[llvm] 5d2393a - [InstCombine] Avoid repeated hash lookups (NFC) (#124243)

[via llvm-commits]

Author: Kazu Hirata
Date: 2025-01-24T08:09:20-08:00
New Revision: 5d2393a222c751723b0906485bf90a28dd4e564b

URL: https://github.com/llvm/llvm-project/commit/5d2393a222c751723b0906485bf90a28dd4e564b
DIFF: https://github.com/llvm/llvm-project/commit/5d2393a222c751723b0906485bf90a28dd4e564b.diff

LOG: [InstCombine] Avoid repeated hash lookups (NFC) (#124243)

Added: 
    

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index a9ae09b8dba438..6860a7cd07b780 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -3060,14 +3060,10 @@ Instruction *InstCombinerImpl::visitShuffleVectorInst(ShuffleVectorInst &SVI) {
       unsigned SrcElemsPerTgtElem = TgtElemBitWidth / SrcElemBitWidth;
       assert(SrcElemsPerTgtElem);
       BegIdx /= SrcElemsPerTgtElem;
-      bool BCAlreadyExists = NewBCs.contains(CastSrcTy);
-      auto *NewBC =
-          BCAlreadyExists
-              ? NewBCs[CastSrcTy]
-              : Builder.CreateBitCast(V, CastSrcTy, SVI.getName() + ".bc");
-      if (!BCAlreadyExists)
-        NewBCs[CastSrcTy] = NewBC;
-      auto *Ext = Builder.CreateExtractElement(NewBC, BegIdx,
+      auto [It, Inserted] = NewBCs.try_emplace(CastSrcTy);
+      if (Inserted)
+        It->second = Builder.CreateBitCast(V, CastSrcTy, SVI.getName() + ".bc");
+      auto *Ext = Builder.CreateExtractElement(It->second, BegIdx,
                                                SVI.getName() + ".extract");
       // The shufflevector isn't being replaced: the bitcast that used it
       // is. InstCombine will visit the newly-created instructions.