[clang] [APINotes] Avoid repeated hash lookups (NFC) (PR #107959)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/107959.diff


1 Files Affected:

- (modified) clang/lib/APINotes/APINotesWriter.cpp (+3-7) 


``````````diff
diff --git a/clang/lib/APINotes/APINotesWriter.cpp b/clang/lib/APINotes/APINotesWriter.cpp
index 2f4e5e803f6a2b..a2b3669a314476 100644
--- a/clang/lib/APINotes/APINotesWriter.cpp
+++ b/clang/lib/APINotes/APINotesWriter.cpp
@@ -129,13 +129,9 @@ class APINotesWriter::Implementation {
     if (Identifier.empty())
       return 0;
 
-    auto Known = IdentifierIDs.find(Identifier);
-    if (Known != IdentifierIDs.end())
-      return Known->second;
-
-    // Add to the identifier table.
-    Known = IdentifierIDs.insert({Identifier, IdentifierIDs.size() + 1}).first;
-    return Known->second;
+    // Add to the identifier table if missing.
+    return IdentifierIDs.try_emplace(Identifier, IdentifierIDs.size() + 1)
+        .first->second;
   }
 
   /// Retrieve the ID for the given selector.

``````````

</details>


https://github.com/llvm/llvm-project/pull/107959