Hi,
On Mon, Aug 29 2022, Richard Biener wrote:
> On Fri, 26 Aug 2022, Martin Jambor wrote:
>
>> Hi,
>>
>> On Fri, Aug 26 2022, Richard Biener wrote:
>> >> Am 26.08.2022 um 18:39 schrieb Martin Jambor <mjam...@suse.cz>:
>> >>
>> >> Hi,
>> >>
>> >> This patch adds constructors of array_slice that are required to
>> >> create them from non-const (heap or auto) vectors or from GC vectors.
>> >>
>> >> The use of non-const array_slices is somewhat limited, as creating one
>> >> from const vec<some_type> still leads to array_slice<const some_type>,
>> >> so I eventually also only resorted to having read-only array_slices.
>> >> But I do need the constructor from the gc vector.
>> >>
>> >> Bootstrapped and tested along code that actually uses it on
>> >> x86_64-linux. OK for trunk?
>> >>
>> >> Thanks,
>> >>
>> >> Martin
>> >>
>> >>
>> >> gcc/ChangeLog:
>> >>
>> >> 2022-08-08 Martin Jambor <mjam...@suse.cz>
>> >>
>> >> * vec.h (array_slice): Add constructors for non-const reference to
>> >> heap vector and pointers to heap vectors.
>> >> ---
>> >> gcc/vec.h | 12 ++++++++++++
>> >> 1 file changed, 12 insertions(+)
>> >>
>> >> diff --git a/gcc/vec.h b/gcc/vec.h
>> >> index eed075addc9..b0477e1044c 100644
>> >> --- a/gcc/vec.h
>> >> +++ b/gcc/vec.h
>> >> @@ -2264,6 +2264,18 @@ public:
>> >> array_slice (const vec<OtherT> &v)
>> >> : m_base (v.address ()), m_size (v.length ()) {}
>> >>
>> >> + template<typename OtherT>
>> >> + array_slice (vec<OtherT> &v)
>> >> + : m_base (v.address ()), m_size (v.length ()) {}
>> >> +
>> >> + template<typename OtherT>
>> >> + array_slice (const vec<OtherT, va_gc> *v)
>> >> + : m_base (v ? v->address () : nullptr), m_size (v ? v->length () :
>> >> 0) {}
>> >> +
>> >> + template<typename OtherT>
>> >> + array_slice (vec<OtherT, va_gc> *v)
>> >> + : m_base (v ? v->address () : nullptr), m_size (v ? v->length () :
>> >> 0) {}
>> >> +
>> >
>> > I don?t quite understand why the generic ctor doesn?t cover the GC case.
>> > It looks more like reference vs pointer?
>> >
>>
>> If you think that this should work:
>>
>> vec<tree, va_gc> *heh = cfun->local_decls;
>> array_slice<tree> arr_slice (*heh);
>>
>> then it does not:
>>
>> /home/mjambor/gcc/mine/src/gcc/ipa-cp.cc:6693:36: error: no matching
>> function for call to ?array_slice<tree_node*>::array_slice(vec<tree_node*,
>> va_gc>&)?
>> 6693 | array_slice<tree> arr_slice (*heh);
>> | ^
>> In file included from /home/mjambor/gcc/mine/src/gcc/hash-table.h:248,
>> from /home/mjambor/gcc/mine/src/gcc/coretypes.h:486,
>> from /home/mjambor/gcc/mine/src/gcc/ipa-cp.cc:105:
>> /home/mjambor/gcc/mine/src/gcc/vec.h:2264:3: note: candidate:
>> ?template<class OtherT> array_slice<T>::array_slice(const vec<OtherT>&)
>> [with T = tree_node*]?
>> 2264 | array_slice (const vec<OtherT> &v)
>> | ^~~~~~~~~~~
>> /home/mjambor/gcc/mine/src/gcc/vec.h:2264:3: note: template argument
>> deduction/substitution failed:
>> /home/mjambor/gcc/mine/src/gcc/ipa-cp.cc:6693:36: note: mismatched types
>> ?va_heap? and ?va_gc?
>> 6693 | array_slice<tree> arr_slice (*heh);
>> | ^
>>
>> [... I trimmed notes about all other candidates...]
>>
>> Or did you mean something else?
>
> Hmm, so what if you change
>
> template<typename OtherT>
> array_slice (const vec<OtherT> &v)
> : m_base (v.address ()), m_size (v.length ()) {}
>
> to
>
> template<typename OtherT, typename l, typename a>
> array_slice (const vec<OtherT, l, a> &v)
> : m_base (v.address ()), m_size (v.length ()) {}
>
> instead? Thus allow any allocation / placement template arg?
I tried this on Friday night too (but I was already only half awake) and
it led to some very weird self-test ICEs (and so I went to bed).
(I can try again but debugging such things is not quite what I wanted to
spend my time on :-)
Martin
