-//===- Thumb1RegisterInfo.cpp - Thumb-1 Register Information ----*- C++ -*-===//
+//===-- Thumb1RegisterInfo.cpp - Thumb-1 Register Information -------------===//
//
// The LLVM Compiler Infrastructure
//
//
//===----------------------------------------------------------------------===//
-#include "ARM.h"
-#include "ARMAddressingModes.h"
+#include "Thumb1RegisterInfo.h"
#include "ARMBaseInstrInfo.h"
#include "ARMMachineFunctionInfo.h"
#include "ARMSubtarget.h"
-#include "Thumb1InstrInfo.h"
-#include "Thumb1RegisterInfo.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
-#include "llvm/LLVMContext.h"
+#include "MCTargetDesc/ARMAddressingModes.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineLocation.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/Target/TargetFrameInfo.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/SmallVector.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/LLVMContext.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/raw_ostream.h"
-using namespace llvm;
+#include "llvm/Target/TargetFrameLowering.h"
+#include "llvm/Target/TargetMachine.h"
+namespace llvm {
extern cl::opt<bool> ReuseFrameIndexVals;
+}
+
+using namespace llvm;
-Thumb1RegisterInfo::Thumb1RegisterInfo(const ARMBaseInstrInfo &tii,
- const ARMSubtarget &sti)
- : ARMBaseRegisterInfo(tii, sti) {
+Thumb1RegisterInfo::Thumb1RegisterInfo(const ARMSubtarget &sti)
+ : ARMBaseRegisterInfo(sti) {
+}
+
+const TargetRegisterClass*
+Thumb1RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC)
+ const {
+ if (ARM::tGPRRegClass.hasSubClassEq(RC))
+ return &ARM::tGPRRegClass;
+ return ARMBaseRegisterInfo::getLargestLegalSuperClass(RC);
+}
+
+const TargetRegisterClass *
+Thumb1RegisterInfo::getPointerRegClass(const MachineFunction &MF, unsigned Kind)
+ const {
+ return &ARM::tGPRRegClass;
}
/// emitLoadConstPool - Emits a load from constpool to materialize the
/// specified immediate.
-void Thumb1RegisterInfo::emitLoadConstPool(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- DebugLoc dl,
- unsigned DestReg, unsigned SubIdx,
- int Val,
- ARMCC::CondCodes Pred,
- unsigned PredReg) const {
+void
+Thumb1RegisterInfo::emitLoadConstPool(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &MBBI,
+ DebugLoc dl,
+ unsigned DestReg, unsigned SubIdx,
+ int Val,
+ ARMCC::CondCodes Pred, unsigned PredReg,
+ unsigned MIFlags) const {
MachineFunction &MF = *MBB.getParent();
+ const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
MachineConstantPool *ConstantPool = MF.getConstantPool();
- Constant *C = ConstantInt::get(
+ const Constant *C = ConstantInt::get(
Type::getInt32Ty(MBB.getParent()->getFunction()->getContext()), Val);
unsigned Idx = ConstantPool->getConstantPoolIndex(C, 4);
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tLDRcp))
- .addReg(DestReg, getDefRegState(true), SubIdx)
- .addConstantPoolIndex(Idx).addImm(Pred).addReg(PredReg);
-}
-
-const TargetRegisterClass*
-Thumb1RegisterInfo::getPhysicalRegisterRegClass(unsigned Reg, EVT VT) const {
- if (isARMLowRegister(Reg))
- return ARM::tGPRRegisterClass;
- switch (Reg) {
- default:
- break;
- case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
- case ARM::R12: case ARM::SP: case ARM::LR: case ARM::PC:
- return ARM::GPRRegisterClass;
- }
-
- return TargetRegisterInfo::getPhysicalRegisterRegClass(Reg, VT);
-}
-
-bool Thumb1RegisterInfo::hasReservedCallFrame(MachineFunction &MF) const {
- const MachineFrameInfo *FFI = MF.getFrameInfo();
- unsigned CFSize = FFI->getMaxCallFrameSize();
- // It's not always a good idea to include the call frame as part of the
- // stack frame. ARM (especially Thumb) has small immediate offset to
- // address the stack frame. So a large call frame can cause poor codegen
- // and may even makes it impossible to scavenge a register.
