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Win64: Stack alignment constraints aren't applied during SET_FPREG 

Stack realignment occurs after the prolog, not during, for Win64.
Because of this, don't factor in the maximum stack alignment when
establishing a frame pointer.

This fixes PR22572.

llvm-svn: 230113
This commit is contained in:
David Majnemer 2015-02-21 01:04:47 +00:00
parent dcc0eddd18
commit 89d0564b6a
3 changed files with 46 additions and 56 deletions
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59
llvm/lib/Target/X86/X86FrameLowering.cpp
View File

@ -458,7 +458,7 @@ static unsigned calculateSetFPREG(uint64_t SPAdjust) {
const uint64_t Win64MaxSEHOffset = 128;
uint64_t SEHFrameOffset = std::min(SPAdjust, Win64MaxSEHOffset);
// Win64 ABI requires 16-byte alignment for the UWOP_SET_FPREG opcode.
return static_cast<unsigned>(RoundUpToAlignment(SEHFrameOffset, 16));
return SEHFrameOffset & -16;
}
// If we're forcing a stack realignment we can't rely on just the frame
@ -672,14 +672,12 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
// If required, include space for extra hidden slot for stashing base pointer.
if (X86FI->getRestoreBasePointer())
FrameSize += SlotSize;
if (RegInfo->needsStackRealignment(MF)) {
// Callee-saved registers are pushed on stack before the stack
// is realigned.
FrameSize -= X86FI->getCalleeSavedFrameSize();
NumBytes = RoundUpToAlignment(FrameSize, MaxAlign);
} else {
NumBytes = FrameSize - X86FI->getCalleeSavedFrameSize();
}
NumBytes = FrameSize - X86FI->getCalleeSavedFrameSize();
// Callee-saved registers are pushed on stack before the stack is realigned.
if (RegInfo->needsStackRealignment(MF) && !IsWinEH)
NumBytes = RoundUpToAlignment(NumBytes, MaxAlign);
// Get the offset of the stack slot for the EBP register, which is
// guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
@ -801,7 +799,10 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
// 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 >= StackProbeSize && UseStackProbe) {
uint64_t AlignedNumBytes = NumBytes;
if (IsWinEH && RegInfo->needsStackRealignment(MF))
AlignedNumBytes = RoundUpToAlignment(AlignedNumBytes, MaxAlign);
if (AlignedNumBytes >= StackProbeSize && UseStackProbe) {
// Check whether EAX is livein for this function.
bool isEAXAlive = isEAXLiveIn(MF);
@ -1005,14 +1006,12 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
if (hasFP(MF)) {
// Calculate required stack adjustment.
uint64_t FrameSize = StackSize - SlotSize;
if (RegInfo->needsStackRealignment(MF)) {
// Callee-saved registers were pushed on stack before the stack
// was realigned.
FrameSize -= CSSize;
NumBytes = (FrameSize + MaxAlign - 1) / MaxAlign * MaxAlign;
} else {
NumBytes = FrameSize - CSSize;
}
NumBytes = FrameSize - CSSize;
// Callee-saved registers were pushed on stack before the stack was
// realigned.
if (RegInfo->needsStackRealignment(MF) && !IsWinEH)
NumBytes = RoundUpToAlignment(FrameSize, MaxAlign);
// Pop EBP.
BuildMI(MBB, MBBI, DL,
@ -1185,25 +1184,15 @@ int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF,
int64_t FPDelta = 0;
if (IsWinEH) {
uint64_t NumBytes = 0;
assert(!MFI->hasCalls() || (StackSize % 16) == 8);
// Calculate required stack adjustment.
uint64_t FrameSize = StackSize - SlotSize;
// If required, include space for extra hidden slot for stashing base pointer.
if (X86FI->getRestoreBasePointer())
FrameSize += SlotSize;
uint64_t SEHStackAllocAmt = StackSize;
if (RegInfo->needsStackRealignment(MF)) {
// Callee-saved registers are pushed on stack before the stack
// is realigned.
FrameSize -= CSSize;
uint64_t NumBytes = FrameSize - CSSize;
uint64_t MaxAlign =
calculateMaxStackAlign(MF); // Desired stack alignment.
NumBytes = RoundUpToAlignment(FrameSize, MaxAlign);
SEHStackAllocAmt = RoundUpToAlignment(SEHStackAllocAmt, 16);
} else {
NumBytes = FrameSize - CSSize;
}
uint64_t SEHFrameOffset = calculateSetFPREG(NumBytes);
if (FI && FI == X86FI->getFAIndex())
return -SEHFrameOffset;
@ -1212,7 +1201,9 @@ int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF,
// pointer followed by return address and the location required by the
// restricted Win64 prologue.
// Add FPDelta to all offsets below that go through the frame pointer.
FPDelta = SEHStackAllocAmt - SEHFrameOffset;
FPDelta = FrameSize - SEHFrameOffset;
assert((!MFI->hasCalls() || (FPDelta % 16) == 0) &&
"FPDelta isn't aligned per the Win64 ABI!");
}
@ -1237,8 +1228,6 @@ int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF,
} else {
if (!HasFP)
return Offset + StackSize;
if (IsWinEH)
return Offset + FPDelta;
// Skip the saved EBP.
Offset += SlotSize;
@ -1249,7 +1238,7 @@ int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF,
Offset -= TailCallReturnAddrDelta;
}
return Offset;
return Offset + FPDelta;
}
int X86FrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI,

