-//======- Thumb1FrameLowering.cpp - Thumb1 Frame Information ---*- C++ -*-====//
+//===-- Thumb1FrameLowering.cpp - Thumb1 Frame Information ----------------===//
//
// The LLVM Compiler Infrastructure
//
//===----------------------------------------------------------------------===//
#include "Thumb1FrameLowering.h"
-#include "ARMBaseInstrInfo.h"
#include "ARMMachineFunctionInfo.h"
+#include "llvm/CodeGen/LivePhysRegs.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
using namespace llvm;
+Thumb1FrameLowering::Thumb1FrameLowering(const ARMSubtarget &sti)
+ : ARMFrameLowering(sti) {}
+
bool Thumb1FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const{
const MachineFrameInfo *FFI = MF.getFrameInfo();
unsigned CFSize = FFI->getMaxCallFrameSize();
emitSPUpdate(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
const TargetInstrInfo &TII, DebugLoc dl,
- const Thumb1RegisterInfo &MRI,
+ const ThumbRegisterInfo &MRI,
int NumBytes, unsigned MIFlags = MachineInstr::NoFlags) {
emitThumbRegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes, TII,
MRI, MIFlags);
}
-void Thumb1FrameLowering::emitPrologue(MachineFunction &MF) const {
- MachineBasicBlock &MBB = MF.front();
+
+void Thumb1FrameLowering::
+eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I) const {
+ const Thumb1InstrInfo &TII =
+ *static_cast<const Thumb1InstrInfo *>(STI.getInstrInfo());
+ const ThumbRegisterInfo *RegInfo =
+ static_cast<const ThumbRegisterInfo *>(STI.getRegisterInfo());
+ 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 = 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, *RegInfo, -Amount);
+ } else {
+ assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
+ emitSPUpdate(MBB, I, TII, dl, *RegInfo, Amount);
+ }
+ }
+ }
+ MBB.erase(I);
+}
+
+void Thumb1FrameLowering::emitPrologue(MachineFunction &MF,
+ MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- const Thumb1RegisterInfo *RegInfo =
- static_cast<const Thumb1RegisterInfo*>(MF.getTarget().getRegisterInfo());
+ MachineModuleInfo &MMI = MF.getMMI();
+ const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
+ const ThumbRegisterInfo *RegInfo =
+ static_cast<const ThumbRegisterInfo *>(STI.getRegisterInfo());
const Thumb1InstrInfo &TII =
- *static_cast<const Thumb1InstrInfo*>(MF.getTarget().getInstrInfo());
+ *static_cast<const Thumb1InstrInfo *>(STI.getInstrInfo());
- unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
+ unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize();
unsigned NumBytes = MFI->getStackSize();
+ assert(NumBytes >= ArgRegsSaveSize &&
+ "ArgRegsSaveSize is included in NumBytes");
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
- DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+
+ // Debug location must be unknown since the first debug location is used
+ // to determine the end of the prologue.
+ DebugLoc dl;
+
unsigned FramePtr = RegInfo->getFrameRegister(MF);
unsigned BasePtr = RegInfo->getBaseRegister();
+ int CFAOffset = 0;
// Thumb add/sub sp, imm8 instructions implicitly multiply the offset by 4.
NumBytes = (NumBytes + 3) & ~3;
unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
int FramePtrSpillFI = 0;
- if (VARegSaveSize)
- emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -VARegSaveSize,
+ if (ArgRegsSaveSize) {
+ emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -ArgRegsSaveSize,
MachineInstr::FrameSetup);
+ CFAOffset -= ArgRegsSaveSize;
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
+ BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex)
+ .setMIFlags(MachineInstr::FrameSetup);
+ }
if (!AFI->hasStackFrame()) {
- if (NumBytes != 0)
- emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -NumBytes,
+ if (NumBytes - ArgRegsSaveSize != 0) {
+ emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -(NumBytes - ArgRegsSaveSize),
MachineInstr::FrameSetup);
+ CFAOffset -= NumBytes - ArgRegsSaveSize;
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
+ BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex)
+ .setMIFlags(MachineInstr::FrameSetup);
+ }
return;
}
unsigned Reg = CSI[i].getReg();
int FI = CSI[i].getFrameIdx();
switch (Reg) {
+ case ARM::R8:
+ case ARM::R9:
+ case ARM::R10:
+ case ARM::R11:
+ if (STI.isTargetMachO()) {
+ GPRCS2Size += 4;
+ break;
+ }
+ // fallthrough
case ARM::R4:
case ARM::R5:
case ARM::R6:
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();
}
// Determine starting offsets of spill areas.
- unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
+ unsigned DPRCSOffset = NumBytes - ArgRegsSaveSize - (GPRCS1Size + GPRCS2Size + DPRCSSize);
unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
- AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + NumBytes);
+ bool HasFP = hasFP(MF);
+ if (HasFP)
+ AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) +
+ NumBytes);
AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
NumBytes = DPRCSOffset;
+ int FramePtrOffsetInBlock = 0;
+ unsigned adjustedGPRCS1Size = GPRCS1Size;
+ if (tryFoldSPUpdateIntoPushPop(STI, MF, std::prev(MBBI), NumBytes)) {
+ FramePtrOffsetInBlock = NumBytes;
+ adjustedGPRCS1Size += NumBytes;
+ NumBytes = 0;
+ }
+
+ if (adjustedGPRCS1Size) {
+ CFAOffset -= adjustedGPRCS1Size;
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
+ BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex)
+ .setMIFlags(MachineInstr::FrameSetup);
+ }
+ for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
+ E = CSI.end(); I != E; ++I) {
+ unsigned Reg = I->getReg();
+ int FI = I->getFrameIdx();
+ switch (Reg) {
+ case ARM::R8:
+ case ARM::R9:
+ case ARM::R10:
+ case ARM::R11:
+ case ARM::R12:
+ if (STI.isTargetMachO())
+ break;
+ // fallthough
+ case ARM::R0:
+ case ARM::R1:
+ case ARM::R2:
+ case ARM::R3:
+ case ARM::R4:
+ case ARM::R5:
+ case ARM::R6:
+ case ARM::R7:
+ case ARM::LR:
+ unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
+ nullptr, MRI->getDwarfRegNum(Reg, true), MFI->getObjectOffset(FI)));
+ BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex)
+ .setMIFlags(MachineInstr::FrameSetup);
+ break;
+ }
+ }
+
// Adjust FP so it point to the stack slot that contains the previous FP.
- if (hasFP(MF)) {
+ if (HasFP) {
+ FramePtrOffsetInBlock +=
+ MFI->getObjectOffset(FramePtrSpillFI) + GPRCS1Size + ArgRegsSaveSize;
AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tADDrSPi), FramePtr)
- .addFrameIndex(FramePtrSpillFI).addImm(0)
+ .addReg(ARM::SP).addImm(FramePtrOffsetInBlock / 4)
.setMIFlags(MachineInstr::FrameSetup));
+ if(FramePtrOffsetInBlock) {
+ CFAOffset += FramePtrOffsetInBlock;
+ unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createDefCfa(
+ nullptr, MRI->getDwarfRegNum(FramePtr, true), CFAOffset));
+ BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex)
+ .setMIFlags(MachineInstr::FrameSetup);
+ } else {
+ unsigned CFIIndex =
+ MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
+ nullptr, MRI->getDwarfRegNum(FramePtr, true)));
+ BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex)
+ .setMIFlags(MachineInstr::FrameSetup);
+ }
if (NumBytes > 508)
// If offset is > 508 then sp cannot be adjusted in a single instruction,
// try restoring from fp instead.
AFI->setShouldRestoreSPFromFP(true);
}
- if (NumBytes)
+ if (NumBytes) {
// Insert it after all the callee-save spills.
emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -NumBytes,
MachineInstr::FrameSetup);
+ if (!HasFP) {
+ CFAOffset -= NumBytes;
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
+ BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex)
+ .setMIFlags(MachineInstr::FrameSetup);
+ }
+ }
- if (STI.isTargetELF() && hasFP(MF))
+ if (STI.isTargetELF() && HasFP)
MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
AFI->getFramePtrSpillOffset());
AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
+ // Thumb1 does not currently support dynamic stack realignment. Report a
+ // fatal error rather then silently generate bad code.
