[llvm] [NFC][msan] Workaround arg evaluation order diff GCC vs Clang (PR #113378)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-llvm-transforms

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Vitaly Buka (vitalybuka)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/113378.diff


1 Files Affected:

- (modified) llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp (+6-6) 


``````````diff
diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index 9e174e2415e719..63810e875ae0a2 100644
--- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -2750,12 +2750,12 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     // its undefined bits. Let [b0, b1] be the interval of possible values of B.
     // Then (A cmp B) is defined iff (a0 cmp b1) == (a1 cmp b0).
     bool IsSigned = I.isSigned();
-    Value *S1 = IRB.CreateICmp(I.getPredicate(),
-                               getLowestPossibleValue(IRB, A, Sa, IsSigned),
-                               getHighestPossibleValue(IRB, B, Sb, IsSigned));
-    Value *S2 = IRB.CreateICmp(I.getPredicate(),
-                               getHighestPossibleValue(IRB, A, Sa, IsSigned),
-                               getLowestPossibleValue(IRB, B, Sb, IsSigned));
+    Value *Amin = getLowestPossibleValue(IRB, A, Sa, IsSigned);
+    Value *Bmax = getHighestPossibleValue(IRB, B, Sb, IsSigned);
+    Value *S1 = IRB.CreateICmp(I.getPredicate(), Amin, Bmax);
+    Value *Amax = getHighestPossibleValue(IRB, A, Sa, IsSigned);
+    Value *Bmin = getLowestPossibleValue(IRB, B, Sb, IsSigned);
+    Value *S2 = IRB.CreateICmp(I.getPredicate(), Amax, Bmin);
     Value *Si = IRB.CreateXor(S1, S2);
     setShadow(&I, Si);
     setOriginForNaryOp(I);

``````````

</details>


https://github.com/llvm/llvm-project/pull/113378