[llvm] b47849b - [SCEV] Avoid repeated hash lookups (NFC) (#112656)

[via llvm-commits]

Author: Kazu Hirata
Date: 2024-10-17T07:46:32-07:00
New Revision: b47849b4cb01a88371536ed660ff4f8aa01512b2

URL: https://github.com/llvm/llvm-project/commit/b47849b4cb01a88371536ed660ff4f8aa01512b2
DIFF: https://github.com/llvm/llvm-project/commit/b47849b4cb01a88371536ed660ff4f8aa01512b2.diff

LOG: [SCEV] Avoid repeated hash lookups (NFC) (#112656)

Added: 
    

Modified: 
    llvm/lib/Analysis/ScalarEvolution.cpp

Removed: 
    


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diff  --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 3d028ab752f2ce..58e23e9556f144 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -9662,14 +9662,14 @@ Constant *
 ScalarEvolution::getConstantEvolutionLoopExitValue(PHINode *PN,
                                                    const APInt &BEs,
                                                    const Loop *L) {
-  auto I = ConstantEvolutionLoopExitValue.find(PN);
-  if (I != ConstantEvolutionLoopExitValue.end())
+  auto [I, Inserted] = ConstantEvolutionLoopExitValue.try_emplace(PN);
+  if (!Inserted)
     return I->second;
 
   if (BEs.ugt(MaxBruteForceIterations))
-    return ConstantEvolutionLoopExitValue[PN] = nullptr;  // Not going to evaluate it.
+    return nullptr; // Not going to evaluate it.
 
-  Constant *&RetVal = ConstantEvolutionLoopExitValue[PN];
+  Constant *&RetVal = I->second;
 
   DenseMap<Instruction *, Constant *> CurrentIterVals;
   BasicBlock *Header = L->getHeader();