xref: /third_party/mesa3d/src/asahi/lib/tiling.c (revision bf215546)
1/*
2 * Copyright (C) 2021 Alyssa Rosenzweig <alyssa@rosenzweig.io>
3 * Copyright (c) 2019 Collabora, Ltd.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 */
24
25#include <stdio.h>
26#include <assert.h>
27#include <stdlib.h>
28#include <stdbool.h>
29#include <stdint.h>
30#include "util/macros.h"
31#include "tiling.h"
32
33/* Z-order with square tiles, at most 64x64:
34 *
35 * 	[y5][x5][y4][x4][y3][x3][y2][x2][y1][x1][y0][x0]
36 *
37 * Efficient tiling algorithm described in
38 * https://fgiesen.wordpress.com/2011/01/17/texture-tiling-and-swizzling/ but
39 * for posterity, we split into X and Y parts, and are faced with the problem
40 * of incrementing:
41 *
42 * 	0 [x5] 0 [x4] 0 [x3] 0 [x2] 0 [x1] 0 [x0]
43 *
44 * To do so, we fill in the "holes" with 1's by adding the bitwise inverse of
45 * the mask of bits we care about
46 *
47 * 	0 [x5] 0 [x4] 0 [x3] 0 [x2] 0 [x1] 0 [x0]
48 *    + 1  0   1  0   1  0   1  0   1  0   1  0
49 *    ------------------------------------------
50 * 	1 [x5] 1 [x4] 1 [x3] 1 [x2] 1 [x1] 1 [x0]
51 *
52 * Then when we add one, the holes are passed over by forcing carry bits high.
53 * Finally, we need to zero out the holes, by ANDing with the mask of bits we
54 * care about. In total, we get the expression (X + ~mask + 1) & mask, and
55 * applying the two's complement identity, we are left with (X - mask) & mask
56 */
57
58/* mask of bits used for X coordinate in a tile */
59#define SPACE_MASK 0x555 // 0b010101010101
60
61typedef struct {
62  uint16_t lo;
63  uint8_t hi;
64} __attribute__((packed)) agx_uint24_t;
65
66typedef struct {
67  uint32_t lo;
68  uint16_t hi;
69} __attribute__((packed)) agx_uint48_t;
70
71typedef struct {
72  uint64_t lo;
73  uint32_t hi;
74} __attribute__((packed)) agx_uint96_t;
75
76typedef struct {
77  uint64_t lo;
78  uint64_t hi;
79} __attribute__((packed)) agx_uint128_t;
80
81static uint32_t
82agx_space_bits(unsigned x)
83{
84   assert(x < 64);
85   return ((x & 1) << 0) | ((x & 2) << 1) | ((x & 4) << 2) |
86          ((x & 8) << 3) | ((x & 16) << 4) | ((x & 32) << 5);
87}
88
89#define TILED_UNALIGNED_TYPE(pixel_t, is_store, tile_shift) { \
90   unsigned tile_size = (1 << tile_shift);\
91   unsigned pixels_per_tile = tile_size * tile_size;\
92	unsigned tiles_per_row = (width + tile_size - 1) >> tile_shift;\
93	unsigned y_offs = agx_space_bits(sy & (tile_size - 1)) << 1;\
94	unsigned x_offs_start = agx_space_bits(sx & (tile_size - 1));\
95   unsigned space_mask = SPACE_MASK & (pixels_per_tile - 1);\
96\
97   pixel_t *linear = _linear; \
98   pixel_t *tiled = _tiled; \
99\
100	for (unsigned y = sy; y < smaxy; ++y) {\
101		unsigned tile_y = (y >> tile_shift);\
102		unsigned tile_row = tile_y * tiles_per_row;\
103		unsigned x_offs = x_offs_start;\
104\
105		pixel_t *linear_row = linear;\
106		\
107		for (unsigned x = sx; x < smaxx; ++x) {\
108			unsigned tile_x = (x >> tile_shift);\
109			unsigned tile_idx = (tile_row + tile_x);\
110			unsigned tile_base = tile_idx * pixels_per_tile;\
111\
112			pixel_t *ptiled = &tiled[tile_base + y_offs + x_offs];\
113			pixel_t *plinear = (linear_row++);\
114			pixel_t *outp = (pixel_t *) (is_store ? ptiled : plinear); \
115			pixel_t *inp = (pixel_t *) (is_store ? plinear : ptiled); \
116			*outp = *inp;\
117			x_offs = (x_offs - space_mask) & space_mask;\
118		}\
119\
120		y_offs = (((y_offs >> 1) - space_mask) & space_mask) << 1;\
121		linear += linear_pitch;\
122	}\
123}
124
125#define TILED_UNALIGNED_TYPES(bpp, store, tile_shift) { \
126   if (bpp == 8) \
127      TILED_UNALIGNED_TYPE(uint8_t, store, tile_shift) \
128   else if (bpp == 16) \
129      TILED_UNALIGNED_TYPE(uint16_t, store, tile_shift) \
130   else if (bpp == 24) \
131      TILED_UNALIGNED_TYPE(agx_uint24_t, store, tile_shift) \
132   else if (bpp == 32) \
133      TILED_UNALIGNED_TYPE(uint32_t, store, tile_shift) \
134   else if (bpp == 48) \
135      TILED_UNALIGNED_TYPE(agx_uint48_t, store, tile_shift) \
136   else if (bpp == 64) \
137      TILED_UNALIGNED_TYPE(uint64_t, store, tile_shift) \
138   else if (bpp == 96) \
139      TILED_UNALIGNED_TYPE(agx_uint96_t, store, tile_shift) \
140   else if (bpp == 128) \
141      TILED_UNALIGNED_TYPE(agx_uint128_t, store, tile_shift) \
142   else \
143      unreachable("Can't tile this bpp\n"); \
144}
145
146void
147agx_detile(void *_tiled, void *_linear,
148           unsigned width, unsigned bpp, unsigned linear_pitch,
149           unsigned sx, unsigned sy, unsigned smaxx, unsigned smaxy, unsigned tile_shift)
150{
151   TILED_UNALIGNED_TYPES(bpp, false, tile_shift);
152}
153
154void
155agx_tile(void *_tiled, void *_linear,
156         unsigned width, unsigned bpp, unsigned linear_pitch,
157         unsigned sx, unsigned sy, unsigned smaxx, unsigned smaxy,
158         unsigned tile_shift)
159{
160   TILED_UNALIGNED_TYPES(bpp, true, tile_shift);
161}
162