void X86InstrInfo::anchor() {}
X86InstrInfo::X86InstrInfo(X86Subtarget &STI)
- : X86GenInstrInfo(
- (STI.isTarget64BitLP64() ? X86::ADJCALLSTACKDOWN64 : X86::ADJCALLSTACKDOWN32),
- (STI.isTarget64BitLP64() ? X86::ADJCALLSTACKUP64 : X86::ADJCALLSTACKUP32)),
+ : X86GenInstrInfo((STI.isTarget64BitLP64() ? X86::ADJCALLSTACKDOWN64
+ : X86::ADJCALLSTACKDOWN32),
+ (STI.isTarget64BitLP64() ? X86::ADJCALLSTACKUP64
+ : X86::ADJCALLSTACKUP32),
+ X86::CATCHRET),
Subtarget(STI), RI(STI.getTargetTriple()) {
static const X86MemoryFoldTableEntry MemoryFoldTable2Addr[] = {
}
/// True if MI has a condition code def, e.g. EFLAGS, that is not marked dead.
-static bool hasLiveCondCodeDef(MachineInstr *MI) {
+bool X86InstrInfo::hasLiveCondCodeDef(MachineInstr *MI) const {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isReg() && MO.isDef() &&
inline static bool isTruncatedShiftCountForLEA(unsigned ShAmt) {
// Left shift instructions can be transformed into load-effective-address
// instructions if we can encode them appropriately.
- // A LEA instruction utilizes a SIB byte to encode it's scale factor.
+ // A LEA instruction utilizes a SIB byte to encode its scale factor.
// The SIB.scale field is two bits wide which means that we can encode any
// shift amount less than 4.
return ShAmt < 4 && ShAmt > 0;
return NewMI;
}
-/// We have a few instructions that must be hacked on to commute them.
-///
-MachineInstr *
-X86InstrInfo::commuteInstruction(MachineInstr *MI, bool NewMI) const {
+MachineInstr *X86InstrInfo::commuteInstructionImpl(MachineInstr *MI,
+ bool NewMI,
+ unsigned OpIdx1,
+ unsigned OpIdx2) const {
switch (MI->getOpcode()) {
case X86::SHRD16rri8: // A = SHRD16rri8 B, C, I -> A = SHLD16rri8 C, B, (16-I)
case X86::SHLD16rri8: // A = SHLD16rri8 B, C, I -> A = SHRD16rri8 C, B, (16-I)
}
MI->setDesc(get(Opc));
MI->getOperand(3).setImm(Size-Amt);
- return TargetInstrInfo::commuteInstruction(MI, NewMI);
+ return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
}
case X86::BLENDPDrri:
case X86::BLENDPSrri:
NewMI = false;
}
MI->getOperand(3).setImm(Mask ^ Imm);
- return TargetInstrInfo::commuteInstruction(MI, NewMI);
+ return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
}
case X86::PCLMULQDQrr:
case X86::VPCLMULQDQrr:{
NewMI = false;
}
MI->getOperand(3).setImm((Src1Hi << 4) | (Src2Hi >> 4));
- return TargetInstrInfo::commuteInstruction(MI, NewMI);
+ return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
}
case X86::CMPPDrri:
case X86::CMPPSrri:
MI = MF.CloneMachineInstr(MI);
NewMI = false;
}
- return TargetInstrInfo::commuteInstruction(MI, NewMI);
+ return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
default:
return nullptr;
}
NewMI = false;
}
MI->getOperand(3).setImm(Imm);
- return TargetInstrInfo::commuteInstruction(MI, NewMI);
+ return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
}
case X86::CMOVB16rr: case X86::CMOVB32rr: case X86::CMOVB64rr:
case X86::CMOVAE16rr: case X86::CMOVAE32rr: case X86::CMOVAE64rr:
// Fallthrough intended.
}
default:
- return TargetInstrInfo::commuteInstruction(MI, NewMI);
+ return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
}
}
-bool X86InstrInfo::findCommutedOpIndices(MachineInstr *MI, unsigned &SrcOpIdx1,
+bool X86InstrInfo::findCommutedOpIndices(MachineInstr *MI,
+ unsigned &SrcOpIdx1,
unsigned &SrcOpIdx2) const {
switch (MI->getOpcode()) {
case X86::CMPPDrri:
// Ordered/Unordered/Equal/NotEqual tests
unsigned Imm = MI->getOperand(3).getImm() & 0x7;
switch (Imm) {
- case 0x00: // EQUAL
- case 0x03: // UNORDERED
- case 0x04: // NOT EQUAL
- case 0x07: // ORDERED
- SrcOpIdx1 = 1;
- SrcOpIdx2 = 2;
- return true;
+ case 0x00: // EQUAL
+ case 0x03: // UNORDERED
+ case 0x04: // NOT EQUAL
+ case 0x07: // ORDERED
+ // The indices of the commutable operands are 1 and 2.