- if (CFSize >= ((1 << 8) - 1) * 4 / 2) // Half of imm8 * 4
- return false;
-
- return !MF.getFrameInfo()->hasVarSizedObjects();
+ BuildMI(MBB, MBBI, dl, TII.get(ARM::tLDRpci))
+ .addReg(DestReg, getDefRegState(true), SubIdx)
+ .addConstantPoolIndex(Idx).addImm(Pred).addReg(PredReg)
+ .setMIFlags(MIFlags);
}
static
void emitThumbRegPlusImmInReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
+ DebugLoc dl,
unsigned DestReg, unsigned BaseReg,
int NumBytes, bool CanChangeCC,
const TargetInstrInfo &TII,
- const Thumb1RegisterInfo& MRI,
- DebugLoc dl) {
+ const ARMBaseRegisterInfo& MRI,
+ unsigned MIFlags = MachineInstr::NoFlags) {
MachineFunction &MF = *MBB.getParent();
bool isHigh = !isARMLowRegister(DestReg) ||
(BaseReg != 0 && !isARMLowRegister(BaseReg));
unsigned LdReg = DestReg;
if (DestReg == ARM::SP) {
assert(BaseReg == ARM::SP && "Unexpected!");
- LdReg = MF.getRegInfo().createVirtualRegister(ARM::tGPRRegisterClass);
+ LdReg = MF.getRegInfo().createVirtualRegister(&ARM::tGPRRegClass);
}
if (NumBytes <= 255 && NumBytes >= 0)
AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVi8), LdReg))
- .addImm(NumBytes);
+ .addImm(NumBytes).setMIFlags(MIFlags);
else if (NumBytes < 0 && NumBytes >= -255) {
AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVi8), LdReg))
- .addImm(NumBytes);
+ .addImm(NumBytes).setMIFlags(MIFlags);
AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tRSB), LdReg))
- .addReg(LdReg, RegState::Kill);
+ .addReg(LdReg, RegState::Kill).setMIFlags(MIFlags);
} else
- MRI.emitLoadConstPool(MBB, MBBI, dl, LdReg, 0, NumBytes);
+ MRI.emitLoadConstPool(MBB, MBBI, dl, LdReg, 0, NumBytes,
+ ARMCC::AL, 0, MIFlags);
// Emit add / sub.
int Opc = (isSub) ? ARM::tSUBrr : (isHigh ? ARM::tADDhirr : ARM::tADDrr);
/// emitThumbRegPlusImmediate - Emits a series of instructions to materialize
/// a destreg = basereg + immediate in Thumb code.
-static
-void emitThumbRegPlusImmediate(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- unsigned DestReg, unsigned BaseReg,
- int NumBytes, const TargetInstrInfo &TII,
- const Thumb1RegisterInfo& MRI,
- DebugLoc dl) {
+void llvm::emitThumbRegPlusImmediate(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &MBBI,
+ DebugLoc dl,
+ unsigned DestReg, unsigned BaseReg,
+ int NumBytes, const TargetInstrInfo &TII,
+ const ARMBaseRegisterInfo& MRI,
+ unsigned MIFlags) {
bool isSub = NumBytes < 0;
unsigned Bytes = (unsigned)NumBytes;
if (isSub) Bytes = -NumBytes;
int Opc = 0;
int ExtraOpc = 0;
bool NeedCC = false;
- bool NeedPred = false;
if (DestReg == BaseReg && BaseReg == ARM::SP) {
assert(isMul4 && "Thumb sp inc / dec size must be multiple of 4!");
} else {
Opc = isSub ? ARM::tSUBi8 : ARM::tADDi8;
NumBits = 8;
- NeedPred = NeedCC = true;
+ NeedCC = true;
}
isTwoAddr = true;
}
if (NumMIs > Threshold) {
// This will expand into too many instructions. Load the immediate from a
// constpool entry.
- emitThumbRegPlusImmInReg(MBB, MBBI, DestReg, BaseReg, NumBytes, true, TII,
- MRI, dl);
+ emitThumbRegPlusImmInReg(MBB, MBBI, dl,
+ DestReg, BaseReg, NumBytes, true,
+ TII, MRI, MIFlags);
return;
}
unsigned Chunk = (1 << 3) - 1;
unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
Bytes -= ThisVal;
- const TargetInstrDesc &TID = TII.get(isSub ? ARM::tSUBi3 : ARM::tADDi3);
+ const MCInstrDesc &MCID = TII.get(isSub ? ARM::tSUBi3 : ARM::tADDi3);
const MachineInstrBuilder MIB =
- AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TID, DestReg));
+ AddDefaultT1CC(BuildMI(MBB, MBBI, dl, MCID, DestReg)
+ .setMIFlags(MIFlags));
AddDefaultPred(MIB.addReg(BaseReg, RegState::Kill).addImm(ThisVal));
} else {
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), DestReg)
- .addReg(BaseReg, RegState::Kill);
+ AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), DestReg)
+ .addReg(BaseReg, RegState::Kill))
+ .setMIFlags(MIFlags);
}
BaseReg = DestReg;
}
MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg);
if (NeedCC)
MIB = AddDefaultT1CC(MIB);
- MIB .addReg(DestReg).addImm(ThisVal);
- if (NeedPred)
- MIB = AddDefaultPred(MIB);
- }
- else {
+ MIB.addReg(DestReg).addImm(ThisVal);
+ MIB = AddDefaultPred(MIB);
+ MIB.setMIFlags(MIFlags);
+ } else {
bool isKill = BaseReg != ARM::SP;
MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg);
if (NeedCC)
MIB = AddDefaultT1CC(MIB);
MIB.addReg(BaseReg, getKillRegState(isKill)).addImm(ThisVal);
- if (NeedPred)
- MIB = AddDefaultPred(MIB);
- BaseReg = DestReg;
+ MIB = AddDefaultPred(MIB);
+ MIB.setMIFlags(MIFlags);
+ BaseReg = DestReg;
if (Opc == ARM::tADDrSPi) {
// r4 = add sp, imm
// r4 = add r4, imm
Scale = 1;
Chunk = ((1 << NumBits) - 1) * Scale;
Opc = isSub ? ARM::tSUBi8 : ARM::tADDi8;
- NeedPred = NeedCC = isTwoAddr = true;
+ NeedCC = isTwoAddr = true;
}
}
}
if (ExtraOpc) {
- const TargetInstrDesc &TID = TII.get(ExtraOpc);
- AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TID, DestReg))
+ const MCInstrDesc &MCID = TII.get(ExtraOpc);
+ AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, MCID, DestReg))
.addReg(DestReg, RegState::Kill)
- .addImm(((unsigned)NumBytes) & 3));
+ .addImm(((unsigned)NumBytes) & 3)
+ .setMIFlags(MIFlags));
}
}
-static void emitSPUpdate(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- const TargetInstrInfo &TII, DebugLoc dl,
- const Thumb1RegisterInfo &MRI,
- int NumBytes) {
- emitThumbRegPlusImmediate(MBB, MBBI, ARM::SP, ARM::SP, NumBytes, TII,
- MRI, dl);
-}
-
-void Thumb1RegisterInfo::
-eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I) const {
- if (!hasReservedCallFrame(MF)) {
- // If we have alloca, convert as follows:
- // ADJCALLSTACKDOWN -> sub, sp, sp, amount
- // ADJCALLSTACKUP -> add, sp, sp, amount
- MachineInstr *Old = I;
- DebugLoc dl = Old->getDebugLoc();
- unsigned Amount = Old->getOperand(0).getImm();
- if (Amount != 0) {
- // We need to keep the stack aligned properly. To do this, we round the
- // amount of space needed for the outgoing arguments up to the next
- // alignment boundary.
- unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
- Amount = (Amount+Align-1)/Align*Align;
-
- // Replace the pseudo instruction with a new instruction...
- unsigned Opc = Old->getOpcode();
- if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) {
- emitSPUpdate(MBB, I, TII, dl, *this, -Amount);
- } else {
- assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
- emitSPUpdate(MBB, I, TII, dl, *this, Amount);
- }
- }
- }
- MBB.erase(I);
-}
-
/// emitThumbConstant - Emit a series of instructions to materialize a
/// constant.
static void emitThumbConstant(MachineBasicBlock &MBB,
DestReg))
.addImm(ThisVal));
if (Imm > 0)
- emitThumbRegPlusImmediate(MBB, MBBI, DestReg, DestReg, Imm, TII, MRI, dl);
+ emitThumbRegPlusImmediate(MBB, MBBI, dl, DestReg, DestReg, Imm, TII, MRI);
if (isSub) {
- const TargetInstrDesc &TID = TII.get(ARM::tRSB);
- AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TID, DestReg))
+ const MCInstrDesc &MCID = TII.get(ARM::tRSB);
+ AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, MCID, DestReg))
.addReg(DestReg, RegState::Kill));
}
}
MI.RemoveOperand(Op);
}
-int Thumb1RegisterInfo::
-rewriteFrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
- unsigned FrameReg, int Offset,
- unsigned MOVOpc, unsigned ADDriOpc, unsigned SUBriOpc) const
-{
- // if/when eliminateFrameIndex() conforms with ARMBaseRegisterInfo
- // version then can pull out Thumb1 specific parts here
- return 0;
-}
-
-/// saveScavengerRegister - Spill the register so it can be used by the
-/// register scavenger. Return true.
-bool
-Thumb1RegisterInfo::saveScavengerRegister(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I,
- MachineBasicBlock::iterator &UseMI,
- const TargetRegisterClass *RC,
- unsigned Reg) const {
- // Thumb1 can't use the emergency spill slot on the stack because
- // ldr/str immediate offsets must be positive, and if we're referencing
- // off the frame pointer (if, for example, there are alloca() calls in
- // the function, the offset will be negative. Use R12 instead since that's
- // a call clobbered register that we know won't be used in Thumb1 mode.
- DebugLoc DL = DebugLoc::getUnknownLoc();
- BuildMI(MBB, I, DL, TII.get(ARM::tMOVtgpr2gpr)).
- addReg(ARM::R12, RegState::Define).addReg(Reg, RegState::Kill);
+/// convertToNonSPOpcode - Change the opcode to the non-SP version, because
+/// we're replacing the frame index with a non-SP register.
+static unsigned convertToNonSPOpcode(unsigned Opcode) {
+ switch (Opcode) {
+ case ARM::tLDRspi:
+ return ARM::tLDRi;
- // The UseMI is where we would like to restore the register. If there's
- // interference with R12 before then, however, we'll need to restore it
- // before that instead and adjust the UseMI.
- bool done = false;
- for (MachineBasicBlock::iterator II = I; !done && II != UseMI ; ++II) {
- // If this instruction affects R12, adjust our restore point.
- for (unsigned i = 0, e = II->getNumOperands(); i != e; ++i) {
- const MachineOperand &MO = II->getOperand(i);
- if (!MO.isReg() || MO.isUndef() || !MO.getReg() ||
- TargetRegisterInfo::isVirtualRegister(MO.getReg()))
- continue;
- if (MO.getReg() == ARM::R12) {
- UseMI = II;
- done = true;
- break;
- }
- }
+ case ARM::tSTRspi:
+ return ARM::tSTRi;
}
- // Restore the register from R12
- BuildMI(MBB, UseMI, DL, TII.get(ARM::tMOVgpr2tgpr)).
