operator ==

[memory_leak]

hmm ... I have just found simple solution to operator "==".

bool operator == (const F32vec4 &a)
{
F32vec4 v = _mm_cmpeq_ps(vec, a);
return v.x && v.y && v.z && v.w;
}

I don't know if it's much more efficient then using ordinary c code

I guess doing just

bool operator == (const F32vec4 &a)
{
return x == v.x && y == v.y && z == v.z && w == v.w;
}

is probably faster & sompler, but finding simd way was educational :).

[jim_dempsey]

The former case (v.x && v.y && v.z && v.w) computes 0. or Junk.Junk. And the return is therefore either

return 0.;

or

return Junk.Junk;

But the return type is bool therefore an implicit conversion will be attempted where 0. implies FALSE and Junk.Junk implies TRUE. IMHO the first operator returns .NOT. what you want it to.

You are on the right track though where you want to perform the 4xDWORD xor then test for all 0's.

Jim

[memory_leak]

yeah - you are right Jim.



having vectors with all values same or all values equal yielded correct result

however vectors where some values are equal and some not gave wrong result (like v1 = 1,0,3,1 & v2 = 1,3,4,1 would give bad result.

I have changed comparison to be

inline bool _vec4f::operator == (const _vec4f &vec)
{

_vec4f v = _mm_cmpeq_ps(vec, m);

return (int)v.x & (int)v.y & (int)v.z & (int)v.w;

}

or in case of != operator:

inline bool _vec4f::operator != (const _vec4f &vec)

{





_vec4f v = _mm_cmpneq_ps(vec, m);





return (int)v.x | (int)v.y | (int)v.z | (int)v.w;
}
which seems to give correct result in all cases

however that code doesn't seem like something that benefits from sse optimization :).

Message Edited by memory_leak on 11-05-2005 03:09 PM

Message Edited by memory_leak on 11-05-2005 03:10 PM

Message Edited by memory_leak on 11-05-2005 03:11 PM

[memory_leak]

for the Christ - where those smileys came from??? :D

[Pourya_Shirazian]

Use _mm_movemask_ps which creates a 4 bit mask for the comparison result. You can check the mask then like this:

if(_mm_movemask_ps(_mm_cmpeq(v, zero)))

return true;

else

return false;