:
case AArch64::ST1Fourv1d:
return AArch64FrameOffsetCannotUpdate;
case AArch64::PRFMui:
Scale = 8;
UnscaledOp = AArch64::PRFUMi;
break;
case AArch64::LDRXui:
Scale = 8;
UnscaledOp = AArch64::LDURXi;
break;
case AArch64::LDRWui:
Scale = 4;
UnscaledOp = AArch64::LDURWi;
break;
case AArch64::LDRBui:
Scale = 1;
UnscaledOp = AArch64::LDURBi;
break;
case AArch64::LDRHui:
Scale = 2;
UnscaledOp = AArch64::LDURHi;
break;
case AArch64::LDRSui:
Scale = 4;
UnscaledOp = AArch64::LDURSi;
break;
case AArch64::LDRDui:
Scale = 8;
UnscaledOp = AArch64::LDURDi;
break;
case AArch64::LDRQui:
Scale = 16;
UnscaledOp = AArch64::LDURQi;
break;
case AArch64::LDRBBui:
Scale = 1;
UnscaledOp = AArch64::LDURBBi;
break;
case AArch64::LDRHHui:
Scale = 2;
UnscaledOp = AArch64::LDURHHi;
break;
case AArch64::LDRSBXui:
Scale = 1;
UnscaledOp = AArch64::LDURSBXi;
break;
case AArch64::LDRSBWui:
Scale = 1;
UnscaledOp = AArch64::LDURSBWi;
break;
case AArch64::LDRSHXui:
Scale = 2;
UnscaledOp = AArch64::LDURSHXi;
break;
case AArch64::LDRSHWui:
Scale = 2;
UnscaledOp = AArch64::LDURSHWi;
break;
case AArch64::LDRSWui:
Scale = 4;
UnscaledOp = AArch64::LDURSWi;
break;
case AArch64::STRXui:
Scale = 8;
UnscaledOp = AArch64::STURXi;
break;
case AArch64::STRWui:
Scale = 4;
UnscaledOp = AArch64::STURWi;
break;
case AArch64::STRBui:
Scale = 1;
UnscaledOp = AArch64::STURBi;
break;
case AArch64::STRHui:
Scale = 2;
UnscaledOp = AArch64::STURHi;
break;
case AArch64::STRSui:
Scale = 4;
UnscaledOp = AArch64::STURSi;
break;
case AArch64::STRDui:
Scale = 8;
UnscaledOp = AArch64::STURDi;
break;
case AArch64::STRQui:
Scale = 16;
UnscaledOp = AArch64::STURQi;
break;
case AArch64::STRBBui:
Scale = 1;
UnscaledOp = AArch64::STURBBi;
break;
case AArch64::STRHHui:
Scale = 2;
UnscaledOp = AArch64::STURHHi;
break;
case AArch64::LDPXi:
case AArch64::LDPDi:
case AArch64::STPXi:
case AArch64::STPDi:
case AArch64::LDNPXi:
case AArch64::LDNPDi:
case AArch64::STNPXi:
case AArch64::STNPDi:
ImmIdx = 3;
IsSigned = true;
Scale = 8;
break;
case AArch64::LDPQi:
case AArch64::STPQi:
case AArch64::LDNPQi:
case AArch64::STNPQi:
ImmIdx = 3;
IsSigned = true;
Scale = 16;
break;
case AArch64::LDPWi:
case AArch64::LDPSi:
case AArch64::STPWi:
case AArch64::STPSi:
case AArch64::LDNPWi:
case AArch64::LDNPSi:
case AArch64::STNPWi:
case AArch64::STNPSi:
ImmIdx = 3;
IsSigned = true;
Scale = 4;
break;
case AArch64::LDURXi:
case AArch64::LDURWi:
case AArch64::LDURBi:
case AArch64::LDURHi:
case AArch64::LDURSi:
case AArch64::LDURDi:
case AArch64::LDURQi:
case AArch64::LDURHHi:
case AArch64::LDURBBi:
case AArch64::LDURSBXi:
case AArch64::LDURSBWi:
case AArch64::LDURSHXi:
case AArch64::LDURSHWi:
case AArch64::LDURSWi:
case AArch64::STURXi:
case AArch64::STURWi:
case AArch64::STURBi:
case AArch64::STURHi:
case AArch64::STURSi:
case AArch64::STURDi:
case AArch64::STURQi:
case AArch64::STURBBi:
case AArch64::STURHHi:
Scale = 1;
break;
}
Offset += MI.getOperand(ImmIdx).getImm() * Scale;
bool useUnscaledOp = false;
// If the offset doesn't match the scale, we rewrite the instruction to
// use the unscaled instruction instead. Likewise, if we have a negative
// offset (and have an unscaled op to use).
if ((Offset & (Scale - 1)) != 0 || (Offset < 0 && UnscaledOp != 0))
useUnscaledOp = true;
// Use an unscaled addressing mode if the instruction has a negative offset
// (or if the instruction is already using an unscaled addressing mode).
unsigned MaskBits;
if (IsSigned) {
// ldp/stp instructions.
MaskBits = 7;
Offset /= Scale;
} else if (UnscaledOp == 0 || useUnscaledOp) {
MaskBits = 9;
IsSigned = true;
Scale = 1;
} else {
MaskBits = 12;
IsSigned = false;
Offset /= Scale;
}
// Attempt to fold address computation.
int MaxOff = (1 << (MaskBits - IsSigned)) - 1;
int MinOff = (IsSigned ? (-MaxOff - 1) : 0);
if (Offset >= MinOff && Offset <= MaxOff) {
if (EmittableOffset)
*EmittableOffset = Offset;
Offset = 0;
} else {
int NewOff = Offset < 0 ? MinOff : MaxOff;
if (EmittableOffset)
*EmittableOffset = NewOff;
Offset = (Offset - NewOff) * Scale;
}
if (OutUseUnscaledOp)
*OutUseUnscaledOp = useUnscaledOp;
if (OutUnscaledOp)
*OutUnscaledOp = UnscaledOp;
return AArch64FrameOffsetCanUpdate |
(Offset == 0 ? AArch64FrameOffsetIsLegal : 0);
}
bool llvm::rewriteAArch64FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
unsigned FrameReg, int &Offset,
const AArch64InstrInfo *TII) {
unsigned Opcode = MI.getOpcode();
unsigned ImmIdx = FrameRegIdx + 1;
if (Opcode == AArch64::ADDSXri || Opcode == AArch64::ADDXri) {
Offset += MI.getOperand(ImmIdx).getImm();
emitFrameOffset(*MI.getParent(), MI, MI.getDebugLoc(),
MI.getOperand(0).getReg(), FrameReg, Offset, TII,
MachineInstr::NoFlags, (Opcode == AArch64::ADDSXri));
MI.eraseFromParent();
Offset = 0;
return true;
}
int NewOffset;
unsigned UnscaledOp;
bool UseUnscaledOp;
int Status = isAArch64FrameOffsetLegal(MI, Offset, &UseUnscaledOp,
&UnscaledOp, &NewOffset);
if (Status & AArch64FrameOffsetCanUpdate) {
if (Status & AArch64FrameOffsetIsLegal)
// Replace the FrameIndex with FrameReg.
MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
if (UseUnscaledOp)
MI.setDesc(TII->get(UnscaledOp));
MI.getOperand(ImmIdx).ChangeToImmediate(NewOffset);
return Offset == 0;
}
return false;
}
void AArch64InstrInfo::getNoopForMachoTarget(MCInst &NopInst) const {
NopInst.setOpcode(AArch64::HINT);
NopInst.addOperand(MCOperand::createImm(0));
}
// AArch64 supports MachineCombiner.
bool AArch64InstrInfo::useMachineCombiner() const {
return true;
}
//
// True when Opc sets flag
static bool isCombineInstrSettingFlag(unsigned Opc) {
switch (Opc) {
case AArch64::ADDSWrr:
case AArch64::ADDSWri:
case AArch64::ADDSXrr:
case AArch64::ADDSXri:
case AArch64::SUBSWrr:
case AArch64::SUBSXrr:
// Note: MSUB Wd,Wn,Wm,Wi -> Wd = Wi - WnxWm, not Wd=WnxWm - Wi.
case AArch64::SUBSWri:
case AArch64::SUBSXri:
return true;
default:
break;
}
return false;
}
//
// 32b Opcodes that can be combined with a MUL
static bool isCombineInstrCandidate32(unsigned Opc) {
switch (Opc) {
case AArch64::ADDWrr:
case AArch64::ADDWri:
case AArch64::SUBWrr:
case AArch64::ADDSWrr:
case AArch64::ADDSWri:
case AArch64::SUBSWrr:
// Note: MSUB Wd,Wn,Wm,Wi -> Wd = Wi - WnxWm, not Wd=WnxWm - Wi.
case AArch64::SUBWri:
case AArch64::SUBSWri:
return true;
default:
break;
}
return false;
}
//
// 64b Opcodes that can be combined with a MUL
static bool isCombineInstrCandidate64(unsigned Opc) {
switch (Opc) {
case AArch64::ADDXrr:
case AArch64::ADDXri:
case AArch64::SUBXrr:
case AArch64::ADDSXrr:
case AArch64::ADDSXri:
case AArch64::SUBSXrr:
// Note: MSUB Wd,Wn,Wm,Wi -> Wd = Wi - WnxWm, not Wd=WnxWm - Wi.
case AArch64::SUBXri:
case AArch64::SUBSXri:
return true;
default:
break;
}
return false;
}
//
// FP Opcodes that can be combined with a FMUL
static bool isCombineInstrCandidateFP(const MachineInstr &Inst) {
switch (Inst.getOpcode()) {
case AArch64::FADDSrr:
case AArch64::FADDDrr:
case AArch64::FADDv2f32:
case AArch64::FADDv2f64:
case AArch64::FADDv4f32:
case AArch64::FSUBSrr:
case AArch64::FSUBDrr:
case AArch64::FSUBv2f32:
case AArch64::FSUBv2f64:
case AArch64::FSUBv4f32:
return Inst.getParent()->getParent()->getTarget().Options.UnsafeFPMath;
default:
break;
}
return false;
}
//
// Opcodes that can be combined with a MUL
static bool isCombineInstrCandidate(unsigned Opc) {
return (isCombineInstrCandidate32(Opc) || isCombineInstrCandidate64(Opc));
}
//
// Utility routine that checks if \param MO is defined by an
// \param CombineOpc instruction in the basic block \param MBB
static bool canCombine(MachineBasicBlock &MBB, MachineOperand &MO,
unsigned CombineOpc, unsigned ZeroReg = 0,
bool CheckZeroReg = false) {
MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
MachineInstr *MI = nullptr;
if (MO.isReg() && TargetRegisterInfo::isVirtualRegister(MO.getReg()))
MI = MRI.getUniqueVRegDef(MO.getReg());
// And it needs to be in the trace (otherwise, it won't have a depth).
if (!MI || MI->getParent() != &MBB || (unsigned)MI->getOpcode() != CombineOpc)
return false;
// Must only used by the user we combine with.
if (!MRI.hasOneNonDBGUse(MI->getOperand(0).getReg()))
return false;
if (CheckZeroReg) {
assert(MI->getNumOperands() >= 4 && MI->getOperand(0).isReg() &&
MI->getOperand(1).isReg() && MI->getOperand(2).isReg() &&
MI->getOperand(3).isReg() && "MAdd/MSub must have a least 4 regs");
// The third input reg must be zero.
if (MI->getOperand(3).getReg() != ZeroReg)
return false;
}
return true;
}
//
// Is \param MO defined by an integer multiply and can be combined?
static bool canCombineWithMUL(MachineBasicBlock &MBB, MachineOperand &MO,
unsigned MulOpc, unsigned ZeroReg) {
return canCombine(MBB, MO, MulOpc, ZeroReg, true);
}
//
// Is \param MO defined by a floating-point multiply and can be combined?
static bool canCombineWithFMUL(MachineBasicBlock &MBB, MachineOperand &MO,
unsigned MulOpc) {
return canCombine(MBB, MO, MulOpc);
}
// TODO: There are many more machine instruction opcodes to match:
// 1. Other data types (integer, vectors)
// 2. Other math / logic operations (xor, or)
// 3. Other forms of the same operation (intrinsics and other variants)
bool AArch64InstrInfo::isAssociativeAndCommutative(const MachineInstr &Inst) const {
switch (Inst.getOpcode()) {
case AArch64::FADDDrr:
case AArch64::FADDSrr:
case AArch64::FADDv2f32:
case AArch64::FADDv2f64:
case AArch64::FADDv4f32:
case AArch64::FMULDrr:
case AArch64::FMULSrr:
case AArch64::FMULX32:
case AArch64::FMULX64:
case AArch64::FMULXv2f32:
case AArch64::FMULXv2f64:
case AArch64::FMULXv4f32:
case AArch64::FMULv2f32:
case AArch64::FMULv2f64:
case AArch64::FMULv4f32:
return Inst.getParent()->getParent()->getTarget().Options.UnsafeFPMath;
default:
return false;
}
}
/// Find instructions that can be turned into madd.
static bool getMaddPatterns(MachineInstr &Root,
SmallVectorImpl<MachineCombinerPattern> &Patterns) {
unsigned Opc = Root.getOpcode();
MachineBasicBlock &MBB = *Root.getParent();
bool Found = false;
if (!isCombineInstrCandidate(Opc))
return false;
if (isCombineInstrSettingFlag(Opc)) {
int Cmp_NZCV = Root.findRegisterDefOperandIdx(AArch64::NZCV, true);
// When NZCV is live bail out.
if (Cmp_NZCV == -1)
return false;
unsigned NewOpc = convertFlagSettingOpcode(Root);
// When opcode can't change bail out.