+ // Assign them to the returned operand indices here.
+ return fixCommutedOpIndices(SrcOpIdx1, SrcOpIdx2, 1, 2);
}
return false;
}
case X86::VFNMADDPSr231rY:
case X86::VFNMSUBPDr231rY:
case X86::VFNMSUBPSr231rY:
- SrcOpIdx1 = 2;
- SrcOpIdx2 = 3;
- return true;
+ // The indices of the commutable operands are 2 and 3.
+ // Assign them to the returned operand indices here.
+ return fixCommutedOpIndices(SrcOpIdx1, SrcOpIdx2, 2, 3);
default:
return TargetInstrInfo::findCommutedOpIndices(MI, SrcOpIdx1, SrcOpIdx2);
}
+ return false;
}
static X86::CondCode getCondFromBranchOpc(unsigned BrOpc) {
return;
}
- // Moving EFLAGS to / from another register requires a push and a pop.
- // Notice that we have to adjust the stack if we don't want to clobber the
- // first frame index. See X86FrameLowering.cpp - clobbersTheStack.
- if (SrcReg == X86::EFLAGS) {
- if (X86::GR64RegClass.contains(DestReg)) {
- BuildMI(MBB, MI, DL, get(X86::PUSHF64));
- BuildMI(MBB, MI, DL, get(X86::POP64r), DestReg);
- return;
- }
- if (X86::GR32RegClass.contains(DestReg)) {
- BuildMI(MBB, MI, DL, get(X86::PUSHF32));
- BuildMI(MBB, MI, DL, get(X86::POP32r), DestReg);
- return;
- }
- }
- if (DestReg == X86::EFLAGS) {
- if (X86::GR64RegClass.contains(SrcReg)) {
- BuildMI(MBB, MI, DL, get(X86::PUSH64r))
- .addReg(SrcReg, getKillRegState(KillSrc));
- BuildMI(MBB, MI, DL, get(X86::POPF64));
- return;
+ bool FromEFLAGS = SrcReg == X86::EFLAGS;
+ bool ToEFLAGS = DestReg == X86::EFLAGS;
+ int Reg = FromEFLAGS ? DestReg : SrcReg;
+ bool is32 = X86::GR32RegClass.contains(Reg);
+ bool is64 = X86::GR64RegClass.contains(Reg);
+ if ((FromEFLAGS || ToEFLAGS) && (is32 || is64)) {
+ // The flags need to be saved, but saving EFLAGS with PUSHF/POPF is
+ // inefficient. Instead:
+ // - Save the overflow flag OF into AL using SETO, and restore it using a
+ // signed 8-bit addition of AL and INT8_MAX.
+ // - Save/restore the bottom 8 EFLAGS bits (CF, PF, AF, ZF, SF) to/from AH
+ // using LAHF/SAHF.
+ // - When RAX/EAX is live and isn't the destination register, make sure it
+ // isn't clobbered by PUSH/POP'ing it before and after saving/restoring
+ // the flags.
+ // This approach is ~2.25x faster than using PUSHF/POPF.
+ //
+ // This is still somewhat inefficient because we don't know which flags are
+ // actually live inside EFLAGS. Were we able to do a single SETcc instead of
+ // SETO+LAHF / ADDB+SAHF the code could be 1.02x faster.
+ //
+ // PUSHF/POPF is also potentially incorrect because it affects other flags
+ // such as TF/IF/DF, which LLVM doesn't model.
+ //
+ // Notice that we have to adjust the stack if we don't want to clobber the
+ // first frame index. See X86FrameLowering.cpp - clobbersTheStack.
