[SelectionDAG] Avoid repeated hash lookups (NFC)

kazutakahirata · kazutakahirata · commit 7447e0e0e96c · 2025-02-26T20:38:36.000-08:00
diff --git 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);
   }

Original file line number	Diff line number	Diff line change
`@@ -343,9 +343,10 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,`
`343`	`343`	`for (auto &KV : EHInfo.UnwindDestToSrcs) {`
`344`	`344`	`const auto Dest = cast<const BasicBlock >(KV.first);`
`345`	`345`	`MachineBasicBlock *DestMBB = getMBB(Dest);`
`346`		`- UnwindDestToSrcs[DestMBB] = SmallPtrSet<BBOrMBB, 4>();`
	`346`	`+ auto &Srcs = UnwindDestToSrcs[DestMBB];`
	`347`	`+ Srcs = SmallPtrSet<BBOrMBB, 4>();`
`347`	`348`	`for (const auto P : KV.second)`
`348`		`- UnwindDestToSrcs[DestMBB].insert(getMBB(cast<const BasicBlock *>(P)));`
	`349`	`+ Srcs.insert(getMBB(cast<const BasicBlock *>(P)));`
`349`	`350`	`}`
`350`	`351`	`EHInfo.UnwindDestToSrcs = std::move(UnwindDestToSrcs);`
`351`	`352`	`}`