// CHECKME: do we miss any cases for opcode conversion?
if (NewOpc == Opc)
return false;
Opc = NewOpc;
}
switch (Opc) {
default:
break;
case AArch64::ADDWrr:
assert(Root.getOperand(1).isReg() && Root.getOperand(2).isReg() &&
"ADDWrr does not have register operands");
if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDWrrr,
AArch64::WZR)) {
Patterns.push_back(MachineCombinerPattern::MULADDW_OP1);
Found = true;
}
if (canCombineWithMUL(MBB, Root.getOperand(2), AArch64::MADDWrrr,
AArch64::WZR)) {
Patterns.push_back(MachineCombinerPattern::MULADDW_OP2);
Found = true;
}
break;
case AArch64::ADDXrr:
if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDXrrr,
AArch64::XZR)) {
Patterns.push_back(MachineCombinerPattern::MULADDX_OP1);
Found = true;
}
if (canCombineWithMUL(MBB, Root.getOperand(2), AArch64::MADDXrrr,
AArch64::XZR)) {
Patterns.push_back(MachineCombinerPattern::MULADDX_OP2);
Found = true;
}
break;
case AArch64::SUBWrr:
if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDWrrr,
AArch64::WZR)) {
Patterns.push_back(MachineCombinerPattern::MULSUBW_OP1);
Found = true;
}
if (canCombineWithMUL(MBB, Root.getOperand(2), AArch64::MADDWrrr,
AArch64::WZR)) {
Patterns.push_back(MachineCombinerPattern::MULSUBW_OP2);
Found = true;
}
break;
case AArch64::SUBXrr:
if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDXrrr,
AArch64::XZR)) {
Patterns.push_back(MachineCombinerPattern::MULSUBX_OP1);
Found = true;
}
if (canCombineWithMUL(MBB, Root.getOperand(2), AArch64::MADDXrrr,
AArch64::XZR)) {
Patterns.push_back(MachineCombinerPattern::MULSUBX_OP2);
Found = true;
}
break;
case AArch64::ADDWri:
if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDWrrr,
AArch64::WZR)) {
Patterns.push_back(MachineCombinerPattern::MULADDWI_OP1);
Found = true;
}
break;
case AArch64::ADDXri:
if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDXrrr,
AArch64::XZR)) {
Patterns.push_back(MachineCombinerPattern::MULADDXI_OP1);
Found = true;
}
break;
case AArch64::SUBWri:
if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDWrrr,
AArch64::WZR)) {
Patterns.push_back(MachineCombinerPattern::MULSUBWI_OP1);
Found = true;
}
break;
case AArch64::SUBXri:
if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDXrrr,
AArch64::XZR)) {
Patterns.push_back(MachineCombinerPattern::MULSUBXI_OP1);
Found = true;
}
break;
}
return Found;
}
/// Floating-Point Support
/// Find instructions that can be turned into madd.
static bool getFMAPatterns(MachineInstr &Root,
SmallVectorImpl<MachineCombinerPattern> &Patterns) {
if (!isCombineInstrCandidateFP(Root))
return 0;
MachineBasicBlock &MBB = *Root.getParent();
bool Found = false;
switch (Root.getOpcode()) {
default:
assert(false && "Unsupported FP instruction in combiner\n");
break;
case AArch64::FADDSrr:
assert(Root.getOperand(1).isReg() && Root.getOperand(2).isReg() &&
"FADDWrr does not have register operands");
if (canCombineWithFMUL(MBB, Root.getOperand(1), AArch64::FMULSrr)) {
Patterns.push_back(MachineCombinerPattern::FMULADDS_OP1);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(1),
AArch64::FMULv1i32_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLAv1i32_indexed_OP1);
Found = true;
}
if (canCombineWithFMUL(MBB, Root.getOperand(2), AArch64::FMULSrr)) {
Patterns.push_back(MachineCombinerPattern::FMULADDS_OP2);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv1i32_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLAv1i32_indexed_OP2);
Found = true;
}
break;
case AArch64::FADDDrr:
if (canCombineWithFMUL(MBB, Root.getOperand(1), AArch64::FMULDrr)) {
Patterns.push_back(MachineCombinerPattern::FMULADDD_OP1);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(1),
AArch64::FMULv1i64_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLAv1i64_indexed_OP1);
Found = true;
}
if (canCombineWithFMUL(MBB, Root.getOperand(2), AArch64::FMULDrr)) {
Patterns.push_back(MachineCombinerPattern::FMULADDD_OP2);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv1i64_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLAv1i64_indexed_OP2);
Found = true;
}
break;
case AArch64::FADDv2f32:
if (canCombineWithFMUL(MBB, Root.getOperand(1),
AArch64::FMULv2i32_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLAv2i32_indexed_OP1);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(1),
AArch64::FMULv2f32)) {
Patterns.push_back(MachineCombinerPattern::FMLAv2f32_OP1);
Found = true;
}
if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv2i32_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLAv2i32_indexed_OP2);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv2f32)) {
Patterns.push_back(MachineCombinerPattern::FMLAv2f32_OP2);
Found = true;
}
break;
case AArch64::FADDv2f64:
if (canCombineWithFMUL(MBB, Root.getOperand(1),
AArch64::FMULv2i64_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLAv2i64_indexed_OP1);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(1),
AArch64::FMULv2f64)) {
Patterns.push_back(MachineCombinerPattern::FMLAv2f64_OP1);
Found = true;
}
if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv2i64_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLAv2i64_indexed_OP2);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv2f64)) {
Patterns.push_back(MachineCombinerPattern::FMLAv2f64_OP2);
Found = true;
}
break;
case AArch64::FADDv4f32:
if (canCombineWithFMUL(MBB, Root.getOperand(1),
AArch64::FMULv4i32_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLAv4i32_indexed_OP1);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(1),
AArch64::FMULv4f32)) {
Patterns.push_back(MachineCombinerPattern::FMLAv4f32_OP1);
Found = true;
}
if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv4i32_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLAv4i32_indexed_OP2);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv4f32)) {
Patterns.push_back(MachineCombinerPattern::FMLAv4f32_OP2);
Found = true;
}
break;
case AArch64::FSUBSrr:
if (canCombineWithFMUL(MBB, Root.getOperand(1), AArch64::FMULSrr)) {
Patterns.push_back(MachineCombinerPattern::FMULSUBS_OP1);
Found = true;
}
if (canCombineWithFMUL(MBB, Root.getOperand(2), AArch64::FMULSrr)) {
Patterns.push_back(MachineCombinerPattern::FMULSUBS_OP2);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv1i32_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLSv1i32_indexed_OP2);
Found = true;
}
break;
case AArch64::FSUBDrr:
if (canCombineWithFMUL(MBB, Root.getOperand(1), AArch64::FMULDrr)) {
Patterns.push_back(MachineCombinerPattern::FMULSUBD_OP1);
Found = true;
}
if (canCombineWithFMUL(MBB, Root.getOperand(2), AArch64::FMULDrr)) {
Patterns.push_back(MachineCombinerPattern::FMULSUBD_OP2);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv1i64_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLSv1i64_indexed_OP2);
Found = true;
}
break;
case AArch64::FSUBv2f32:
if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv2i32_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLSv2i32_indexed_OP2);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv2f32)) {
Patterns.push_back(MachineCombinerPattern::FMLSv2f32_OP2);
Found = true;
}
break;
case AArch64::FSUBv2f64:
if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv2i64_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLSv2i64_indexed_OP2);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv2f64)) {
Patterns.push_back(MachineCombinerPattern::FMLSv2f64_OP2);
Found = true;
}
break;
case AArch64::FSUBv4f32:
if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv4i32_indexed)) {
Patterns.push_back(MachineCombinerPattern::FMLSv4i32_indexed_OP2);
Found = true;
} else if (canCombineWithFMUL(MBB, Root.getOperand(2),
AArch64::FMULv4f32)) {
Patterns.push_back(MachineCombinerPattern::FMLSv4f32_OP2);
Found = true;
}
break;
}
return Found;
}
/// Return true when a code sequence can improve throughput. It
/// should be called only for instructions in loops.
