xref: /aosp_15_r20/external/mesa3d/src/compiler/nir/nir_lower_uniforms_to_ubo.c (revision 6104692788411f58d303aa86923a9ff6ecaded22)
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 nir_load_ubo or nir_load_ubo_vec4 accesses
26  * of UBO binding point 0. Simultaneously, remap existing UBO accesses by
27  * increasing their binding point by 1.
28  *
29  * For PIPE_CAP_PACKED_UNIFORMS, dword_packed should be set to indicate that
30  * nir_intrinsic_load_uniform is in increments of dwords instead of vec4s.
31  *
32  * If load_vec4 is set, then nir_intrinsic_load_ubo_vec4 will be generated
33  * instead of nir_intrinsic_load_ubo, saving addressing math for hardawre
34  * needing aligned vec4 loads in increments of vec4s (such as TGSI CONST file
35  * loads).
36  */
37 
38 #include "nir.h"
39 #include "nir_builder.h"
40 
41 struct nir_lower_uniforms_to_ubo_state {
42    bool dword_packed;
43    bool load_vec4;
44 };
45 
46 static bool
nir_lower_uniforms_to_ubo_instr(nir_builder * b,nir_instr * instr,void * data)47 nir_lower_uniforms_to_ubo_instr(nir_builder *b, nir_instr *instr, void *data)
48 {
49    struct nir_lower_uniforms_to_ubo_state *state = data;
50 
51    if (instr->type != nir_instr_type_intrinsic)
52       return false;
53 
54    nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
55 
56    b->cursor = nir_before_instr(&intr->instr);
57 
58    /* Increase all UBO binding points by 1. */
59    if (intr->intrinsic == nir_intrinsic_load_ubo &&
60        !b->shader->info.first_ubo_is_default_ubo) {
61       nir_def *old_idx = intr->src[0].ssa;
62       nir_def *new_idx = nir_iadd_imm(b, old_idx, 1);
63       nir_src_rewrite(&intr->src[0], new_idx);
64       return true;
65    }
66 
67    if (intr->intrinsic == nir_intrinsic_load_uniform) {
68       nir_def *ubo_idx = nir_imm_int(b, 0);
69       nir_def *uniform_offset = intr->src[0].ssa;
70 
71       assert(intr->def.bit_size >= 8);
72       nir_def *load_result;
73       if (state->load_vec4) {
74          /* No asking us to generate load_vec4 when you've packed your uniforms
75           * as dwords instead of vec4s.
76           */
77          assert(!state->dword_packed);
78          load_result = nir_load_ubo_vec4(b, intr->num_components, intr->def.bit_size,
79                                          ubo_idx, uniform_offset, .base = nir_intrinsic_base(intr));
80       } else {
81          /* For PIPE_CAP_PACKED_UNIFORMS, the uniforms are packed with the
82           * base/offset in dword units instead of vec4 units.
83           */
84          int multiplier = state->dword_packed ? 4 : 16;
85          load_result = nir_load_ubo(b, intr->num_components, intr->def.bit_size,
86                                     ubo_idx,
87                                     nir_iadd_imm(b, nir_imul_imm(b, uniform_offset, multiplier),
88                                                  nir_intrinsic_base(intr) * multiplier));
89          nir_intrinsic_instr *load = nir_instr_as_intrinsic(load_result->parent_instr);
90 
91          /* If it's const, set the alignment to our known constant offset.  If
92           * not, set it to a pessimistic value based on the multiplier (or the
93           * scalar size, for qword loads).
94           *
95           * We could potentially set up stricter alignments for indirects by
96           * knowing what features are enabled in the APIs (see comment in
97           * nir_lower_ubo_vec4.c)
98           */
99          if (nir_src_is_const(intr->src[0])) {
100             nir_intrinsic_set_align(load, NIR_ALIGN_MUL_MAX,
101                                     (nir_src_as_uint(intr->src[0]) +
102                                      nir_intrinsic_base(intr) * multiplier) %
103                                        NIR_ALIGN_MUL_MAX);
104          } else {
105             nir_intrinsic_set_align(load, MAX2(multiplier, intr->def.bit_size / 8), 0);
106          }
107 
108          nir_intrinsic_set_range_base(load, nir_intrinsic_base(intr) * multiplier);
109          nir_intrinsic_set_range(load, nir_intrinsic_range(intr) * multiplier);
110       }
111       nir_def_replace(&intr->def, load_result);
112       return true;
113    }
114 
115    return false;
116 }
117 
118 bool
nir_lower_uniforms_to_ubo(nir_shader * shader,bool dword_packed,bool load_vec4)119 nir_lower_uniforms_to_ubo(nir_shader *shader, bool dword_packed, bool load_vec4)
120 {
121    bool progress = false;
122 
123    struct nir_lower_uniforms_to_ubo_state state = {
124       .dword_packed = dword_packed,
125       .load_vec4 = load_vec4,
126    };
127 
128    progress = nir_shader_instructions_pass(shader,
129                                            nir_lower_uniforms_to_ubo_instr,
130                                            nir_metadata_control_flow,
131                                            &state);
132 
133    if (progress) {
134       if (!shader->info.first_ubo_is_default_ubo) {
135          nir_foreach_variable_with_modes(var, shader, nir_var_mem_ubo) {
136             var->data.binding++;
137             if (var->data.driver_location != -1)
138                var->data.driver_location++;
139             /* only increment location for ubo arrays */
140             if (glsl_without_array(var->type) == var->interface_type &&
141                 glsl_type_is_array(var->type))
142                var->data.location++;
143          }
144       }
145       shader->info.num_ubos++;
146 
147       if (shader->num_uniforms > 0) {
148          const struct glsl_type *type = glsl_array_type(glsl_vec4_type(),
149                                                         shader->num_uniforms, 16);
150          nir_variable *ubo = nir_variable_create(shader, nir_var_mem_ubo, type,
151                                                  "uniform_0");
152          ubo->data.binding = 0;
153          ubo->data.explicit_binding = 1;
154 
155          struct glsl_struct_field field = {
156             .type = type,
157             .name = "data",
158             .location = -1,
159          };
160          ubo->interface_type =
161             glsl_interface_type(&field, 1, GLSL_INTERFACE_PACKING_STD430,
162                                 false, "__ubo0_interface");
163       }
164    }
165 
166    shader->info.first_ubo_is_default_ubo = true;
167    return progress;
168 }
169