- addReg(Reg, RegState::Define).addReg(ARM::R12, RegState::Kill);
- return true;
+ return Opcode;
}
-unsigned
-Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
- int SPAdj, int *Value,
- RegScavenger *RS) const{
- unsigned VReg = 0;
- unsigned i = 0;
+bool Thumb1RegisterInfo::
+rewriteFrameIndex(MachineBasicBlock::iterator II, unsigned FrameRegIdx,
+ unsigned FrameReg, int &Offset,
+ const ARMBaseInstrInfo &TII) const {
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
- MachineFunction &MF = *MBB.getParent();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
DebugLoc dl = MI.getDebugLoc();
-
- while (!MI.getOperand(i).isFI()) {
- ++i;
- assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
- }
-
- unsigned FrameReg = ARM::SP;
- int FrameIndex = MI.getOperand(i).getIndex();
- int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
- MF.getFrameInfo()->getStackSize() + SPAdj;
-
- if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
- Offset -= AFI->getGPRCalleeSavedArea1Offset();
- else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
- Offset -= AFI->getGPRCalleeSavedArea2Offset();
- else if (MF.getFrameInfo()->hasVarSizedObjects()) {
- assert(SPAdj == 0 && hasFP(MF) && "Unexpected");
- // There are alloca()'s in this function, must reference off the frame
- // pointer instead.
- FrameReg = getFrameRegister(MF);
- Offset -= AFI->getFramePtrSpillOffset();
- }
-
+ MachineInstrBuilder MIB(*MBB.getParent(), &MI);
unsigned Opcode = MI.getOpcode();
- const TargetInstrDesc &Desc = MI.getDesc();
+ const MCInstrDesc &Desc = MI.getDesc();
unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
if (Opcode == ARM::tADDrSPi) {
- Offset += MI.getOperand(i+1).getImm();
+ Offset += MI.getOperand(FrameRegIdx+1).getImm();
// Can't use tADDrSPi if it's based off the frame pointer.
unsigned NumBits = 0;
unsigned Scale = 1;
if (FrameReg != ARM::SP) {
Opcode = ARM::tADDi3;
- MI.setDesc(TII.get(Opcode));
NumBits = 3;
} else {
NumBits = 8;
unsigned PredReg;
if (Offset == 0 && getInstrPredicate(&MI, PredReg) == ARMCC::AL) {
// Turn it into a move.
- MI.setDesc(TII.get(ARM::tMOVgpr2tgpr));
- MI.getOperand(i).ChangeToRegister(FrameReg, false);
- // Remove offset and remaining explicit predicate operands.
- do MI.RemoveOperand(i+1);
- while (MI.getNumOperands() > i+1 &&
- (!MI.getOperand(i+1).isReg() || !MI.getOperand(i+1).isImm()));
- return 0;
+ MI.setDesc(TII.get(ARM::tMOVr));
+ MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
+ // Remove offset
+ MI.RemoveOperand(FrameRegIdx+1);
+ return true;
}
// Common case: small offset, fits into instruction.
if (((Offset / Scale) & ~Mask) == 0) {
// Replace the FrameIndex with sp / fp
if (Opcode == ARM::tADDi3) {
- removeOperands(MI, i);
- MachineInstrBuilder MIB(&MI);
+ MI.setDesc(TII.get(Opcode));
+ removeOperands(MI, FrameRegIdx);
AddDefaultPred(AddDefaultT1CC(MIB).addReg(FrameReg)
.addImm(Offset / Scale));
} else {
- MI.getOperand(i).ChangeToRegister(FrameReg, false);
- MI.getOperand(i+1).ChangeToImmediate(Offset / Scale);
+ MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
+ MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset / Scale);
}
- return 0;
+ return true;
}
unsigned DestReg = MI.getOperand(0).getReg();
// MI would expand into a large number of instructions. Don't try to
// simplify the immediate.
