1 /*
2 * Copyright (C) 2010 Marek Olšák <maraeo@gmail.com>
3 *
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining
7 * a copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sublicense, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial
16 * portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21 * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
22 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
23 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
24 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 */
27
28 #include <stdlib.h>
29 #include "radeon_remove_constants.h"
30 #include "radeon_dataflow.h"
31
32 struct mark_used_data {
33 unsigned char * const_used;
34 unsigned * has_rel_addr;
35 };
36
remap_regs(void * userdata,struct rc_instruction * inst,rc_register_file * pfile,unsigned int * pindex)37 static void remap_regs(void * userdata, struct rc_instruction * inst,
38 rc_register_file * pfile, unsigned int * pindex)
39 {
40 unsigned *inv_remap_table = userdata;
41
42 if (*pfile == RC_FILE_CONSTANT) {
43 *pindex = inv_remap_table[*pindex];
44 }
45 }
46
mark_used(void * userdata,struct rc_instruction * inst,struct rc_src_register * src)47 static void mark_used(void * userdata, struct rc_instruction * inst,
48 struct rc_src_register * src)
49 {
50 struct mark_used_data * d = userdata;
51
52 if (src->File == RC_FILE_CONSTANT) {
53 if (src->RelAddr) {
54 *d->has_rel_addr = 1;
55 } else {
56 d->const_used[src->Index] = 1;
57 }
58 }
59 }
60
rc_remove_unused_constants(struct radeon_compiler * c,void * user)61 void rc_remove_unused_constants(struct radeon_compiler *c, void *user)
62 {
63 unsigned **out_remap_table = (unsigned**)user;
64 unsigned char *const_used;
65 unsigned *remap_table;
66 unsigned *inv_remap_table;
67 unsigned has_rel_addr = 0;
68 unsigned is_identity = 1;
69 unsigned are_externals_remapped = 0;
70 struct rc_constant *constants = c->Program.Constants.Constants;
71 struct mark_used_data d;
72 unsigned new_count;
73
74 if (!c->Program.Constants.Count) {
75 *out_remap_table = NULL;
76 return;
77 }
78
79 const_used = malloc(c->Program.Constants.Count);
80 memset(const_used, 0, c->Program.Constants.Count);
81
82 d.const_used = const_used;
83 d.has_rel_addr = &has_rel_addr;
84
85 /* Pass 1: Mark used constants. */
86 for (struct rc_instruction *inst = c->Program.Instructions.Next;
87 inst != &c->Program.Instructions; inst = inst->Next) {
88 rc_for_all_reads_src(inst, mark_used, &d);
89 }
90
91 /* Pass 2: If there is relative addressing or dead constant elimination
92 * is disabled, mark all externals as used. */
93 if (has_rel_addr || !c->remove_unused_constants) {
94 for (unsigned i = 0; i < c->Program.Constants.Count; i++)
95 if (constants[i].Type == RC_CONSTANT_EXTERNAL)
96 const_used[i] = 1;
97 }
98
99 /* Pass 3: Make the remapping table and remap constants.
100 * This pass removes unused constants simply by overwriting them by other constants. */
101 remap_table = malloc(c->Program.Constants.Count * sizeof(unsigned));
102 inv_remap_table = malloc(c->Program.Constants.Count * sizeof(unsigned));
103 new_count = 0;
104
105 for (unsigned i = 0; i < c->Program.Constants.Count; i++) {
106 if (const_used[i]) {
107 remap_table[new_count] = i;
108 inv_remap_table[i] = new_count;
109
110 if (i != new_count) {
111 if (constants[i].Type == RC_CONSTANT_EXTERNAL)
112 are_externals_remapped = 1;
113
114 constants[new_count] = constants[i];
115 is_identity = 0;
116 }
117 new_count++;
118 }
119 }
120
121 /* is_identity ==> new_count == old_count
122 * !is_identity ==> new_count < old_count */
123 assert( is_identity || new_count < c->Program.Constants.Count);
124 assert(!((has_rel_addr || !c->remove_unused_constants) && are_externals_remapped));
125
126 /* Pass 4: Redirect reads of all constants to their new locations. */
127 if (!is_identity) {
128 for (struct rc_instruction *inst = c->Program.Instructions.Next;
129 inst != &c->Program.Instructions; inst = inst->Next) {
130 rc_remap_registers(inst, remap_regs, inv_remap_table);
131 }
132 }
133
134 /* Set the new constant count. Note that new_count may be less than
135 * Count even though the remapping function is identity. In that case,
136 * the constants have been removed at the end of the array. */
137 c->Program.Constants.Count = new_count;
138
139 if (are_externals_remapped) {
140 *out_remap_table = remap_table;
141 } else {
142 *out_remap_table = NULL;
143 free(remap_table);
144 }
145
146 free(const_used);
147 free(inv_remap_table);
148
149 if (c->Debug & RC_DBG_LOG)
150 rc_constants_print(&c->Program.Constants);
151 }
152