Skip to content

[clang] Avoid evaluating the BitWidth expression over and over again #66203

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

[clang] Avoid evaluating the BitWidth expression over and over again #66203

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 8 additions & 0 deletions clang/lib/AST/Decl.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -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();
}

Expand Down