/// \param Pattern - combiner pattern
bool
AArch64InstrInfo::isThroughputPattern(MachineCombinerPattern Pattern) const {
switch (Pattern) {
default:
break;
case MachineCombinerPattern::FMULADDS_OP1:
case MachineCombinerPattern::FMULADDS_OP2:
case MachineCombinerPattern::FMULSUBS_OP1:
case MachineCombinerPattern::FMULSUBS_OP2:
case MachineCombinerPattern::FMULADDD_OP1:
case MachineCombinerPattern::FMULADDD_OP2:
case MachineCombinerPattern::FMULSUBD_OP1:
case MachineCombinerPattern::FMULSUBD_OP2:
case MachineCombinerPattern::FMLAv1i32_indexed_OP1:
case MachineCombinerPattern::FMLAv1i32_indexed_OP2:
case MachineCombinerPattern::FMLAv1i64_indexed_OP1:
case MachineCombinerPattern::FMLAv1i64_indexed_OP2:
case MachineCombinerPattern::FMLAv2f32_OP2:
case MachineCombinerPattern::FMLAv2f32_OP1:
case MachineCombinerPattern::FMLAv2f64_OP1:
case MachineCombinerPattern::FMLAv2f64_OP2:
case MachineCombinerPattern::FMLAv2i32_indexed_OP1:
case MachineCombinerPattern::FMLAv2i32_indexed_OP2:
case MachineCombinerPattern::FMLAv2i64_indexed_OP1:
case MachineCombinerPattern::FMLAv2i64_indexed_OP2:
case MachineCombinerPattern::FMLAv4f32_OP1:
case MachineCombinerPattern::FMLAv4f32_OP2:
case MachineCombinerPattern::FMLAv4i32_indexed_OP1:
case MachineCombinerPattern::FMLAv4i32_indexed_OP2:
case MachineCombinerPattern::FMLSv1i32_indexed_OP2:
case MachineCombinerPattern::FMLSv1i64_indexed_OP2:
case MachineCombinerPattern::FMLSv2i32_indexed_OP2:
case MachineCombinerPattern::FMLSv2i64_indexed_OP2:
case MachineCombinerPattern::FMLSv2f32_OP2:
case MachineCombinerPattern::FMLSv2f64_OP2:
case MachineCombinerPattern::FMLSv4i32_indexed_OP2:
case MachineCombinerPattern::FMLSv4f32_OP2:
return true;
} // end switch (Pattern)
return false;
}
/// Return true when there is potentially a faster code sequence for an
/// instruction chain ending in \p Root. All potential patterns are listed in
/// the \p Pattern vector. Pattern should be sorted in priority order since the
/// pattern evaluator stops checking as soon as it finds a faster sequence.
bool AArch64InstrInfo::getMachineCombinerPatterns(
MachineInstr &Root,
SmallVectorImpl<MachineCombinerPattern> &Patterns) const {
// Integer patterns
if (getMaddPatterns(Root, Patterns))
return true;
// Floating point patterns
if (getFMAPatterns(Root, Patterns))
return true;
return TargetInstrInfo::getMachineCombinerPatterns(Root, Patterns);
}
enum class FMAInstKind { Default, Indexed, Accumulator };
/// genFusedMultiply - Generate fused multiply instructions.
/// This function supports both integer and floating point instructions.
/// A typical example:
/// F|MUL I=A,B,0
/// F|ADD R,I,C
/// ==> F|MADD R,A,B,C
/// \param Root is the F|ADD instruction
/// \param [out] InsInstrs is a vector of machine instructions and will
/// contain the generated madd instruction
/// \param IdxMulOpd is index of operand in Root that is the result of
/// the F|MUL. In the example above IdxMulOpd is 1.
