1/*
2 * Copyright (C) 2018 Alyssa Rosenzweig
3 * Copyright (C) 2019 Collabora, Ltd.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 */
24
25#include "compiler.h"
26#include "midgard_ops.h"
27
28bool
29midgard_opt_copy_prop(compiler_context *ctx, midgard_block *block)
30{
31        bool progress = false;
32
33        mir_foreach_instr_in_block_safe(block, ins) {
34                if (ins->type != TAG_ALU_4) continue;
35                if (!OP_IS_MOVE(ins->op)) continue;
36                if (ins->is_pack) continue;
37
38                unsigned from = ins->src[1];
39                unsigned to = ins->dest;
40
41                /* We only work on pure SSA */
42
43                if (to & PAN_IS_REG) continue;
44                if (from & PAN_IS_REG) continue;
45
46                /* Constant propagation is not handled here, either */
47                if (ins->has_inline_constant) continue;
48                if (ins->has_constants) continue;
49
50                /* Modifier propagation is not handled here */
51                if (mir_nontrivial_mod(ins, 1, false)) continue;
52                if (mir_nontrivial_outmod(ins)) continue;
53
54                /* Shortened arguments (bias for textures, extra load/store
55                 * arguments, etc.) do not get a swizzle, only a start
56                 * component and even that is restricted. Fragment writeout
57                 * doesn't even get that much */
58
59                bool skip = false;
60
61                mir_foreach_instr_global(ctx, q) {
62                        bool is_tex = q->type == TAG_TEXTURE_4;
63                        bool is_ldst = q->type == TAG_LOAD_STORE_4;
64                        bool is_branch = q->compact_branch;
65
66                        if (!(is_tex || is_ldst || is_branch)) continue;
67
68                        /* For textures, we get a real swizzle for the
69                         * coordinate and the content. For stores, we get one.
70                         * For loads, we get none. */
71
72                        unsigned start =
73                                is_tex ? 2 :
74                                OP_IS_STORE(q->op) ? 1 : 0;
75
76                        mir_foreach_src(q, s) {
77                                if ((s >= start) && q->src[s] == to) {
78                                        skip = true;
79                                        break;
80                                }
81                        }
82                }
83
84                if (skip)
85                        continue;
86
87                if (ctx->blend_src1 == to)
88                        ctx->blend_src1 = from;
89
90                /* We're clear -- rewrite, composing the swizzle */
91                mir_rewrite_index_src_swizzle(ctx, to, from, ins->swizzle[1]);
92                mir_remove_instruction(ins);
93                progress |= true;
94        }
95
96        return progress;
97}
98