1 /*
2 * Copyright © 2020 Collabora, Ltd.
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 * Authors:
24 * Erik Faye-Lund <[email protected]>
25 */
26
27 #include "nir.h"
28 #include "nir_builder.h"
29 #include "nir_deref.h"
30
31 static nir_def *
get_io_index(nir_builder * b,nir_deref_instr * deref)32 get_io_index(nir_builder *b, nir_deref_instr *deref)
33 {
34 nir_deref_path path;
35 nir_deref_path_init(&path, deref, NULL);
36
37 assert(path.path[0]->deref_type == nir_deref_type_var);
38 nir_deref_instr **p = &path.path[1];
39
40 /* Just emit code and let constant-folding go to town */
41 nir_def *offset = nir_imm_int(b, 0);
42
43 for (; *p; p++) {
44 if ((*p)->deref_type == nir_deref_type_array) {
45 unsigned size = glsl_get_length((*p)->type);
46
47 nir_def *mul =
48 nir_amul_imm(b, (*p)->arr.index.ssa, size);
49
50 offset = nir_iadd(b, offset, mul);
51 } else
52 unreachable("Unsupported deref type");
53 }
54
55 nir_deref_path_finish(&path);
56
57 return offset;
58 }
59
60 static void
nir_lower_texcoord_replace_impl(nir_function_impl * impl,unsigned coord_replace,bool point_coord_is_sysval,bool yinvert)61 nir_lower_texcoord_replace_impl(nir_function_impl *impl,
62 unsigned coord_replace,
63 bool point_coord_is_sysval,
64 bool yinvert)
65 {
66 nir_builder b = nir_builder_at(nir_before_impl(impl));
67
68 nir_def *new_coord;
69 if (point_coord_is_sysval) {
70 new_coord = nir_load_system_value(&b, nir_intrinsic_load_point_coord,
71 0, 2, 32);
72 BITSET_SET(b.shader->info.system_values_read, SYSTEM_VALUE_POINT_COORD);
73 } else {
74 /* find or create pntc */
75 nir_variable *pntc = nir_get_variable_with_location(b.shader, nir_var_shader_in,
76 VARYING_SLOT_PNTC, glsl_vec_type(2));
77 b.shader->info.inputs_read |= BITFIELD64_BIT(VARYING_SLOT_PNTC);
78 new_coord = nir_load_var(&b, pntc);
79 }
80
81 /* point-coord is two-component, need to add two implicit ones in case of
82 * projective texturing etc.
83 */
84 nir_def *zero = nir_imm_zero(&b, 1, new_coord->bit_size);
85 nir_def *one = nir_imm_floatN_t(&b, 1.0, new_coord->bit_size);
86 nir_def *y = nir_channel(&b, new_coord, 1);
87 if (yinvert)
88 y = nir_fsub_imm(&b, 1.0, y);
89 new_coord = nir_vec4(&b, nir_channel(&b, new_coord, 0),
90 y,
91 zero, one);
92
93 nir_foreach_block(block, impl) {
94 nir_foreach_instr_safe(instr, block) {
95 if (instr->type != nir_instr_type_intrinsic)
96 continue;
97
98 nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
99 if (intrin->intrinsic != nir_intrinsic_load_deref)
100 continue;
101
102 nir_variable *var = nir_intrinsic_get_var(intrin, 0);
103 if (var->data.mode != nir_var_shader_in ||
104 var->data.location < VARYING_SLOT_TEX0 ||
105 var->data.location > VARYING_SLOT_TEX7)
106 continue;
107 unsigned base = var->data.location - VARYING_SLOT_TEX0;
108
109 b.cursor = nir_after_instr(instr);
110 uint32_t component_mask = BITFIELD_MASK(glsl_get_vector_elements(var->type)) << var->data.location_frac;
111 nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
112 nir_def *index = get_io_index(&b, deref);
113 nir_def *mask =
114 nir_ishl(&b, nir_imm_int(&b, 1),
115 nir_iadd_imm(&b, index, base));
116
117 nir_def *cond = nir_test_mask(&b, mask, coord_replace);
118 nir_def *result = nir_bcsel(&b, cond, nir_channels(&b, new_coord, component_mask),
119 &intrin->def);
120
121 nir_def_rewrite_uses_after(&intrin->def,
122 result,
123 result->parent_instr);
124 }
125 }
126
127 nir_metadata_preserve(impl, nir_metadata_control_flow);
128 }
129
130 void
nir_lower_texcoord_replace(nir_shader * s,unsigned coord_replace,bool point_coord_is_sysval,bool yinvert)131 nir_lower_texcoord_replace(nir_shader *s, unsigned coord_replace,
132 bool point_coord_is_sysval, bool yinvert)
133 {
134 assert(s->info.stage == MESA_SHADER_FRAGMENT);
135 assert(coord_replace != 0);
136
137 nir_foreach_function_impl(impl, s) {
138 nir_lower_texcoord_replace_impl(impl, coord_replace,
139 point_coord_is_sysval, yinvert);
140 }
141 }
142