Support for gcc vector attributes, SIMD builtins

[Jacob Carlborg]

On 2011-02-06 07:24, Mike Farnsworth wrote:
> On 02/01/2011 10:38 AM, Iain Buclaw wrote:
>> I haven't given it much thought on how internal representation could be, but I'd
>> lean on using unions in D code for usage in the language. As its probably most
>> portable.
>>
>> For example, one of the older 'hello vectors' I know of:
>>
>> import std.c.stdio;
>>
>> pragma(set_attribute, __v4sf, vector_size(16));
>> typedef float __v4sf;
>>
>> union f4vector
>> {
>>      __v4sf v;
>>      float[4] f;
>> }
>>
>> int main()
>> {
>>      f4vector a, b, c;
>>
>>      a.f = [1, 2, 3, 4];
>>      b.f = [5, 6, 7, 8];
>>
>>      c.v = a.v + b.v;
>>      printf("%f, %f, %f, %f\n", c.f[0], c.f[1], c.f[2], c.f[3]);
>>
>>      return 0;
>> }
>
> I've been giving this a serious try, and while the above works, I can't
> get any __builtin_... functions to actually work.  I've added support
> for the VECTOR_TYPE tree code in gcc_type_to_d_type(tree) function (in
> d_builtins2.cc):
>
>          case VECTOR_TYPE:
>          {
>              tree baseType = TREE_TYPE(t);
>              d = gcc_type_to_d_type(baseType, printstuff);
>              if (d)
>                  return d;
>              break;
>          }
>
> This allows it to succeed in interpreting the SSE-related builtins in
> gcc_type_to_d_type(tree).  Note that all it does is grab the base vector
> element type and convert that to a D type so as not to confuse the
> frontend; this way it matches the typedef for __v4sf, so as long as we
> use the union we won't lose data before we can pass it to a builtin.
>
> I've verified (with a bunch of verbatim(...) calls) that the compiler
> *is* pushing function declarations of things like __builtin_ia32_addps,
> but I cannot for the life of me get my actual D code to see any of those
> functions:
>
> ========
> pragma(set_attribute, __v4sf, vector_size(16));
> typedef float __v4sf;
>
> union v4f
> {
>      __v4sf v;
>      float[4] f;
> }
>
> import gcc.builtins;
>
> pragma(set_attribute, _mm_add_ps, always_inline, artificial);
>
> __v4sf _mm_add_ps(__v4sf __A, __v4sf __B)
> {
>      return __builtin_ia32_addps(__A, __B);
> }
> ========
>
> And I get:
> ../../Vectors.d:24: Error: undefined identifier __builtin_ia32_addps
>
> If I explicitly prefix the call as
> gcc.builtins.__builtin_ia32_addps(__A, __B)
>
> I get:
> ../../Vectors.d:24: Error: undefined identifier module
> builtins.__builtin_ia32_addps
>
> Which doesn't make a whole lot of sense.
>
> I thought there might be something wrong recognizing the argument types,
> so I tried __isnanf and __isnan builtins as well, and...same failures.
> I don't think any of the builtins besides the alias declarations are
> working, honestly.  (__builtin_Clong, __builtin_Culong, etc do work, but
> that's the only thing from gcc.builtins that I can access without errors).
>
> Any hints?
>
> -Mike

Don't know it it has anything to do with it but you should wrap any 
non-standard pragmas in a version block.

-- 
/Jacob Carlborg