Add support to 3-addressify 16-bit instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91104 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2009-12-11 06:01:48 +00:00
parent ac94863a1c
commit 656e51454a
2 changed files with 138 additions and 91 deletions

View File

@ -1058,6 +1058,107 @@ static bool hasLiveCondCodeDef(MachineInstr *MI) {
return false;
}
/// convertToThreeAddressWithLEA - Helper for convertToThreeAddress when 16-bit
/// 16-bit LEA is disabled, use 32-bit LEA to form 3-address code by promoting
/// to a 32-bit superregister and then truncating back down to a 16-bit
/// subregister.
MachineInstr *
X86InstrInfo::convertToThreeAddressWithLEA(unsigned MIOpc,
MachineFunction::iterator &MFI,
MachineBasicBlock::iterator &MBBI,
LiveVariables *LV) const {
MachineInstr *MI = MBBI;
unsigned Dest = MI->getOperand(0).getReg();
unsigned Src = MI->getOperand(1).getReg();
bool isDead = MI->getOperand(0).isDead();
bool isKill = MI->getOperand(1).isKill();
unsigned Opc = TM.getSubtarget<X86Subtarget>().is64Bit()
? X86::LEA64_32r : X86::LEA32r;
MachineRegisterInfo &RegInfo = MFI->getParent()->getRegInfo();
unsigned leaInReg = RegInfo.createVirtualRegister(&X86::GR32RegClass);
unsigned leaOutReg = RegInfo.createVirtualRegister(&X86::GR32RegClass);
// Build and insert into an implicit UNDEF value. This is OK because
// well be shifting and then extracting the lower 16-bits.
BuildMI(*MFI, MBBI, MI->getDebugLoc(), get(X86::IMPLICIT_DEF), leaInReg);
MachineInstr *InsMI =
BuildMI(*MFI, MBBI, MI->getDebugLoc(), get(X86::INSERT_SUBREG),leaInReg)
.addReg(leaInReg)
.addReg(Src, getKillRegState(isKill))
.addImm(X86::SUBREG_16BIT);
MachineInstrBuilder MIB = BuildMI(*MFI, MBBI, MI->getDebugLoc(),
get(Opc), leaOutReg);
switch (MIOpc) {
default:
llvm_unreachable(0);
break;
case X86::SHL16ri: {
unsigned ShAmt = MI->getOperand(2).getImm();
MIB.addReg(0).addImm(1 << ShAmt)
.addReg(leaInReg, RegState::Kill).addImm(0);
break;
}
case X86::INC16r:
case X86::INC64_16r:
addLeaRegOffset(MIB, leaInReg, true, 1);
break;
case X86::DEC16r:
case X86::DEC64_16r:
addLeaRegOffset(MIB, leaInReg, true, -1);
break;
case X86::ADD16ri:
case X86::ADD16ri8:
addLeaRegOffset(MIB, leaInReg, true, MI->getOperand(2).getImm());
break;
case X86::ADD16rr: {
unsigned Src2 = MI->getOperand(2).getReg();
bool isKill2 = MI->getOperand(2).isKill();
unsigned leaInReg2 = 0;
MachineInstr *InsMI2 = 0;
if (Src == Src2) {
// ADD16rr %reg1028<kill>, %reg1028
// just a single insert_subreg.
addRegReg(MIB, leaInReg, true, leaInReg, false);
} else {
leaInReg2 = RegInfo.createVirtualRegister(&X86::GR32RegClass);
// Build and insert into an implicit UNDEF value. This is OK because
// well be shifting and then extracting the lower 16-bits.
BuildMI(*MFI, MIB, MI->getDebugLoc(), get(X86::IMPLICIT_DEF), leaInReg2);
InsMI2 =
BuildMI(*MFI, MIB, MI->getDebugLoc(), get(X86::INSERT_SUBREG),leaInReg2)
.addReg(leaInReg2)
.addReg(Src2, getKillRegState(isKill2))
.addImm(X86::SUBREG_16BIT);
addRegReg(MIB, leaInReg, true, leaInReg2, true);
}
if (LV && isKill2 && InsMI2)
LV->replaceKillInstruction(Src2, MI, InsMI2);
break;
}
}
MachineInstr *NewMI = MIB;
MachineInstr *ExtMI =
BuildMI(*MFI, MBBI, MI->getDebugLoc(), get(X86::EXTRACT_SUBREG))
.addReg(Dest, RegState::Define | getDeadRegState(isDead))
.addReg(leaOutReg, RegState::Kill)
.addImm(X86::SUBREG_16BIT);
if (LV) {
// Update live variables
LV->getVarInfo(leaInReg).Kills.push_back(NewMI);
LV->getVarInfo(leaOutReg).Kills.push_back(ExtMI);
if (isKill)
LV->replaceKillInstruction(Src, MI, InsMI);
if (isDead)
LV->replaceKillInstruction(Dest, MI, ExtMI);
}
return ExtMI;
}
/// convertToThreeAddress - This method must be implemented by targets that
/// set the M_CONVERTIBLE_TO_3_ADDR flag. When this flag is set, the target
/// may be able to convert a two-address instruction into a true
@ -1137,51 +1238,13 @@ X86InstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
unsigned ShAmt = MI->getOperand(2).getImm();
if (ShAmt == 0 || ShAmt >= 4) return 0;
if (DisableLEA16) {
// If 16-bit LEA is disabled, use 32-bit LEA via subregisters.