/// \param MaddOpc the opcode fo the f|madd instruction
static MachineInstr *
genFusedMultiply(MachineFunction &MF, MachineRegisterInfo &MRI,
const TargetInstrInfo *TII, MachineInstr &Root,
SmallVectorImpl<MachineInstr *> &InsInstrs, unsigned IdxMulOpd,
unsigned MaddOpc, const TargetRegisterClass *RC,
FMAInstKind kind = FMAInstKind::Default) {
assert(IdxMulOpd == 1 || IdxMulOpd == 2);
unsigned IdxOtherOpd = IdxMulOpd == 1 ? 2 : 1;
MachineInstr *MUL = MRI.getUniqueVRegDef(Root.getOperand(IdxMulOpd).getReg());
unsigned ResultReg = Root.getOperand(0).getReg();
unsigned SrcReg0 = MUL->getOperand(1).getReg();
bool Src0IsKill = MUL->getOperand(1).isKill();
unsigned SrcReg1 = MUL->getOperand(2).getReg();
bool Src1IsKill = MUL->getOperand(2).isKill();
unsigned SrcReg2 = Root.getOperand(IdxOtherOpd).getReg();
bool Src2IsKill = Root.getOperand(IdxOtherOpd).isKill();
if (TargetRegisterInfo::isVirtualRegister(ResultReg))
MRI.constrainRegClass(ResultReg, RC);
if (TargetRegisterInfo::isVirtualRegister(SrcReg0))
MRI.constrainRegClass(SrcReg0, RC);
if (TargetRegisterInfo::isVirtualRegister(SrcReg1))
MRI.constrainRegClass(SrcReg1, RC);
if (TargetRegisterInfo::isVirtualRegister(SrcReg2))
MRI.constrainRegClass(SrcReg2, RC);
MachineInstrBuilder MIB;
if (kind == FMAInstKind::Default)
MIB = BuildMI(MF, Root.getDebugLoc(), TII->get(MaddOpc), ResultReg)
.addReg(SrcReg0, getKillRegState(Src0IsKill))
.addReg(SrcReg1, getKillRegState(Src1IsKill))
.addReg(SrcReg2, getKillRegState(Src2IsKill));
else if (kind == FMAInstKind::Indexed)
MIB = BuildMI(MF, Root.getDebugLoc(), TII->get(MaddOpc), ResultReg)
.addReg(SrcReg2, getKillRegState(Src2IsKill))
.addReg(SrcReg0, getKillRegState(Src0IsKill))
.addReg(SrcReg1, getKillRegState(Src1IsKill))
.addImm(MUL->getOperand(3).getImm());
else if (kind == FMAInstKind::Accumulator)
MIB = BuildMI(MF, Root.getDebugLoc(), TII->get(MaddOpc), ResultReg)
.addReg(SrcReg2, getKillRegState(Src2IsKill))
.addReg(SrcReg0, getKillRegState(Src0IsKill))
.addReg(SrcReg1, getKillRegState(Src1IsKill));
else
assert(false && "Invalid FMA instruction kind \n");
// Insert the MADD (MADD, FMA, FMS, FMLA, FMSL)
InsInstrs.push_back(MIB);
return MUL;
}
/// genMaddR - Generate madd instruction and combine mul and add using
/// an extra virtual register
/// Example - an ADD intermediate needs to be stored in a register:
/// MUL I=A,B,0
/// ADD R,I,Imm
/// ==> ORR V, ZR, Imm
/// ==> MADD R,A,B,V
/// \param Root is the ADD instruction
/// \param [out] InsInstrs is a vector of machine instructions and will
/// contain the generated madd instruction
/// \param IdxMulOpd is index of operand in Root that is the result of
/// the MUL. In the example above IdxMulOpd is 1.
/// \param MaddOpc the opcode fo the madd instruction
/// \param VR is a virtual register that holds the value of an ADD operand
/// (V in the example above).
static MachineInstr *genMaddR(MachineFunction &MF, MachineRegisterInfo &MRI,
const TargetInstrInfo *TII, MachineInstr &Root,
SmallVectorImpl<MachineInstr *> &InsInstrs,
unsigned IdxMulOpd, unsigned MaddOpc,
unsigned VR, const TargetRegisterClass *RC) {
assert(IdxMulOpd == 1 || IdxMulOpd == 2);
MachineInstr *MUL = MRI.getUniqueVRegDef(Root.getOperand(IdxMulOpd).getReg());
unsigned ResultReg = Root.getOperand(0).getReg();
unsigned SrcReg0 = MUL->getOperand(1).getReg();
bool Src0IsKill = MUL->getOperand(1).isKill();
unsigned SrcReg1 = MUL->getOperand(2).getReg();
bool Src1IsKill = MUL->getOperand(2).isKill();
if (TargetRegisterInfo::isVirtualRegister(ResultReg))
MRI.constrainRegClass(ResultReg, RC);
if (TargetRegisterInfo::isVirtualRegister(SrcReg0))
MRI.constrainRegClass(SrcReg0, RC);
if (TargetRegisterInfo::isVirtualRegister(SrcReg1))
MRI.constrainRegClass(SrcReg1, RC);
if (TargetRegisterInfo::isVirtualRegister(VR))
MRI.constrainRegClass(VR, RC);
MachineInstrBuilder MIB = BuildMI(MF, Root.getDebugLoc(), TII->get(MaddOpc),
ResultReg)
.addReg(SrcReg0, getKillRegState(Src0IsKill))
.addReg(SrcReg1, getKillRegState(Src1IsKill))
.addReg(VR);
// Insert the MADD
InsInstrs.push_back(MIB);
return MUL;
}
/// When getMachineCombinerPatterns() finds potential patterns,
/// this function generates the instructions that could replace the
/// original code sequence
void AArch64InstrInfo::genAlternativeCodeSequence(
MachineInstr &Root, MachineCombinerPattern Pattern,
SmallVectorImpl<MachineInstr *> &InsInstrs,
SmallVectorImpl<MachineInstr *> &DelInstrs,
DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const {
MachineBasicBlock &MBB = *Root.getParent();
MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
MachineFunction &MF = *MBB.getParent();
const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
MachineInstr *MUL;
const TargetRegisterClass *RC;
unsigned Opc;
switch (Pattern) {
default:
// Reassociate instructions.
TargetInstrInfo::genAlternativeCodeSequence(Root, Pattern, InsInstrs,
DelInstrs, InstrIdxForVirtReg);
return;
case MachineCombinerPattern::MULADDW_OP1:
case MachineCombinerPattern::MULADDX_OP1:
// MUL I=A,B,0
// ADD R,I,C
// ==> MADD R,A,B,C
// --- Create(MADD);
if (Pattern == MachineCombinerPattern::MULADDW_OP1) {
Opc = AArch64::MADDWrrr;
RC = &AArch64::GPR32RegClass;
} else {
Opc = AArch64::MADDXrrr;
RC = &AArch64::GPR64RegClass;
}
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC);
break;
case MachineCombinerPattern::MULADDW_OP2:
case MachineCombinerPattern::MULADDX_OP2:
// MUL I=A,B,0
// ADD R,C,I
// ==> MADD R,A,B,C
// --- Create(MADD);
if (Pattern == MachineCombinerPattern::MULADDW_OP2) {
Opc = AArch64::MADDWrrr;