+ if (RegInfo->needsStackRealignment(MF))
+ report_fatal_error("Dynamic stack realignment not supported for thumb1.");
+
// If we need a base pointer, set it up here. It's whatever the value
// of the stack pointer is at this point. Any variable size objects
// will be allocated after this, so we can still use the base pointer
AFI->setShouldRestoreSPFromFP(true);
}
-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) {
+static bool isCSRestore(MachineInstr *MI, const MCPhysReg *CSRegs) {
if (MI->getOpcode() == ARM::tLDRspi &&
MI->getOperand(1).isFI() &&
isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs))
void Thumb1FrameLowering::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
- MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
- assert((MBBI->getOpcode() == ARM::tBX_RET ||
- MBBI->getOpcode() == ARM::tPOP_RET) &&
- "Can only insert epilog into returning blocks");
- DebugLoc dl = MBBI->getDebugLoc();
+ MachineBasicBlock::iterator MBBI = MBB.getFirstTerminator();
+ DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
MachineFrameInfo *MFI = MF.getFrameInfo();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- const Thumb1RegisterInfo *RegInfo =
- static_cast<const Thumb1RegisterInfo*>(MF.getTarget().getRegisterInfo());
+ const ThumbRegisterInfo *RegInfo =
+ static_cast<const ThumbRegisterInfo *>(STI.getRegisterInfo());
const Thumb1InstrInfo &TII =
- *static_cast<const Thumb1InstrInfo*>(MF.getTarget().getInstrInfo());
+ *static_cast<const Thumb1InstrInfo *>(STI.getInstrInfo());
- unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
+ unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize();
int NumBytes = (int)MFI->getStackSize();
- const unsigned *CSRegs = RegInfo->getCalleeSavedRegs();
+ assert((unsigned)NumBytes >= ArgRegsSaveSize &&
+ "ArgRegsSaveSize is included in NumBytes");
+ const MCPhysReg *CSRegs = RegInfo->getCalleeSavedRegs(&MF);
unsigned FramePtr = RegInfo->getFrameRegister(MF);
if (!AFI->hasStackFrame()) {
- if (NumBytes != 0)
- emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, NumBytes);
+ if (NumBytes - ArgRegsSaveSize != 0)
+ emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, NumBytes - ArgRegsSaveSize);
} else {
// Unwind MBBI to point to first LDR / VLDRD.
if (MBBI != MBB.begin()) {
// Move SP to start of FP callee save spill area.
NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
AFI->getGPRCalleeSavedArea2Size() +
- AFI->getDPRCalleeSavedAreaSize());
+ AFI->getDPRCalleeSavedAreaSize() +
+ ArgRegsSaveSize);
if (AFI->shouldRestoreSPFromFP()) {
NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
// frame pointer stack slot, the target is ELF and the function has FP, or
// the target uses var sized objects.
if (NumBytes) {
- assert(MF.getRegInfo().isPhysRegUsed(ARM::R4) &&
+ assert(!MFI->getPristineRegs(MF).test(ARM::R4) &&
"No scratch register to restore SP from FP!");
emitThumbRegPlusImmediate(MBB, MBBI, dl, ARM::R4, FramePtr, -NumBytes,
TII, *RegInfo);
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, *RegInfo, NumBytes);
- } else
+ if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tBX_RET &&
+ &MBB.front() != MBBI && std::prev(MBBI)->getOpcode() == ARM::tPOP) {
+ MachineBasicBlock::iterator PMBBI = std::prev(MBBI);
+ if (!tryFoldSPUpdateIntoPushPop(STI, MF, PMBBI, NumBytes))
+ emitSPUpdate(MBB, PMBBI, TII, dl, *RegInfo, NumBytes);
+ } else if (!tryFoldSPUpdateIntoPushPop(STI, MF, MBBI, NumBytes))
emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, NumBytes);
}
}
- if (VARegSaveSize) {
- // Unlike T2 and ARM mode, the T1 pop instruction cannot restore
- // to LR, and we can't pop the value directly to the PC since
- // we need to update the SP after popping the value. Therefore, we
- // pop the old LR into R3 as a temporary.
