1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
/*
* Copyright © 2014 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Jason Ekstrand (jason@jlekstrand.net)
*
*/
#include "nir.h"
#include "compiler/nir_types.h"
/*
* Lowers all copy intrinsics to sequences of load/store intrinsics.
*/
/* Walks down the deref chain and returns the next deref in the chain whose
* child is a wildcard. In other words, given the chain a[1].foo[*].bar,
* this function will return the deref to foo. Calling it a second time
* with the [*].bar, it will return NULL.
*/
static nir_deref *
deref_next_wildcard_parent(nir_deref *deref)
{
for (nir_deref *tail = deref; tail->child; tail = tail->child) {
if (tail->child->deref_type != nir_deref_type_array)
continue;
nir_deref_array *arr = nir_deref_as_array(tail->child);
if (arr->deref_array_type == nir_deref_array_type_wildcard)
return tail;
}
return NULL;
}
/* This function recursively walks the given deref chain and replaces the
* given copy instruction with an equivalent sequence load/store
* operations.
*
* @copy_instr The copy instruction to replace; new instructions will be
* inserted before this one
*
* @dest_head The head of the destination variable deref chain
*
* @src_head The head of the source variable deref chain
*
* @dest_tail The current tail of the destination variable deref chain;
* this is used for recursion and external callers of this
* function should call it with tail == head
*
* @src_tail The current tail of the source variable deref chain;
* this is used for recursion and external callers of this
* function should call it with tail == head
*
* @state The current variable lowering state
*/
static void
emit_copy_load_store(nir_intrinsic_instr *copy_instr,
nir_deref_var *dest_head, nir_deref_var *src_head,
nir_deref *dest_tail, nir_deref *src_tail,
nir_shader *shader)
{
/* Find the next pair of wildcards */
nir_deref *src_arr_parent = deref_next_wildcard_parent(src_tail);
nir_deref *dest_arr_parent = deref_next_wildcard_parent(dest_tail);
if (src_arr_parent || dest_arr_parent) {
/* Wildcards had better come in matched pairs */
assert(src_arr_parent && dest_arr_parent);
nir_deref_array *src_arr = nir_deref_as_array(src_arr_parent->child);
nir_deref_array *dest_arr = nir_deref_as_array(dest_arr_parent->child);
unsigned length = glsl_get_length(src_arr_parent->type);
/* The wildcards should represent the same number of elements */
assert(length == glsl_get_length(dest_arr_parent->type));
assert(length > 0);
/* Walk over all of the elements that this wildcard refers to and
* call emit_copy_load_store on each one of them */
src_arr->deref_array_type = nir_deref_array_type_direct;
dest_arr->deref_array_type = nir_deref_array_type_direct;
for (unsigned i = 0; i < length; i++) {
src_arr->base_offset = i;
dest_arr->base_offset = i;
emit_copy_load_store(copy_instr, dest_head, src_head,
&dest_arr->deref, &src_arr->deref, shader);
}
src_arr->deref_array_type = nir_deref_array_type_wildcard;
dest_arr->deref_array_type = nir_deref_array_type_wildcard;
} else {
/* In this case, we have no wildcards anymore, so all we have to do
* is just emit the load and store operations. */
src_tail = nir_deref_tail(src_tail);
dest_tail = nir_deref_tail(dest_tail);
assert(src_tail->type == dest_tail->type);
unsigned num_components = glsl_get_vector_elements(src_tail->type);
unsigned bit_size = glsl_get_bit_size(src_tail->type);
nir_intrinsic_instr *load =
nir_intrinsic_instr_create(shader, nir_intrinsic_load_var);
load->num_components = num_components;
load->variables[0] = nir_deref_var_clone(src_head, load);
nir_ssa_dest_init(&load->instr, &load->dest, num_components, bit_size,
NULL);
nir_instr_insert_before(©_instr->instr, &load->instr);
nir_intrinsic_instr *store =
nir_intrinsic_instr_create(shader, nir_intrinsic_store_var);
store->num_components = num_components;
nir_intrinsic_set_write_mask(store, (1 << num_components) - 1);
store->variables[0] = nir_deref_var_clone(dest_head, store);
store->src[0].is_ssa = true;
store->src[0].ssa = &load->dest.ssa;
nir_instr_insert_before(©_instr->instr, &store->instr);
}
}
/* Lowers a copy instruction to a sequence of load/store instructions
*
* The new instructions are placed before the copy instruction in the IR.
*/
void
nir_lower_var_copy_instr(nir_intrinsic_instr *copy, nir_shader *shader)
{
assert(copy->intrinsic == nir_intrinsic_copy_var);
emit_copy_load_store(copy, copy->variables[0], copy->variables[1],
©->variables[0]->deref,
©->variables[1]->deref, shader);
}
static void
lower_var_copies_impl(nir_function_impl *impl)
{
nir_shader *shader = impl->function->shader;
nir_foreach_block(block, impl) {
nir_foreach_instr_safe(instr, block) {
if (instr->type != nir_instr_type_intrinsic)
continue;
nir_intrinsic_instr *copy = nir_instr_as_intrinsic(instr);
if (copy->intrinsic != nir_intrinsic_copy_var)
continue;
nir_lower_var_copy_instr(copy, shader);
nir_instr_remove(©->instr);
ralloc_free(copy);
}
}
}
/* Lowers every copy_var instruction in the program to a sequence of
* load/store instructions.
*/
void
nir_lower_var_copies(nir_shader *shader)
{
nir_foreach_function(function, shader) {
if (function->impl)
lower_var_copies_impl(function->impl);
}
}
|
