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

[Kazu Hirata via llvm-commits]

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

>From 7447e0e0e96c976062596a4470e733d1146d506c Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Wed, 26 Feb 2025 07:43:26 -0800
Subject: [PATCH 1/2] [SelectionDAG] Avoid repeated hash lookups (NFC)

---
 llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

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);
   }

>From dccb94f1432fdbd79e37d1014169487aae2a06d4 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Wed, 26 Feb 2025 21:32:16 -0800
Subject: [PATCH 2/2] Address a comment.

---
 llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 95d0c39b84aba..8bc288f1d29fc 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -344,7 +344,6 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
       const auto *Dest = cast<const BasicBlock *>(KV.first);
       MachineBasicBlock *DestMBB = getMBB(Dest);
       auto &Srcs = UnwindDestToSrcs[DestMBB];
-      Srcs = SmallPtrSet<BBOrMBB, 4>();
       for (const auto P : KV.second)
         Srcs.insert(getMBB(cast<const BasicBlock *>(P)));
     }