[fpc-devel] using sse2 packed doubles

[Florian Klaempfl]

Vincent Snijders schrieb:
> Hi,
> 
> I wondered if it is possible to add support for using sse2 packed 
> doubles in fpc.
> 
> I tried to create a sse2doubles type and define a operator + on it. 
> Eventually I want to move this type and all operators on it to a 
> separate sse2 unit, so that the user of this type doesn't need to see 
> the assembler. The following program works, but not as efficiently as I 
> had hoped, because the operator is not inlined, probably because of the 
> assembler code.

Indeed.

> 
> Is it possible to create this purely in RTL /units 

No.

> or is compiler 
> support needed? 

Yes.

> Does it make sense to create a 'feature request'bug 
> tracker item for this? Compiler hacking is out of my league.

Do you think it's allowed to use in the benchmarks?

> 
> program optsse2;
> 
> {$mode objfpc}{$H+}{$ASMMODE ATT}
> {$FPUTYPE SSE2}
> 
> type
>   sse2doubles = record
>                  d1, d2: double;
>                end;
> 
> operator + (d1, d2: sse2doubles) : sse2doubles; assembler; inline;
> {begin
>   result.d1 := d1.d1 + d2.d1;
>   result.d2 := d1.d2 + d2.d2;
> end;}
> asm
>   movupd (%eax), %xmm0
>   addpd (%edx), %xmm0
>   movupd %xmm0, (%ecx)
> end;
> 
> procedure test;
> var
>   sd1, sd2, sd3: sse2doubles;
> begin
>   sd1.d1 := 1;
>   sd1.d2 := 2;
>   sd2.d1 := 3;
>   sd2.d2 := 4;
>   sd3 := sd1 + sd2;
>   writeln(sd3.d1);
>   writeln(sd3.d2);
> end;
> 
> begin
>   test;
> end.
> 
> _______________________________________________
> fpc-devel maillist  -  fpc-devel at lists.freepascal.org
> http://lists.freepascal.org/mailman/listinfo/fpc-devel