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

Summary: This is a bug fix for further issues in PR43585.

Reviewers: rnk, RKSimon, craig.topper, andrew.w.kaylor

Subscribers: hiraditya, llvm-commits, annita.zhang

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70224

(cherry picked from commit 8723b95)

Author: phoebewang

llvm/lib/Target/X86/X86FrameLowering.cpp

@@ -1869,7 +1869,7 @@ int X86FrameLowering::getWin64EHFrameIndexRef(const MachineFunction &MF,
     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,

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

@@ -85,17 +85,17 @@ try.cont:                                         ; preds = %catchret.dest, %inv
 ; CHECK: subq    $88, %rsp
 ; CHECK: .seh_stackalloc 88
 ; CHECK: leaq    112(%rdx), %rbp
-; CHECK: vmovaps %xmm8, 48(%rsp)
-; CHECK: .seh_savexmm 8, 48
-; CHECK: vmovaps %xmm7, 64(%rsp)
-; CHECK: .seh_savexmm 7, 64
-; CHECK: vmovaps %xmm6, 80(%rsp)
-; CHECK: .seh_savexmm 6, 80
+; CHECK: vmovaps %xmm8, 32(%rsp)
+; CHECK: .seh_savexmm 8, 32
+; CHECK: vmovaps %xmm7, 48(%rsp)
+; CHECK: .seh_savexmm 7, 48
+; CHECK: vmovaps %xmm6, 64(%rsp)
+; CHECK: .seh_savexmm 6, 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