1 /*
2  * Copyright 2017 Advanced Micro Devices, Inc.
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  * on the rights to use, copy, modify, merge, publish, distribute, sub
8  * license, and/or sell copies of the Software, and to permit persons to whom
9  * the 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 NON-INFRINGEMENT. IN NO EVENT SHALL
18  * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
21  * USE OR OTHER DEALINGS IN THE SOFTWARE.
22  */
23 
24 /*
25  * Remap load_uniform intrinsics to UBO accesses of UBO binding point 0.
26  * Simultaneously, remap existing UBO accesses by increasing their binding
27  * point by 1.
28  *
29  * Note that nir_intrinsic_load_uniform base/ranges can be set in different
30  * units, and the multiplier argument caters to supporting these different
31  * units.
32  *
33  * For example:
34  * - st_glsl_to_nir for PIPE_CAP_PACKED_UNIFORMS uses dwords (4 bytes) so the
35  *   multiplier should be 4
36  * - st_glsl_to_nir for !PIPE_CAP_PACKED_UNIFORMS uses vec4s so the
37  *   multiplier should be 16
38  * - tgsi_to_nir uses vec4s, so the multiplier should be 16
39  */
40 
41 #include "nir.h"
42 #include "nir_builder.h"
43 
44 static bool
lower_instr(nir_intrinsic_instr * instr,nir_builder * b,int multiplier)45 lower_instr(nir_intrinsic_instr *instr, nir_builder *b, int multiplier)
46 {
47    b->cursor = nir_before_instr(&instr->instr);
48 
49    /* Increase all UBO binding points by 1. */
50    if (instr->intrinsic == nir_intrinsic_load_ubo &&
51        !b->shader->info.first_ubo_is_default_ubo) {
52       nir_ssa_def *old_idx = nir_ssa_for_src(b, instr->src[0], 1);
53       nir_ssa_def *new_idx = nir_iadd(b, old_idx, nir_imm_int(b, 1));
54       nir_instr_rewrite_src(&instr->instr, &instr->src[0],
55                             nir_src_for_ssa(new_idx));
56       return true;
57    }
58 
59    if (instr->intrinsic == nir_intrinsic_load_uniform) {
60       nir_ssa_def *ubo_idx = nir_imm_int(b, 0);
61       nir_ssa_def *ubo_offset =
62          nir_iadd(b, nir_imm_int(b, multiplier * nir_intrinsic_base(instr)),
63                   nir_imul(b, nir_imm_int(b, multiplier),
64                            nir_ssa_for_src(b, instr->src[0], 1)));
65 
66       nir_intrinsic_instr *load =
67          nir_intrinsic_instr_create(b->shader, nir_intrinsic_load_ubo);
68       load->num_components = instr->num_components;
69       load->src[0] = nir_src_for_ssa(ubo_idx);
70       load->src[1] = nir_src_for_ssa(ubo_offset);
71       assert(instr->dest.ssa.bit_size >= 8);
72 
73       /* If it's const, set the alignment to our known constant offset.  If
74        * not, set it to a pessimistic value based on the multiplier (or the
75        * scalar size, for qword loads).
76        *
77        * We could potentially set up stricter alignments for indirects by
78        * knowing what features are enabled in the APIs (see comment in
79        * nir_lower_ubo_vec4.c)
80        */
81       if (nir_src_is_const(instr->src[0])) {
82          nir_intrinsic_set_align(load, NIR_ALIGN_MUL_MAX,
83                                  (nir_src_as_uint(instr->src[0]) +
84                                   nir_intrinsic_base(instr) * multiplier) %
85                                  NIR_ALIGN_MUL_MAX);
86       } else {
87          nir_intrinsic_set_align(load, MAX2(multiplier,
88                                             instr->dest.ssa.bit_size / 8), 0);
89       }
90       nir_ssa_dest_init(&load->instr, &load->dest,
91                         load->num_components, instr->dest.ssa.bit_size,
92                         instr->dest.ssa.name);
93       nir_builder_instr_insert(b, &load->instr);
94       nir_ssa_def_rewrite_uses(&instr->dest.ssa, nir_src_for_ssa(&load->dest.ssa));
95 
96       nir_intrinsic_set_range_base(load, nir_intrinsic_base(instr) * multiplier);
97       nir_intrinsic_set_range(load, nir_intrinsic_range(instr) * multiplier);
98 
99       nir_instr_remove(&instr->instr);
100       return true;
101    }
102 
103    return false;
104 }
105 
106 bool
nir_lower_uniforms_to_ubo(nir_shader * shader,int multiplier)107 nir_lower_uniforms_to_ubo(nir_shader *shader, int multiplier)
108 {
109    bool progress = false;
110 
111    nir_foreach_function(function, shader) {
112       if (function->impl) {
113          nir_builder builder;
114          nir_builder_init(&builder, function->impl);
115          nir_foreach_block(block, function->impl) {
116             nir_foreach_instr_safe(instr, block) {
117                if (instr->type == nir_instr_type_intrinsic)
118                   progress |= lower_instr(nir_instr_as_intrinsic(instr),
119                                           &builder,
120                                           multiplier);
121             }
122          }
123 
124          nir_metadata_preserve(function->impl, nir_metadata_block_index |
125                                                nir_metadata_dominance);
126       }
127    }
128 
129    if (progress) {
130       if (!shader->info.first_ubo_is_default_ubo) {
131          nir_foreach_variable_with_modes(var, shader, nir_var_mem_ubo) {
132             var->data.binding++;
133             /* only increment location for ubo arrays */
134             if (glsl_without_array(var->type) == var->interface_type &&
135                 glsl_type_is_array(var->type))
136                var->data.location++;
137          }
138       }
139       shader->info.num_ubos++;
140 
141       if (shader->num_uniforms > 0) {
142          const struct glsl_type *type = glsl_array_type(glsl_vec4_type(),
143                                                         shader->num_uniforms, 0);
144          nir_variable *ubo = nir_variable_create(shader, nir_var_mem_ubo, type,
145                                                  "uniform_0");
146          ubo->data.binding = 0;
147 
148          struct glsl_struct_field field = {
149             .type = type,
150             .name = "data",
151             .location = -1,
152          };
153          ubo->interface_type =
154                glsl_interface_type(&field, 1, GLSL_INTERFACE_PACKING_STD430,
155                                    false, "__ubo0_interface");
156       }
157    }
158 
159    shader->info.first_ubo_is_default_ubo = true;
160    return progress;
161 }
162