}
}
- uint64_t ThisVal = (Offset > Chunk) ? Chunk : Offset;
+ uint64_t ThisVal = std::min(Offset, Chunk);
if (ThisVal == (Is64BitTarget ? 8 : 4)) {
// Use push / pop instead.
unsigned Reg = isSub
- for 32-bit code, substitute %e?? registers for %r??
*/
-void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
- MachineBasicBlock &MBB = MF.front(); // Prologue goes in entry BB.
+void X86FrameLowering::emitPrologue(MachineFunction &MF,
+ MachineBasicBlock &MBB) const {
+ assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
const Function *Fn = MF.getFunction();
bool Is64Bit = STI.is64Bit();
// standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
const bool Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
- bool IsWin64 = STI.isTargetWin64();
+ bool IsWin64 = STI.isCallingConvWin64(Fn->getCallingConv());
// Not necessarily synonymous with IsWin64.
bool IsWinEH = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
bool NeedsWinEH = IsWinEH && Fn->needsUnwindTableEntry();
if (Is64Bit) {
// Handle the 64-bit Windows ABI case where we need to call __chkstk.
// Function prologue is responsible for adjusting the stack pointer.
- BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64ri), X86::RAX)
- .addImm(NumBytes)
- .setMIFlag(MachineInstr::FrameSetup);
+ if (isUInt<32>(NumBytes)) {
+ BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
+ .addImm(NumBytes)
+ .setMIFlag(MachineInstr::FrameSetup);
+ } else if (isInt<32>(NumBytes)) {
+ BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64ri32), X86::RAX)
+ .addImm(NumBytes)
+ .setMIFlag(MachineInstr::FrameSetup);
+ } else {
+ BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64ri), X86::RAX)
+ .addImm(NumBytes)
+ .setMIFlag(MachineInstr::FrameSetup);
+ }
} else {
// Allocate NumBytes-4 bytes on stack in case of isEAXAlive.
// We'll also use 4 already allocated bytes for EAX.
bool Is64Bit = STI.is64Bit();
// standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
const bool Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
+ bool HasFP = hasFP(MF);
const bool Is64BitILP32 = STI.isTarget64BitILP32();
- bool UseLEA = STI.useLeaForSP();
unsigned SlotSize = RegInfo->getSlotSize();
unsigned FramePtr = RegInfo->getFrameRegister(MF);
unsigned MachineFramePtr =
bool IsWinEH = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
bool NeedsWinEH = IsWinEH && MF.getFunction()->needsUnwindTableEntry();
+ bool UseLEAForSP = false;
+
+ // We can't use LEA instructions for adjusting the stack pointer if this is a
+ // leaf function in the Win64 ABI. Only ADD instructions may be used to
+ // deallocate the stack.
+ if (STI.useLeaForSP()) {
+ if (!IsWinEH) {
+ // We *aren't* using the Win64 ABI which means we are free to use LEA.
+ UseLEAForSP = true;
+ } else if (HasFP) {
+ // We *have* a frame pointer which means we are permitted to use LEA.
+ UseLEAForSP = true;
+ }
+ }
switch (RetOpcode) {
default:
if (RegInfo->needsStackRealignment(MF) || MFI->hasVarSizedObjects()) {
if (RegInfo->needsStackRealignment(MF))
MBBI = FirstCSPop;
- if (IsWinEH) {
- // There are only two legal forms of epilogue:
- // - add SEHAllocationSize, %rsp
- // - lea SEHAllocationSize(%FramePtr), %rsp
- //
- // We are *not* permitted to use 'mov %FramePtr, %rsp' because the Win64
- // unwinder will not recognize 'mov' as an epilogue instruction.
- unsigned SEHFrameOffset = calculateSetFPREG(SEHStackAllocAmt);
- addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(X86::LEA64r), StackPtr),
- FramePtr, false, SEHStackAllocAmt - SEHFrameOffset);
- --MBBI;
- } else if (CSSize != 0) {
+ unsigned SEHFrameOffset = calculateSetFPREG(SEHStackAllocAmt);
+ uint64_t LEAAmount = IsWinEH ? SEHStackAllocAmt - SEHFrameOffset : -CSSize;
+
+ // There are only two legal forms of epilogue:
+ // - add SEHAllocationSize, %rsp
+ // - lea SEHAllocationSize(%FramePtr), %rsp
+ //
+ // 'mov %FramePtr, %rsp' will not be recognized as an epilogue sequence.
+ // However, we may use this sequence if we have a frame pointer because the
+ // effects of the prologue can safely be undone.
+ if (LEAAmount != 0) {
unsigned Opc = getLEArOpcode(Uses64BitFramePtr);
addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr),
- FramePtr, false, -CSSize);
+ FramePtr, false, LEAAmount);
--MBBI;
} else {
unsigned Opc = (Uses64BitFramePtr ? X86::MOV64rr : X86::MOV32rr);
}
} else if (NumBytes) {
// Adjust stack pointer back: ESP += numbytes.
- emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, Uses64BitFramePtr, UseLEA,
- TII, *RegInfo);
+ emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, Uses64BitFramePtr,
+ UseLEAForSP, TII, *RegInfo);
--MBBI;
}
// Check for possible merge with preceding ADD instruction.
Offset += mergeSPUpdates(MBB, MBBI, StackPtr, true);
emitSPUpdate(MBB, MBBI, StackPtr, Offset, Is64Bit, Uses64BitFramePtr,
- UseLEA, TII, *RegInfo);
+ UseLEAForSP, TII, *RegInfo);
}
// Jump to label or value in register.