+
+ int Mov = is64 ? X86::MOV64rr : X86::MOV32rr;
+ int Push = is64 ? X86::PUSH64r : X86::PUSH32r;
+ int Pop = is64 ? X86::POP64r : X86::POP32r;
+ int AX = is64 ? X86::RAX : X86::EAX;
+
+ bool AXDead = (Reg == AX) ||
+ (MachineBasicBlock::LQR_Dead ==
+ MBB.computeRegisterLiveness(&getRegisterInfo(), AX, MI));
+
+ if (!AXDead)
+ BuildMI(MBB, MI, DL, get(Push)).addReg(AX, getKillRegState(true));
+ if (FromEFLAGS) {
+ BuildMI(MBB, MI, DL, get(X86::SETOr), X86::AL);
+ BuildMI(MBB, MI, DL, get(X86::LAHF));
+ BuildMI(MBB, MI, DL, get(Mov), Reg).addReg(AX);
}
- if (X86::GR32RegClass.contains(SrcReg)) {
- BuildMI(MBB, MI, DL, get(X86::PUSH32r))
- .addReg(SrcReg, getKillRegState(KillSrc));
- BuildMI(MBB, MI, DL, get(X86::POPF32));
- return;
+ if (ToEFLAGS) {
+ BuildMI(MBB, MI, DL, get(Mov), AX).addReg(Reg, getKillRegState(KillSrc));
+ BuildMI(MBB, MI, DL, get(X86::ADD8ri), X86::AL)
+ .addReg(X86::AL)
+ .addImm(INT8_MAX);
+ BuildMI(MBB, MI, DL, get(X86::SAHF));
}
+ if (!AXDead)
+ BuildMI(MBB, MI, DL, get(Pop), AX);
+ return;
}
DEBUG(dbgs() << "Cannot copy " << RI.getName(SrcReg)
const GlobalValue *GV =
cast<GlobalValue>((*MIB->memoperands_begin())->getValue());
unsigned Flag = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant;
- MachineMemOperand *MMO = MBB.getParent()->
- getMachineMemOperand(MachinePointerInfo::getGOT(), Flag, 8, 8);
+ MachineMemOperand *MMO = MBB.getParent()->getMachineMemOperand(
+ MachinePointerInfo::getGOT(*MBB.getParent()), Flag, 8, 8);
MachineBasicBlock::iterator I = MIB.getInstr();
BuildMI(MBB, I, DL, TII.get(X86::MOV64rm), Reg).addReg(X86::RIP).addImm(1)
return true;
case X86::KSET0B:
case X86::KSET0W: return Expand2AddrUndef(MIB, get(X86::KXORWrr));
+ case X86::KSET0D: return Expand2AddrUndef(MIB, get(X86::KXORDrr));
+ case X86::KSET0Q: return Expand2AddrUndef(MIB, get(X86::KXORQrr));
case X86::KSET1B:
case X86::KSET1W: return Expand2AddrUndef(MIB, get(X86::KXNORWrr));
+ case X86::KSET1D: return Expand2AddrUndef(MIB, get(X86::KXNORDrr));
+ case X86::KSET1Q: return Expand2AddrUndef(MIB, get(X86::KXNORQrr));
case TargetOpcode::LOAD_STACK_GUARD:
expandLoadStackGuard(MIB, *this);
return true;
// If the instruction and target operand are commutable, commute the
// instruction and try again.
if (AllowCommute) {
- unsigned OriginalOpIdx = OpNum, CommuteOpIdx1, CommuteOpIdx2;
+ unsigned CommuteOpIdx1 = OpNum, CommuteOpIdx2 = CommuteAnyOperandIndex;
if (findCommutedOpIndices(MI, CommuteOpIdx1, CommuteOpIdx2)) {
bool HasDef = MI->getDesc().getNumDefs();
unsigned Reg0 = HasDef ? MI->getOperand(0).getReg() : 0;
unsigned Reg1 = MI->getOperand(CommuteOpIdx1).getReg();
unsigned Reg2 = MI->getOperand(CommuteOpIdx2).getReg();
- bool Tied0 =
- 0 == MI->getDesc().getOperandConstraint(CommuteOpIdx1, MCOI::TIED_TO);
bool Tied1 =
+ 0 == MI->getDesc().getOperandConstraint(CommuteOpIdx1, MCOI::TIED_TO);
+ bool Tied2 =
0 == MI->getDesc().getOperandConstraint(CommuteOpIdx2, MCOI::TIED_TO);
// If either of the commutable operands are tied to the destination
// then we can not commute + fold.
