2 * Copyright (C) 2005-2007 Brian Paul All Rights Reserved.
3 * Copyright (C) 2008 VMware, Inc. All Rights Reserved.
4 * Copyright © 2014 Intel Corporation
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
23 * DEALINGS IN THE SOFTWARE.
27 #include "nir_builder.h"
30 lower_tex_src_to_offset(nir_builder
*b
,
31 nir_tex_instr
*instr
, unsigned src_idx
)
33 nir_ssa_def
*index
= NULL
;
34 unsigned base_index
= 0;
35 unsigned array_elements
= 1;
36 nir_tex_src
*src
= &instr
->src
[src_idx
];
37 bool is_sampler
= src
->src_type
== nir_tex_src_sampler_deref
;
39 /* We compute first the offsets */
40 nir_deref_instr
*deref
= nir_instr_as_deref(src
->src
.ssa
->parent_instr
);
41 while (deref
->deref_type
!= nir_deref_type_var
) {
42 assert(deref
->parent
.is_ssa
);
43 nir_deref_instr
*parent
=
44 nir_instr_as_deref(deref
->parent
.ssa
->parent_instr
);
46 assert(deref
->deref_type
== nir_deref_type_array
);
48 if (nir_src_is_const(deref
->arr
.index
) && index
== NULL
) {
49 /* We're still building a direct index */
50 base_index
+= nir_src_as_uint(deref
->arr
.index
) * array_elements
;
53 /* We used to be direct but not anymore */
54 index
= nir_imm_int(b
, base_index
);
58 index
= nir_iadd(b
, index
,
59 nir_imul(b
, nir_imm_int(b
, array_elements
),
60 nir_ssa_for_src(b
, deref
->arr
.index
, 1)));
63 array_elements
*= glsl_get_length(parent
->type
);
69 index
= nir_umin(b
, index
, nir_imm_int(b
, array_elements
- 1));
71 /* We hit the deref_var. This is the end of the line */
72 assert(deref
->deref_type
== nir_deref_type_var
);
74 base_index
+= deref
->var
->data
.binding
;
76 /* We have the offsets, we apply them, rewriting the source or removing
80 nir_instr_rewrite_src(&instr
->instr
, &src
->src
,
81 nir_src_for_ssa(index
));
83 src
->src_type
= is_sampler
?
84 nir_tex_src_sampler_offset
:
85 nir_tex_src_texture_offset
;
87 nir_tex_instr_remove_src(instr
, src_idx
);
91 instr
->sampler_index
= base_index
;
93 instr
->texture_index
= base_index
;
98 lower_sampler(nir_builder
*b
, nir_tex_instr
*instr
)
101 nir_tex_instr_src_index(instr
, nir_tex_src_texture_deref
);
103 if (texture_idx
>= 0) {
104 b
->cursor
= nir_before_instr(&instr
->instr
);
106 lower_tex_src_to_offset(b
, instr
, texture_idx
);
110 nir_tex_instr_src_index(instr
, nir_tex_src_sampler_deref
);
112 if (sampler_idx
>= 0) {
113 lower_tex_src_to_offset(b
, instr
, sampler_idx
);
116 if (texture_idx
< 0 && sampler_idx
< 0)
123 lower_impl(nir_function_impl
*impl
)
126 nir_builder_init(&b
, impl
);
127 bool progress
= false;
129 nir_foreach_block(block
, impl
) {
130 nir_foreach_instr(instr
, block
) {
131 if (instr
->type
== nir_instr_type_tex
)
132 progress
|= lower_sampler(&b
, nir_instr_as_tex(instr
));
137 nir_metadata_preserve(impl
, nir_metadata_block_index
|
138 nir_metadata_dominance
);
140 nir_metadata_preserve(impl
, nir_metadata_all
);
147 nir_lower_samplers(nir_shader
*shader
)
149 bool progress
= false;
151 /* Next, lower derefs to offsets. */
152 nir_foreach_function(function
, shader
) {
154 progress
|= lower_impl(function
->impl
);