On 27 May 2013 09:21, Manu <turkey...@gmail.com> wrote:
> Actually, I think the C counterpart is actually
> __attribute__((__target__("targetstring"))), with bonus underscores ;)
>
>
> On 27 May 2013 18:15, Manu <turkey...@gmail.com> wrote:
>>
>> So we talked about this at DConf.
>>
>> Working on std.simd, I need to be able to change the target parameter on a
>> per-function basis.
>> GCC supports this via: __attribute__((target("sse2"))) for instance.
>>
>> I need the ability to set this from D, but the trick is, I need to be able
>> to set the target string according to a template arg.
>>
>> Eg:
>> enum Targets { SSE2, SSE3 };
>> enum targets[] = [ "sse2", "sse3" ];
>>
>> @attribute("target", targets[T]) // <- attribute needs to refer to the
>> template arg T
>> void func(Targets T)();
>>
>>
I'll turn on rudimentary support, as the backend takes care of pretty
much all the work. But I think this should work as UDAs work off CTFE
with string manipulation.
>> {
>> // this way, it is possibly to produce dynamic selection of code paths
>> optimised for different CPU features (a task which is usually very tedious
>> in C/C++)
>> func!(Targets.SSE2)();
>> }
>>
>
As a small experiment, I could turn on versioning for these
functions... However is only available for x86 targets.
eg:
void foo() @target("sse") // mangled 'foo.sse'
{
}
void foo() @target("mmx") // mangled 'foo.mmx'
{
}
Regards
--
Iain Buclaw
*(p < e ? p++ : p) = (c & 0x0f) + '0';
