1 /*
2  * Copyright © 2014 Broadcom
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 /**
25  * @file vc4_reorder_uniforms.c
26  *
27  * After optimization has occurred, rewrites the shader to have uniform reads
28  * reading from the c->uniform_contents[] in order, exactly once each.
29  *
30  * This allows optimization and instruction scheduling to move things around
31  * without worrying about how the hardware has the "each uniform read bumps
32  * the uniform read address" property.
33  */
34 
35 #include "util/ralloc.h"
36 #include "util/u_math.h"
37 #include "vc4_qir.h"
38 
39 void
qir_reorder_uniforms(struct vc4_compile * c)40 qir_reorder_uniforms(struct vc4_compile *c)
41 {
42         uint32_t *uniform_index = NULL;
43         uint32_t uniform_index_size = 0;
44         uint32_t next_uniform = 0;
45 
46         qir_for_each_inst_inorder(inst, c) {
47                 uint32_t new = ~0;
48 
49                 for (int i = 0; i < qir_get_nsrc(inst); i++) {
50                         if (inst->src[i].file != QFILE_UNIF)
51                                 continue;
52 
53                         if (new == ~0) {
54                                 new = next_uniform++;
55                                 if (uniform_index_size <= new) {
56                                         uniform_index_size =
57                                                 MAX2(uniform_index_size * 2, 16);
58                                         uniform_index =
59                                                 realloc(uniform_index,
60                                                         uniform_index_size *
61                                                         sizeof(uint32_t));
62                                 }
63                         } else {
64                                 /* If we've got two uniform references in this
65                                  * instruction, they need to be the same
66                                  * uniform value.
67                                  */
68                                 assert(inst->src[i].index == uniform_index[new]);
69                         }
70 
71                         uniform_index[new] = inst->src[i].index;
72                         inst->src[i].index = new;
73                 }
74         }
75 
76         uint32_t *uniform_data = ralloc_array(c, uint32_t, next_uniform);
77         enum quniform_contents *uniform_contents =
78                 ralloc_array(c, enum quniform_contents, next_uniform);
79 
80         for (uint32_t i = 0; i < next_uniform; i++) {
81                 uniform_data[i] = c->uniform_data[uniform_index[i]];
82                 uniform_contents[i] = c->uniform_contents[uniform_index[i]];
83         }
84 
85         ralloc_free(c->uniform_data);
86         c->uniform_data = uniform_data;
87         ralloc_free(c->uniform_contents);
88         c->uniform_contents = uniform_contents;
89         c->num_uniforms = next_uniform;
90 
91         free(uniform_index);
92 }
93