20fa801b45d4abe169a1210be73fc30f1c4ec18f
[mesa.git] / src / compiler / nir / nir_lower_input_attachments.c
1 /*
2 * Copyright © 2016 Intel Corporation
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 "nir.h"
25 #include "nir_builder.h"
26
27 static nir_ssa_def *
28 load_frag_coord(nir_builder *b)
29 {
30 nir_variable *pos =
31 nir_find_variable_with_location(b->shader, nir_var_shader_in,
32 VARYING_SLOT_POS);
33 if (pos == NULL) {
34 pos = nir_variable_create(b->shader, nir_var_shader_in,
35 glsl_vec4_type(), NULL);
36 pos->data.location = VARYING_SLOT_POS;
37 }
38 /**
39 * From Vulkan spec:
40 * "The OriginLowerLeft execution mode must not be used; fragment entry
41 * points must declare OriginUpperLeft."
42 *
43 * So at this point origin_upper_left should be true
44 */
45 assert(b->shader->info.fs.origin_upper_left == true);
46
47 return nir_load_var(b, pos);
48 }
49
50 static bool
51 try_lower_input_load(nir_function_impl *impl, nir_intrinsic_instr *load,
52 bool use_fragcoord_sysval)
53 {
54 nir_deref_instr *deref = nir_src_as_deref(load->src[0]);
55 assert(glsl_type_is_image(deref->type));
56
57 enum glsl_sampler_dim image_dim = glsl_get_sampler_dim(deref->type);
58 if (image_dim != GLSL_SAMPLER_DIM_SUBPASS &&
59 image_dim != GLSL_SAMPLER_DIM_SUBPASS_MS)
60 return false;
61
62 const bool multisampled = (image_dim == GLSL_SAMPLER_DIM_SUBPASS_MS);
63
64 nir_builder b;
65 nir_builder_init(&b, impl);
66 b.cursor = nir_instr_remove(&load->instr);
67
68 nir_ssa_def *frag_coord = use_fragcoord_sysval ? nir_load_frag_coord(&b)
69 : load_frag_coord(&b);
70 frag_coord = nir_f2i32(&b, frag_coord);
71 nir_ssa_def *offset = nir_ssa_for_src(&b, load->src[1], 2);
72 nir_ssa_def *pos = nir_iadd(&b, frag_coord, offset);
73
74 nir_ssa_def *layer = nir_load_layer_id(&b);
75 nir_ssa_def *coord =
76 nir_vec3(&b, nir_channel(&b, pos, 0), nir_channel(&b, pos, 1), layer);
77
78 nir_tex_instr *tex = nir_tex_instr_create(b.shader, 3 + multisampled);
79
80 tex->op = nir_texop_txf;
81 tex->sampler_dim = image_dim;
82
83 switch (glsl_get_sampler_result_type(deref->type)) {
84 case GLSL_TYPE_FLOAT:
85 tex->dest_type = nir_type_float;
86 break;
87 case GLSL_TYPE_INT:
88 tex->dest_type = nir_type_int;
89 break;
90 case GLSL_TYPE_UINT:
91 tex->dest_type = nir_type_uint;
92 break;
93 default:
94 unreachable("Invalid image type");
95 }
96 tex->is_array = true;
97 tex->is_shadow = false;
98
99 tex->texture_index = 0;
100 tex->sampler_index = 0;
101
102 tex->src[0].src_type = nir_tex_src_texture_deref;
103 tex->src[0].src = nir_src_for_ssa(&deref->dest.ssa);
104
105 tex->src[1].src_type = nir_tex_src_coord;
106 tex->src[1].src = nir_src_for_ssa(coord);
107 tex->coord_components = 3;
108
109 tex->src[2].src_type = nir_tex_src_lod;
110 tex->src[2].src = nir_src_for_ssa(nir_imm_int(&b, 0));
111
112 if (image_dim == GLSL_SAMPLER_DIM_SUBPASS_MS) {
113 tex->op = nir_texop_txf_ms;
114 tex->src[3].src_type = nir_tex_src_ms_index;
115 tex->src[3].src = load->src[2];
116 }
117
118 tex->texture_non_uniform = nir_intrinsic_access(load) & ACCESS_NON_UNIFORM;
119
120 nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
121 nir_builder_instr_insert(&b, &tex->instr);
122
123 nir_ssa_def_rewrite_uses(&load->dest.ssa,
124 nir_src_for_ssa(&tex->dest.ssa));
125
126 return true;
127 }
128
129 static bool
130 try_lower_input_texop(nir_function_impl *impl, nir_tex_instr *tex,
131 bool use_fragcoord_sysval)
132 {
133 nir_deref_instr *deref = nir_src_as_deref(tex->src[0].src);
134
135 if (glsl_get_sampler_dim(deref->type) != GLSL_SAMPLER_DIM_SUBPASS_MS)
136 return false;
137
138 nir_builder b;
139 nir_builder_init(&b, impl);
140 b.cursor = nir_before_instr(&tex->instr);
141
142 nir_ssa_def *frag_coord = use_fragcoord_sysval ? nir_load_frag_coord(&b)
143 : load_frag_coord(&b);
144 frag_coord = nir_f2i32(&b, frag_coord);
145
146 nir_ssa_def *layer = nir_load_layer_id(&b);
147 nir_ssa_def *coord = nir_vec3(&b, nir_channel(&b, frag_coord, 0),
148 nir_channel(&b, frag_coord, 1), layer);
149
150 tex->coord_components = 3;
151
152 nir_instr_rewrite_src(&tex->instr, &tex->src[1].src, nir_src_for_ssa(coord));
153
154 return true;
155 }
156
157 bool
158 nir_lower_input_attachments(nir_shader *shader, bool use_fragcoord_sysval)
159 {
160 assert(shader->info.stage == MESA_SHADER_FRAGMENT);
161 bool progress = false;
162
163 nir_foreach_function(function, shader) {
164 if (!function->impl)
165 continue;
166
167 nir_foreach_block(block, function->impl) {
168 nir_foreach_instr_safe(instr, block) {
169 switch (instr->type) {
170 case nir_instr_type_tex: {
171 nir_tex_instr *tex = nir_instr_as_tex(instr);
172
173 if (tex->op == nir_texop_fragment_mask_fetch ||
174 tex->op == nir_texop_fragment_fetch) {
175 progress |= try_lower_input_texop(function->impl, tex,
176 use_fragcoord_sysval);
177 }
178 break;
179 }
180 case nir_instr_type_intrinsic: {
181 nir_intrinsic_instr *load = nir_instr_as_intrinsic(instr);
182
183 if (load->intrinsic == nir_intrinsic_image_deref_load) {
184 progress |= try_lower_input_load(function->impl, load,
185 use_fragcoord_sysval);
186 }
187 break;
188 }
189 default:
190 break;
191 }
192 }
193 }
194 }
195
196 return progress;
197 }