Fix: Violation of strict weak ordering in engine name sorter
[openttd-github.git] / src / viewport_sprite_sorter_sse4.cpp
blob46068c41d2d8045ef4dc460ef46b8d8f73f59331
1 /*
2 * This file is part of OpenTTD.
3 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
4 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
5 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
6 */
8 /** @file viewport_sprite_sorter_sse4.cpp Sprite sorter that uses SSE4.1. */
10 #ifdef WITH_SSE
12 #include "stdafx.h"
13 #include "cpu.h"
14 #include "smmintrin.h"
15 #include "viewport_sprite_sorter.h"
17 #include "safeguards.h"
19 #ifdef _SQ64
20 assert_compile((sizeof(ParentSpriteToDraw) % 16) == 0);
21 #define LOAD_128 _mm_load_si128
22 #else
23 #define LOAD_128 _mm_loadu_si128
24 #endif
26 /** Sort parent sprites pointer array using SSE4.1 optimizations. */
27 void ViewportSortParentSpritesSSE41(ParentSpriteToSortVector *psdv)
29 const __m128i mask_ptest = _mm_setr_epi8(-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 0, 0, 0);
30 auto const psdvend = psdv->end();
31 auto psd = psdv->begin();
32 while (psd != psdvend) {
33 ParentSpriteToDraw * const ps = *psd;
35 if (ps->comparison_done) {
36 psd++;
37 continue;
40 ps->comparison_done = true;
42 for (auto psd2 = psd + 1; psd2 != psdvend; psd2++) {
43 ParentSpriteToDraw * const ps2 = *psd2;
45 if (ps2->comparison_done) continue;
48 * Decide which comparator to use, based on whether the bounding boxes overlap
50 * Original code:
51 * if (ps->xmax >= ps2->xmin && ps->xmin <= ps2->xmax && // overlap in X?
52 * ps->ymax >= ps2->ymin && ps->ymin <= ps2->ymax && // overlap in Y?
53 * ps->zmax >= ps2->zmin && ps->zmin <= ps2->zmax) { // overlap in Z?
55 * Above conditions are equivalent to:
56 * 1/ !( (ps->xmax >= ps2->xmin) && (ps->ymax >= ps2->ymin) && (ps->zmax >= ps2->zmin) && (ps->xmin <= ps2->xmax) && (ps->ymin <= ps2->ymax) && (ps->zmin <= ps2->zmax) )
57 * 2/ !( (ps->xmax >= ps2->xmin) && (ps->ymax >= ps2->ymin) && (ps->zmax >= ps2->zmin) && (ps2->xmax >= ps->xmin) && (ps2->ymax >= ps->ymin) && (ps2->zmax >= ps->zmin) )
58 * 3/ !( ( (ps->xmax >= ps2->xmin) && (ps->ymax >= ps2->ymin) && (ps->zmax >= ps2->zmin) ) && ( (ps2->xmax >= ps->xmin) && (ps2->ymax >= ps->ymin) && (ps2->zmax >= ps->zmin) ) )
59 * 4/ !( !( (ps->xmax < ps2->xmin) || (ps->ymax < ps2->ymin) || (ps->zmax < ps2->zmin) ) && !( (ps2->xmax < ps->xmin) || (ps2->ymax < ps->ymin) || (ps2->zmax < ps->zmin) ) )
60 * 5/ PTEST <---------------------------------- rslt1 ----------------------------------> <------------------------------ rslt2 -------------------------------------->
62 __m128i ps1_max = LOAD_128((__m128i*) &ps->xmax);
63 __m128i ps2_min = LOAD_128((__m128i*) &ps2->xmin);
64 __m128i rslt1 = _mm_cmplt_epi32(ps1_max, ps2_min);
65 if (!_mm_testz_si128(mask_ptest, rslt1))
66 continue;
68 __m128i ps1_min = LOAD_128((__m128i*) &ps->xmin);
69 __m128i ps2_max = LOAD_128((__m128i*) &ps2->xmax);
70 __m128i rslt2 = _mm_cmplt_epi32(ps2_max, ps1_min);
71 if (_mm_testz_si128(mask_ptest, rslt2)) {
72 /* Use X+Y+Z as the sorting order, so sprites closer to the bottom of
73 * the screen and with higher Z elevation, are drawn in front.
74 * Here X,Y,Z are the coordinates of the "center of mass" of the sprite,
75 * i.e. X=(left+right)/2, etc.
76 * However, since we only care about order, don't actually divide / 2
78 if (ps->xmin + ps->xmax + ps->ymin + ps->ymax + ps->zmin + ps->zmax <=
79 ps2->xmin + ps2->xmax + ps2->ymin + ps2->ymax + ps2->zmin + ps2->zmax) {
80 continue;
84 /* Move ps2 in front of ps */
85 ParentSpriteToDraw * const temp = ps2;
86 for (auto psd3 = psd2; psd3 > psd; psd3--) {
87 *psd3 = *(psd3 - 1);
89 *psd = temp;
94 /**
95 * Check whether the current CPU supports SSE 4.1.
96 * @return True iff the CPU supports SSE 4.1.
98 bool ViewportSortParentSpritesSSE41Checker()
100 return HasCPUIDFlag(1, 2, 19);
103 #endif /* WITH_SSE */