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
190
191
192
193
194
|
/*
* 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"
/*
* This pass lowers the neg, abs, and sat operations to source modifiers on
* ALU operations to make things nicer for the backend. It's just much
* easier to not have them when we're doing optimizations.
*/
static bool
nir_lower_to_source_mods_block(nir_block *block)
{
nir_foreach_instr(instr, block) {
if (instr->type != nir_instr_type_alu)
continue;
nir_alu_instr *alu = nir_instr_as_alu(instr);
for (unsigned i = 0; i < nir_op_infos[alu->op].num_inputs; i++) {
if (!alu->src[i].src.is_ssa)
continue;
if (alu->src[i].src.ssa->parent_instr->type != nir_instr_type_alu)
continue;
nir_alu_instr *parent = nir_instr_as_alu(alu->src[i].src.ssa->parent_instr);
if (parent->dest.saturate)
continue;
switch (nir_alu_type_get_base_type(nir_op_infos[alu->op].input_types[i])) {
case nir_type_float:
if (parent->op != nir_op_fmov)
continue;
break;
case nir_type_int:
if (parent->op != nir_op_imov)
continue;
break;
default:
continue;
}
/* We can only do a rewrite if the source we are copying is SSA.
* Otherwise, moving the read might invalidly reorder reads/writes
* on a register.
*/
if (!parent->src[0].src.is_ssa)
continue;
nir_instr_rewrite_src(instr, &alu->src[i].src, parent->src[0].src);
if (alu->src[i].abs) {
/* abs trumps both neg and abs, do nothing */
} else {
alu->src[i].negate = (alu->src[i].negate != parent->src[0].negate);
alu->src[i].abs |= parent->src[0].abs;
}
for (int j = 0; j < 4; ++j) {
if (!nir_alu_instr_channel_used(alu, i, j))
continue;
alu->src[i].swizzle[j] = parent->src[0].swizzle[alu->src[i].swizzle[j]];
}
if (list_empty(&parent->dest.dest.ssa.uses) &&
list_empty(&parent->dest.dest.ssa.if_uses))
nir_instr_remove(&parent->instr);
}
switch (alu->op) {
case nir_op_fsat:
alu->op = nir_op_fmov;
alu->dest.saturate = true;
break;
case nir_op_ineg:
alu->op = nir_op_imov;
alu->src[0].negate = !alu->src[0].negate;
break;
case nir_op_fneg:
alu->op = nir_op_fmov;
alu->src[0].negate = !alu->src[0].negate;
break;
case nir_op_iabs:
alu->op = nir_op_imov;
alu->src[0].abs = true;
alu->src[0].negate = false;
break;
case nir_op_fabs:
alu->op = nir_op_fmov;
alu->src[0].abs = true;
alu->src[0].negate = false;
break;
default:
break;
}
/* We've covered sources. Now we're going to try and saturate the
* destination if we can.
*/
if (!alu->dest.dest.is_ssa)
continue;
/* We can only saturate float destinations */
if (nir_alu_type_get_base_type(nir_op_infos[alu->op].output_type) !=
nir_type_float)
continue;
if (!list_empty(&alu->dest.dest.ssa.if_uses))
continue;
bool all_children_are_sat = true;
nir_foreach_use(&alu->dest.dest.ssa, child_src) {
assert(child_src->is_ssa);
nir_instr *child = child_src->parent_instr;
if (child->type != nir_instr_type_alu) {
all_children_are_sat = false;
continue;
}
nir_alu_instr *child_alu = nir_instr_as_alu(child);
if (child_alu->src[0].negate || child_alu->src[0].abs) {
all_children_are_sat = false;
continue;
}
if (child_alu->op != nir_op_fsat &&
!(child_alu->op == nir_op_fmov && child_alu->dest.saturate)) {
all_children_are_sat = false;
continue;
}
}
if (!all_children_are_sat)
continue;
alu->dest.saturate = true;
nir_foreach_use(&alu->dest.dest.ssa, child_src) {
assert(child_src->is_ssa);
nir_instr *child = child_src->parent_instr;
assert(child->type == nir_instr_type_alu);
nir_alu_instr *child_alu = nir_instr_as_alu(child);
child_alu->op = nir_op_fmov;
child_alu->dest.saturate = false;
/* We could propagate the dest of our instruction to the
* destinations of the uses here. However, one quick round of
* copy propagation will clean that all up and then we don't have
* the complexity.
*/
}
}
return true;
}
void
nir_lower_to_source_mods(nir_shader *shader)
{
nir_foreach_function(shader, function) {
if (function->impl) {
nir_foreach_block(block, function->impl) {
nir_lower_to_source_mods_block(block);
}
}
}
}
|
