[llvm] [SelectionDAG] Avoid repeated hash lookups (NFC) (PR #128999)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-selectiondag

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/128999.diff


1 Files Affected:

- (modified) llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp (+3-2) 


``````````diff
diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 33c6341744478..95d0c39b84aba 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -343,9 +343,10 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
     for (auto &KV : EHInfo.UnwindDestToSrcs) {
       const auto *Dest = cast<const BasicBlock *>(KV.first);
       MachineBasicBlock *DestMBB = getMBB(Dest);
-      UnwindDestToSrcs[DestMBB] = SmallPtrSet<BBOrMBB, 4>();
+      auto &Srcs = UnwindDestToSrcs[DestMBB];
+      Srcs = SmallPtrSet<BBOrMBB, 4>();
       for (const auto P : KV.second)
-        UnwindDestToSrcs[DestMBB].insert(getMBB(cast<const BasicBlock *>(P)));
+        Srcs.insert(getMBB(cast<const BasicBlock *>(P)));
     }
     EHInfo.UnwindDestToSrcs = std::move(UnwindDestToSrcs);
   }

``````````

</details>


https://github.com/llvm/llvm-project/pull/128999