[llvm] fe0c37f - [ADT] Avoid repeated hash lookups (NFC) (#125812)

[via llvm-commits]

Author: Kazu Hirata
Date: 2025-02-05T07:17:11-08:00
New Revision: fe0c37f0026dfd84aaeae01d4a2dec74e20a4e72

URL: https://github.com/llvm/llvm-project/commit/fe0c37f0026dfd84aaeae01d4a2dec74e20a4e72
DIFF: https://github.com/llvm/llvm-project/commit/fe0c37f0026dfd84aaeae01d4a2dec74e20a4e72.diff

LOG: [ADT] Avoid repeated hash lookups (NFC) (#125812)

Added: 
    

Modified: 
    llvm/include/llvm/ADT/GenericCycleImpl.h

Removed: 
    


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diff  --git a/llvm/include/llvm/ADT/GenericCycleImpl.h b/llvm/include/llvm/ADT/GenericCycleImpl.h
index 41ba8bf8fde14b3..4b2e01bcd9c53ee 100644
--- a/llvm/include/llvm/ADT/GenericCycleImpl.h
+++ b/llvm/include/llvm/ADT/GenericCycleImpl.h
@@ -454,7 +454,9 @@ void GenericCycleInfoCompute<ContextT>::dfs(BlockT *EntryBlock) {
     BlockT *Block = TraverseStack.back();
     LLVM_DEBUG(errs() << "DFS visiting block: " << Info.Context.print(Block)
                       << "\n");
-    if (!BlockDFSInfo.count(Block)) {
+    if (BlockDFSInfo.try_emplace(Block, Counter + 1).second) {
+      ++Counter;
+
       // We're visiting the block for the first time. Open its DFSInfo, add
       // successors to the traversal stack, and remember the traversal stack
       // depth at which the block was opened, so that we can correctly record
@@ -465,9 +467,6 @@ void GenericCycleInfoCompute<ContextT>::dfs(BlockT *EntryBlock) {
       DFSTreeStack.emplace_back(TraverseStack.size());
       llvm::append_range(TraverseStack, successors(Block));
 
-      bool Added = BlockDFSInfo.try_emplace(Block, ++Counter).second;
-      (void)Added;
-      assert(Added);
       BlockPreorder.push_back(Block);
       LLVM_DEBUG(errs() << "  preorder number: " << Counter << "\n");
     } else {