[all-commits] [llvm/llvm-project] 7c6609: [msan] Simplify 'maskedCheckAVXIndexShadow' (#147839)

[Thurston Dang via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 7c66099545e84374d1df18da168ac12a4a9422cb
      https://github.com/llvm/llvm-project/commit/7c66099545e84374d1df18da168ac12a4a9422cb
  Author: Thurston Dang <thurston at google.com>
  Date:   2025-07-09 (Wed, 09 Jul 2025)

  Changed paths:
    M llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
    M llvm/test/Instrumentation/MemorySanitizer/X86/avx-intrinsics-x86.ll
    M llvm/test/Instrumentation/MemorySanitizer/X86/avx512-intrinsics-upgrade.ll
    M llvm/test/Instrumentation/MemorySanitizer/X86/avx512-intrinsics.ll
    M llvm/test/Instrumentation/MemorySanitizer/X86/avx512bw-intrinsics-upgrade.ll
    M llvm/test/Instrumentation/MemorySanitizer/X86/avx512bw-intrinsics.ll
    M llvm/test/Instrumentation/MemorySanitizer/X86/avx512vl-intrinsics.ll
    M llvm/test/Instrumentation/MemorySanitizer/X86/x86-vpermi2.ll
    M llvm/test/Instrumentation/MemorySanitizer/i386/avx-intrinsics-i386.ll

  Log Message:
  -----------
  [msan] Simplify 'maskedCheckAVXIndexShadow' (#147839)

The current instrumentation has more or and element extraction than a
coal mine:

```
[[TMP10:%.*]] = extractelement <16 x i32> [[TMP9]], i64 0
[[TMP11:%.*]] = and i32 [[TMP10]], 15
[[TMP43:%.*]] = or i32 [[TMP10]], [[TMP11]]
[[TMP12:%.*]] = extractelement <16 x i32> [[TMP9]], i64 1
[[TMP13:%.*]] = and i32 [[TMP12]], 15
[[TMP44:%.*]] = or i32 [[TMP12]], [[TMP13]]
    ...
[[TMP40:%.*]] = extractelement <16 x i32> [[TMP9]], i64 15
[[TMP41:%.*]] = and i32 [[TMP40]], 15
[[TMP57:%.*]] = or i32 [[TMP40]], [[TMP41]]
[[_MSCMP:%.*]] = icmp ne i32 [[TMP57]], 0
br i1 [[_MSCMP]], label [[TMP102:%.*]], label [[TMP103:%.*]], !prof [[PROF1]]
```

Simplify it to:

```
[[TMP10:%.*]] = trunc <16 x i32> [[T]] to <16 x i4>
[[TMP12:%.*]] = bitcast <16 x i4> [[TMP10]] to i64
[[_MSCMP:%.*]] = icmp ne i64 [[TMP12]], 0
br i1 [[_MSCMP]], label %[[BB13:.*]], label %[[BB14:.*]], !prof [[PROF1]]
```



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