[llvm] [Utils] Avoid repeated hash lookups (NFC) (PR #126856)

[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/126856.diff


1 Files Affected:

- (modified) llvm/include/llvm/Transforms/Utils/SampleProfileLoaderBaseImpl.h (+6-4) 


``````````diff
diff --git a/llvm/include/llvm/Transforms/Utils/SampleProfileLoaderBaseImpl.h b/llvm/include/llvm/Transforms/Utils/SampleProfileLoaderBaseImpl.h
index d86630decd3ae..44cb5183fb31d 100644
--- a/llvm/include/llvm/Transforms/Utils/SampleProfileLoaderBaseImpl.h
+++ b/llvm/include/llvm/Transforms/Utils/SampleProfileLoaderBaseImpl.h
@@ -881,19 +881,21 @@ void SampleProfileLoaderBaseImpl<BT>::buildEdges(FunctionT &F) {
 
     // Add predecessors for B1.
     SmallPtrSet<BasicBlockT *, 16> Visited;
-    if (!Predecessors[B1].empty())
+    auto &Preds = Predecessors[B1];
+    if (!Preds.empty())
       llvm_unreachable("Found a stale predecessors list in a basic block.");
     for (auto *B2 : getPredecessors(B1))
       if (Visited.insert(B2).second)
-        Predecessors[B1].push_back(B2);
+        Preds.push_back(B2);
 
     // Add successors for B1.
     Visited.clear();
-    if (!Successors[B1].empty())
+    auto &Succs = Successors[B1];
+    if (!Succs.empty())
       llvm_unreachable("Found a stale successors list in a basic block.");
     for (auto *B2 : getSuccessors(B1))
       if (Visited.insert(B2).second)
-        Successors[B1].push_back(B2);
+        Succs.push_back(B2);
   }
 }
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/126856