[llvm] [Scalar] Avoid repeated hash lookups (NFC) (PR #135751)

[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/135751.diff


1 Files Affected:

- (modified) llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp (+4-4) 


``````````diff
diff --git a/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp b/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
index f98a693804645..299aa3bebe58a 100644
--- a/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
+++ b/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
@@ -3332,10 +3332,10 @@ static void computeLiveInValues(DominatorTree &DT, Function &F,
     LiveTmp.set_subtract(Data.KillSet[BB]);
 
     assert(Data.LiveIn.count(BB));
-    const SetVector<Value *> &OldLiveIn = Data.LiveIn[BB];
-    // assert: OldLiveIn is a subset of LiveTmp
-    if (OldLiveIn.size() != LiveTmp.size()) {
-      Data.LiveIn[BB] = LiveTmp;
+    SetVector<Value *> &LiveIn = Data.LiveIn[BB];
+    // assert: LiveIn is a subset of LiveTmp
+    if (LiveIn.size() != LiveTmp.size()) {
+      LiveIn = std::move(LiveTmp);
       Worklist.insert_range(predecessors(BB));
     }
   } // while (!Worklist.empty())

``````````

</details>


https://github.com/llvm/llvm-project/pull/135751