+ if (needPopSpecialFixUp(MF)) {
+ bool Done = emitPopSpecialFixUp(MBB, /* DoIt */ true);
+ (void)Done;
+ assert(Done && "Emission of the special fixup failed!?");
+ }
+}
+
+bool Thumb1FrameLowering::canUseAsEpilogue(const MachineBasicBlock &MBB) const {
+ if (!needPopSpecialFixUp(*MBB.getParent()))
+ return true;
- // 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(ARM::R3, RegState::Define);
+ MachineBasicBlock *TmpMBB = const_cast<MachineBasicBlock *>(&MBB);
+ return emitPopSpecialFixUp(*TmpMBB, /* DoIt */ false);
+}
- emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, VARegSaveSize);
+bool Thumb1FrameLowering::needPopSpecialFixUp(const MachineFunction &MF) const {
+ ARMFunctionInfo *AFI =
+ const_cast<MachineFunction *>(&MF)->getInfo<ARMFunctionInfo>();
+ if (AFI->getArgRegsSaveSize())
+ return true;
- AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tBX_RET_vararg))
- .addReg(ARM::R3, RegState::Kill));
+ bool IsV4PopReturn = false;
+ for (const CalleeSavedInfo &CSI : MF.getFrameInfo()->getCalleeSavedInfo())
+ if (CSI.getReg() == ARM::LR)
+ IsV4PopReturn = true;
+ return IsV4PopReturn && STI.hasV4TOps() && !STI.hasV5TOps();
+}
+
+bool Thumb1FrameLowering::emitPopSpecialFixUp(MachineBasicBlock &MBB,
+ bool DoIt) const {
+ MachineFunction &MF = *MBB.getParent();
+ ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
+ unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize();
+ const TargetInstrInfo &TII = *STI.getInstrInfo();
+ const ThumbRegisterInfo *RegInfo =
+ static_cast<const ThumbRegisterInfo *>(STI.getRegisterInfo());
+
+ // When we need a special fix up for POP, this means that
+ // we either cannot use PC in POP or we have to update
+ // SP after poping the return address.
+ // In other words, we cannot use a pop {pc} like construction
+ // here, no matter what.
+ auto MBBI = MBB.getFirstTerminator();
+
+ // Look for a temporary register to use.
+ // First, compute the liveness information.
+ LivePhysRegs UsedRegs(STI.getRegisterInfo());
+ UsedRegs.addLiveOuts(&MBB, /*AddPristines*/ true);
+ // The semantic of pristines changed recently and now,
+ // the callee-saved registers that are touched in the function
+ // are not part of the pristines set anymore.
+ // Add those callee-saved now.
+ const TargetRegisterInfo *TRI = STI.getRegisterInfo();
+ const MCPhysReg *CSRegs = TRI->getCalleeSavedRegs(&MF);
+ for (unsigned i = 0; CSRegs[i]; ++i)
+ UsedRegs.addReg(CSRegs[i]);
+
+ DebugLoc dl = DebugLoc();
+ if (MBBI != MBB.end()) {
+ dl = MBBI->getDebugLoc();
+ auto InstUpToMBBI = MBB.end();
+ // The post-decrement is on purpose here.
+ // We want to have the liveness right before MBBI.
+ while (InstUpToMBBI-- != MBBI)
+ UsedRegs.stepBackward(*InstUpToMBBI);
+ }
+
+ // Look for a register that can be directly use in the POP.
+ unsigned PopReg = 0;
+ // And some temporary register, just in case.
+ unsigned TemporaryReg = 0;
+ BitVector PopFriendly =
+ TRI->getAllocatableSet(MF, TRI->getRegClass(ARM::tGPRRegClassID));
+ assert(PopFriendly.any() && "No allocatable pop-friendly register?!");
+ // Rebuild the GPRs from the high registers because they are removed
+ // form the GPR reg class for thumb1.
