• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright © 2015 Red Hat
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 FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  */
23 
24 #include "nir.h"
25 #include "nir_builder.h"
26 
27 static void
lower_impl(nir_function_impl * impl)28 lower_impl(nir_function_impl *impl)
29 {
30    nir_shader *shader = impl->function->shader;
31    nir_builder b;
32    nir_variable *in, *out;
33    nir_ssa_def *def;
34 
35    nir_builder_init(&b, impl);
36    b.cursor = nir_before_cf_list(&impl->body);
37 
38    /* The edge flag is the last input in st/mesa. */
39    assert(shader->num_inputs == util_bitcount64(shader->info.inputs_read));
40 
41    /* Lowered IO only uses intrinsics. It doesn't use variables. */
42    if (shader->info.io_lowered) {
43       assert(shader->num_outputs ==
44              util_bitcount64(shader->info.outputs_written));
45 
46       /* Load an edge flag. */
47       nir_intrinsic_instr *load =
48          nir_intrinsic_instr_create(shader, nir_intrinsic_load_input);
49       load->num_components = 1;
50       load->src[0] = nir_src_for_ssa(nir_imm_int(&b, 0));
51       nir_ssa_dest_init(&load->instr, &load->dest,
52                         load->num_components, 32, NULL);
53 
54       nir_intrinsic_set_base(load, shader->num_inputs++);
55       nir_intrinsic_set_component(load, 0);
56       nir_intrinsic_set_dest_type(load, nir_type_float32);
57 
58       nir_io_semantics load_sem = {0};
59       load_sem.location = VERT_ATTRIB_EDGEFLAG;
60       load_sem.num_slots = 1;
61       nir_intrinsic_set_io_semantics(load, load_sem);
62       nir_builder_instr_insert(&b, &load->instr);
63 
64       /* Store an edge flag. */
65       nir_intrinsic_instr *store =
66          nir_intrinsic_instr_create(shader, nir_intrinsic_store_output);
67       store->num_components = 1;
68       store->src[0] = nir_src_for_ssa(&load->dest.ssa);
69       store->src[1] = nir_src_for_ssa(nir_imm_int(&b, 0));
70 
71       nir_intrinsic_set_base(store, shader->num_outputs++);
72       nir_intrinsic_set_component(store, 0);
73       nir_intrinsic_set_src_type(store, nir_type_float32);
74       nir_intrinsic_set_write_mask(store, 0x1);
75 
76       nir_io_semantics semantics = {0};
77       semantics.location = VARYING_SLOT_EDGE;
78       semantics.num_slots = 1;
79       nir_intrinsic_set_io_semantics(store, semantics);
80       nir_builder_instr_insert(&b, &store->instr);
81 
82       nir_metadata_preserve(impl, nir_metadata_block_index |
83                                   nir_metadata_dominance);
84       return;
85    }
86 
87    in  = nir_variable_create(shader, nir_var_shader_in,
88                              glsl_vec4_type(), "edgeflag_in");
89    in->data.location = VERT_ATTRIB_EDGEFLAG;
90 
91    in->data.driver_location = shader->num_inputs++;
92    shader->info.inputs_read |= BITFIELD64_BIT(VERT_ATTRIB_EDGEFLAG);
93 
94    out = nir_variable_create(shader, nir_var_shader_out,
95                              glsl_vec4_type(), "edgeflag_out");
96    out->data.location = VARYING_SLOT_EDGE;
97 
98    def = nir_load_var(&b, in);
99    nir_store_var(&b, out, def, 0xf);
100 
101    nir_metadata_preserve(impl, nir_metadata_block_index |
102                                nir_metadata_dominance);
103 }
104 
nir_lower_passthrough_edgeflags(nir_shader * shader)105 void nir_lower_passthrough_edgeflags(nir_shader *shader)
106 {
107    lower_impl(nir_shader_get_entrypoint(shader));
108 }
109