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 "anv_nir.h"
25#include "nir/nir_builder.h"
26
27static nir_ssa_def *
28load_frag_coord(nir_builder *b)
29{
30   nir_foreach_variable(var, &b->shader->inputs) {
31      if (var->data.location == VARYING_SLOT_POS)
32         return nir_load_var(b, var);
33   }
34
35   nir_variable *pos = nir_variable_create(b->shader, nir_var_shader_in,
36                                           glsl_vec4_type(), NULL);
37   pos->data.location = VARYING_SLOT_POS;
38   pos->data.origin_upper_left = true;
39
40   return nir_load_var(b, pos);
41}
42
43static void
44try_lower_input_load(nir_function_impl *impl, nir_intrinsic_instr *load)
45{
46
47   const struct glsl_type *image_type =
48      glsl_without_array(load->variables[0]->var->type);
49   enum glsl_sampler_dim image_dim = glsl_get_sampler_dim(image_type);
50   if (image_dim != GLSL_SAMPLER_DIM_SUBPASS &&
51       image_dim != GLSL_SAMPLER_DIM_SUBPASS_MS)
52      return;
53
54   const bool multisampled = (image_dim == GLSL_SAMPLER_DIM_SUBPASS_MS);
55
56   nir_builder b;
57   nir_builder_init(&b, impl);
58   b.cursor = nir_before_instr(&load->instr);
59
60   nir_ssa_def *frag_coord = nir_f2i(&b, load_frag_coord(&b));
61   nir_ssa_def *offset = nir_ssa_for_src(&b, load->src[0], 2);
62   nir_ssa_def *pos = nir_iadd(&b, frag_coord, offset);
63
64   nir_ssa_def *layer =
65      nir_load_system_value(&b, nir_intrinsic_load_layer_id, 0);
66   nir_ssa_def *coord =
67      nir_vec3(&b, nir_channel(&b, pos, 0), nir_channel(&b, pos, 1), layer);
68
69   nir_tex_instr *tex = nir_tex_instr_create(b.shader, 2 + multisampled);
70
71   tex->op = nir_texop_txf;
72
73   switch (glsl_get_sampler_result_type(image_type)) {
74   case GLSL_TYPE_FLOAT:
75      tex->dest_type = nir_type_float;
76      break;
77   case GLSL_TYPE_INT:
78      tex->dest_type = nir_type_int;
79      break;
80   case GLSL_TYPE_UINT:
81      tex->dest_type = nir_type_uint;
82      break;
83   default:
84      unreachable("Invalid image type");
85   }
86   tex->is_array = true;
87   tex->is_shadow = false;
88
89   tex->texture = nir_deref_var_clone(load->variables[0], tex);
90   tex->sampler = NULL;
91   tex->texture_index = 0;
92   tex->sampler_index = 0;
93
94   tex->src[0].src_type = nir_tex_src_coord;
95   tex->src[0].src = nir_src_for_ssa(coord);
96   tex->coord_components = 3;
97
98   tex->src[1].src_type = nir_tex_src_lod;
99   tex->src[1].src = nir_src_for_ssa(nir_imm_int(&b, 0));
100
101   if (image_dim == GLSL_SAMPLER_DIM_SUBPASS_MS) {
102      tex->op = nir_texop_txf_ms;
103      tex->src[2].src_type = nir_tex_src_ms_index;
104      tex->src[2].src = load->src[1];
105   }
106
107   nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
108   nir_builder_instr_insert(&b, &tex->instr);
109
110   nir_ssa_def_rewrite_uses(&load->dest.ssa,
111                            nir_src_for_ssa(&tex->dest.ssa));
112}
113
114void
115anv_nir_lower_input_attachments(nir_shader *shader)
116{
117   assert(shader->stage == MESA_SHADER_FRAGMENT);
118
119   nir_foreach_function(function, shader) {
120      if (!function->impl)
121         continue;
122
123      nir_foreach_block(block, function->impl) {
124         nir_foreach_instr(instr, block) {
125            if (instr->type != nir_instr_type_intrinsic)
126               continue;
127
128            nir_intrinsic_instr *load = nir_instr_as_intrinsic(instr);
129
130            if (load->intrinsic != nir_intrinsic_image_load)
131               continue;
132
133            try_lower_input_load(function->impl, load);
134         }
135      }
136   }
137}
138