+ BitVector GPRsNoLRSP =
+ TRI->getAllocatableSet(MF, TRI->getRegClass(ARM::hGPRRegClassID));
+ GPRsNoLRSP |= PopFriendly;
+ GPRsNoLRSP.reset(ARM::LR);
+ GPRsNoLRSP.reset(ARM::SP);
+ GPRsNoLRSP.reset(ARM::PC);
+ for (int Register = GPRsNoLRSP.find_first(); Register != -1;
+ Register = GPRsNoLRSP.find_next(Register)) {
+ if (!UsedRegs.contains(Register)) {
+ // Remember the first pop-friendly register and exit.
+ if (PopFriendly.test(Register)) {
+ PopReg = Register;
+ TemporaryReg = 0;
+ break;
+ }
+ // Otherwise, remember that the register will be available to
+ // save a pop-friendly register.
+ TemporaryReg = Register;
+ }
+ }
+
+ if (!DoIt && !PopReg && !TemporaryReg)
+ return false;
+
+ assert((PopReg || TemporaryReg) && "Cannot get LR");
+
+ if (TemporaryReg) {
+ assert(!PopReg && "Unnecessary MOV is about to be inserted");
+ PopReg = PopFriendly.find_first();
+ AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr))
+ .addReg(TemporaryReg, RegState::Define)
+ .addReg(PopReg, RegState::Kill));
+ }
+
+ assert(PopReg && "Do not know how to get LR");
+ AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tPOP)))
+ .addReg(PopReg, RegState::Define);
+
+ emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, ArgRegsSaveSize);
+
+ if (!TemporaryReg && MBBI != MBB.end() && MBBI->getOpcode() == ARM::tBX_RET) {
+ MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(ARM::tBX))
+ .addReg(PopReg, RegState::Kill);
+ AddDefaultPred(MIB);
+ MIB.copyImplicitOps(&*MBBI);
// erase the old tBX_RET instruction
MBB.erase(MBBI);
+ return true;
+ }
+
+ AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr))
+ .addReg(ARM::LR, RegState::Define)
+ .addReg(PopReg, RegState::Kill));
+
+ if (TemporaryReg) {
+ AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr))
+ .addReg(PopReg, RegState::Define)
+ .addReg(TemporaryReg, RegState::Kill));
}
+
+ return true;
}
bool Thumb1FrameLowering::
return false;
DebugLoc DL;
- MachineFunction &MF = *MBB.getParent();
- const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
-
- if (MI != MBB.end()) DL = MI->getDebugLoc();
+ const TargetInstrInfo &TII = *STI.getInstrInfo();
MachineInstrBuilder MIB = BuildMI(MBB, MI, DL, TII.get(ARM::tPUSH));
AddDefaultPred(MIB);
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+ const TargetInstrInfo &TII = *STI.getInstrInfo();
- bool isVarArg = AFI->getVarArgsRegSaveSize() > 0;
- DebugLoc DL = MI->getDebugLoc();
+ bool isVarArg = AFI->getArgRegsSaveSize() > 0;
+ DebugLoc DL = MI != MBB.end() ? MI->getDebugLoc() : DebugLoc();
MachineInstrBuilder MIB = BuildMI(MF, DL, TII.get(ARM::tPOP));
AddDefaultPred(MIB);
bool NumRegs = false;
for (unsigned i = CSI.size(); i != 0; --i) {
unsigned Reg = CSI[i-1].getReg();
- if (Reg == ARM::LR) {
+ if (Reg == ARM::LR && MBB.succ_empty()) {
// Special epilogue for vararg functions. See emitEpilogue
if (isVarArg)
continue;
+ // ARMv4T requires BX, see emitEpilogue
+ if (STI.hasV4TOps() && !STI.hasV5TOps())
+ continue;
Reg = ARM::PC;
(*MIB).setDesc(TII.get(ARM::tPOP_RET));
+ if (MI != MBB.end())
+ MIB.copyImplicitOps(&*MI);
MI = MBB.erase(MI);
}
MIB.addReg(Reg, getDefRegState(true));
projects / oota-llvm.git / blobdiff