https://github.com/tbaederr created
https://github.com/llvm/llvm-project/pull/66203:
It's usually a ConstantExpr with a saved constant integer anyway, so we can
just return that.
>From 7668b4e5eb09b05c50ef67b23671dc2d19e12046 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbae...@redhat.com>
Date: Wed, 13 Sep 2023 14:11:00 +0200
Subject: [PATCH] [clang] Avoid evaluating the BitWidth expression over and
over again
It's usually a ConstantExpr with a saved constant integer anyway, so we
can just return that.
---
clang/lib/AST/Decl.cpp | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 6109829cf20a678..0e964b7f1372227 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -4471,6 +4471,14 @@ void
FieldDecl::setLazyInClassInitializer(LazyDeclStmtPtr NewInit) {
unsigned FieldDecl::getBitWidthValue(const ASTContext &Ctx) const {
assert(isBitField() && "not a bitfield");
+
+ // Try to avoid evaluating the expression in the overwhelmingly
+ // common case that we have a ConstantExpr.
+ if (const auto *CE = dyn_cast<ConstantExpr>(getBitWidth())) {
+ assert(CE->hasAPValueResult());
+ return CE->getResultAsAPSInt().getZExtValue();
+ }
+
return getBitWidth()->EvaluateKnownConstInt(Ctx).getZExtValue();
}
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
