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Cycles: Add AVX2 path to subsurface triangle intersection 

Similar to regular triangle intersection case. Gives about 3% speedup rendering
SSS object on my desktop,

Question: how to avoid such a code duplication in a nice way without speed loss?
This commit is contained in:
Sergey Sharybin 2016-10-24 16:56:41 +02:00
parent da8f5d6eac
commit 10a25b655a
Notes: blender-bot 2023-02-14 07:28:08 +01:00 
Referenced by issue #51313, blender crashes after adding texture node to compositing tree
Referenced by issue #49857, blender crashes after adding texture node to compositing tree
1 changed files with 62 additions and 0 deletions
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62
intern/cycles/kernel/geom/geom_triangle_intersect.h
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@ -269,6 +269,67 @@ ccl_device_inline void triangle_intersect_subsurface(
const float4 tri_a = kernel_tex_fetch(__prim_tri_verts, tri_vindex+0),
tri_b = kernel_tex_fetch(__prim_tri_verts, tri_vindex+1),
tri_c = kernel_tex_fetch(__prim_tri_verts, tri_vindex+2);
#if defined(__KERNEL_AVX2__)
const avxf avxf_P(P.m128, P.m128);
const avxf tri_ab = kernel_tex_fetch_avxf(__prim_tri_verts, tri_vindex + 0);
const avxf tri_bc = kernel_tex_fetch_avxf(__prim_tri_verts, tri_vindex + 1);
const avxf AB = tri_ab - avxf_P;
const avxf BC = tri_bc - avxf_P;
const __m256i permuteMask = _mm256_set_epi32(0x3, kz, ky, kx, 0x3, kz, ky, kx);
const avxf AB_k = shuffle(AB, permuteMask);
const avxf BC_k = shuffle(BC, permuteMask);
/* Akz, Akz, Bkz, Bkz, Bkz, Bkz, Ckz, Ckz */
const avxf ABBC_kz = shuffle<2>(AB_k, BC_k);
/* Akx, Aky, Bkx, Bky, Bkx,Bky, Ckx, Cky */
const avxf ABBC_kxy = shuffle<0,1,0,1>(AB_k, BC_k);
const avxf Sxy(Sy, Sx, Sy, Sx);
/* Ax, Ay, Bx, By, Bx, By, Cx, Cy */
const avxf ABBC_xy = nmadd(ABBC_kz, Sxy, ABBC_kxy);
float ABBC_kz_array[8];
_mm256_storeu_ps((float*)&ABBC_kz_array, ABBC_kz);
const float A_kz = ABBC_kz_array[0];
const float B_kz = ABBC_kz_array[2];
const float C_kz = ABBC_kz_array[6];
/* By, Bx, Cy, Cx, By, Bx, Ay, Ax */
const avxf BCBA_yx = permute<3,2,7,6,3,2,1,0>(ABBC_xy);
const avxf negMask(0,0,0,0,0x80000000, 0x80000000, 0x80000000, 0x80000000);
/* W U V
* (AxBy-AyBx) (BxCy-ByCx) XX XX (BxBy-ByBx) (CxAy-CyAx) XX XX
*/
const avxf WUxxxxVxx_neg = _mm256_hsub_ps(ABBC_xy * BCBA_yx, negMask /* Dont care */);
const avxf WUVWnegWUVW = permute<0,1,5,0,0,1,5,0>(WUxxxxVxx_neg) ^ negMask;
/* Calculate scaled barycentric coordinates. */
float WUVW_array[4];
_mm_storeu_ps((float*)&WUVW_array, _mm256_castps256_ps128 (WUVWnegWUVW));
const float W = WUVW_array[0];
const float U = WUVW_array[1];
const float V = WUVW_array[2];
const int WUVW_mask = 0x7 & _mm256_movemask_ps(WUVWnegWUVW);
const int WUVW_zero = 0x7 & _mm256_movemask_ps(_mm256_cmp_ps(WUVWnegWUVW,
_mm256_setzero_ps(), 0));
if(!((WUVW_mask == 7) || (WUVW_mask == 0)) && ((WUVW_mask | WUVW_zero) != 7)) {
return;
}
#else
const float3 A = make_float3(tri_a.x - P.x, tri_a.y - P.y, tri_a.z - P.z);
const float3 B = make_float3(tri_b.x - P.x, tri_b.y - P.y, tri_b.z - P.z);
const float3 C = make_float3(tri_c.x - P.x, tri_c.y - P.y, tri_c.z - P.z);
@ -295,6 +356,7 @@ ccl_device_inline void triangle_intersect_subsurface(
{
return;
}
#endif
/* Calculate determinant. */
float det = U + V + W;