1 /*
2 * Copyright © 2015 Broadcom
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24 #include "v3d_compiler.h"
25 #include "compiler/nir/nir_builder.h"
26
27 /** @file v3d_nir_lower_txf_ms.c
28 *
29 * V3D's MSAA surfaces are laid out in UIF textures where each pixel is a 2x2
30 * quad in the texture. This pass lowers the txf_ms with a ms_index source to
31 * a plain txf with the sample_index pulling out the correct texel from the
32 * 2x2 quad.
33 */
34
35 #define V3D_MAX_SAMPLES 4
36
37 static nir_ssa_def *
v3d_nir_lower_txf_ms_instr(nir_builder * b,nir_instr * in_instr,void * data)38 v3d_nir_lower_txf_ms_instr(nir_builder *b, nir_instr *in_instr, void *data)
39 {
40 nir_tex_instr *instr = nir_instr_as_tex(in_instr);
41
42 b->cursor = nir_before_instr(&instr->instr);
43
44 int coord_index = nir_tex_instr_src_index(instr, nir_tex_src_coord);
45 int sample_index = nir_tex_instr_src_index(instr, nir_tex_src_ms_index);
46 nir_ssa_def *coord = instr->src[coord_index].src.ssa;
47 nir_ssa_def *sample = instr->src[sample_index].src.ssa;
48
49 nir_ssa_def *one = nir_imm_int(b, 1);
50 nir_ssa_def *x = nir_iadd(b,
51 nir_ishl(b, nir_channel(b, coord, 0), one),
52 nir_iand(b, sample, one));
53 nir_ssa_def *y = nir_iadd(b,
54 nir_ishl(b, nir_channel(b, coord, 1), one),
55 nir_iand(b, nir_ushr(b, sample, one), one));
56 if (instr->is_array)
57 coord = nir_vec3(b, x, y, nir_channel(b, coord, 2));
58 else
59 coord = nir_vec2(b, x, y);
60
61 nir_instr_rewrite_src(&instr->instr,
62 &instr->src[nir_tex_src_coord].src,
63 nir_src_for_ssa(coord));
64 nir_tex_instr_remove_src(instr, sample_index);
65 instr->op = nir_texop_txf;
66 instr->sampler_dim = GLSL_SAMPLER_DIM_2D;
67
68 return NIR_LOWER_INSTR_PROGRESS;
69 }
70
71 static bool
v3d_nir_lower_txf_ms_filter(const nir_instr * instr,const void * data)72 v3d_nir_lower_txf_ms_filter(const nir_instr *instr, const void *data)
73 {
74 return (instr->type == nir_instr_type_tex &&
75 nir_instr_as_tex(instr)->op == nir_texop_txf_ms);
76 }
77
78 void
v3d_nir_lower_txf_ms(nir_shader * s,struct v3d_compile * c)79 v3d_nir_lower_txf_ms(nir_shader *s, struct v3d_compile *c)
80 {
81 nir_shader_lower_instructions(s,
82 v3d_nir_lower_txf_ms_filter,
83 v3d_nir_lower_txf_ms_instr,
84 NULL);
85 }
86