if (NumMIs > 2) {
- emitThumbRegPlusImmediate(MBB, II, DestReg, FrameReg, Offset, TII,
- *this, dl);
+ emitThumbRegPlusImmediate(MBB, II, dl, DestReg, FrameReg, Offset, TII,
+ *this);
MBB.erase(II);
- return 0;
+ return true;
}
if (Offset > 0) {
// r0 = add sp, 255*4
// r0 = add r0, (imm - 255*4)
if (Opcode == ARM::tADDi3) {
- removeOperands(MI, i);
- MachineInstrBuilder MIB(&MI);
+ MI.setDesc(TII.get(Opcode));
+ removeOperands(MI, FrameRegIdx);
AddDefaultPred(AddDefaultT1CC(MIB).addReg(FrameReg).addImm(Mask));
} else {
- MI.getOperand(i).ChangeToRegister(FrameReg, false);
- MI.getOperand(i+1).ChangeToImmediate(Mask);
+ MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
+ MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Mask);
}
Offset = (Offset - Mask * Scale);
- MachineBasicBlock::iterator NII = llvm::next(II);
- emitThumbRegPlusImmediate(MBB, NII, DestReg, DestReg, Offset, TII,
- *this, dl);
+ MachineBasicBlock::iterator NII = std::next(II);
+ emitThumbRegPlusImmediate(MBB, NII, dl, DestReg, DestReg, Offset, TII,
+ *this);
} else {
// Translate r0 = add sp, -imm to
- // r0 = -imm (this is then translated into a series of instructons)
+ // r0 = -imm (this is then translated into a series of instructions)
// r0 = add r0, sp
emitThumbConstant(MBB, II, DestReg, Offset, TII, *this, dl);
MI.setDesc(TII.get(ARM::tADDhirr));
- MI.getOperand(i).ChangeToRegister(DestReg, false, false, true);
- MI.getOperand(i+1).ChangeToRegister(FrameReg, false);
- if (Opcode == ARM::tADDi3) {
- MachineInstrBuilder MIB(&MI);
- AddDefaultPred(MIB);
- }
+ MI.getOperand(FrameRegIdx).ChangeToRegister(DestReg, false, false, true);
+ MI.getOperand(FrameRegIdx+1).ChangeToRegister(FrameReg, false);
}
- return 0;
+ return true;
} else {
- unsigned ImmIdx = 0;
- int InstrOffs = 0;
- unsigned NumBits = 0;
- unsigned Scale = 1;
- switch (AddrMode) {
- case ARMII::AddrModeT1_s: {
- ImmIdx = i+1;
- InstrOffs = MI.getOperand(ImmIdx).getImm();
- NumBits = (FrameReg == ARM::SP) ? 8 : 5;
- Scale = 4;
- break;
- }
- default:
+ if (AddrMode != ARMII::AddrModeT1_s)
llvm_unreachable("Unsupported addressing mode!");
- break;
- }
+
+ unsigned ImmIdx = FrameRegIdx + 1;
+ int InstrOffs = MI.getOperand(ImmIdx).getImm();
+ unsigned NumBits = (FrameReg == ARM::SP) ? 8 : 5;
+ unsigned Scale = 4;
Offset += InstrOffs * Scale;
- assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
+ assert((Offset & (Scale - 1)) == 0 && "Can't encode this offset!");
// Common case: small offset, fits into instruction.
MachineOperand &ImmOp = MI.getOperand(ImmIdx);
int ImmedOffset = Offset / Scale;
unsigned Mask = (1 << NumBits) - 1;
+
if ((unsigned)Offset <= Mask * Scale) {
- // Replace the FrameIndex with sp
- MI.getOperand(i).ChangeToRegister(FrameReg, false);
+ // Replace the FrameIndex with the frame register (e.g., sp).
+ MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
ImmOp.ChangeToImmediate(ImmedOffset);
- return 0;
- }
- bool isThumSpillRestore = Opcode == ARM::tRestore || Opcode == ARM::tSpill;
- if (AddrMode == ARMII::AddrModeT1_s) {
- // Thumb tLDRspi, tSTRspi. These will change to instructions that use
- // a different base register.
- NumBits = 5;
- Mask = (1 << NumBits) - 1;
+ // If we're using a register where sp was stored, convert the instruction
+ // to the non-SP version.
+ unsigned NewOpc = convertToNonSPOpcode(Opcode);
+ if (NewOpc != Opcode && FrameReg != ARM::SP)
+ MI.setDesc(TII.get(NewOpc));
+
+ return true;
}
+
+ NumBits = 5;
+ Mask = (1 << NumBits) - 1;
+
// If this is a thumb spill / restore, we will be using a constpool load to
// materialize the offset.
- if (AddrMode == ARMII::AddrModeT1_s && isThumSpillRestore)
+ if (Opcode == ARM::tLDRspi || Opcode == ARM::tSTRspi) {
ImmOp.ChangeToImmediate(0);
- else {
+ } else {
// Otherwise, it didn't fit. Pull in what we can to simplify the immed.
ImmedOffset = ImmedOffset & Mask;
ImmOp.ChangeToImmediate(ImmedOffset);
- Offset &= ~(Mask*Scale);
+ Offset &= ~(Mask * Scale);
}
}
+ return Offset == 0;
+}
+
+void
+Thumb1RegisterInfo::resolveFrameIndex(MachineBasicBlock::iterator I,
+ unsigned BaseReg, int64_t Offset) const {
+ MachineInstr &MI = *I;
+ const ARMBaseInstrInfo &TII =
+ *static_cast<const ARMBaseInstrInfo*>(
+ MI.getParent()->getParent()->getTarget().getInstrInfo());
+ int Off = Offset; // ARM doesn't need the general 64-bit offsets
+ unsigned i = 0;
+
+ while (!MI.getOperand(i).isFI()) {
+ ++i;
+ assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
+ }
+ bool Done = rewriteFrameIndex(MI, i, BaseReg, Off, TII);
+ assert (Done && "Unable to resolve frame index!");
+ (void)Done;
+}
+
+/// saveScavengerRegister - Spill the register so it can be used by the
+/// register scavenger. Return true.
+bool
+Thumb1RegisterInfo::saveScavengerRegister(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I,
+ MachineBasicBlock::iterator &UseMI,
+ const TargetRegisterClass *RC,
+ unsigned Reg) const {
+ // Thumb1 can't use the emergency spill slot on the stack because
+ // ldr/str immediate offsets must be positive, and if we're referencing
+ // off the frame pointer (if, for example, there are alloca() calls in
+ // the function, the offset will be negative. Use R12 instead since that's
+ // a call clobbered register that we know won't be used in Thumb1 mode.