- if ((HasDef && Reg0 == Reg1 && Tied0) ||
- (HasDef && Reg0 == Reg2 && Tied1))
+ if ((HasDef && Reg0 == Reg1 && Tied1) ||
+ (HasDef && Reg0 == Reg2 && Tied2))
return nullptr;
- if ((CommuteOpIdx1 == OriginalOpIdx) ||
- (CommuteOpIdx2 == OriginalOpIdx)) {
- MachineInstr *CommutedMI = commuteInstruction(MI, false);
- if (!CommutedMI) {
- // Unable to commute.
- return nullptr;
- }
- if (CommutedMI != MI) {
- // New instruction. We can't fold from this.
- CommutedMI->eraseFromParent();
- return nullptr;
- }
+ MachineInstr *CommutedMI =
+ commuteInstruction(MI, false, CommuteOpIdx1, CommuteOpIdx2);
+ if (!CommutedMI) {
+ // Unable to commute.
+ return nullptr;
+ }
+ if (CommutedMI != MI) {
+ // New instruction. We can't fold from this.
+ CommutedMI->eraseFromParent();
+ return nullptr;
+ }
- // Attempt to fold with the commuted version of the instruction.
- unsigned CommuteOp =
- (CommuteOpIdx1 == OriginalOpIdx ? CommuteOpIdx2 : CommuteOpIdx1);
- NewMI =
- foldMemoryOperandImpl(MF, MI, CommuteOp, MOs, InsertPt, Size, Align,
- /*AllowCommute=*/false);
- if (NewMI)
- return NewMI;
-
- // Folding failed again - undo the commute before returning.
- MachineInstr *UncommutedMI = commuteInstruction(MI, false);
- if (!UncommutedMI) {
- // Unable to commute.
- return nullptr;
- }
- if (UncommutedMI != MI) {
- // New instruction. It doesn't need to be kept.
- UncommutedMI->eraseFromParent();
- return nullptr;
- }
+ // Attempt to fold with the commuted version of the instruction.
+ NewMI = foldMemoryOperandImpl(MF, MI, CommuteOpIdx2, MOs, InsertPt,
+ Size, Align, /*AllowCommute=*/false);
+ if (NewMI)
+ return NewMI;
- // Return here to prevent duplicate fuse failure report.
+ // Folding failed again - undo the commute before returning.
+ MachineInstr *UncommutedMI =
+ commuteInstruction(MI, false, CommuteOpIdx1, CommuteOpIdx2);
+ if (!UncommutedMI) {
+ // Unable to commute.
+ return nullptr;
+ }
+ if (UncommutedMI != MI) {
+ // New instruction. It doesn't need to be kept.
+ UncommutedMI->eraseFromParent();
return nullptr;
}
+
+ // Return here to prevent duplicate fuse failure report.
+ return nullptr;
}
}
// Unless optimizing for size, don't fold to avoid partial
// register update stalls
- // FIXME: Use Function::optForSize().
- if (!MF.getFunction()->hasFnAttribute(Attribute::OptimizeForSize) &&
- hasPartialRegUpdate(MI->getOpcode()))
+ if (!MF.getFunction()->optForSize() && hasPartialRegUpdate(MI->getOpcode()))
return nullptr;
const MachineFrameInfo *MFI = MF.getFrameInfo();
// Check switch flag
if (NoFusing) return nullptr;
- // Unless optimizing for size, don't fold to avoid partial
- // register update stalls
- // FIXME: Use Function::optForSize().
- if (!MF.getFunction()->hasFnAttribute(Attribute::OptimizeForSize) &&
- hasPartialRegUpdate(MI->getOpcode()))
+ // Avoid partial register update stalls unless optimizing for size.
+ if (!MF.getFunction()->optForSize() && hasPartialRegUpdate(MI->getOpcode()))
return nullptr;
// Determine the alignment of the load.
const MCInstrDesc &MCID = get(Opc);
const TargetRegisterClass *RC = getRegClass(MCID, Index, &RI, MF);
+ // TODO: Check if 32-byte or greater accesses are slow too?
if (!MI->hasOneMemOperand() &&
RC == &X86::VR128RegClass &&
- !Subtarget.isUnalignedMemAccessFast())
+ Subtarget.isUnalignedMem16Slow())
// Without memoperands, loadRegFromAddr and storeRegToStackSlot will
// conservatively assume the address is unaligned. That's bad for
// performance.
cast<MachineSDNode>(N)->memoperands_end());
if (!(*MMOs.first) &&
RC == &X86::VR128RegClass &&
- !Subtarget.isUnalignedMemAccessFast())
+ Subtarget.isUnalignedMem16Slow())
// Do not introduce a slow unaligned load.