MachineRegisterInfo &RegInfo = MFI->getParent()->getRegInfo();
unsigned Opc = TM.getSubtarget<X86Subtarget>().is64Bit()
? X86::LEA64_32r : X86::LEA32r;
unsigned leaInReg = RegInfo.createVirtualRegister(&X86::GR32RegClass);
unsigned leaOutReg = RegInfo.createVirtualRegister(&X86::GR32RegClass);
// Build and insert into an implicit UNDEF value. This is OK because
// well be shifting and then extracting the lower 16-bits.
BuildMI(*MFI, MBBI, MI->getDebugLoc(), get(X86::IMPLICIT_DEF), leaInReg);
MachineInstr *InsMI =
BuildMI(*MFI, MBBI, MI->getDebugLoc(), get(X86::INSERT_SUBREG),leaInReg)
.addReg(leaInReg)
.addReg(Src, getKillRegState(isKill))
.addImm(X86::SUBREG_16BIT);
NewMI = BuildMI(*MFI, MBBI, MI->getDebugLoc(), get(Opc), leaOutReg)
.addReg(0).addImm(1 << ShAmt)
.addReg(leaInReg, RegState::Kill)
.addImm(0);
MachineInstr *ExtMI =
BuildMI(*MFI, MBBI, MI->getDebugLoc(), get(X86::EXTRACT_SUBREG))
.addReg(Dest, RegState::Define | getDeadRegState(isDead))
.addReg(leaOutReg, RegState::Kill)
.addImm(X86::SUBREG_16BIT);
if (LV) {
// Update live variables
LV->getVarInfo(leaInReg).Kills.push_back(NewMI);
LV->getVarInfo(leaOutReg).Kills.push_back(ExtMI);
if (isKill)
LV->replaceKillInstruction(Src, MI, InsMI);
if (isDead)
LV->replaceKillInstruction(Dest, MI, ExtMI);
}
return ExtMI;
} else {
NewMI = BuildMI(MF, MI->getDebugLoc(), get(X86::LEA16r))
.addReg(Dest, RegState::Define | getDeadRegState(isDead))
.addReg(0).addImm(1 << ShAmt)
.addReg(Src, getKillRegState(isKill))
.addImm(0);
}
if (DisableLEA16)
return convertToThreeAddressWithLEA(MIOpc, MFI, MBBI, LV);
NewMI = BuildMI(MF, MI->getDebugLoc(), get(X86::LEA16r))
.addReg(Dest, RegState::Define | getDeadRegState(isDead))
.addReg(0).addImm(1 << ShAmt)
.addReg(Src, getKillRegState(isKill))
.addImm(0);
break;
}
default: {
@ -1208,7 +1271,8 @@ X86InstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
}
case X86::INC16r:
case X86::INC64_16r:
if (DisableLEA16) return 0;
if (DisableLEA16)
return convertToThreeAddressWithLEA(MIOpc, MFI, MBBI, LV);
assert(MI->getNumOperands() >= 2 && "Unknown inc instruction!");
NewMI = addRegOffset(BuildMI(MF, MI->getDebugLoc(), get(X86::LEA16r))
.addReg(Dest, RegState::Define |
@ -1229,7 +1293,8 @@ X86InstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
}
case X86::DEC16r:
case X86::DEC64_16r:
if (DisableLEA16) return 0;
if (DisableLEA16)
return convertToThreeAddressWithLEA(MIOpc, MFI, MBBI, LV);
assert(MI->getNumOperands() >= 2 && "Unknown dec instruction!");
NewMI = addRegOffset(BuildMI(MF, MI->getDebugLoc(), get(X86::LEA16r))
.addReg(Dest, RegState::Define |
@ -1252,7 +1317,8 @@ X86InstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
break;
}
case X86::ADD16rr: {
if (DisableLEA16) return 0;
if (DisableLEA16)
return convertToThreeAddressWithLEA(MIOpc, MFI, MBBI, LV);
assert(MI->getNumOperands() >= 3 && "Unknown add instruction!");
unsigned Src2 = MI->getOperand(2).getReg();
