[llvm] [Analysis] Avoid repeated hash lookups (NFC) (PR #126011)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/126011

None

>From d502cd4cd3af963451bee2b9af66d59c683dadd1 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Wed, 5 Feb 2025 21:31:03 -0800
Subject: [PATCH] [Analysis] Avoid repeated hash lookups (NFC)

---
 llvm/include/llvm/Analysis/BlockFrequencyInfoImpl.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/llvm/include/llvm/Analysis/BlockFrequencyInfoImpl.h b/llvm/include/llvm/Analysis/BlockFrequencyInfoImpl.h
index 7a7a9594f47603d..c0b6b526cd8f4df 100644
--- a/llvm/include/llvm/Analysis/BlockFrequencyInfoImpl.h
+++ b/llvm/include/llvm/Analysis/BlockFrequencyInfoImpl.h
@@ -1143,14 +1143,15 @@ void BlockFrequencyInfoImpl<BT>::calculate(const FunctionT &F,
 template <class BT>
 void BlockFrequencyInfoImpl<BT>::setBlockFreq(const BlockT *BB,
                                               BlockFrequency Freq) {
-  if (Nodes.count(BB))
+  auto [It, Inserted] = Nodes.try_emplace(BB);
+  if (!Inserted)
     BlockFrequencyInfoImplBase::setBlockFreq(getNode(BB), Freq);
   else {
     // If BB is a newly added block after BFI is done, we need to create a new
     // BlockNode for it assigned with a new index. The index can be determined
     // by the size of Freqs.
     BlockNode NewNode(Freqs.size());
-    Nodes[BB] = {NewNode, BFICallbackVH(BB, this)};
+    It->second = {NewNode, BFICallbackVH(BB, this)};
     Freqs.emplace_back();
     BlockFrequencyInfoImplBase::setBlockFreq(NewNode, Freq);
   }