return false;
+ // FIXME: If a VR128 can have size 32, we should be checking if a 32-byte
+ // memory access is slow above.
unsigned Alignment = RC->getSize() == 32 ? 32 : 16;
bool isAligned = (*MMOs.first) &&
(*MMOs.first)->getAlignment() >= Alignment;
cast<MachineSDNode>(N)->memoperands_end());
if (!(*MMOs.first) &&
RC == &X86::VR128RegClass &&
- !Subtarget.isUnalignedMemAccessFast())
+ Subtarget.isUnalignedMem16Slow())
// Do not introduce a slow unaligned store.
return false;
+ // FIXME: If a VR128 can have size 32, we should be checking if a 32-byte
+ // memory access is slow above.
unsigned Alignment = RC->getSize() == 32 ? 32 : 16;
bool isAligned = (*MMOs.first) &&
(*MMOs.first)->getAlignment() >= Alignment;
return isHighLatencyDef(DefMI->getOpcode());
}
-static bool hasReassociableOperands(const MachineInstr &Inst,
- const MachineBasicBlock *MBB) {
+bool X86InstrInfo::hasReassociableOperands(const MachineInstr &Inst,
+ const MachineBasicBlock *MBB) const {
assert((Inst.getNumOperands() == 3 || Inst.getNumOperands() == 4) &&
"Reassociation needs binary operators");
- const MachineOperand &Op1 = Inst.getOperand(1);
- const MachineOperand &Op2 = Inst.getOperand(2);
- const MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
// Integer binary math/logic instructions have a third source operand:
// the EFLAGS register. That operand must be both defined here and never
if (!Inst.getOperand(3).isDead())
return false;
}
-
- // We need virtual register definitions for the operands that we will
- // reassociate.
- MachineInstr *MI1 = nullptr;
- MachineInstr *MI2 = nullptr;
- if (Op1.isReg() && TargetRegisterInfo::isVirtualRegister(Op1.getReg()))
- MI1 = MRI.getUniqueVRegDef(Op1.getReg());
- if (Op2.isReg() && TargetRegisterInfo::isVirtualRegister(Op2.getReg()))
- MI2 = MRI.getUniqueVRegDef(Op2.getReg());
-
- // And they need to be in the trace (otherwise, they won't have a depth).
- if (MI1 && MI2 && MI1->getParent() == MBB && MI2->getParent() == MBB)
- return true;
- return false;
-}
-
-static bool hasReassociableSibling(const MachineInstr &Inst, bool &Commuted) {
- const MachineBasicBlock *MBB = Inst.getParent();
- const MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
- MachineInstr *MI1 = MRI.getUniqueVRegDef(Inst.getOperand(1).getReg());
- MachineInstr *MI2 = MRI.getUniqueVRegDef(Inst.getOperand(2).getReg());
- unsigned AssocOpcode = Inst.getOpcode();
-
- // If only one operand has the same opcode and it's the second source operand,
- // the operands must be commuted.
- Commuted = MI1->getOpcode() != AssocOpcode && MI2->getOpcode() == AssocOpcode;
- if (Commuted)
- std::swap(MI1, MI2);
-
- // 1. The previous instruction must be the same type as Inst.
- // 2. The previous instruction must have virtual register definitions for its
- // operands in the same basic block as Inst.
- // 3. The previous instruction's result must only be used by Inst.
- if (MI1->getOpcode() == AssocOpcode &&
- hasReassociableOperands(*MI1, MBB) &&
- MRI.hasOneNonDBGUse(MI1->getOperand(0).getReg()))
- return true;
-
- return false;
+ return TargetInstrInfo::hasReassociableOperands(Inst, MBB);
}
// TODO: There are many more machine instruction opcodes to match:
// 1. Other data types (integer, vectors)
-// 2. Other math / logic operations (and, or)
-static bool isAssociativeAndCommutative(const MachineInstr &Inst) {
+// 2. Other math / logic operations (xor, or)
+// 3. Other forms of the same operation (intrinsics and other variants)
+bool X86InstrInfo::isAssociativeAndCommutative(const MachineInstr &Inst) const {
switch (Inst.getOpcode()) {
+ case X86::AND8rr:
+ case X86::AND16rr:
+ case X86::AND32rr:
+ case X86::AND64rr:
+ case X86::OR8rr:
+ case X86::OR16rr:
+ case X86::OR32rr:
+ case X86::OR64rr:
+ case X86::XOR8rr:
+ case X86::XOR16rr:
+ case X86::XOR32rr:
+ case X86::XOR64rr:
case X86::IMUL16rr:
case X86::IMUL32rr:
case X86::IMUL64rr:
+ case X86::PANDrr:
+ case X86::PORrr:
+ case X86::PXORrr:
+ case X86::VPANDrr:
+ case X86::VPANDYrr:
+ case X86::VPORrr:
+ case X86::VPORYrr:
+ case X86::VPXORrr:
+ case X86::VPXORYrr:
+ // Normal min/max instructions are not commutative because of NaN and signed
+ // zero semantics, but these are. Thus, there's no need to check for global
+ // relaxed math; the instructions themselves have the properties we need.
