[WinEH] Fix the wrong alignment orientation during calculating EH frame.

[pengfei]

Summary

This is a bug fix for further issues in PR43585.

[rnk]

lgtm

llvm/test/CodeGen/X86/win64-funclet-savexmm.ll

92

So, this was wrong, it was storing to memory at RSP+[80-96], which would overwrite pushq %rbx from above. Yikes.

[pengfei]

Hi @rnk, I guess we need to merge it to 9.0 branch, right? I haven't did such before, do I need wait for someone approval? Is there someone responsible for committing, or I can do it myself?

llvm/test/CodeGen/X86/win64-funclet-savexmm.ll

92

Sorry for the mistake.

[rnk]

In D70224#1746846, @pengfei wrote:

Hi @rnk, I guess we need to merge it to 9.0 branch, right? I haven't did such before, do I need wait for someone approval? Is there someone responsible for committing, or I can do it myself?

I don't know if there is a separate list of committers who can push to the release/9.x branch. I'd suggest trying it. Merging should be a matter of doing the following:

$ git pull # make sure up to date
$ git checkout release/9.x  # check out current 9.0.1 release, typically slow
$ git cherry-pick -x ${githash}  # cherry pick this patch. -x adds a note about the original hash.
$ git push ${remote} release/9.x  # push to the llvm github remote release/9.x branch

Fill in appropriate values of githash and remote. If it doesn't work, I'll give it a shot next week.

Thanks for following up! Bugs happen.

[pengfei]

Thanks for the detailed guidance. I have merged it to 9.0 branch now. Thank you!

[efriedma]

Anyone can commit to the release branch, yes, but nobody is supposed to unless the release manager approves. See http://llvm.org/docs/HowToReleaseLLVM.html#release-patch-rules .

I guess with the move to GitHub, we could start applying per-branch permissions to enforce that?

[pengfei]

Thanks for the reminding! I will follow this rule in future work.

llvm/lib/Target/X86/X86FrameLowering.cpp

int X86FrameLowering::getWin64EHFrameIndexRef(const MachineFunction &MF,
   const X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
   const auto& WinEHXMMSlotInfo = X86FI->getWinEHXMMSlotInfo();
   const auto it = WinEHXMMSlotInfo.find(FI);
 
   if (it == WinEHXMMSlotInfo.end())
     return getFrameIndexReference(MF, FI, FrameReg);
 
   FrameReg = TRI->getStackRegister();
-  return alignTo(MFI.getMaxCallFrameSize(), getStackAlignment()) + it->second;
+  return alignDown(MFI.getMaxCallFrameSize(), getStackAlignment()) + it->second;
 }
 
 int X86FrameLowering::getFrameIndexReferenceSP(const MachineFunction &MF,
                                                int FI, unsigned &FrameReg,
                                                int Adjustment) const {
   const MachineFrameInfo &MFI = MF.getFrameInfo();
   FrameReg = TRI->getStackRegister();
   return MFI.getObjectOffset(FI) - getOffsetOfLocalArea() + Adjustment;

llvm/test/CodeGen/X86/win64-funclet-savexmm.ll

 ; CHECK: movq    %rdx, 16(%rsp)
 ; CHECK: pushq   %rbp
 ; CHECK: .seh_pushreg %rbp
 ; CHECK: pushq   %rbx
 ; CHECK: .seh_pushreg %rbx
 ; CHECK: subq    $88, %rsp
 ; CHECK: .seh_stackalloc 88
 ; CHECK: leaq    112(%rdx), %rbp
-; CHECK: vmovaps %xmm8, 48(%rsp)
-; CHECK: .seh_savexmm %xmm8, 48
-; CHECK: vmovaps %xmm7, 64(%rsp)
-; CHECK: .seh_savexmm %xmm7, 64
-; CHECK: vmovaps %xmm6, 80(%rsp)
-; CHECK: .seh_savexmm %xmm6, 80
+; CHECK: vmovaps %xmm8, 32(%rsp)
+; CHECK: .seh_savexmm %xmm8, 32
+; CHECK: vmovaps %xmm7, 48(%rsp)
+; CHECK: .seh_savexmm %xmm7, 48
+; CHECK: vmovaps %xmm6, 64(%rsp)
+; CHECK: .seh_savexmm %xmm6, 64
 ; CHECK: .seh_endprologue
 ; CHECK: movl   -{{[0-9]+}}(%rbp), %ecx
-; CHECK: vmovaps 80(%rsp), %xmm6
-; CHECK: vmovaps 64(%rsp), %xmm7
-; CHECK: vmovaps 48(%rsp), %xmm8
+; CHECK: vmovaps 64(%rsp), %xmm6
+; CHECK: vmovaps 48(%rsp), %xmm7
+; CHECK: vmovaps 32(%rsp), %xmm8
 ; CHECK: leaq    .LBB0_1(%rip), %rax
 ; CHECK: addq    $88, %rsp
 ; CHECK: popq    %rbx
 ; CHECK: popq    %rbp
 ; CHECK: retq # CATCHRET
 
 ; CHECK-LABEL: "$handlerMap$0$?foo@@YAXHHHHH@Z":
 ; CHECK-NEXT: .long   64                      # Adjectives