[llvm] [SPIRV] Avoid repeated hash lookups (NFC) (PR #128398)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/128398

None

>From 9bf27456e2dd44a94adb58806d5a52811924126a Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Sat, 22 Feb 2025 02:30:04 -0800
Subject: [PATCH] [SPIRV] Avoid repeated hash lookups (NFC)

---
 llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h
index c7f846b8e9bcc..2b3599259a739 100644
--- a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h
+++ b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h
@@ -197,12 +197,10 @@ struct ModuleAnalysisInfo {
   // Convert MBB's number to corresponding ID register.
   Register getOrCreateMBBRegister(const MachineBasicBlock &MBB) {
     auto Key = std::make_pair(MBB.getParent(), MBB.getNumber());
-    auto It = BBNumToRegMap.find(Key);
-    if (It != BBNumToRegMap.end())
-      return It->second;
-    Register NewReg = Register::index2VirtReg(getNextID());
-    BBNumToRegMap[Key] = NewReg;
-    return NewReg;
+    auto [It, Inserted] = BBNumToRegMap.try_emplace(Key);
+    if (Inserted)
+      It->second = Register::index2VirtReg(getNextID());
+    return It->second;
   }
 };
 } // namespace SPIRV