RC = &AArch64::GPR32RegClass;
} else {
Opc = AArch64::MADDXrrr;
RC = &AArch64::GPR64RegClass;
}
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC);
break;
case MachineCombinerPattern::MULADDWI_OP1:
case MachineCombinerPattern::MULADDXI_OP1: {
// MUL I=A,B,0
// ADD R,I,Imm
// ==> ORR V, ZR, Imm
// ==> MADD R,A,B,V
// --- Create(MADD);
const TargetRegisterClass *OrrRC;
unsigned BitSize, OrrOpc, ZeroReg;
if (Pattern == MachineCombinerPattern::MULADDWI_OP1) {
OrrOpc = AArch64::ORRWri;
OrrRC = &AArch64::GPR32spRegClass;
BitSize = 32;
ZeroReg = AArch64::WZR;
Opc = AArch64::MADDWrrr;
RC = &AArch64::GPR32RegClass;
} else {
OrrOpc = AArch64::ORRXri;
OrrRC = &AArch64::GPR64spRegClass;
BitSize = 64;
ZeroReg = AArch64::XZR;
Opc = AArch64::MADDXrrr;
RC = &AArch64::GPR64RegClass;
}
unsigned NewVR = MRI.createVirtualRegister(OrrRC);
uint64_t Imm = Root.getOperand(2).getImm();
if (Root.getOperand(3).isImm()) {
unsigned Val = Root.getOperand(3).getImm();
Imm = Imm << Val;
}
uint64_t UImm = Imm << (64 - BitSize) >> (64 - BitSize);
uint64_t Encoding;
if (AArch64_AM::processLogicalImmediate(UImm, BitSize, Encoding)) {
MachineInstrBuilder MIB1 =
BuildMI(MF, Root.getDebugLoc(), TII->get(OrrOpc), NewVR)
.addReg(ZeroReg)
.addImm(Encoding);
InsInstrs.push_back(MIB1);
InstrIdxForVirtReg.insert(std::make_pair(NewVR, 0));
MUL = genMaddR(MF, MRI, TII, Root, InsInstrs, 1, Opc, NewVR, RC);
}
break;
}
case MachineCombinerPattern::MULSUBW_OP1:
case MachineCombinerPattern::MULSUBX_OP1: {
// MUL I=A,B,0
// SUB R,I, C
// ==> SUB V, 0, C
// ==> MADD R,A,B,V // = -C + A*B
// --- Create(MADD);
const TargetRegisterClass *SubRC;
unsigned SubOpc, ZeroReg;
if (Pattern == MachineCombinerPattern::MULSUBW_OP1) {
SubOpc = AArch64::SUBWrr;
SubRC = &AArch64::GPR32spRegClass;
ZeroReg = AArch64::WZR;
Opc = AArch64::MADDWrrr;
RC = &AArch64::GPR32RegClass;
} else {
SubOpc = AArch64::SUBXrr;
SubRC = &AArch64::GPR64spRegClass;
ZeroReg = AArch64::XZR;
Opc = AArch64::MADDXrrr;
RC = &AArch64::GPR64RegClass;
}
unsigned NewVR = MRI.createVirtualRegister(SubRC);
// SUB NewVR, 0, C
MachineInstrBuilder MIB1 =
BuildMI(MF, Root.getDebugLoc(), TII->get(SubOpc), NewVR)
.addReg(ZeroReg)
.addOperand(Root.getOperand(2));
InsInstrs.push_back(MIB1);
InstrIdxForVirtReg.insert(std::make_pair(NewVR, 0));
MUL = genMaddR(MF, MRI, TII, Root, InsInstrs, 1, Opc, NewVR, RC);
break;
}
case MachineCombinerPattern::MULSUBW_OP2:
case MachineCombinerPattern::MULSUBX_OP2:
// MUL I=A,B,0
// SUB R,C,I
// ==> MSUB R,A,B,C (computes C - A*B)
// --- Create(MSUB);
if (Pattern == MachineCombinerPattern::MULSUBW_OP2) {
Opc = AArch64::MSUBWrrr;
RC = &AArch64::GPR32RegClass;
} else {
Opc = AArch64::MSUBXrrr;
RC = &AArch64::GPR64RegClass;
}
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC);
break;
case MachineCombinerPattern::MULSUBWI_OP1:
case MachineCombinerPattern::MULSUBXI_OP1: {
// MUL I=A,B,0
// SUB R,I, Imm
// ==> ORR V, ZR, -Imm
// ==> MADD R,A,B,V // = -Imm + A*B
// --- Create(MADD);
const TargetRegisterClass *OrrRC;
unsigned BitSize, OrrOpc, ZeroReg;
if (Pattern == MachineCombinerPattern::MULSUBWI_OP1) {
OrrOpc = AArch64::ORRWri;
OrrRC = &AArch64::GPR32spRegClass;
BitSize = 32;
ZeroReg = AArch64::WZR;
Opc = AArch64::MADDWrrr;
RC = &AArch64::GPR32RegClass;
} else {
OrrOpc = AArch64::ORRXri;
OrrRC = &AArch64::GPR64spRegClass;
BitSize = 64;
ZeroReg = AArch64::XZR;
Opc = AArch64::MADDXrrr;
RC = &AArch64::GPR64RegClass;
}
unsigned NewVR = MRI.createVirtualRegister(OrrRC);
int Imm = Root.getOperand(2).getImm();
if (Root.getOperand(3).isImm()) {
unsigned Val = Root.getOperand(3).getImm();
Imm = Imm << Val;
}
uint64_t UImm = -Imm << (64 - BitSize) >> (64 - BitSize);
uint64_t Encoding;
if (AArch64_AM::processLogicalImmediate(UImm, BitSize, Encoding)) {
MachineInstrBuilder MIB1 =
BuildMI(MF, Root.getDebugLoc(), TII->get(OrrOpc), NewVR)
.addReg(ZeroReg)
.addImm(Encoding);
InsInstrs.push_back(MIB1);
InstrIdxForVirtReg.insert(std::make_pair(NewVR, 0));
MUL = genMaddR(MF, MRI, TII, Root, InsInstrs, 1, Opc, NewVR, RC);
}
break;
}
// Floating Point Support
case MachineCombinerPattern::FMULADDS_OP1:
case MachineCombinerPattern::FMULADDD_OP1:
// MUL I=A,B,0
// ADD R,I,C
// ==> MADD R,A,B,C
// --- Create(MADD);
if (Pattern == MachineCombinerPattern::FMULADDS_OP1) {
Opc = AArch64::FMADDSrrr;
RC = &AArch64::FPR32RegClass;
} else {
Opc = AArch64::FMADDDrrr;
RC = &AArch64::FPR64RegClass;
}
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC);
break;
case MachineCombinerPattern::FMULADDS_OP2:
case MachineCombinerPattern::FMULADDD_OP2:
// FMUL I=A,B,0
// FADD R,C,I
// ==> FMADD R,A,B,C
// --- Create(FMADD);
if (Pattern == MachineCombinerPattern::FMULADDS_OP2) {
Opc = AArch64::FMADDSrrr;
RC = &AArch64::FPR32RegClass;
} else {
Opc = AArch64::FMADDDrrr;
RC = &AArch64::FPR64RegClass;
}
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC);
break;
case MachineCombinerPattern::FMLAv1i32_indexed_OP1:
Opc = AArch64::FMLAv1i32_indexed;
RC = &AArch64::FPR32RegClass;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC,
FMAInstKind::Indexed);
break;
case MachineCombinerPattern::FMLAv1i32_indexed_OP2:
Opc = AArch64::FMLAv1i32_indexed;
RC = &AArch64::FPR32RegClass;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Indexed);
break;
case MachineCombinerPattern::FMLAv1i64_indexed_OP1:
Opc = AArch64::FMLAv1i64_indexed;
RC = &AArch64::FPR64RegClass;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC,
FMAInstKind::Indexed);
break;
case MachineCombinerPattern::FMLAv1i64_indexed_OP2:
Opc = AArch64::FMLAv1i64_indexed;
