1 /*
2 * Copyright (C) 2021 Collabora, Ltd.
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 FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 */
23
24 #include "compiler.h"
25 #include "util/u_memory.h"
26
27 /* Validatation doesn't make sense in release builds */
28 #ifndef NDEBUG
29
30 /* Validate that all sources are initialized in all read components. This is
31 * required for correct register allocation. We check a weaker condition, that
32 * all sources that are read are written at some point (equivalently, the live
33 * set is empty at the start of the program). TODO: Strengthen */
34
35 bool
bi_validate_initialization(bi_context * ctx)36 bi_validate_initialization(bi_context *ctx)
37 {
38 bool success = true;
39
40 /* Calculate the live set */
41 bi_block *entry = bi_entry_block(ctx);
42 unsigned temp_count = bi_max_temp(ctx);
43 bi_compute_liveness(ctx);
44
45 /* Validate that the live set is indeed empty */
46 for (unsigned i = 0; i < temp_count; ++i) {
47 if (entry->live_in[i] == 0) continue;
48
49 fprintf(stderr, "%s%u\n", (i & PAN_IS_REG) ? "r" : "", i >> 1);
50 success = false;
51 }
52
53 return success;
54 }
55
56 /*
57 * Validate that there are no bi_registers accessed except at the beginning of
58 * the start block, and that preloads are unique. This ensures RA can coalesce
59 * preloads without interference tracking.
60 */
61 static bool
bi_validate_preload(bi_context * ctx)62 bi_validate_preload(bi_context *ctx)
63 {
64 bool start = true;
65 uint64_t preloaded = 0;
66
67 bi_foreach_block(ctx, block) {
68 bi_foreach_instr_in_block(block, I) {
69 /* No instruction should have a register destination */
70 bi_foreach_dest(I, d) {
71 if (I->dest[d].type == BI_INDEX_REGISTER)
72 return false;
73 }
74
75 /* Preloads are register moves at the start */
76 bool is_preload =
77 start && I->op == BI_OPCODE_MOV_I32 &&
78 I->src[0].type == BI_INDEX_REGISTER;
79
80 /* After the first nonpreload, we're done preloading */
81 start &= is_preload;
82
83 /* Only preloads may have a register source */
84 bi_foreach_src(I, s) {
85 if (I->src[s].type == BI_INDEX_REGISTER && !is_preload)
86 return false;
87 }
88
89 /* Check uniqueness */
90 if (is_preload) {
91 unsigned r = I->src[0].value;
92
93 if (preloaded & BITFIELD64_BIT(r))
94 return false;
95
96 preloaded |= BITFIELD64_BIT(r);
97 }
98 }
99
100 /* Only the first block may preload */
101 start = false;
102 }
103
104 return true;
105 }
106
107 /*
108 * Type check the dimensionality of sources and destinations. This occurs in two
109 * passes, first to gather all destination sizes, second to validate all source
110 * sizes. Depends on SSA form.
111 */
112 static bool
bi_validate_width(bi_context * ctx)113 bi_validate_width(bi_context *ctx)
114 {
115 bool succ = true;
116 uint8_t *width = calloc(ctx->ssa_alloc, sizeof(uint8_t));
117
118 bi_foreach_instr_global(ctx, I) {
119 bi_foreach_dest(I, d) {
120 if (bi_is_null(I->dest[d])) continue;
121 if (!bi_is_ssa(I->dest[d])) continue;
122
123 unsigned v = I->dest[d].value;
124 assert(width[v] == 0 && "broken SSA");
125
126 width[v] = bi_count_write_registers(I, d);
127 }
128 }
129
130 bi_foreach_instr_global(ctx, I) {
131 bi_foreach_src(I, s) {
132 if (!bi_is_ssa(I->src[s])) continue;
133
134 unsigned v = I->src[s].value;
135 unsigned n = bi_count_read_registers(I, s);
136
137 if (width[v] != n) {
138 succ = false;
139 fprintf(stderr,
140 "source %u, expected width %u, got width %u\n",
141 s, n, width[v]);
142 bi_print_instr(I, stderr);
143 fprintf(stderr, "\n");
144 }
145 }
146 }
147
148 free(width);
149 return succ;
150 }
151
152 void
bi_validate(bi_context * ctx,const char * after)153 bi_validate(bi_context *ctx, const char *after)
154 {
155 bool fail = false;
156
157 if (bifrost_debug & BIFROST_DBG_NOVALIDATE)
158 return;
159
160 if (!bi_validate_initialization(ctx)) {
161 fprintf(stderr, "Uninitialized data read after %s\n", after);
162 fail = true;
163 }
164
165 if (!bi_validate_preload(ctx)) {
166 fprintf(stderr, "Unexpected preload after %s\n", after);
167 fail = true;
168 }
169
170 if (!bi_validate_width(ctx)) {
171 fprintf(stderr, "Unexpected vector with after %s\n", after);
172 fail = true;
173 }
174
175 if (fail) {
176 bi_print_shader(ctx, stderr);
177 exit(1);
178 }
179 }
180
181 #endif /* NDEBUG */
182