[llvm] [Utils] Avoid repeated hash lookups (NFC) (PR #136414)

Kazu Hirata via llvm-commits llvm-commits at lists.llvm.org
Sat Apr 19 01:14:00 PDT 2025


https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/136414

None

>From 274b6cfebb02568b9dd599dfa6992f3eeb03ede6 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Sat, 19 Apr 2025 00:56:35 -0700
Subject: [PATCH] [Utils] Avoid repeated hash lookups (NFC)

---
 .../Transforms/Utils/ScalarEvolutionExpander.cpp   | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
index 31d8acb706997..fb5e73727b2ef 100644
--- a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
@@ -1633,13 +1633,13 @@ void SCEVExpander::replaceCongruentIVInc(
   // If this phi has the same width but is more canonical, replace the
   // original with it. As part of the "more canonical" determination,
   // respect a prior decision to use an IV chain.
-  if (OrigPhi->getType() == Phi->getType() &&
-      !(ChainedPhis.count(Phi) ||
-        isExpandedAddRecExprPHI(OrigPhi, OrigInc, L)) &&
-      (ChainedPhis.count(Phi) ||
-       isExpandedAddRecExprPHI(Phi, IsomorphicInc, L))) {
-    std::swap(OrigPhi, Phi);
-    std::swap(OrigInc, IsomorphicInc);
+  if (OrigPhi->getType() == Phi->getType()) {
+    bool Chained = ChainedPhis.contains(Phi);
+    if (!(Chained || isExpandedAddRecExprPHI(OrigPhi, OrigInc, L)) &&
+        (Chained || isExpandedAddRecExprPHI(Phi, IsomorphicInc, L))) {
+      std::swap(OrigPhi, Phi);
+      std::swap(OrigInc, IsomorphicInc);
+    }
   }
 
   // Replacing the congruent phi is sufficient because acyclic



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