[llvm] [Utils] Avoid repeated hash lookups (NFC) (PR #130892)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/130892.diff


1 Files Affected:

- (modified) llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp (+3-2) 


``````````diff
diff --git a/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp b/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
index 054b0ba2ba664..8470f0333d249 100644
--- a/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
@@ -400,9 +400,10 @@ llvm::UnrollAndJamLoop(Loop *L, unsigned Count, unsigned TripCount,
       Last = New;
       for (ValueToValueMapTy::iterator VI = VMap.begin(), VE = VMap.end();
            VI != VE; ++VI) {
+        auto &LVM = LastValueMap[VI->first];
         PrevItValueMap[VI->second] =
-            const_cast<Value *>(It == 1 ? VI->first : LastValueMap[VI->first]);
-        LastValueMap[VI->first] = VI->second;
+            const_cast<Value *>(It == 1 ? VI->first : LVM);
+        LVM = VI->second;
       }
 
       NewBlocks.push_back(New);

``````````

</details>


https://github.com/llvm/llvm-project/pull/130892