On Tue, Jul 30, 2019 at 10:07 AM Martin Liška <mli...@suse.cz> wrote:
>
> On 7/30/19 9:46 AM, Martin Liška wrote:
> > Anyway that's not a candidate for DCE. I'm testing following patch.
>
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>
> One alternative approach can be to drop DECL_SET_IS_OPERATOR_DELETE in:
> cat -n gcc/cp/decl.c | less
> ...
> 4410 deltype = cp_build_type_attribute_variant (deltype,
> extvisattr);
> 4411 deltype = build_exception_variant (deltype,
> empty_except_spec);
> 4412 opdel = push_cp_library_fn (DELETE_EXPR, deltype,
> ECF_NOTHROW);
> 4413 DECL_SET_IS_OPERATOR_DELETE (opdel, true);
> 4414 opdel = push_cp_library_fn (VEC_DELETE_EXPR, deltype,
> ECF_NOTHROW);
> 4415 DECL_SET_IS_OPERATOR_DELETE (opdel, true);
> 4416
> 4417 if (flag_sized_deallocation)
> 4418 {
> 4419 /* operator delete (void *, size_t, align_val_t); */
> 4420 deltype = build_function_type_list (void_type_node,
> ptr_type_node,
> 4421 size_type_node,
> align_type_node,
> 4422 NULL_TREE);
> 4423 deltype = cp_build_type_attribute_variant (deltype,
> extvisattr);
> 4424 deltype = build_exception_variant (deltype,
> empty_except_spec);
> 4425 opdel = push_cp_library_fn (DELETE_EXPR, deltype,
> ECF_NOTHROW);
> 4426 DECL_SET_IS_OPERATOR_DELETE (opdel, true);
> 4427 opdel = push_cp_library_fn (VEC_DELETE_EXPR, deltype,
> ECF_NOTHROW);
> 4428 DECL_SET_IS_OPERATOR_DELETE (opdel, true);
> 4429 }
> 4430 }
>
> at lines 4426 and 4428.
>
> Richi what do you prefer?
I don't understand why a "not simple" delete operator isn't fine to be
DCEd? Does C++
somehow allow mismatching size specifications here? And what's the semantics
then?
Thus I'd rather go with your earlier patch to mark the op necessary.
Richard.
> Martin
