[Transforms] Avoid repeated hash lookups (NFC)

[kazutakahirata]

No description provided.

[llvmbot]

@llvm/pr-subscribers-mlir

@llvm/pr-subscribers-mlir-core

Author: Kazu Hirata (kazutakahirata)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/108322.diff

1 Files Affected:

• (modified) mlir/lib/Transforms/Mem2Reg.cpp (+1-2)

diff --git a/mlir/lib/Transforms/Mem2Reg.cpp b/mlir/lib/Transforms/Mem2Reg.cpp
index 4bc2bbd12b0945..144f9f01142a09 100644
--- a/mlir/lib/Transforms/Mem2Reg.cpp
+++ b/mlir/lib/Transforms/Mem2Reg.cpp
@@ -343,9 +343,8 @@ SmallPtrSet<Block *, 16> MemorySlotPromotionAnalyzer::computeSlotLiveIn(
   // blocks.
   SmallPtrSet<Block *, 16> visited;
   for (Operation *user : slot.ptr.getUsers()) {
-    if (visited.contains(user->getBlock()))
+    if (!visited.insert(user->getBlock()).second)
       continue;
-    visited.insert(user->getBlock());
 
     for (Operation &op : user->getBlock()->getOperations()) {
       if (auto memOp = dyn_cast<PromotableMemOpInterface>(op)) {