[llvm] [CodeGen] Avoid repeated hash lookups (NFC) (PR #126852)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/126852

None

>From c7969c3982843f686916a3c0d207c1e34ffbff22 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Tue, 11 Feb 2025 09:13:00 -0800
Subject: [PATCH] [CodeGen] Avoid repeated hash lookups (NFC)

---
 llvm/include/llvm/CodeGen/MachinePipeliner.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/llvm/include/llvm/CodeGen/MachinePipeliner.h b/llvm/include/llvm/CodeGen/MachinePipeliner.h
index f95a02aad4559..0362b501ed347 100644
--- a/llvm/include/llvm/CodeGen/MachinePipeliner.h
+++ b/llvm/include/llvm/CodeGen/MachinePipeliner.h
@@ -468,9 +468,10 @@ class NodeSet {
         SUnit *SuccSUnit = Succ.getDst();
         if (V != SuccSUnit)
           continue;
-        if (SUnitToDistance[U] + Succ.getLatency() > SUnitToDistance[V]) {
-          SUnitToDistance[V] = SUnitToDistance[U] + Succ.getLatency();
-        }
+        unsigned &DU = SUnitToDistance[U];
+        unsigned &DV = SUnitToDistance[V];
+        if (DU + Succ.getLatency() > DV)
+          DV = DU + Succ.getLatency();
       }
     }
     // Handle a back-edge in loop carried dependencies