[llvm] [CodeGen] Avoid repeated hash lookups (NFC) (PR #132585)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/132585

None

>From 57f2874c3e74244cf4042f1ac1c024df3749b777 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Sat, 22 Mar 2025 08:21:50 -0700
Subject: [PATCH] [CodeGen] Avoid repeated hash lookups (NFC)

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

diff --git a/llvm/include/llvm/CodeGen/MachinePipeliner.h b/llvm/include/llvm/CodeGen/MachinePipeliner.h
index 120b559c20305..fee6937e7d502 100644
--- a/llvm/include/llvm/CodeGen/MachinePipeliner.h
+++ b/llvm/include/llvm/CodeGen/MachinePipeliner.h
@@ -486,8 +486,9 @@ class NodeSet {
       if (PI.getSrc() != FirstNode || !PI.isOrderDep() ||
           !DAG->isLoopCarriedDep(PI))
         continue;
-      SUnitToDistance[FirstNode] =
-          std::max(SUnitToDistance[FirstNode], SUnitToDistance[LastNode] + 1);
+      unsigned &First = SUnitToDistance[FirstNode];
+      unsigned Last = SUnitToDistance[LastNode];
+      First = std::max(First, Last + 1);
     }
 
     // The latency is the distance from the source node to itself.