RC = &AArch64::FPR64RegClass;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Indexed);
break;
case MachineCombinerPattern::FMLAv2i32_indexed_OP1:
case MachineCombinerPattern::FMLAv2f32_OP1:
RC = &AArch64::FPR64RegClass;
if (Pattern == MachineCombinerPattern::FMLAv2i32_indexed_OP1) {
Opc = AArch64::FMLAv2i32_indexed;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC,
FMAInstKind::Indexed);
} else {
Opc = AArch64::FMLAv2f32;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC,
FMAInstKind::Accumulator);
}
break;
case MachineCombinerPattern::FMLAv2i32_indexed_OP2:
case MachineCombinerPattern::FMLAv2f32_OP2:
RC = &AArch64::FPR64RegClass;
if (Pattern == MachineCombinerPattern::FMLAv2i32_indexed_OP2) {
Opc = AArch64::FMLAv2i32_indexed;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Indexed);
} else {
Opc = AArch64::FMLAv2f32;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Accumulator);
}
break;
case MachineCombinerPattern::FMLAv2i64_indexed_OP1:
case MachineCombinerPattern::FMLAv2f64_OP1:
RC = &AArch64::FPR128RegClass;
if (Pattern == MachineCombinerPattern::FMLAv2i64_indexed_OP1) {
Opc = AArch64::FMLAv2i64_indexed;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC,
FMAInstKind::Indexed);
} else {
Opc = AArch64::FMLAv2f64;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC,
FMAInstKind::Accumulator);
}
break;
case MachineCombinerPattern::FMLAv2i64_indexed_OP2:
case MachineCombinerPattern::FMLAv2f64_OP2:
RC = &AArch64::FPR128RegClass;
if (Pattern == MachineCombinerPattern::FMLAv2i64_indexed_OP2) {
Opc = AArch64::FMLAv2i64_indexed;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Indexed);
} else {
Opc = AArch64::FMLAv2f64;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Accumulator);
}
break;
case MachineCombinerPattern::FMLAv4i32_indexed_OP1:
case MachineCombinerPattern::FMLAv4f32_OP1:
RC = &AArch64::FPR128RegClass;
if (Pattern == MachineCombinerPattern::FMLAv4i32_indexed_OP1) {
Opc = AArch64::FMLAv4i32_indexed;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC,
FMAInstKind::Indexed);
} else {
Opc = AArch64::FMLAv4f32;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC,
FMAInstKind::Accumulator);
}
break;
case MachineCombinerPattern::FMLAv4i32_indexed_OP2:
case MachineCombinerPattern::FMLAv4f32_OP2:
RC = &AArch64::FPR128RegClass;
if (Pattern == MachineCombinerPattern::FMLAv4i32_indexed_OP2) {
Opc = AArch64::FMLAv4i32_indexed;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Indexed);
} else {
Opc = AArch64::FMLAv4f32;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Accumulator);
}
break;
case MachineCombinerPattern::FMULSUBS_OP1:
case MachineCombinerPattern::FMULSUBD_OP1: {
// FMUL I=A,B,0
// FSUB R,I,C
// ==> FNMSUB R,A,B,C // = -C + A*B
// --- Create(FNMSUB);
if (Pattern == MachineCombinerPattern::FMULSUBS_OP1) {
Opc = AArch64::FNMSUBSrrr;
RC = &AArch64::FPR32RegClass;
} else {
Opc = AArch64::FNMSUBDrrr;
RC = &AArch64::FPR64RegClass;
}
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 1, Opc, RC);
break;
}
case MachineCombinerPattern::FMULSUBS_OP2:
case MachineCombinerPattern::FMULSUBD_OP2: {
// FMUL I=A,B,0
// FSUB R,C,I
// ==> FMSUB R,A,B,C (computes C - A*B)
// --- Create(FMSUB);
if (Pattern == MachineCombinerPattern::FMULSUBS_OP2) {
Opc = AArch64::FMSUBSrrr;
RC = &AArch64::FPR32RegClass;
} else {
Opc = AArch64::FMSUBDrrr;
RC = &AArch64::FPR64RegClass;
}
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC);
break;
case MachineCombinerPattern::FMLSv1i32_indexed_OP2:
Opc = AArch64::FMLSv1i32_indexed;
RC = &AArch64::FPR32RegClass;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Indexed);
break;
case MachineCombinerPattern::FMLSv1i64_indexed_OP2:
Opc = AArch64::FMLSv1i64_indexed;
RC = &AArch64::FPR64RegClass;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Indexed);
break;
case MachineCombinerPattern::FMLSv2f32_OP2:
case MachineCombinerPattern::FMLSv2i32_indexed_OP2:
RC = &AArch64::FPR64RegClass;
if (Pattern == MachineCombinerPattern::FMLSv2i32_indexed_OP2) {
Opc = AArch64::FMLSv2i32_indexed;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Indexed);
} else {
Opc = AArch64::FMLSv2f32;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Accumulator);
}
break;
case MachineCombinerPattern::FMLSv2f64_OP2:
case MachineCombinerPattern::FMLSv2i64_indexed_OP2:
RC = &AArch64::FPR128RegClass;
if (Pattern == MachineCombinerPattern::FMLSv2i64_indexed_OP2) {
Opc = AArch64::FMLSv2i64_indexed;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Indexed);
} else {
Opc = AArch64::FMLSv2f64;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Accumulator);
}
break;
case MachineCombinerPattern::FMLSv4f32_OP2:
case MachineCombinerPattern::FMLSv4i32_indexed_OP2:
RC = &AArch64::FPR128RegClass;
if (Pattern == MachineCombinerPattern::FMLSv4i32_indexed_OP2) {
Opc = AArch64::FMLSv4i32_indexed;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Indexed);
} else {
Opc = AArch64::FMLSv4f32;
MUL = genFusedMultiply(MF, MRI, TII, Root, InsInstrs, 2, Opc, RC,
FMAInstKind::Accumulator);
}
break;
}
} // end switch (Pattern)
// Record MUL and ADD/SUB for deletion
DelInstrs.push_back(MUL);
DelInstrs.push_back(&Root);
return;
}
/// \brief Replace csincr-branch sequence by simple conditional branch
///
/// Examples:
/// 1.
/// csinc w9, wzr, wzr, <condition code>
/// tbnz w9, #0, 0x44
/// to
/// b.<inverted condition code>
///
/// 2.
/// csinc w9, wzr, wzr, <condition code>
/// tbz w9, #0, 0x44
/// to
/// b.<condition code>
///
/// Replace compare and branch sequence by TBZ/TBNZ instruction when the
/// compare's constant operand is power of 2.
