[llvm] [AMDGPU] Avoid repeated hash lookups (NFC) (PR #128393)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/128393

None

>From e6e4757b3f94492edec7b568f060226abd17fa75 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Sat, 22 Feb 2025 02:29:40 -0800
Subject: [PATCH] [AMDGPU] Avoid repeated hash lookups (NFC)

---
 llvm/lib/Target/AMDGPU/SIFoldOperands.cpp | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
index fa15e73bc31d5..641365d319a50 100644
--- a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
+++ b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
@@ -1084,13 +1084,11 @@ void SIFoldOperandsImpl::foldOperand(
           }
 
           if (CopyToVGPR.Reg) {
-            Register Vgpr;
-            if (VGPRCopies.count(CopyToVGPR)) {
-              Vgpr = VGPRCopies[CopyToVGPR];
-            } else {
+            auto [It, Inserted] = VGPRCopies.try_emplace(CopyToVGPR);
+            Register &Vgpr = It->second;
+            if (Inserted) {
               Vgpr = MRI->createVirtualRegister(&AMDGPU::VGPR_32RegClass);
               BuildMI(MBB, UseMI, DL, TII->get(AMDGPU::COPY), Vgpr).add(*Def);
-              VGPRCopies[CopyToVGPR] = Vgpr;
             }
             auto Tmp = MRI->createVirtualRegister(&AMDGPU::AGPR_32RegClass);
             BuildMI(MBB, UseMI, DL,