[llvm] 60aeea2 - [InstCombine] Fix uninitialized variable usage

[Benjamin Kramer via llvm-commits]

Author: Benjamin Kramer
Date: 2023-12-13T16:31:19+01:00
New Revision: 60aeea21fd885de1e03b354f455b91c47ed0d7e1

URL: https://github.com/llvm/llvm-project/commit/60aeea21fd885de1e03b354f455b91c47ed0d7e1
DIFF: https://github.com/llvm/llvm-project/commit/60aeea21fd885de1e03b354f455b91c47ed0d7e1.diff

LOG: [InstCombine] Fix uninitialized variable usage

m_Specific can only be used if the previous check suceeded. Found by
msan.

Added: 
    

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 104c736022236..1539fa9a3269e 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -4227,12 +4227,9 @@ InstCombinerImpl::foldCommutativeIntrinsicOverSelects(IntrinsicInst &II) {
   assert(II.isCommutative());
 
   Value *A, *B, *C;
-  bool LHSIsSelect =
-      match(II.getOperand(0), m_Select(m_Value(A), m_Value(B), m_Value(C)));
-  bool RHSIsSymmetricalSelect = match(
-      II.getOperand(1), m_Select(m_Specific(A), m_Specific(C), m_Specific(B)));
-
-  if (LHSIsSelect && RHSIsSymmetricalSelect) {
+  if (match(II.getOperand(0), m_Select(m_Value(A), m_Value(B), m_Value(C))) &&
+      match(II.getOperand(1),
+            m_Select(m_Specific(A), m_Specific(C), m_Specific(B)))) {
     replaceOperand(II, 0, B);
     replaceOperand(II, 1, C);
     return ⅈ