[llvm] [AMDGPU] Avoid repeated hash lookups (NFC) (PR #126001)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-amdgpu

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/126001.diff


1 Files Affected:

- (modified) llvm/lib/Target/AMDGPU/SILoadStoreOptimizer.cpp (+8-6) 


``````````diff
diff --git a/llvm/lib/Target/AMDGPU/SILoadStoreOptimizer.cpp b/llvm/lib/Target/AMDGPU/SILoadStoreOptimizer.cpp
index 904321a344db115..708acc9f88445a2 100644
--- a/llvm/lib/Target/AMDGPU/SILoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/AMDGPU/SILoadStoreOptimizer.cpp
@@ -2174,12 +2174,13 @@ bool SILoadStoreOptimizer::promoteConstantOffsetToImm(
 
   // Step1: Find the base-registers and a 64bit constant offset.
   MachineOperand &Base = *TII->getNamedOperand(MI, AMDGPU::OpName::vaddr);
+  auto [It, Inserted] = Visited.try_emplace(&MI);
   MemAddress MAddr;
-  if (!Visited.contains(&MI)) {
+  if (Inserted) {
     processBaseWithConstOffset(Base, MAddr);
-    Visited[&MI] = MAddr;
+    It->second = MAddr;
   } else
-    MAddr = Visited[&MI];
+    MAddr = It->second;
 
   if (MAddr.Offset == 0) {
     LLVM_DEBUG(dbgs() << "  Failed to extract constant-offset or there are no"
@@ -2239,11 +2240,12 @@ bool SILoadStoreOptimizer::promoteConstantOffsetToImm(
     const MachineOperand &BaseNext =
       *TII->getNamedOperand(MINext, AMDGPU::OpName::vaddr);
     MemAddress MAddrNext;
-    if (!Visited.contains(&MINext)) {
+    auto [It, Inserted] = Visited.try_emplace(&MINext);
+    if (Inserted) {
       processBaseWithConstOffset(BaseNext, MAddrNext);
-      Visited[&MINext] = MAddrNext;
+      It->second = MAddrNext;
     } else
-      MAddrNext = Visited[&MINext];
+      MAddrNext = It->second;
 
     if (MAddrNext.Base.LoReg != MAddr.Base.LoReg ||
         MAddrNext.Base.HiReg != MAddr.Base.HiReg ||

``````````

</details>


https://github.com/llvm/llvm-project/pull/126001