+ const TargetInstrInfo &TII = *MBB.getParent()->getTarget().getInstrInfo();
+ DebugLoc DL;
+ AddDefaultPred(BuildMI(MBB, I, DL, TII.get(ARM::tMOVr))
+ .addReg(ARM::R12, RegState::Define)
+ .addReg(Reg, RegState::Kill));
+
+ // The UseMI is where we would like to restore the register. If there's
+ // interference with R12 before then, however, we'll need to restore it
+ // before that instead and adjust the UseMI.
+ bool done = false;
+ for (MachineBasicBlock::iterator II = I; !done && II != UseMI ; ++II) {
+ if (II->isDebugValue())
+ continue;
+ // If this instruction affects R12, adjust our restore point.
+ for (unsigned i = 0, e = II->getNumOperands(); i != e; ++i) {
+ const MachineOperand &MO = II->getOperand(i);
+ if (MO.isRegMask() && MO.clobbersPhysReg(ARM::R12)) {
+ UseMI = II;
+ done = true;
+ break;
+ }
+ if (!MO.isReg() || MO.isUndef() || !MO.getReg() ||
+ TargetRegisterInfo::isVirtualRegister(MO.getReg()))
+ continue;
+ if (MO.getReg() == ARM::R12) {
+ UseMI = II;
+ done = true;
+ break;
+ }
+ }
+ }
+ // Restore the register from R12
+ AddDefaultPred(BuildMI(MBB, UseMI, DL, TII.get(ARM::tMOVr)).
+ addReg(Reg, RegState::Define).addReg(ARM::R12, RegState::Kill));
+
+ return true;
+}
+
+void
+Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
+ int SPAdj, unsigned FIOperandNum,
+ RegScavenger *RS) const {
+ unsigned VReg = 0;
+ MachineInstr &MI = *II;
+ MachineBasicBlock &MBB = *MI.getParent();
+ MachineFunction &MF = *MBB.getParent();
+ const ARMBaseInstrInfo &TII =
+ *static_cast<const ARMBaseInstrInfo*>(MF.getTarget().getInstrInfo());
+ ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
+ DebugLoc dl = MI.getDebugLoc();
+ MachineInstrBuilder MIB(*MBB.getParent(), &MI);
+
+ unsigned FrameReg = ARM::SP;
+ int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
+ int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
+ MF.getFrameInfo()->getStackSize() + SPAdj;
+
+ if (MF.getFrameInfo()->hasVarSizedObjects()) {
+ assert(SPAdj == 0 && MF.getTarget().getFrameLowering()->hasFP(MF) &&
+ "Unexpected");
+ // There are alloca()'s in this function, must reference off the frame
+ // pointer or base pointer instead.
+ if (!hasBasePointer(MF)) {
+ FrameReg = getFrameRegister(MF);
+ Offset -= AFI->getFramePtrSpillOffset();
+ } else
+ FrameReg = BasePtr;
+ }
+
+ // PEI::scavengeFrameVirtualRegs() cannot accurately track SPAdj because the
+ // call frame setup/destroy instructions have already been eliminated. That
+ // means the stack pointer cannot be used to access the emergency spill slot
+ // when !hasReservedCallFrame().
+#ifndef NDEBUG
+ if (RS && FrameReg == ARM::SP && RS->isScavengingFrameIndex(FrameIndex)){
+ assert(MF.getTarget().getFrameLowering()->hasReservedCallFrame(MF) &&
+ "Cannot use SP to access the emergency spill slot in "
+ "functions without a reserved call frame");
+ assert(!MF.getFrameInfo()->hasVarSizedObjects() &&
+ "Cannot use SP to access the emergency spill slot in "
+ "functions with variable sized frame objects");
+ }
+#endif // NDEBUG
+
+ // Special handling of dbg_value instructions.
+ if (MI.isDebugValue()) {
+ MI.getOperand(FIOperandNum). ChangeToRegister(FrameReg, false /*isDef*/);
+ MI.getOperand(FIOperandNum+1).ChangeToImmediate(Offset);
+ return;
+ }
+
+ // Modify MI as necessary to handle as much of 'Offset' as possible
+ assert(AFI->isThumbFunction() &&
+ "This eliminateFrameIndex only supports Thumb1!");
+ if (rewriteFrameIndex(MI, FIOperandNum, FrameReg, Offset, TII))
+ return;
+
// If we get here, the immediate doesn't fit into the instruction. We folded
// as much as possible above, handle the rest, providing a register that is
// SP+LargeImm.
assert(Offset && "This code isn't needed if offset already handled!");
+ unsigned Opcode = MI.getOpcode();
+
// Remove predicate first.
int PIdx = MI.findFirstPredOperandIdx();
if (PIdx != -1)
removeOperands(MI, PIdx);
- if (Desc.mayLoad()) {
+ if (MI.mayLoad()) {
// Use the destination register to materialize sp + offset.
unsigned TmpReg = MI.getOperand(0).getReg();
bool UseRR = false;
- if (Opcode == ARM::tRestore) {
+ if (Opcode == ARM::tLDRspi) {
if (FrameReg == ARM::SP)
- emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,
- Offset, false, TII, *this, dl);
+ emitThumbRegPlusImmInReg(MBB, II, dl, TmpReg, FrameReg,
+ Offset, false, TII, *this);
else {
emitLoadConstPool(MBB, II, dl, TmpReg, 0, Offset);
UseRR = true;
}
} else {
- emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII,
- *this, dl);
+ emitThumbRegPlusImmediate(MBB, II, dl, TmpReg, FrameReg, Offset, TII,
+ *this);
}
- MI.setDesc(TII.get(ARM::tLDR));
- MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
+ MI.setDesc(TII.get(UseRR ? ARM::tLDRr : ARM::tLDRi));
+ MI.getOperand(FIOperandNum).ChangeToRegister(TmpReg, false, false, true);
if (UseRR)
- // Use [reg, reg] addrmode.
- MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
- else // tLDR has an extra register operand.
- MI.addOperand(MachineOperand::CreateReg(0, false));
- } else if (Desc.mayStore()) {
- VReg = MF.getRegInfo().createVirtualRegister(ARM::tGPRRegisterClass);
- assert (Value && "Frame index virtual allocated, but Value arg is NULL!");
- *Value = Offset;
+ // Use [reg, reg] addrmode. Replace the immediate operand w/ the frame
+ // register. The offset is already handled in the vreg value.
+ MI.getOperand(FIOperandNum+1).ChangeToRegister(FrameReg, false, false,
+ false);
+ } else if (MI.mayStore()) {
+ VReg = MF.getRegInfo().createVirtualRegister(&ARM::tGPRRegClass);
bool UseRR = false;
- bool TrackVReg = FrameReg == ARM::SP;
- if (Opcode == ARM::tSpill) {
+ if (Opcode == ARM::tSTRspi) {
if (FrameReg == ARM::SP)
- emitThumbRegPlusImmInReg(MBB, II, VReg, FrameReg,
- Offset, false, TII, *this, dl);
+ emitThumbRegPlusImmInReg(MBB, II, dl, VReg, FrameReg,
+ Offset, false, TII, *this);
else {
emitLoadConstPool(MBB, II, dl, VReg, 0, Offset);
UseRR = true;
- TrackVReg = false;
}
} else
- emitThumbRegPlusImmediate(MBB, II, VReg, FrameReg, Offset, TII,
- *this, dl);
- MI.setDesc(TII.get(ARM::tSTR));
- MI.getOperand(i).ChangeToRegister(VReg, false, false, true);
- if (UseRR) // Use [reg, reg] addrmode.
- MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
- else // tSTR has an extra register operand.
- MI.addOperand(MachineOperand::CreateReg(0, false));
- if (!ReuseFrameIndexVals || !TrackVReg)
- VReg = 0;
- } else
- assert(false && "Unexpected opcode!");
-
- // Add predicate back if it's needed.
- if (MI.getDesc().isPredicable()) {
- MachineInstrBuilder MIB(&MI);
- AddDefaultPred(MIB);
- }
- return VReg;
-}
-
-void Thumb1RegisterInfo::emitPrologue(MachineFunction &MF) const {
- MachineBasicBlock &MBB = MF.front();
- MachineBasicBlock::iterator MBBI = MBB.begin();
- MachineFrameInfo *MFI = MF.getFrameInfo();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
- unsigned NumBytes = MFI->getStackSize();
- const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
- DebugLoc dl = (MBBI != MBB.end() ?
- MBBI->getDebugLoc() : DebugLoc::getUnknownLoc());
-
- // Thumb add/sub sp, imm8 instructions implicitly multiply the offset by 4.
- NumBytes = (NumBytes + 3) & ~3;
- MFI->setStackSize(NumBytes);
-
- // Determine the sizes of each callee-save spill areas and record which frame
- // belongs to which callee-save spill areas.
- unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
- int FramePtrSpillFI = 0;
-
- if (VARegSaveSize)
- emitSPUpdate(MBB, MBBI, TII, dl, *this, -VARegSaveSize);
-
- if (!AFI->hasStackFrame()) {
- if (NumBytes != 0)
- emitSPUpdate(MBB, MBBI, TII, dl, *this, -NumBytes);
- return;
- }
-
- for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
- unsigned Reg = CSI[i].getReg();
- int FI = CSI[i].getFrameIdx();
- switch (Reg) {
- case ARM::R4:
- case ARM::R5:
- case ARM::R6:
- case ARM::R7:
- case ARM::LR:
- if (Reg == FramePtr)
- FramePtrSpillFI = FI;
- AFI->addGPRCalleeSavedArea1Frame(FI);
- GPRCS1Size += 4;
- break;
- case ARM::R8:
- case ARM::R9:
- case ARM::R10:
- case ARM::R11:
- if (Reg == FramePtr)
- FramePtrSpillFI = FI;
- if (STI.isTargetDarwin()) {
- AFI->addGPRCalleeSavedArea2Frame(FI);
- GPRCS2Size += 4;
- } else {
- AFI->addGPRCalleeSavedArea1Frame(FI);
- GPRCS1Size += 4;
- }
- break;
- default:
- AFI->addDPRCalleeSavedAreaFrame(FI);
- DPRCSSize += 8;
- }
- }
-
- if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tPUSH) {
- ++MBBI;
- if (MBBI != MBB.end())
- dl = MBBI->getDebugLoc();
- }
-
- // Darwin ABI requires FP to point to the stack slot that contains the
- // previous FP.
