aboutsummaryrefslogtreecommitdiffstats
path: root/src/compiler/nir/nir_sweep.c
blob: b6b56aa078c91599fdee911286f39b12d3f1a3b5 (plain)
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
/*
 * Copyright © 2015 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.
 */

#include "nir.h"

/**
 * \file nir_sweep.c
 *
 * The nir_sweep() pass performs a mark and sweep pass over a nir_shader's associated
 * memory - anything still connected to the program will be kept, and any dead memory
 * we dropped on the floor will be freed.
 *
 * The expectation is that drivers should call this when finished compiling the shader
 * (after any optimization, lowering, and so on).  However, it's also fine to call it
 * earlier, and even many times, trading CPU cycles for memory savings.
 */

#define steal_list(mem_ctx, type, list) \
   foreach_list_typed(type, obj, node, list) { ralloc_steal(mem_ctx, obj); }

static void sweep_cf_node(nir_shader *nir, nir_cf_node *cf_node);

static bool
sweep_src_indirect(nir_src *src, void *nir)
{
   if (!src->is_ssa && src->reg.indirect)
      ralloc_steal(nir, src->reg.indirect);

   return true;
}

static bool
sweep_dest_indirect(nir_dest *dest, void *nir)
{
   if (!dest->is_ssa && dest->reg.indirect)
      ralloc_steal(nir, dest->reg.indirect);

   return true;
}

static void
sweep_block(nir_shader *nir, nir_block *block)
{
   ralloc_steal(nir, block);

   /* sweep_impl will mark all metadata invalid.  We can safely release all of
    * this here.
    */
   ralloc_free(block->live_in);
   block->live_in = NULL;

   ralloc_free(block->live_out);
   block->live_out = NULL;

   nir_foreach_instr(instr, block) {
      ralloc_steal(nir, instr);

      nir_foreach_src(instr, sweep_src_indirect, nir);
      nir_foreach_dest(instr, sweep_dest_indirect, nir);
   }
}

static void
sweep_if(nir_shader *nir, nir_if *iff)
{
   ralloc_steal(nir, iff);

   foreach_list_typed(nir_cf_node, cf_node, node, &iff->then_list) {
      sweep_cf_node(nir, cf_node);
   }

   foreach_list_typed(nir_cf_node, cf_node, node, &iff->else_list) {
      sweep_cf_node(nir, cf_node);
   }
}

static void
sweep_loop(nir_shader *nir, nir_loop *loop)
{
   ralloc_steal(nir, loop);

   foreach_list_typed(nir_cf_node, cf_node, node, &loop->body) {
      sweep_cf_node(nir, cf_node);
   }
}

static void
sweep_cf_node(nir_shader *nir, nir_cf_node *cf_node)
{
   switch (cf_node->type) {
   case nir_cf_node_block:
      sweep_block(nir, nir_cf_node_as_block(cf_node));
      break;
   case nir_cf_node_if:
      sweep_if(nir, nir_cf_node_as_if(cf_node));
      break;
   case nir_cf_node_loop:
      sweep_loop(nir, nir_cf_node_as_loop(cf_node));
      break;
   default:
      unreachable("Invalid CF node type");
   }
}

static void
sweep_impl(nir_shader *nir, nir_function_impl *impl)
{
   ralloc_steal(nir, impl);

   steal_list(nir, nir_variable, &impl->locals);
   steal_list(nir, nir_register, &impl->registers);

   foreach_list_typed(nir_cf_node, cf_node, node, &impl->body) {
      sweep_cf_node(nir, cf_node);
   }

   sweep_block(nir, impl->end_block);

   /* Wipe out all the metadata, if any. */
   nir_metadata_preserve(impl, nir_metadata_none);
}

static void
sweep_function(nir_shader *nir, nir_function *f)
{
   ralloc_steal(nir, f);
   ralloc_steal(nir, f->params);

   if (f->impl)
      sweep_impl(nir, f->impl);
}

void
nir_sweep(nir_shader *nir)
{
   void *rubbish = ralloc_context(NULL);

   /* First, move ownership of all the memory to a temporary context; assume dead. */
   ralloc_adopt(rubbish, nir);

   ralloc_steal(nir, (char *)nir->info.name);
   if (nir->info.label)
      ralloc_steal(nir, (char *)nir->info.label);

   /* Variables and registers are not dead.  Steal them back. */
   steal_list(nir, nir_variable, &nir->uniforms);
   steal_list(nir, nir_variable, &nir->inputs);
   steal_list(nir, nir_variable, &nir->outputs);
   steal_list(nir, nir_variable, &nir->shared);
   steal_list(nir, nir_variable, &nir->globals);
   steal_list(nir, nir_variable, &nir->system_values);
   steal_list(nir, nir_register, &nir->registers);

   /* Recurse into functions, stealing their contents back. */
   foreach_list_typed(nir_function, func, node, &nir->functions) {
      sweep_function(nir, func);
   }

   ralloc_steal(nir, nir->constant_data);

   /* Free everything we didn't steal back. */
   ralloc_free(rubbish);
}