[clang] [Frontend] Avoid repeated hash lookups (NFC) (PR #108738)

[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/108738.diff


1 Files Affected:

- (modified) clang/lib/Frontend/Rewrite/RewriteObjC.cpp (+1-2) 


``````````diff
diff --git a/clang/lib/Frontend/Rewrite/RewriteObjC.cpp b/clang/lib/Frontend/Rewrite/RewriteObjC.cpp
index 9db6ddbf0b8908..fd5e8dc5298950 100644
--- a/clang/lib/Frontend/Rewrite/RewriteObjC.cpp
+++ b/clang/lib/Frontend/Rewrite/RewriteObjC.cpp
@@ -4111,9 +4111,8 @@ void RewriteObjC::RewriteBlockPointerDecl(NamedDecl *ND) {
 std::string RewriteObjC::SynthesizeByrefCopyDestroyHelper(VarDecl *VD,
                                                           int flag) {
   std::string S;
-  if (CopyDestroyCache.count(flag))
+  if (!CopyDestroyCache.insert(flag).second)
     return S;
-  CopyDestroyCache.insert(flag);
   S = "static void __Block_byref_id_object_copy_";
   S += utostr(flag);
   S += "(void *dst, void *src) {\n";

``````````

</details>


https://github.com/llvm/llvm-project/pull/108738