[clang] da3ea31 - [clang][bytecode] Avoid copying function call arguments (#218399)

[via cfe-commits]

Author: Timm Baeder
Date: 2026-08-24T16:48:31+02:00
New Revision: da3ea310333e17d1882efb633439602dea7c4460

URL: https://github.com/llvm/llvm-project/commit/da3ea310333e17d1882efb633439602dea7c4460
DIFF: https://github.com/llvm/llvm-project/commit/da3ea310333e17d1882efb633439602dea7c4460.diff

LOG: [clang][bytecode] Avoid copying function call arguments (#218399)

In most cases, we dony' need the SmallVector (we only use it to reverse
the arguments in the assignment operator case).

Added: 
    

Modified: 
    clang/lib/AST/ByteCode/Compiler.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index a6378cdf63243..3f641911895d2 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -6206,7 +6206,8 @@ bool Compiler<Emitter>::VisitCallExpr(const CallExpr *E) {
     }
   }
 
-  SmallVector<const Expr *, 8> Args(ArrayRef(E->getArgs(), E->getNumArgs()));
+  ArrayRef<const Expr *> Args(E->getArgs(), E->getNumArgs());
+  const Expr *ReversedArgs[2];
 
   bool IsAssignmentOperatorCall = false;
   bool ActivateLHS = false;
@@ -6219,7 +6220,9 @@ bool Compiler<Emitter>::VisitCallExpr(const CallExpr *E) {
     const CXXRecordDecl *LHSRecord = Args[0]->getType()->getAsCXXRecordDecl();
     ActivateLHS = LHSRecord && LHSRecord->hasTrivialDefaultConstructor();
     IsAssignmentOperatorCall = true;
-    std::reverse(Args.begin(), Args.end());
+    ReversedArgs[0] = Args[1];
+    ReversedArgs[1] = Args[0];
+    Args = ReversedArgs;
   }
   // Calling a static operator will still
   // pass the instance, but we don't need it.
@@ -6230,7 +6233,7 @@ bool Compiler<Emitter>::VisitCallExpr(const CallExpr *E) {
       if (!this->discard(E->getArg(0)))
         return false;
       // Drop first arg.
-      Args.erase(Args.begin());
+      Args = Args.drop_front();
     }
   }