}
}
+static bool isEAXLiveIn(MachineFunction &MF) {
+ for (MachineRegisterInfo::livein_iterator II = MF.getRegInfo().livein_begin(),
+ EE = MF.getRegInfo().livein_end(); II != EE; ++II) {
+ unsigned Reg = II->first;
+
+ if (Reg == X86::EAX || Reg == X86::AX ||
+ Reg == X86::AH || Reg == X86::AL)
+ return true;
+ }
+
+ return false;
+}
+
/// emitPrologue - Push callee-saved registers onto the stack, which
/// automatically adjust the stack pointer. Adjust the stack pointer to allocate
/// space for local variables. Also emit labels used by the exception handler to
!needsStackRealignment(MF) &&
!MFI->hasVarSizedObjects() && // No dynamic alloca.
!MFI->adjustsStack() && // No calls.
- !Subtarget->isTargetWin64()) { // Win64 has no Red Zone
+ !IsWin64) { // Win64 has no Red Zone
uint64_t MinSize = X86FI->getCalleeSavedFrameSize();
if (HasFP) MinSize += SlotSize;
StackSize = std::max(MinSize, StackSize > 128 ? StackSize - 128 : 0);
MFI->setStackSize(StackSize);
- } else if (Subtarget->isTargetWin64()) {
+ } else if (IsWin64) {
// We need to always allocate 32 bytes as register spill area.
// FIXME: We might reuse these 32 bytes for leaf functions.
StackSize += 32;
DL = MBB.findDebugLoc(MBBI);
+ // If there is an SUB32ri of ESP immediately before this instruction, merge
+ // the two. This can be the case when tail call elimination is enabled and
+ // the callee has more arguments then the caller.
+ NumBytes -= mergeSPUpdates(MBB, MBBI, StackPtr, true);
+
+ // If there is an ADD32ri or SUB32ri of ESP immediately after this
+ // instruction, merge the two instructions.
+ mergeSPUpdatesDown(MBB, MBBI, StackPtr, &NumBytes);
+
// Adjust stack pointer: ESP -= numbytes.
// Windows and cygwin/mingw require a prologue helper routine when allocating
// more than 4K bytes on the stack. Windows uses __chkstk and cygwin/mingw
- // uses __alloca. __alloca and the 32-bit version of __chkstk will probe
- // the stack and adjust the stack pointer in one go. The 64-bit version
- // of __chkstk is only responsible for probing the stack. The 64-bit
- // prologue is responsible for adjusting the stack pointer. Touching the
- // stack at 4K increments is necessary to ensure that the guard pages used
- // by the OS virtual memory manager are allocated in correct sequence.
+ // uses __alloca. __alloca and the 32-bit version of __chkstk will probe the
+ // stack and adjust the stack pointer in one go. The 64-bit version of
+ // __chkstk is only responsible for probing the stack. The 64-bit prologue is
+ // responsible for adjusting the stack pointer. Touching the stack at 4K
+ // increments is necessary to ensure that the guard pages used by the OS
+ // virtual memory manager are allocated in correct sequence.
if (NumBytes >= 4096 &&
(Subtarget->isTargetCygMing() || Subtarget->isTargetWin32())) {
- // Check, whether EAX is livein for this function.
- bool isEAXAlive = false;
- for (MachineRegisterInfo::livein_iterator
- II = MF.getRegInfo().livein_begin(),
- EE = MF.getRegInfo().livein_end(); (II != EE) && !isEAXAlive; ++II) {
- unsigned Reg = II->first;
- isEAXAlive = (Reg == X86::EAX || Reg == X86::AX ||
- Reg == X86::AH || Reg == X86::AL);
- }
-
+ // Check whether EAX is livein for this function.
+ bool isEAXAlive = isEAXLiveIn(MF);
const char *StackProbeSymbol =
Subtarget->isTargetWindows() ? "_chkstk" : "_alloca";
StackPtr, false, NumBytes - 4);
MBB.insert(MBBI, MI);
}
- } else if (NumBytes) {
- // If there is an SUB32ri of ESP immediately before this instruction, merge
- // the two. This can be the case when tail call elimination is enabled and
- // the callee has more arguments then the caller.
- NumBytes -= mergeSPUpdates(MBB, MBBI, StackPtr, true);
-
- // If there is an ADD32ri or SUB32ri of ESP immediately after this
- // instruction, merge the two instructions.
- mergeSPUpdatesDown(MBB, MBBI, StackPtr, &NumBytes);
-
- if (NumBytes)
- emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, TII);
- }
+ } else if (NumBytes >= 4096 && Subtarget->isTargetWin64()) {
+ // Sanity check that EAX is not livein for this function. It should
+ // should not be, so throw an assert.
+ assert(!isEAXLiveIn(MF) && "EAX is livein in the Win64 case!");
+
+ // 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::MOV32ri), X86::EAX)
+ .addImm(NumBytes);
+ BuildMI(MBB, MBBI, DL, TII.get(X86::WINCALL64pcrel32))
+ .addExternalSymbol("__chkstk")
+ .addReg(StackPtr, RegState::Define | RegState::Implicit);
+ emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, TII);
+ } else if (NumBytes)
+ emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, TII);
if ((NumBytes || PushedRegs) && needsFrameMoves) {
// Mark end of stack pointer adjustment.
projects / oota-llvm.git / commitdiff