+ case X86::MAXCPDrr:
+ case X86::MAXCPSrr:
+ case X86::MAXCSDrr:
+ case X86::MAXCSSrr:
+ case X86::MINCPDrr:
+ case X86::MINCPSrr:
+ case X86::MINCSDrr:
+ case X86::MINCSSrr:
+ case X86::VMAXCPDrr:
+ case X86::VMAXCPSrr:
+ case X86::VMAXCPDYrr:
+ case X86::VMAXCPSYrr:
+ case X86::VMAXCSDrr:
+ case X86::VMAXCSSrr:
+ case X86::VMINCPDrr:
+ case X86::VMINCPSrr:
+ case X86::VMINCPDYrr:
+ case X86::VMINCPSYrr:
+ case X86::VMINCSDrr:
+ case X86::VMINCSSrr:
return true;
+ case X86::ADDPDrr:
+ case X86::ADDPSrr:
case X86::ADDSDrr:
case X86::ADDSSrr:
- case X86::VADDSDrr:
- case X86::VADDSSrr:
+ case X86::MULPDrr:
+ case X86::MULPSrr:
case X86::MULSDrr:
case X86::MULSSrr:
+ case X86::VADDPDrr:
+ case X86::VADDPSrr:
+ case X86::VADDPDYrr:
+ case X86::VADDPSYrr:
+ case X86::VADDSDrr:
+ case X86::VADDSSrr:
+ case X86::VMULPDrr:
+ case X86::VMULPSrr:
+ case X86::VMULPDYrr:
+ case X86::VMULPSYrr:
case X86::VMULSDrr:
case X86::VMULSSrr:
return Inst.getParent()->getParent()->getTarget().Options.UnsafeFPMath;
}
}
-/// Return true if the input instruction is part of a chain of dependent ops
-/// that are suitable for reassociation, otherwise return false.
-/// If the instruction's operands must be commuted to have a previous
-/// instruction of the same type define the first source operand, Commuted will
-/// be set to true.
-static bool isReassociationCandidate(const MachineInstr &Inst, bool &Commuted) {
- // 1. The operation must be associative and commutative.
- // 2. The instruction must have virtual register definitions for its
- // operands in the same basic block.
- // 3. The instruction must have a reassociable sibling.
- if (isAssociativeAndCommutative(Inst) &&
- hasReassociableOperands(Inst, Inst.getParent()) &&
- hasReassociableSibling(Inst, Commuted))
- return true;
-
- return false;
-}
-
-// FIXME: This has the potential to be expensive (compile time) while not
-// improving the code at all. Some ways to limit the overhead:
-// 1. Track successful transforms; bail out if hit rate gets too low.
-// 2. Only enable at -O3 or some other non-default optimization level.
-// 3. Pre-screen pattern candidates here: if an operand of the previous
-// instruction is known to not increase the critical path, then don't match
-// that pattern.
-bool X86InstrInfo::getMachineCombinerPatterns(MachineInstr &Root,
- SmallVectorImpl<MachineCombinerPattern::MC_PATTERN> &Patterns) const {
- // TODO: There is nothing x86-specific here except the instruction type.
- // This logic could be hoisted into the machine combiner pass itself.
-
- // Look for this reassociation pattern:
- // B = A op X (Prev)
- // C = B op Y (Root)
-
- bool Commute;
- if (isReassociationCandidate(Root, Commute)) {
- // We found a sequence of instructions that may be suitable for a
- // reassociation of operands to increase ILP. Specify each commutation
- // possibility for the Prev instruction in the sequence and let the
- // machine combiner decide if changing the operands is worthwhile.
