[llvm] [CodeGen] Avoid repeated hash lookups (NFC) (PR #132658)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/132658

None

>From 0af0aa6b631e59fcd4086479595eac00b4b7498c Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Sun, 23 Mar 2025 07:59:52 -0700
Subject: [PATCH] [CodeGen] Avoid repeated hash lookups (NFC)

---
 llvm/lib/CodeGen/WinEHPrepare.cpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/CodeGen/WinEHPrepare.cpp b/llvm/lib/CodeGen/WinEHPrepare.cpp
index 37f6726bafca9..74cef6c134736 100644
--- a/llvm/lib/CodeGen/WinEHPrepare.cpp
+++ b/llvm/lib/CodeGen/WinEHPrepare.cpp
@@ -448,11 +448,12 @@ static void calculateCXXStateNumbers(WinEHFuncInfo &FuncInfo,
 
     // It's possible for a cleanup to be visited twice: it might have multiple
     // cleanupret instructions.
-    if (FuncInfo.EHPadStateMap.count(CleanupPad))
+    auto [It, Inserted] = FuncInfo.EHPadStateMap.try_emplace(CleanupPad);
+    if (!Inserted)
       return;
 
     int CleanupState = addUnwindMapEntry(FuncInfo, ParentState, BB);
-    FuncInfo.EHPadStateMap[CleanupPad] = CleanupState;
+    It->second = CleanupState;
     LLVM_DEBUG(dbgs() << "Assigning state #" << CleanupState << " to BB "
                       << BB->getName() << '\n');
     for (const BasicBlock *PredBlock : predecessors(BB)) {
@@ -554,11 +555,12 @@ static void calculateSEHStateNumbers(WinEHFuncInfo &FuncInfo,
 
     // It's possible for a cleanup to be visited twice: it might have multiple
     // cleanupret instructions.
-    if (FuncInfo.EHPadStateMap.count(CleanupPad))
+    auto [It, Inserted] = FuncInfo.EHPadStateMap.try_emplace(CleanupPad);
+    if (!Inserted)
       return;
 
     int CleanupState = addSEHFinally(FuncInfo, ParentState, BB);
-    FuncInfo.EHPadStateMap[CleanupPad] = CleanupState;
+    It->second = CleanupState;
     LLVM_DEBUG(dbgs() << "Assigning state #" << CleanupState << " to BB "
                       << BB->getName() << '\n');
     for (const BasicBlock *PredBlock : predecessors(BB))