[fpc-devel] using sse2 packed doubles

[Vincent Snijders]

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.

Is it possible to create this purely in RTL /units or is compiler support needed? 
Does it make sense to create a 'feature request'bug tracker item for this? Compiler 
hacking is out of my league.

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.