foo_r (float x, int i)
{
switch (i)
{
case 0:
return _mm512_setr_ps (x, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
case 1:
return _mm512_setr_ps (0, x, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
case 2:
return _mm512_setr_ps (0, 0, x, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
case 3:
return _mm512_setr_ps (0, 0, 0, x, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
case 4:
return _mm512_setr_ps (0, 0, 0, 0, x, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
case 5:
return _mm512_setr_ps (0, 0, 0, 0, 0, x, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
case 6:
return _mm512_setr_ps (0, 0, 0, 0, 0, 0, x, 0, 0, 0, 0, 0, 0, 0, 0, 0);
case 7:
return _mm512_setr_ps (0, 0, 0, 0, 0, 0, 0, x, 0, 0, 0, 0, 0, 0, 0, 0);
case 8:
return _mm512_setr_ps (0, 0, 0, 0, 0, 0, 0, 0, x, 0, 0, 0, 0, 0, 0, 0);
case 9:
return _mm512_setr_ps (0, 0, 0, 0, 0, 0, 0, 0, 0, x, 0, 0, 0, 0, 0, 0);
case 10:
return _mm512_setr_ps (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, x, 0, 0, 0, 0, 0);
case 11:
return _mm512_setr_ps (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, x, 0, 0, 0, 0);
case 12:
return _mm512_setr_ps (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, x, 0, 0, 0);
case 13:
return _mm512_setr_ps (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, x, 0, 0);
case 14:
return _mm512_setr_ps (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, x, 0);
case 15:
return _mm512_setr_ps (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, x);
default:
abort ();
}
}
foo_r (float x)
{
return _mm512_setr_ps (x, x, x, x, x, x, x, x,
x, x, x, x, x, x, x, x);
}
void AVX512BW_mandelbrot(
float Re_min, float Re_max,
float Im_min, float Im_max,
float threshold,
int maxiters,
int width, int height,
uint8_t *data)
{
float dRe, dIm;
int x, y;
__m128i* ptr = (__m128i*)data;
// step on Re and Im axis
dRe = (Re_max - Re_min)/width;
dIm = (Im_max - Im_min)/height;
// prepare vectors
// 1. threshold
const __m512 vec_threshold = _mm512_set1_ps(threshold);
// 2. Cim
__m512 Cim = _mm512_set1_ps(Im_min);
// 3. Re advance every x iteration
const __m512 vec_dRe = _mm512_set1_ps(16*dRe);
// 4. Im advance every y iteration
const __m512 vec_dIm = _mm512_set1_ps(dIm);
// calculations
for (y=0; y < height; y++) {
__m512 Cre = _mm512_setr_ps(
Re_min + 0*dRe, Re_min + 1*dRe, Re_min + 2*dRe, Re_min + 3*dRe,
Re_min + 4*dRe, Re_min + 5*dRe, Re_min + 6*dRe, Re_min + 7*dRe,
Re_min + 8*dRe, Re_min + 9*dRe, Re_min + 10*dRe, Re_min + 11*dRe,
Re_min + 12*dRe, Re_min + 13*dRe, Re_min + 14*dRe, Re_min + 15*dRe
);
for (x=0; x < width; x+=16) {
__m512 Xre = _mm512_setzero_ps();
__m512 Xim = _mm512_setzero_ps();
__m128i itercount = _mm_setzero_si128();
int i;
for (i=0; i < maxiters; i++) {
// Tre = Xre^2 - Xim^2 + Cim
const __m512 Xre2 = _mm512_mul_ps(Xre, Xre);
const __m512 Xim2 = _mm512_mul_ps(Xim, Xim);
const __m512 Tre = _mm512_add_ps(Cre, _mm512_sub_ps(Xre2, Xim2));
// Tim = 2*Xre*Xim + Cre
const __m512 t1 = _mm512_mul_ps(Xre, Xim);
const __m512 Tim = _mm512_add_ps(Cim, _mm512_add_ps(t1, t1));
// sqr_dist = Tre^2 + Tim^2
__m512 Tre2 = _mm512_mul_ps(Tre, Tre);
__m512 Tim2 = _mm512_mul_ps(Tim, Tim);
__m512 sqr_dist = _mm512_add_ps(Tre2, Tim2);
// sqr_dist < threshold => 16-bit mask
__mmask16 mask = _mm512_cmp_ps_mask(sqr_dist, vec_threshold, _CMP_LE_OS);
if (mask == 0) {
break;
}
// Note: unlike SSE/AVX2 versions itercount is a packed byte vector,
// thus conversion packed dword -> byte is not needed.
itercount = _mm_sub_epi8(itercount, _mm_movm_epi8(mask));
Xre = Tre;
Xim = Tim;
} // for
*ptr++ = itercount;
// advance Cre vector
Cre = _mm512_add_ps(Cre, vec_dRe);
}
// advance Cim vector
Cim = _mm512_add_ps(Cim, vec_dIm);
}
}
