[llvm] [ReachingDefAnalysis] Simpilify `getGlobalReachingDefs` (PR #175169)

[Mikhail Gudim via llvm-commits]

https://github.com/mgudim created https://github.com/llvm/llvm-project/pull/175169

This call to getUniqueReachingMIDef` was an overkill. Replace it with simpler `getReachingLocalMIDef`.

>From 6ca40edb963515913ca97188d50a9483a0d454b8 Mon Sep 17 00:00:00 2001
From: Mikhail Gudim <mgudim at qti.qualcomm.com>
Date: Thu, 8 Jan 2026 15:01:22 -0800
Subject: [PATCH] [ReachingDefAnalysis] Simpilify `getGlobalReachingDefs`

This call to getUniqueReachingMIDef` was an overkill. Replace it with simpler
`getReachingLocalMIDef`.
---
 llvm/lib/CodeGen/ReachingDefAnalysis.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/CodeGen/ReachingDefAnalysis.cpp b/llvm/lib/CodeGen/ReachingDefAnalysis.cpp
index b12a5bc64ca0b..eb2e6b3944ddd 100644
--- a/llvm/lib/CodeGen/ReachingDefAnalysis.cpp
+++ b/llvm/lib/CodeGen/ReachingDefAnalysis.cpp
@@ -533,7 +533,8 @@ void ReachingDefInfo::getGlobalUses(MachineInstr *MI, Register Reg,
 
 void ReachingDefInfo::getGlobalReachingDefs(MachineInstr *MI, Register Reg,
                                             InstSet &Defs) const {
-  if (auto *Def = getUniqueReachingMIDef(MI, Reg)) {
+  // If there's a local def before MI, return it.
+  if (MachineInstr *LocalDef = getReachingLocalMIDef(MI, Reg);) {
     Defs.insert(Def);
     return;
   }