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_qir_emit_uniform_stream_resets.c
26  *
27  * Adds updates to the uniform stream address at the start of each basic block
28  * that uses uniforms.
29  *
30  * This will be done just before the translation to QPU instructions, once we
31  * have performed optimization know how many uniforms are used in each block.
32  */
33 
34 #include "vc4_qir.h"
35 #include "util/hash_table.h"
36 #include "util/u_math.h"
37 
38 static bool
block_reads_any_uniform(struct qblock * block)39 block_reads_any_uniform(struct qblock *block)
40 {
41         qir_for_each_inst(inst, block) {
42                 if (qir_has_uniform_read(inst))
43                         return true;
44         }
45 
46         return false;
47 }
48 
49 void
qir_emit_uniform_stream_resets(struct vc4_compile * c)50 qir_emit_uniform_stream_resets(struct vc4_compile *c)
51 {
52         uint32_t uniform_count = 0;
53 
54         qir_for_each_block(block, c) {
55                 if (block != qir_entry_block(c) &&
56                     (block_reads_any_uniform(block) ||
57                      block == qir_exit_block(c))) {
58                         struct qreg t = qir_get_temp(c);
59                         struct qreg uni_addr =
60                                 qir_uniform(c, QUNIFORM_UNIFORMS_ADDRESS, 0);
61 
62                         /* Load the offset of the next uniform in the stream
63                          * after the one we're generating here.
64                          */
65                         struct qinst *load_imm =
66                                 qir_inst(QOP_LOAD_IMM,
67                                          t,
68                                          qir_reg(QFILE_LOAD_IMM,
69                                                  (uniform_count + 1) * 4),
70                                          c->undef);
71                         struct qinst *add =
72                                 qir_inst(QOP_UNIFORMS_RESET, c->undef,
73                                          t, uni_addr);
74 
75                         /* Pushes to the top of the block, so in reverse
76                          * order.
77                          */
78                         list_add(&add->link, &block->instructions);
79                         list_add(&load_imm->link, &block->instructions);
80                 }
81 
82                 qir_for_each_inst(inst, block) {
83                         if (qir_has_uniform_read(inst))
84                                 uniform_count++;
85                 }
86         }
87 }
88