[llvm] [CodeGen] Avoid repeated map lookups (NFC) (PR #140662)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/140662

None

>From e7d45ce2ee7e3fbd175ff59375f76862d3414032 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Mon, 19 May 2025 12:38:11 -0700
Subject: [PATCH] [CodeGen] Avoid repeated map lookups (NFC)

---
 llvm/lib/CodeGen/RDFLiveness.cpp | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/llvm/lib/CodeGen/RDFLiveness.cpp b/llvm/lib/CodeGen/RDFLiveness.cpp
index b0f0f2501515a..318422b46e811 100644
--- a/llvm/lib/CodeGen/RDFLiveness.cpp
+++ b/llvm/lib/CodeGen/RDFLiveness.cpp
@@ -603,11 +603,8 @@ void Liveness::computePhiInfo() {
       for (NodeAddr<DefNode *> D : Ds) {
         if (D.Addr->getFlags() & NodeAttrs::PhiRef) {
           NodeId RP = D.Addr->getOwner(DFG).Id;
-          std::map<NodeId, RegisterAggr> &M = PhiUp[PUA.Id];
-          auto F = M.find(RP);
-          if (F == M.end())
-            M.insert(std::make_pair(RP, DefRRs));
-          else
+          auto [F, Inserted] = PhiUp[PUA.Id].try_emplace(RP, DefRRs);
+          if (!Inserted)
             F->second.insert(DefRRs);
         }
         DefRRs.insert(D.Addr->getRegRef(DFG));