[llvm] [CodeGen] Avoid aligning alloca size. (PR #132064)

[via llvm-commits]

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@@ -114,7 +114,7 @@ define void @f5() {
 ; CHECK-NEXT:    lgr %r11, %r15
 ; CHECK-NEXT:    .cfi_def_cfa_register %r11
 ; CHECK-NEXT:    lgr %r1, %r15
-; CHECK-NEXT:    aghi %r1, -128
+; CHECK-NEXT:    aghi %r1, -124
 ; CHECK-NEXT:    la %r2, 280(%r1)
 ; CHECK-NEXT:    nill %r2, 65408
 ; CHECK-NEXT:    lgr %r15, %r1
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jcogan-nv wrote:

Off hand I am surprised my change has kicked in for this test since it is a static alloca:
```
void SelectionDAGBuilder::visitAlloca(const AllocaInst &I) {
  // If this is a fixed sized alloca in the entry block of the function,
  // allocate it statically on the stack.
  if (FuncInfo.StaticAllocaMap.count(&I))
    return;   // getValue will auto-populate this.
```

I expected this return to be reached but it is not. I will investigate further and get back once I understand the issue.

https://github.com/llvm/llvm-project/pull/132064