[clang] e579632 - [clang] Avoid unnecessary call to clang::NamespaceDecl::isRedundantInlineQualifierFor(). (#115196)

[via cfe-commits]

Author: Zequan Wu
Date: 2024-11-08T14:18:45-05:00
New Revision: e5796321cee0f6b3c2fbf33813d6b3af1ddd8f18

URL: https://github.com/llvm/llvm-project/commit/e5796321cee0f6b3c2fbf33813d6b3af1ddd8f18
DIFF: https://github.com/llvm/llvm-project/commit/e5796321cee0f6b3c2fbf33813d6b3af1ddd8f18.diff

LOG: [clang] Avoid unnecessary call to clang::NamespaceDecl::isRedundantInlineQualifierFor(). (#115196)

We observed 2X slowdown in lldb's expression evaluation with
https://github.com/llvm/llvm-project/pull/109147 in some cases. It turns
out that calling `isRedundantInlineQualifierFor` is quite expensive.
Using short-circuit evaluation in the if statement to avoid unnecessary
calls to that function.

Added: 
    

Modified: 
    clang/lib/AST/Decl.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 047f354b200745..f33d2fb1530d17 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -1738,13 +1738,12 @@ void NamedDecl::printNestedNameSpecifier(raw_ostream &OS,
 
     // Suppress inline namespace if it doesn't make the result ambiguous.
     if (Ctx->isInlineNamespace() && NameInScope) {
-      bool isRedundant =
-          cast<NamespaceDecl>(Ctx)->isRedundantInlineQualifierFor(NameInScope);
       if (P.SuppressInlineNamespace ==
               PrintingPolicy::SuppressInlineNamespaceMode::All ||
           (P.SuppressInlineNamespace ==
                PrintingPolicy::SuppressInlineNamespaceMode::Redundant &&
-           isRedundant)) {
+           cast<NamespaceDecl>(Ctx)->isRedundantInlineQualifierFor(
+               NameInScope))) {
         continue;
       }
     }