- if (Commute) {
- Patterns.push_back(MachineCombinerPattern::MC_REASSOC_AX_YB);
- Patterns.push_back(MachineCombinerPattern::MC_REASSOC_XA_YB);
- } else {
- Patterns.push_back(MachineCombinerPattern::MC_REASSOC_AX_BY);
- Patterns.push_back(MachineCombinerPattern::MC_REASSOC_XA_BY);
- }
- return true;
- }
-
- return false;
-}
-
/// This is an architecture-specific helper function of reassociateOps.
/// Set special operand attributes for new instructions after reassociation.
-static void setSpecialOperandAttr(MachineInstr &OldMI1, MachineInstr &OldMI2,
- MachineInstr &NewMI1, MachineInstr &NewMI2) {
+void X86InstrInfo::setSpecialOperandAttr(MachineInstr &OldMI1,
+ MachineInstr &OldMI2,
+ MachineInstr &NewMI1,
+ MachineInstr &NewMI2) const {
// Integer instructions define an implicit EFLAGS source register operand as
// the third source (fourth total) operand.
if (OldMI1.getNumOperands() != 4 || OldMI2.getNumOperands() != 4)
assert(NewMI1.getNumOperands() == 4 && NewMI2.getNumOperands() == 4 &&
"Unexpected instruction type for reassociation");
-
+
MachineOperand &OldOp1 = OldMI1.getOperand(3);
MachineOperand &OldOp2 = OldMI2.getOperand(3);
MachineOperand &NewOp1 = NewMI1.getOperand(3);
NewOp2.setIsDead();
}
-/// Attempt the following reassociation to reduce critical path length:
-/// B = A op X (Prev)
-/// C = B op Y (Root)
-/// ===>
-/// B = X op Y
-/// C = A op B
-static void reassociateOps(MachineInstr &Root, MachineInstr &Prev,
- MachineCombinerPattern::MC_PATTERN Pattern,
- SmallVectorImpl<MachineInstr *> &InsInstrs,
- SmallVectorImpl<MachineInstr *> &DelInstrs,
- DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) {
- MachineFunction *MF = Root.getParent()->getParent();
- MachineRegisterInfo &MRI = MF->getRegInfo();
- const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
- const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
- const TargetRegisterClass *RC = Root.getRegClassConstraint(0, TII, TRI);
-
- // This array encodes the operand index for each parameter because the
- // operands may be commuted. Each row corresponds to a pattern value,
- // and each column specifies the index of A, B, X, Y.
- unsigned OpIdx[4][4] = {
- { 1, 1, 2, 2 },
- { 1, 2, 2, 1 },
- { 2, 1, 1, 2 },
- { 2, 2, 1, 1 }
- };
-
- MachineOperand &OpA = Prev.getOperand(OpIdx[Pattern][0]);
- MachineOperand &OpB = Root.getOperand(OpIdx[Pattern][1]);
- MachineOperand &OpX = Prev.getOperand(OpIdx[Pattern][2]);
- MachineOperand &OpY = Root.getOperand(OpIdx[Pattern][3]);
- MachineOperand &OpC = Root.getOperand(0);
-
- unsigned RegA = OpA.getReg();
- unsigned RegB = OpB.getReg();
- unsigned RegX = OpX.getReg();
- unsigned RegY = OpY.getReg();
- unsigned RegC = OpC.getReg();
-
- if (TargetRegisterInfo::isVirtualRegister(RegA))
- MRI.constrainRegClass(RegA, RC);
- if (TargetRegisterInfo::isVirtualRegister(RegB))
- MRI.constrainRegClass(RegB, RC);
- if (TargetRegisterInfo::isVirtualRegister(RegX))
- MRI.constrainRegClass(RegX, RC);
- if (TargetRegisterInfo::isVirtualRegister(RegY))
- MRI.constrainRegClass(RegY, RC);
- if (TargetRegisterInfo::isVirtualRegister(RegC))
- MRI.constrainRegClass(RegC, RC);
-
- // Create a new virtual register for the result of (X op Y) instead of
- // recycling RegB because the MachineCombiner's computation of the critical
- // path requires a new register definition rather than an existing one.
- unsigned NewVR = MRI.createVirtualRegister(RC);
- InstrIdxForVirtReg.insert(std::make_pair(NewVR, 0));
-
- unsigned Opcode = Root.getOpcode();
- bool KillA = OpA.isKill();
- bool KillX = OpX.isKill();
- bool KillY = OpY.isKill();
-
- // Create new instructions for insertion.
