commit fe3e9c2b46504e7b197245b3946abfec563e77d4
author Kazu Hirata <kazu@google.com> Mon Mar 31 23:17:44 2025 -0700
committer GitHub <noreply@github.com> Mon Mar 31 23:17:44 2025 -0700
tree 8b1d058bcc0434919763839756dd3f97894ce7ec
parent d3be29642fa65e5ade434d860cfcc193f8278d4e

[Analysis] Avoid repeated hash lookups (NFC) (#133045)

llvm/lib/Analysis/ScalarEvolution.cpp

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 3612067..14f9a1b 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -15440,9 +15440,9 @@
       // Bail out, unless we have a non-wrapping, monotonic range.
       if (ExactRegion.isWrappedSet() || ExactRegion.isFullSet())
         return false;
-      auto I = RewriteMap.find(LHSUnknown);
-      const SCEV *RewrittenLHS = I != RewriteMap.end() ? I->second : LHSUnknown;
-      RewriteMap[LHSUnknown] = SE.getUMaxExpr(
+      auto [I, Inserted] = RewriteMap.try_emplace(LHSUnknown);
+      const SCEV *RewrittenLHS = Inserted ? LHSUnknown : I->second;
+      I->second = SE.getUMaxExpr(
           SE.getConstant(ExactRegion.getUnsignedMin()),
           SE.getUMinExpr(RewrittenLHS,
                          SE.getConstant(ExactRegion.getUnsignedMax())));