1 /*
2 * Copyright © 2014 Valve Corporation
3 * SPDX-License-Identifier: MIT
4 */
5
6 #include "ir3.h"
7
8 #define XXH_INLINE_ALL
9 #include "util/xxhash.h"
10
11 /* This pass handles CSE'ing repeated expressions created in the process of
12 * translating from NIR. Currently this is just collect's. Also, currently
13 * this is intra-block only, to make it work over multiple block we'd need to
14 * bring forward dominance calculation.
15 */
16
17 #define HASH(hash, data) XXH32(&(data), sizeof(data), hash)
18
19 static uint32_t
hash_instr(const void * data)20 hash_instr(const void *data)
21 {
22 const struct ir3_instruction *instr = data;
23 uint32_t hash = 0;
24
25 hash = HASH(hash, instr->opc);
26 hash = HASH(hash, instr->dsts[0]->flags);
27 foreach_src (src, (struct ir3_instruction *)instr) {
28 if (src->flags & IR3_REG_CONST) {
29 if (src->flags & IR3_REG_RELATIV)
30 hash = HASH(hash, src->array.offset);
31 else
32 hash = HASH(hash, src->num);
33 } else if (src->flags & IR3_REG_IMMED) {
34 hash = HASH(hash, src->uim_val);
35 } else {
36 if (src->flags & IR3_REG_ARRAY)
37 hash = HASH(hash, src->array.offset);
38 hash = HASH(hash, src->def);
39 }
40 }
41
42 if (opc_cat(instr->opc) == 1) {
43 hash = HASH(hash, instr->cat1.dst_type);
44 hash = HASH(hash, instr->cat1.src_type);
45 hash = HASH(hash, instr->cat1.round);
46 }
47
48 return hash;
49 }
50
51 static bool
instrs_equal(const struct ir3_instruction * i1,const struct ir3_instruction * i2)52 instrs_equal(const struct ir3_instruction *i1, const struct ir3_instruction *i2)
53 {
54 if (i1->opc != i2->opc)
55 return false;
56
57 if (i1->dsts_count != i2->dsts_count)
58 return false;
59
60 if (i1->srcs_count != i2->srcs_count)
61 return false;
62
63 if (i1->dsts[0]->flags != i2->dsts[0]->flags)
64 return false;
65
66 for (unsigned i = 0; i < i1->srcs_count; i++) {
67 const struct ir3_register *i1_reg = i1->srcs[i], *i2_reg = i2->srcs[i];
68
69 if (i1_reg->flags != i2_reg->flags)
70 return false;
71
72 if (i1_reg->flags & IR3_REG_CONST) {
73 if (i1_reg->flags & IR3_REG_RELATIV) {
74 if (i1_reg->array.offset != i2_reg->array.offset)
75 return false;
76 } else {
77 if (i1_reg->num != i2_reg->num)
78 return false;
79 }
80 } else if (i1_reg->flags & IR3_REG_IMMED) {
81 if (i1_reg->uim_val != i2_reg->uim_val)
82 return false;
83 } else {
84 if (i1_reg->flags & IR3_REG_ARRAY) {
85 if (i1_reg->array.offset != i2_reg->array.offset)
86 return false;
87 }
88 if (i1_reg->def != i2_reg->def)
89 return false;
90 }
91 }
92
93 if (opc_cat(i1->opc) == 1) {
94 if (i1->cat1.dst_type != i2->cat1.dst_type ||
95 i1->cat1.src_type != i2->cat1.src_type ||
96 i1->cat1.round != i2->cat1.round)
97 return false;
98 }
99
100 return true;
101 }
102
103 static bool
instr_can_cse(const struct ir3_instruction * instr)104 instr_can_cse(const struct ir3_instruction *instr)
105 {
106 if (instr->opc != OPC_META_COLLECT && instr->opc != OPC_MOV)
107 return false;
108
109 if (!is_dest_gpr(instr->dsts[0]) || (instr->dsts[0]->flags & IR3_REG_ARRAY))
110 return false;
111
112 return true;
113 }
114
115 static bool
cmp_func(const void * data1,const void * data2)116 cmp_func(const void *data1, const void *data2)
117 {
118 return instrs_equal(data1, data2);
119 }
120
121 bool
ir3_cse(struct ir3 * ir)122 ir3_cse(struct ir3 *ir)
123 {
124 struct set *instr_set = _mesa_set_create(NULL, hash_instr, cmp_func);
125 foreach_block (block, &ir->block_list) {
126 _mesa_set_clear(instr_set, NULL);
127
128 foreach_instr (instr, &block->instr_list) {
129 instr->data = NULL;
130
131 if (!instr_can_cse(instr))
132 continue;
133
134 bool found;
135 struct set_entry *entry =
136 _mesa_set_search_or_add(instr_set, instr, &found);
137 if (found)
138 instr->data = (void *)entry->key;
139 }
140 }
141
142 bool progress = false;
143 foreach_block (block, &ir->block_list) {
144 foreach_instr (instr, &block->instr_list) {
145 foreach_src (src, instr) {
146 if ((src->flags & IR3_REG_SSA) && src->def &&
147 src->def->instr->data) {
148 progress = true;
149 struct ir3_instruction *instr = src->def->instr->data;
150 src->def = instr->dsts[0];
151 }
152 }
153 }
154 }
155
156 _mesa_set_destroy(instr_set, NULL);
157 return progress;
158 }
159