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[Analysis] Avoid repeated hash lookups (NFC) #125462

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kazutakahirata
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@kazutakahirata kazutakahirata requested a review from nikic February 3, 2025 07:04
@llvmbot llvmbot added the llvm:analysis Includes value tracking, cost tables and constant folding label Feb 3, 2025
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llvmbot commented Feb 3, 2025

@llvm/pr-subscribers-llvm-analysis

Author: Kazu Hirata (kazutakahirata)

Changes

Full diff: https://github.com/llvm/llvm-project/pull/125462.diff

1 Files Affected:

  • (modified) llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h (+3-2)
diff --git a/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h b/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
index 6eb1aca1cf76ad..872746b7df5ca9 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
@@ -944,10 +944,11 @@ class SCEVLoopAddRecRewriter
       Operands.push_back(visit(Op));
 
     const Loop *L = Expr->getLoop();
-    if (0 == Map.count(L))
+    auto It = Map.find(L);
+    if (It == Map.end())
       return SE.getAddRecExpr(Operands, L, Expr->getNoWrapFlags());
 
-    return SCEVAddRecExpr::evaluateAtIteration(Operands, Map[L], SE);
+    return SCEVAddRecExpr::evaluateAtIteration(Operands, It->second, SE);
   }
 
 private:

@kazutakahirata kazutakahirata merged commit 36fb886 into llvm:main Feb 3, 2025
7 of 10 checks passed
@kazutakahirata kazutakahirata deleted the cleanup_001_repeated_hash_lookups_llvm_Analysis branch February 3, 2025 20:29
Icohedron pushed a commit to Icohedron/llvm-project that referenced this pull request Feb 11, 2025
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3 participants