On Fri, Dec 29, 2017 at 2:55 PM, Tom de Vries <tom_devr...@mentor.com> wrote:
> [ was: Re: [libgomp, openacc, openmp, PR83046] Prune removed funcs from
> offload table ]
>
> On 12/28/2017 05:06 PM, Jakub Jelinek wrote:
>>
>> On Thu, Dec 28, 2017 at 04:53:29PM +0100, Tom de Vries wrote:
>>>
>>> --- a/gcc/lto-cgraph.c
>>> +++ b/gcc/lto-cgraph.c
>>> @@ -1111,6 +1111,16 @@ output_offload_tables (void)
>>> struct lto_simple_output_block *ob
>>> = lto_create_simple_output_block (LTO_section_offload_table);
>>> + for (unsigned i = 0; i < vec_safe_length (offload_funcs);)
>>> + {
>>> + if (!cgraph_node::get ((*offload_funcs)[i]))
>>> + {
>>> + offload_funcs->ordered_remove (i);
>>> + continue;
>>> + }
>>> + i++;
>>> + }
>
>
>> This has O(n^2) complexity for n == vec_safe_length (offload_funcs).
>> Can't you instead just have 2 IVs, one for where we read the vector elt
>> and
>> one for where we write it if the 2 are different, then truncate the vector
>> if needed at the end?
>
>
> I wonder if it makes sense to add this function to the vec interface.
>
> Any comments?
Hmm. We do have quite some cases in the tree doing this kind of
operation - can you try finding one or two and see if it fits?
If we only could use lambdas here...
Oh, and I somehow miss a start/end index for operating on a vector part?
Richard.
> Thanks,
> - Tom
