[llvm] 2df51fd - [Transforms] Avoid repeated hash lookups (NFC) (#132146)

[via llvm-commits]

Author: Kazu Hirata
Date: 2025-03-20T09:11:56-07:00
New Revision: 2df51fd9c491ef1ad90fbad5ce18ea8ff8bd3117

URL: https://github.com/llvm/llvm-project/commit/2df51fd9c491ef1ad90fbad5ce18ea8ff8bd3117
DIFF: https://github.com/llvm/llvm-project/commit/2df51fd9c491ef1ad90fbad5ce18ea8ff8bd3117.diff

LOG: [Transforms] Avoid repeated hash lookups (NFC) (#132146)

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 584da9b7baef5..8c40c3753a79a 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -4392,13 +4392,15 @@ void LoopVectorizationPlanner::emitInvalidCostRemarks(
   DenseMap<VPRecipeBase *, unsigned> Numbering;
   unsigned I = 0;
   for (auto &Pair : InvalidCosts)
-    if (!Numbering.count(Pair.first))
-      Numbering[Pair.first] = I++;
+    if (Numbering.try_emplace(Pair.first, I).second)
+      ++I;
 
   // Sort the list, first on recipe(number) then on VF.
   sort(InvalidCosts, [&Numbering](RecipeVFPair &A, RecipeVFPair &B) {
-    if (Numbering[A.first] != Numbering[B.first])
-      return Numbering[A.first] < Numbering[B.first];
+    unsigned NA = Numbering[A.first];
+    unsigned NB = Numbering[B.first];
+    if (NA != NB)
+      return NA < NB;
     return ElementCount::isKnownLT(A.second, B.second);
   });