[llvm] NaryReassociate: Check pattern before user scan (PR #134587)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Matt Arsenault (arsenm)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/134587.diff


1 Files Affected:

- (modified) llvm/lib/Transforms/Scalar/NaryReassociate.cpp (+6-6) 


``````````diff
diff --git a/llvm/lib/Transforms/Scalar/NaryReassociate.cpp b/llvm/lib/Transforms/Scalar/NaryReassociate.cpp
index 3b3f32a0ea591..ec17443b37143 100644
--- a/llvm/lib/Transforms/Scalar/NaryReassociate.cpp
+++ b/llvm/lib/Transforms/Scalar/NaryReassociate.cpp
@@ -611,15 +611,15 @@ Value *NaryReassociatePass::tryReassociateMinOrMax(Instruction *I,
   Value *A = nullptr, *B = nullptr;
   MaxMinT m_MaxMin(m_Value(A), m_Value(B));
 
+  if (!match(LHS, m_MaxMin))
+    return nullptr;
+
   if (LHS->hasNUsesOrMore(3) ||
       // The optimization is profitable only if LHS can be removed in the end.
       // In other words LHS should be used (directly or indirectly) by I only.
-      llvm::any_of(LHS->users(),
-                    [&](auto *U) {
-                      return U != I &&
-                             !(U->hasOneUser() && *U->users().begin() == I);
-                    }) ||
-      !match(LHS, m_MaxMin))
+      llvm::any_of(LHS->users(), [&](auto *U) {
+        return U != I && !(U->hasOneUser() && *U->users().begin() == I);
+      }))
     return nullptr;
 
   auto tryCombination = [&](Value *A, const SCEV *AExpr, Value *B,

``````````

</details>


https://github.com/llvm/llvm-project/pull/134587