carry out the same changes in the gcc backend

This commit is contained in:
Ralf Jung 2023-08-28 16:35:22 +02:00
parent dc70fb6528
commit 99d76a4027

View File

@ -182,23 +182,16 @@ impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> {
/// of that field's type - this is useful for taking the address of
/// that field and ensuring the struct has the right alignment.
fn gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc> {
// This must produce the same result for `repr(transparent)` wrappers as for the inner type!
// In other words, this should generally not look at the type at all, but only at the
// layout.
if let Abi::Scalar(ref scalar) = self.abi {
// Use a different cache for scalars because pointers to DSTs
// can be either fat or thin (data pointers of fat pointers).
if let Some(&ty) = cx.scalar_types.borrow().get(&self.ty) {
return ty;
}
let ty =
match *self.ty.kind() {
ty::Ref(_, ty, _) | ty::RawPtr(ty::TypeAndMut { ty, .. }) => {
cx.type_ptr_to(cx.layout_of(ty).gcc_type(cx))
}
ty::Adt(def, _) if def.is_box() => {
cx.type_ptr_to(cx.layout_of(self.ty.boxed_ty()).gcc_type(cx))
}
ty::FnPtr(sig) => cx.fn_ptr_backend_type(&cx.fn_abi_of_fn_ptr(sig, ty::List::empty())),
_ => self.scalar_gcc_type_at(cx, scalar, Size::ZERO),
};
let ty = self.scalar_gcc_type_at(cx, scalar, Size::ZERO);
cx.scalar_types.borrow_mut().insert(self.ty, ty);
return ty;
}
@ -273,22 +266,9 @@ impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> {
}
fn scalar_pair_element_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, index: usize, immediate: bool) -> Type<'gcc> {
// TODO(antoyo): remove llvm hack:
// HACK(eddyb) special-case fat pointers until LLVM removes
// pointee types, to avoid bitcasting every `OperandRef::deref`.
match self.ty.kind() {
ty::Ref(..) | ty::RawPtr(_) => {
return self.field(cx, index).gcc_type(cx);
}
// only wide pointer boxes are handled as pointers
// thin pointer boxes with scalar allocators are handled by the general logic below
ty::Adt(def, args) if def.is_box() && cx.layout_of(args.type_at(1)).is_zst() => {
let ptr_ty = Ty::new_mut_ptr(cx.tcx,self.ty.boxed_ty());
return cx.layout_of(ptr_ty).scalar_pair_element_gcc_type(cx, index, immediate);
}
_ => {}
}
// This must produce the same result for `repr(transparent)` wrappers as for the inner type!
// In other words, this should generally not look at the type at all, but only at the
// layout.
let (a, b) = match self.abi {
Abi::ScalarPair(ref a, ref b) => (a, b),
_ => bug!("TyAndLayout::scalar_pair_element_llty({:?}): not applicable", self),