///
/// Examples:
/// and w8, w8, #0x400
/// cbnz w8, L1
/// to
/// tbnz w8, #10, L1
///
/// \param MI Conditional Branch
/// \return True when the simple conditional branch is generated
///
bool AArch64InstrInfo::optimizeCondBranch(MachineInstr &MI) const {
bool IsNegativeBranch = false;
bool IsTestAndBranch = false;
unsigned TargetBBInMI = 0;
switch (MI.getOpcode()) {
default:
llvm_unreachable("Unknown branch instruction?");
case AArch64::Bcc:
return false;
case AArch64::CBZW:
case AArch64::CBZX:
TargetBBInMI = 1;
break;
case AArch64::CBNZW:
case AArch64::CBNZX:
TargetBBInMI = 1;
IsNegativeBranch = true;
break;
case AArch64::TBZW:
case AArch64::TBZX:
TargetBBInMI = 2;
IsTestAndBranch = true;
break;
case AArch64::TBNZW:
case AArch64::TBNZX:
TargetBBInMI = 2;
IsNegativeBranch = true;
IsTestAndBranch = true;
break;
}
// So we increment a zero register and test for bits other
// than bit 0? Conservatively bail out in case the verifier
// missed this case.
if (IsTestAndBranch && MI.getOperand(1).getImm())
return false;
// Find Definition.
assert(MI.getParent() && "Incomplete machine instruciton\n");
MachineBasicBlock *MBB = MI.getParent();
MachineFunction *MF = MBB->getParent();
MachineRegisterInfo *MRI = &MF->getRegInfo();
unsigned VReg = MI.getOperand(0).getReg();
if (!TargetRegisterInfo::isVirtualRegister(VReg))
return false;
MachineInstr *DefMI = MRI->getVRegDef(VReg);
// Look through COPY instructions to find definition.
while (DefMI->isCopy()) {
unsigned CopyVReg = DefMI->getOperand(1).getReg();
if (!MRI->hasOneNonDBGUse(CopyVReg))
return false;
if (!MRI->hasOneDef(CopyVReg))
return false;
DefMI = MRI->getVRegDef(CopyVReg);
}
switch (DefMI->getOpcode()) {
default:
return false;
// Fold AND into a TBZ/TBNZ if constant operand is power of 2.
case AArch64::ANDWri:
case AArch64::ANDXri: {
if (IsTestAndBranch)
return false;
if (DefMI->getParent() != MBB)
return false;
if (!MRI->hasOneNonDBGUse(VReg))
return false;
bool Is32Bit = (DefMI->getOpcode() == AArch64::ANDWri);
uint64_t Mask = AArch64_AM::decodeLogicalImmediate(
DefMI->getOperand(2).getImm(), Is32Bit ? 32 : 64);
if (!isPowerOf2_64(Mask))
return false;
MachineOperand &MO = DefMI->getOperand(1);
unsigned NewReg = MO.getReg();
if (!TargetRegisterInfo::isVirtualRegister(NewReg))
return false;
assert(!MRI->def_empty(NewReg) && "Register must be defined.");
MachineBasicBlock &RefToMBB = *MBB;
MachineBasicBlock *TBB = MI.getOperand(1).getMBB();
DebugLoc DL = MI.getDebugLoc();
unsigned Imm = Log2_64(Mask);
unsigned Opc = (Imm < 32)
? (IsNegativeBranch ? AArch64::TBNZW : AArch64::TBZW)
: (IsNegativeBranch ? AArch64::TBNZX : AArch64::TBZX);
MachineInstr *NewMI = BuildMI(RefToMBB, MI, DL, get(Opc))
.addReg(NewReg)
.addImm(Imm)
.addMBB(TBB);
// Register lives on to the CBZ now.
MO.setIsKill(false);
// For immediate smaller than 32, we need to use the 32-bit
// variant (W) in all cases. Indeed the 64-bit variant does not
// allow to encode them.
// Therefore, if the input register is 64-bit, we need to take the
// 32-bit sub-part.
if (!Is32Bit && Imm < 32)
NewMI->getOperand(0).setSubReg(AArch64::sub_32);
MI.eraseFromParent();
return true;
}
// Look for CSINC
case AArch64::CSINCWr:
case AArch64::CSINCXr: {
if (!(DefMI->getOperand(1).getReg() == AArch64::WZR &&
DefMI->getOperand(2).getReg() == AArch64::WZR) &&
!(DefMI->getOperand(1).getReg() == AArch64::XZR &&
DefMI->getOperand(2).getReg() == AArch64::XZR))
return false;
if (DefMI->findRegisterDefOperandIdx(AArch64::NZCV, true) != -1)
return false;
AArch64CC::CondCode CC = (AArch64CC::CondCode)DefMI->getOperand(3).getImm();
// Convert only when the condition code is not modified between
// the CSINC and the branch. The CC may be used by other
// instructions in between.
if (areCFlagsAccessedBetweenInstrs(DefMI, MI, &getRegisterInfo(), AK_Write))
return false;
MachineBasicBlock &RefToMBB = *MBB;
MachineBasicBlock *TBB = MI.getOperand(TargetBBInMI).getMBB();
DebugLoc DL = MI.getDebugLoc();
if (IsNegativeBranch)
CC = AArch64CC::getInvertedCondCode(CC);
BuildMI(RefToMBB, MI, DL, get(AArch64::Bcc)).addImm(CC).addMBB(TBB);
MI.eraseFromParent();
return true;
}
}
}
std::pair<unsigned, unsigned>
AArch64InstrInfo::decomposeMachineOperandsTargetFlags(unsigned TF) const {
const unsigned Mask = AArch64II::MO_FRAGMENT;
return std::make_pair(TF & Mask, TF & ~Mask);
}
ArrayRef<std::pair<unsigned, const char *>>
AArch64InstrInfo::getSerializableDirectMachineOperandTargetFlags() const {
using namespace AArch64II;
static const std::pair<unsigned, const char *> TargetFlags[] = {
{MO_PAGE, "aarch64-page"},
{MO_PAGEOFF, "aarch64-pageoff"},
{MO_G3, "aarch64-g3"},
{MO_G2, "aarch64-g2"},
{MO_G1, "aarch64-g1"},
{MO_G0, "aarch64-g0"},
{MO_HI12, "aarch64-hi12"}};
return makeArrayRef(TargetFlags);
}
ArrayRef<std::pair<unsigned, const char *>>
AArch64InstrInfo::getSerializableBitmaskMachineOperandTargetFlags() const {
using namespace AArch64II;
static const std::pair<unsigned, const char *> TargetFlags[] = {
{MO_GOT, "aarch64-got"},
{MO_NC, "aarch64-nc"},
{MO_TLS, "aarch64-tls"}};
return makeArrayRef(TargetFlags);
}