// Check for possible merge with preceding ADD instruction.
delta += mergeSPUpdates(MBB, MBBI, StackPtr, true);
- emitSPUpdate(MBB, MBBI, StackPtr, delta, Is64Bit, Uses64BitFramePtr, UseLEA, TII,
- *RegInfo);
+ emitSPUpdate(MBB, MBBI, StackPtr, delta, Is64Bit, Uses64BitFramePtr,
+ UseLEAForSP, TII, *RegInfo);
}
}
// limit.
static const uint64_t kSplitStackAvailable = 256;
-void
-X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
- MachineBasicBlock &prologueMBB = MF.front();
+void X86FrameLowering::adjustForSegmentedStacks(
+ MachineFunction &MF, MachineBasicBlock &PrologueMBB) const {
+ assert(&PrologueMBB == &MF.front() &&
+ "Shrink-wrapping is not implemented yet");
MachineFrameInfo *MFI = MF.getFrameInfo();
const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
const TargetInstrInfo &TII = *STI.getInstrInfo();
// The MOV R10, RAX needs to be in a different block, since the RET we emit in
// allocMBB needs to be last (terminating) instruction.
- for (MachineBasicBlock::livein_iterator i = prologueMBB.livein_begin(),
- e = prologueMBB.livein_end(); i != e; i++) {
+ for (MachineBasicBlock::livein_iterator i = PrologueMBB.livein_begin(),
+ e = PrologueMBB.livein_end();
+ i != e; i++) {
allocMBB->addLiveIn(*i);
checkMBB->addLiveIn(*i);
}
// This jump is taken if SP >= (Stacklet Limit + Stack Space required).
// It jumps to normal execution of the function body.
- BuildMI(checkMBB, DL, TII.get(X86::JA_1)).addMBB(&prologueMBB);
+ BuildMI(checkMBB, DL, TII.get(X86::JA_1)).addMBB(&PrologueMBB);
// On 32 bit we first push the arguments size and then the frame size. On 64
// bit, we pass the stack frame size in r10 and the argument size in r11.
else
BuildMI(allocMBB, DL, TII.get(X86::MORESTACK_RET));
- allocMBB->addSuccessor(&prologueMBB);
+ allocMBB->addSuccessor(&PrologueMBB);
checkMBB->addSuccessor(allocMBB);
- checkMBB->addSuccessor(&prologueMBB);
+ checkMBB->addSuccessor(&PrologueMBB);
#ifdef XDEBUG
MF.verify();
/// call inc_stack # doubles the stack space
/// temp0 = sp - MaxStack
/// if( temp0 < SP_LIMIT(P) ) goto IncStack else goto OldStart
-void X86FrameLowering::adjustForHiPEPrologue(MachineFunction &MF) const {
+void X86FrameLowering::adjustForHiPEPrologue(
+ MachineFunction &MF, MachineBasicBlock &PrologueMBB) const {
const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
const TargetInstrInfo &TII = *STI.getInstrInfo();
MachineFrameInfo *MFI = MF.getFrameInfo();
// If the stack frame needed is larger than the guaranteed then runtime checks
// and calls to "inc_stack_0" BIF should be inserted in the assembly prologue.
if (MaxStack > Guaranteed) {
- MachineBasicBlock &prologueMBB = MF.front();
+ assert(&PrologueMBB == &MF.front() &&
+ "Shrink-wrapping is not implemented yet");
MachineBasicBlock *stackCheckMBB = MF.CreateMachineBasicBlock();
MachineBasicBlock *incStackMBB = MF.CreateMachineBasicBlock();
- for (MachineBasicBlock::livein_iterator I = prologueMBB.livein_begin(),
- E = prologueMBB.livein_end(); I != E; I++) {
+ for (MachineBasicBlock::livein_iterator I = PrologueMBB.livein_begin(),
+ E = PrologueMBB.livein_end();
+ I != E; I++) {
stackCheckMBB->addLiveIn(*I);
incStackMBB->addLiveIn(*I);
}
// SPLimitOffset is in a fixed heap location (pointed by BP).
addRegOffset(BuildMI(stackCheckMBB, DL, TII.get(CMPop))
.addReg(ScratchReg), PReg, false, SPLimitOffset);
- BuildMI(stackCheckMBB, DL, TII.get(X86::JAE_1)).addMBB(&prologueMBB);
+ BuildMI(stackCheckMBB, DL, TII.get(X86::JAE_1)).addMBB(&PrologueMBB);
// Create new MBB for IncStack:
BuildMI(incStackMBB, DL, TII.get(CALLop)).
.addReg(ScratchReg), PReg, false, SPLimitOffset);
BuildMI(incStackMBB, DL, TII.get(X86::JLE_1)).addMBB(incStackMBB);
- stackCheckMBB->addSuccessor(&prologueMBB, 99);
+ stackCheckMBB->addSuccessor(&PrologueMBB, 99);
stackCheckMBB->addSuccessor(incStackMBB, 1);
- incStackMBB->addSuccessor(&prologueMBB, 99);
+ incStackMBB->addSuccessor(&PrologueMBB, 99);
incStackMBB->addSuccessor(incStackMBB, 1);
}
#ifdef XDEBUG
const X86RegisterInfo &RegInfo = *STI.getRegisterInfo();
unsigned StackPtr = RegInfo.getStackRegister();
bool reserveCallFrame = hasReservedCallFrame(MF);
- int Opcode = I->getOpcode();
+ unsigned Opcode = I->getOpcode();
bool isDestroy = Opcode == TII.getCallFrameDestroyOpcode();
bool IsLP64 = STI.isTarget64BitLP64();
DebugLoc DL = I->getDebugLoc();
projects / oota-llvm.git / blobdiff