summaryrefslogtreecommitdiff
path: root/src/mesa/drivers/dri/r300/compiler/radeon_remove_constants.c
blob: d111319d3d980bad0fcc4d091db9e2e5a5d43489 (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
/*
 * Copyright (C) 2010 Marek Olšák <maraeo@gmail.com>
 *
 * All Rights Reserved.
 *
 * 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 COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS 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 "radeon_remove_constants.h"
#include "radeon_dataflow.h"

static void remap_regs(void * userdata, struct rc_instruction * inst,
			rc_register_file * pfile, unsigned int * pindex)
{
        unsigned *inv_remap_table = userdata;

        if (*pfile == RC_FILE_CONSTANT) {
                *pindex = inv_remap_table[*pindex];
        }
}

void rc_remove_unused_constants(struct radeon_compiler *c, void *user)
{
	unsigned **out_remap_table = (unsigned**)user;
        unsigned char *const_used;
        unsigned *remap_table;
        unsigned *inv_remap_table;
        unsigned has_rel_addr = 0;
        unsigned is_identity = 1;
	unsigned are_externals_remapped = 0;
        struct rc_constant *constants = c->Program.Constants.Constants;

        if (!c->Program.Constants.Count) {
                *out_remap_table = NULL;
                return;
        }

        const_used = malloc(c->Program.Constants.Count);
        memset(const_used, 0, c->Program.Constants.Count);

	/* Pass 1: Mark used constants. */
        for (struct rc_instruction *inst = c->Program.Instructions.Next;
             inst != &c->Program.Instructions; inst = inst->Next) {
                const struct rc_opcode_info *opcode = rc_get_opcode_info(inst->U.I.Opcode);

                /* XXX: This loop and the if statement after it should be
                 * replaced by a call to one of the rc_for_all_reads_* functions.
                 * The reason it does not use one of those functions now is
                 * because none of them have RelAddr as an argument. */
                for (unsigned i = 0; i < opcode->NumSrcRegs; i++) {
                        if (inst->U.I.SrcReg[i].File == RC_FILE_CONSTANT) {
                                if (inst->U.I.SrcReg[i].RelAddr) {
                                        has_rel_addr = 1;
                                } else {
                                        const_used[inst->U.I.SrcReg[i].Index] = 1;
                                }
                        }
                }
                if (inst->U.I.PreSub.Opcode != RC_PRESUB_NONE) {
			unsigned int i;
			unsigned int srcp_regs = rc_presubtract_src_reg_count(
							inst->U.I.PreSub.Opcode);
			for( i = 0; i < srcp_regs; i++) {
                                if (inst->U.I.PreSub.SrcReg[i].File ==
                                                        RC_FILE_CONSTANT) {
                                        const_used[
                                            inst->U.I.PreSub.SrcReg[i].Index] = 1;
                                }
                        }
		}
        }

        /* Pass 2: If there is relative addressing, mark all externals as used. */
        if (has_rel_addr) {
                for (unsigned i = 0; i < c->Program.Constants.Count; i++)
                        if (constants[i].Type == RC_CONSTANT_EXTERNAL)
                                const_used[i] = 1;
        }

        /* Pass 3: Make the remapping table and remap constants.
	 * This pass removes unused constants simply by overwriting them by other constants. */
        remap_table = malloc(c->Program.Constants.Count * sizeof(unsigned));
        inv_remap_table = malloc(c->Program.Constants.Count * sizeof(unsigned));
        unsigned new_count = 0;

        for (unsigned i = 0; i < c->Program.Constants.Count; i++) {
                if (const_used[i]) {
                        remap_table[new_count] = i;
                        inv_remap_table[i] = new_count;

                        if (i != new_count) {
				if (constants[i].Type == RC_CONSTANT_EXTERNAL)
					are_externals_remapped = 1;

				constants[new_count] = constants[i];
                                is_identity = 0;
                        }
                        new_count++;
                }
        }

	/*  is_identity ==> new_count == old_count
	 * !is_identity ==> new_count <  old_count */
	assert( is_identity || new_count <  c->Program.Constants.Count);
	assert(!(has_rel_addr && are_externals_remapped));

        /* Pass 4: Redirect reads of all constants to their new locations. */
        if (!is_identity) {
                for (struct rc_instruction *inst = c->Program.Instructions.Next;
                     inst != &c->Program.Instructions; inst = inst->Next) {
                        rc_remap_registers(inst, remap_regs, inv_remap_table);
                }

	}

	/* Set the new constant count. Note that new_count may be less than
	 * Count even though the remapping function is identity. In that case,
	 * the constants have been removed at the end of the array. */
	c->Program.Constants.Count = new_count;

	if (are_externals_remapped) {
                *out_remap_table = remap_table;
        } else {
                *out_remap_table = NULL;
                free(remap_table);
        }

        free(const_used);
        free(inv_remap_table);
}