bool isKill2 = MI->getOperand(2).isKill();
@ -1267,55 +1333,31 @@ X86InstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
case X86::ADD64ri32:
case X86::ADD64ri8:
assert(MI->getNumOperands() >= 3 && "Unknown add instruction!");
if (MI->getOperand(2).isImm())
NewMI = addLeaRegOffset(BuildMI(MF, MI->getDebugLoc(), get(X86::LEA64r))
.addReg(Dest, RegState::Define |
getDeadRegState(isDead)),
Src, isKill, MI->getOperand(2).getImm());
NewMI = addLeaRegOffset(BuildMI(MF, MI->getDebugLoc(), get(X86::LEA64r))
.addReg(Dest, RegState::Define |
getDeadRegState(isDead)),
Src, isKill, MI->getOperand(2).getImm());
break;
case X86::ADD32ri:
case X86::ADD32ri8:
case X86::ADD32ri8: {
assert(MI->getNumOperands() >= 3 && "Unknown add instruction!");
if (MI->getOperand(2).isImm()) {
unsigned Opc = is64Bit ? X86::LEA64_32r : X86::LEA32r;
NewMI = addLeaRegOffset(BuildMI(MF, MI->getDebugLoc(), get(Opc))
.addReg(Dest, RegState::Define |
getDeadRegState(isDead)),
unsigned Opc = is64Bit ? X86::LEA64_32r : X86::LEA32r;
NewMI = addLeaRegOffset(BuildMI(MF, MI->getDebugLoc(), get(Opc))
.addReg(Dest, RegState::Define |
getDeadRegState(isDead)),
Src, isKill, MI->getOperand(2).getImm());
}
break;
case X86::ADD16ri:
case X86::ADD16ri8:
if (DisableLEA16) return 0;
assert(MI->getNumOperands() >= 3 && "Unknown add instruction!");
if (MI->getOperand(2).isImm())
NewMI = addRegOffset(BuildMI(MF, MI->getDebugLoc(), get(X86::LEA16r))
.addReg(Dest, RegState::Define |
getDeadRegState(isDead)),
Src, isKill, MI->getOperand(2).getImm());
break;
case X86::SHL16ri:
if (DisableLEA16) return 0;
case X86::SHL32ri:
case X86::SHL64ri: {
assert(MI->getNumOperands() >= 3 && MI->getOperand(2).isImm() &&
"Unknown shl instruction!");
unsigned ShAmt = MI->getOperand(2).getImm();
if (ShAmt == 1 || ShAmt == 2 || ShAmt == 3) {
X86AddressMode AM;
AM.Scale = 1 << ShAmt;
AM.IndexReg = Src;
unsigned Opc = MIOpc == X86::SHL64ri ? X86::LEA64r
: (MIOpc == X86::SHL32ri
? (is64Bit ? X86::LEA64_32r : X86::LEA32r) : X86::LEA16r);
NewMI = addFullAddress(BuildMI(MF, MI->getDebugLoc(), get(Opc))
.addReg(Dest, RegState::Define |
getDeadRegState(isDead)), AM);
if (isKill)
NewMI->getOperand(3).setIsKill(true);
}
break;
}
case X86::ADD16ri:
case X86::ADD16ri8:
if (DisableLEA16)
return convertToThreeAddressWithLEA(MIOpc, MFI, MBBI, LV);
assert(MI->getNumOperands() >= 3 && "Unknown add instruction!");
NewMI = addLeaRegOffset(BuildMI(MF, MI->getDebugLoc(), get(X86::LEA16r))
.addReg(Dest, RegState::Define |
getDeadRegState(isDead)),
Src, isKill, MI->getOperand(2).getImm());
break;
}
}
}

View File

@ -637,6 +637,11 @@ public:
unsigned getGlobalBaseReg(MachineFunction *MF) const;
private:
MachineInstr * convertToThreeAddressWithLEA(unsigned MIOpc,
MachineFunction::iterator &MFI,
MachineBasicBlock::iterator &MBBI,
LiveVariables *LV) const;
MachineInstr* foldMemoryOperandImpl(MachineFunction &MF,
MachineInstr* MI,
unsigned OpNum,