- MachineInstrBuilder MIB1 =
- BuildMI(*MF, Prev.getDebugLoc(), TII->get(Opcode), NewVR)
- .addReg(RegX, getKillRegState(KillX))
- .addReg(RegY, getKillRegState(KillY));
- MachineInstrBuilder MIB2 =
- BuildMI(*MF, Root.getDebugLoc(), TII->get(Opcode), RegC)
- .addReg(RegA, getKillRegState(KillA))
- .addReg(NewVR, getKillRegState(true));
-
- setSpecialOperandAttr(Root, Prev, *MIB1, *MIB2);
-
- // Record new instructions for insertion and old instructions for deletion.
- InsInstrs.push_back(MIB1);
- InsInstrs.push_back(MIB2);
- DelInstrs.push_back(&Prev);
- DelInstrs.push_back(&Root);
+std::pair<unsigned, unsigned>
+X86InstrInfo::decomposeMachineOperandsTargetFlags(unsigned TF) const {
+ return std::make_pair(TF, 0u);
}
-void X86InstrInfo::genAlternativeCodeSequence(
- MachineInstr &Root,
- MachineCombinerPattern::MC_PATTERN Pattern,
- SmallVectorImpl<MachineInstr *> &InsInstrs,
- SmallVectorImpl<MachineInstr *> &DelInstrs,
- DenseMap<unsigned, unsigned> &InstIdxForVirtReg) const {
- MachineRegisterInfo &MRI = Root.getParent()->getParent()->getRegInfo();
-
- // Select the previous instruction in the sequence based on the input pattern.
- MachineInstr *Prev = nullptr;
- switch (Pattern) {
- case MachineCombinerPattern::MC_REASSOC_AX_BY:
- case MachineCombinerPattern::MC_REASSOC_XA_BY:
- Prev = MRI.getUniqueVRegDef(Root.getOperand(1).getReg());
- break;
- case MachineCombinerPattern::MC_REASSOC_AX_YB:
- case MachineCombinerPattern::MC_REASSOC_XA_YB:
- Prev = MRI.getUniqueVRegDef(Root.getOperand(2).getReg());
- }
- assert(Prev && "Unknown pattern for machine combiner");
-
- reassociateOps(Root, *Prev, Pattern, InsInstrs, DelInstrs, InstIdxForVirtReg);
- return;
+ArrayRef<std::pair<unsigned, const char *>>
+X86InstrInfo::getSerializableDirectMachineOperandTargetFlags() const {
+ using namespace X86II;
+ static const std::pair<unsigned, const char *> TargetFlags[] = {
+ {MO_GOT_ABSOLUTE_ADDRESS, "x86-got-absolute-address"},
+ {MO_PIC_BASE_OFFSET, "x86-pic-base-offset"},
+ {MO_GOT, "x86-got"},
+ {MO_GOTOFF, "x86-gotoff"},
+ {MO_GOTPCREL, "x86-gotpcrel"},
+ {MO_PLT, "x86-plt"},
+ {MO_TLSGD, "x86-tlsgd"},
+ {MO_TLSLD, "x86-tlsld"},
+ {MO_TLSLDM, "x86-tlsldm"},
+ {MO_GOTTPOFF, "x86-gottpoff"},
+ {MO_INDNTPOFF, "x86-indntpoff"},
+ {MO_TPOFF, "x86-tpoff"},
+ {MO_DTPOFF, "x86-dtpoff"},
+ {MO_NTPOFF, "x86-ntpoff"},
+ {MO_GOTNTPOFF, "x86-gotntpoff"},
+ {MO_DLLIMPORT, "x86-dllimport"},
+ {MO_DARWIN_STUB, "x86-darwin-stub"},
+ {MO_DARWIN_NONLAZY, "x86-darwin-nonlazy"},
+ {MO_DARWIN_NONLAZY_PIC_BASE, "x86-darwin-nonlazy-pic-base"},
+ {MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE, "x86-darwin-hidden-nonlazy-pic-base"},
+ {MO_TLVP, "x86-tlvp"},
+ {MO_TLVP_PIC_BASE, "x86-tlvp-pic-base"},
+ {MO_SECREL, "x86-secrel"}};
+ return makeArrayRef(TargetFlags);
}
namespace {
projects / oota-llvm.git / blobdiff