- if (STI.isTargetDarwin() || hasFP(MF)) {
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tADDrSPi), FramePtr)
- .addFrameIndex(FramePtrSpillFI).addImm(0);
- }
-
- // Determine starting offsets of spill areas.
- unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
- unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
- unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
- AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + NumBytes);
- AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
- AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
- AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
-
- NumBytes = DPRCSOffset;
- if (NumBytes) {
- // Insert it after all the callee-save spills.
- emitSPUpdate(MBB, MBBI, TII, dl, *this, -NumBytes);
- }
-
- if (STI.isTargetELF() && hasFP(MF)) {
- MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
- AFI->getFramePtrSpillOffset());
- }
-
- AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
- AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
- AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
-}
-
-static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
- for (unsigned i = 0; CSRegs[i]; ++i)
- if (Reg == CSRegs[i])
- return true;
- return false;
-}
-
-static bool isCSRestore(MachineInstr *MI, const unsigned *CSRegs) {
- if (MI->getOpcode() == ARM::tRestore &&
- MI->getOperand(1).isFI() &&
- isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs))
- return true;
- else if (MI->getOpcode() == ARM::tPOP) {
- // The first three operands are predicates and such. The last two are
- // imp-def and imp-use of SP. Check everything in between.
- for (int i = 3, e = MI->getNumOperands() - 2; i != e; ++i)
- if (!isCalleeSavedRegister(MI->getOperand(i).getReg(), CSRegs))
- return false;
- return true;
- }
- return false;
-}
-
-void Thumb1RegisterInfo::emitEpilogue(MachineFunction &MF,
- MachineBasicBlock &MBB) const {
- MachineBasicBlock::iterator MBBI = prior(MBB.end());
- assert((MBBI->getOpcode() == ARM::tBX_RET ||
- MBBI->getOpcode() == ARM::tPOP_RET) &&
- "Can only insert epilog into returning blocks");
- DebugLoc dl = MBBI->getDebugLoc();
- MachineFrameInfo *MFI = MF.getFrameInfo();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
- int NumBytes = (int)MFI->getStackSize();
- const unsigned *CSRegs = getCalleeSavedRegs();
-
- if (!AFI->hasStackFrame()) {
- if (NumBytes != 0)
- emitSPUpdate(MBB, MBBI, TII, dl, *this, NumBytes);
+ emitThumbRegPlusImmediate(MBB, II, dl, VReg, FrameReg, Offset, TII,
+ *this);
+ MI.setDesc(TII.get(UseRR ? ARM::tSTRr : ARM::tSTRi));
+ MI.getOperand(FIOperandNum).ChangeToRegister(VReg, false, false, true);
+ if (UseRR)
+ // Use [reg, reg] addrmode. Replace the immediate operand w/ the frame
+ // register. The offset is already handled in the vreg value.
+ MI.getOperand(FIOperandNum+1).ChangeToRegister(FrameReg, false, false,
+ false);
} else {
- // Unwind MBBI to point to first LDR / VLDRD.
- if (MBBI != MBB.begin()) {
- do
- --MBBI;
- while (MBBI != MBB.begin() && isCSRestore(MBBI, CSRegs));
- if (!isCSRestore(MBBI, CSRegs))
- ++MBBI;
- }
-
- // Move SP to start of FP callee save spill area.
- NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
- AFI->getGPRCalleeSavedArea2Size() +
- AFI->getDPRCalleeSavedAreaSize());
-
- if (hasFP(MF)) {
- NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
- // Reset SP based on frame pointer only if the stack frame extends beyond
- // frame pointer stack slot or target is ELF and the function has FP.
- if (NumBytes)
- emitThumbRegPlusImmediate(MBB, MBBI, ARM::SP, FramePtr, -NumBytes,
- TII, *this, dl);
- else
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVtgpr2gpr), ARM::SP)
- .addReg(FramePtr);
- } else {
- if (MBBI->getOpcode() == ARM::tBX_RET &&
- &MBB.front() != MBBI &&
- prior(MBBI)->getOpcode() == ARM::tPOP) {
- MachineBasicBlock::iterator PMBBI = prior(MBBI);
- emitSPUpdate(MBB, PMBBI, TII, dl, *this, NumBytes);
- } else
- emitSPUpdate(MBB, MBBI, TII, dl, *this, NumBytes);
- }
+ llvm_unreachable("Unexpected opcode!");
}
- if (VARegSaveSize) {
- // Move back past the callee-saved register restoration
- while (MBBI != MBB.end() && isCSRestore(MBBI, CSRegs))
- ++MBBI;
- // Epilogue for vararg functions: pop LR to R3 and branch off it.
- AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tPOP)))
- .addReg(0) // No write back.
- .addReg(ARM::R3, RegState::Define);
-
- emitSPUpdate(MBB, MBBI, TII, dl, *this, VARegSaveSize);
-
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tBX_RET_vararg))
- .addReg(ARM::R3, RegState::Kill);
- // erase the old tBX_RET instruction
- MBB.erase(MBBI);
- }
+ // Add predicate back if it's needed.
+ if (MI.isPredicable())
+ AddDefaultPred(MIB);
}
projects / oota-llvm.git / blobdiff