20
llvm/test/CodeGen/X86/win64_eh.ll
View File

@ -150,18 +150,18 @@ entry:
; WIN64: .seh_pushreg 7
; WIN64: pushq %rbx
; WIN64: .seh_pushreg 3
; WIN64: subq $128, %rsp
; WIN64: .seh_stackalloc 128
; WIN64: leaq 128(%rsp), %rbp
; WIN64: .seh_setframe 5, 128
; WIN64: movaps %xmm7, -32(%rbp) # 16-byte Spill
; WIN64: .seh_savexmm 7, 96
; WIN64: movaps %xmm6, -48(%rbp) # 16-byte Spill
; WIN64: .seh_savexmm 6, 80
; WIN64: subq $96, %rsp
; WIN64: .seh_stackalloc 96
; WIN64: leaq 96(%rsp), %rbp
; WIN64: .seh_setframe 5, 96
; WIN64: movaps %xmm7, -16(%rbp) # 16-byte Spill
; WIN64: .seh_savexmm 7, 80
; WIN64: movaps %xmm6, -32(%rbp) # 16-byte Spill
; WIN64: .seh_savexmm 6, 64
; WIN64: .seh_endprologue
; WIN64: andq $-64, %rsp
; WIN64: movaps -48(%rbp), %xmm6 # 16-byte Reload
; WIN64: movaps -32(%rbp), %xmm7 # 16-byte Reload
; WIN64: movaps -32(%rbp), %xmm6 # 16-byte Reload
; WIN64: movaps -16(%rbp), %xmm7 # 16-byte Reload
; WIN64: leaq (%rbp), %rsp
; WIN64: popq %rbx
; WIN64: popq %rdi

23
llvm/test/CodeGen/X86/win64_frame.ll
View File

@ -9,10 +9,10 @@ define i32 @f1(i32 %p1, i32 %p2, i32 %p3, i32 %p4, i32 %p5) "no-frame-pointer-el
define void @f2(i32 %p, ...) "no-frame-pointer-elim"="true" {
; CHECK-LABEL: f2:
; CHECK: .seh_stackalloc 8
; CHECK: leaq 16(%rsp), %rbp
; CHECK: .seh_setframe 5, 16
; CHECK: movq %rdx, 16(%rbp)
; CHECK: leaq 16(%rbp), %rax
; CHECK: leaq (%rsp), %rbp
; CHECK: .seh_setframe 5, 0
; CHECK: movq %rdx, 32(%rbp)
; CHECK: leaq 32(%rbp), %rax
%ap = alloca i8, align 8
call void @llvm.va_start(i8* %ap)
ret void
@ -76,20 +76,21 @@ define i32 @f7(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e) "no-frame-pointer-elim"="
; CHECK-LABEL: f7:
; CHECK: pushq %rbp
; CHECK: .seh_pushreg 5
; CHECK: subq $320, %rsp
; CHECK: .seh_stackalloc 320
; CHECK: subq $304, %rsp
; CHECK: .seh_stackalloc 304
; CHECK: leaq 128(%rsp), %rbp
; CHECK: .seh_setframe 5, 128
; CHECK: movl 240(%rbp), %eax
; CHECK: leaq 192(%rbp), %rsp
; CHECK: andq $-64, %rsp
; CHECK: movl 224(%rbp), %eax
; CHECK: leaq 176(%rbp), %rsp
alloca [300 x i8], align 64
ret i32 %e
}
define i32 @f8(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e) "no-frame-pointer-elim"="true" {
; CHECK-LABEL: f8:
; CHECK: subq $384, %rsp
; CHECK: .seh_stackalloc 384
; CHECK: subq $352, %rsp
; CHECK: .seh_stackalloc 352
; CHECK: leaq 128(%rsp), %rbp
; CHECK: .seh_setframe 5, 128
@ -113,7 +114,7 @@ define i32 @f8(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e) "no-frame-pointer-elim"="
ret i32 %e
; CHECK: movl %esi, %eax
; CHECK: leaq 256(%rbp), %rsp
; CHECK: leaq 224(%rbp), %rsp
}
declare i8* @llvm.returnaddress(i32) nounwind readnone