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
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
/* Shared code for before and after reload gcse implementations.
Copyright (C) 1997-2016 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>.
It is expected that more hunks of gcse.c and postreload-gcse.c should
migrate into this file. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "rtl.h"
#include "df.h"
#include "gcse-common.h"
/* Record all of the canonicalized MEMs of record_last_mem_set_info's insn.
Note we store a pair of elements in the list, so they have to be
taken off pairwise. */
void
canon_list_insert (rtx dest, const_rtx x ATTRIBUTE_UNUSED, void *data)
{
rtx dest_addr;
int bb;
modify_pair pair;
while (GET_CODE (dest) == SUBREG
|| GET_CODE (dest) == ZERO_EXTRACT
|| GET_CODE (dest) == STRICT_LOW_PART)
dest = XEXP (dest, 0);
/* If DEST is not a MEM, then it will not conflict with a load. Note
that function calls are assumed to clobber memory, but are handled
elsewhere. */
if (! MEM_P (dest))
return;
dest_addr = get_addr (XEXP (dest, 0));
dest_addr = canon_rtx (dest_addr);
rtx_insn *insn = ((struct gcse_note_stores_info *)data)->insn;
bb = BLOCK_FOR_INSN (insn)->index;
pair.dest = dest;
pair.dest_addr = dest_addr;
vec<modify_pair> *canon_mem_list
= ((struct gcse_note_stores_info *)data)->canon_mem_list;
canon_mem_list[bb].safe_push (pair);
}
/* Record memory modification information for INSN. We do not actually care
about the memory location(s) that are set, or even how they are set (consider
a CALL_INSN). We merely need to record which insns modify memory. */
void
record_last_mem_set_info_common (rtx_insn *insn,
vec<rtx_insn *> *modify_mem_list,
vec<modify_pair> *canon_modify_mem_list,
bitmap modify_mem_list_set,
bitmap blocks_with_calls)
{
int bb;
bb = BLOCK_FOR_INSN (insn)->index;
modify_mem_list[bb].safe_push (insn);
bitmap_set_bit (modify_mem_list_set, bb);
if (CALL_P (insn))
bitmap_set_bit (blocks_with_calls, bb);
else
{
struct gcse_note_stores_info data;
data.insn = insn;
data.canon_mem_list = canon_modify_mem_list;
note_stores (PATTERN (insn), canon_list_insert, (void*) &data);
}
}
/* For each block, compute whether X is transparent. X is either an
expression or an assignment [though we don't care which, for this context
an assignment is treated as an expression]. For each block where an
element of X is modified, reset the INDX bit in BMAP.
BLOCKS_WITH_CALLS indicates which blocks contain CALL_INSNs which kill
memory.
MODIFY_MEM_LIST_SET indicates which blocks have memory stores which might
kill a particular memory location.
CANON_MODIFY_MEM_LIST is the canonicalized list of memory locations modified
for each block. */
void
compute_transp (const_rtx x, int indx, sbitmap *bmap,
bitmap blocks_with_calls,
bitmap modify_mem_list_set,
vec<modify_pair> *canon_modify_mem_list)
{
int i, j;
enum rtx_code code;
const char *fmt;
/* repeat is used to turn tail-recursion into iteration since GCC
can't do it when there's no return value. */
repeat:
if (x == 0)
return;
code = GET_CODE (x);
switch (code)
{
case REG:
{
df_ref def;
for (def = DF_REG_DEF_CHAIN (REGNO (x));
def;
def = DF_REF_NEXT_REG (def))
bitmap_clear_bit (bmap[DF_REF_BB (def)->index], indx);
}
return;
case MEM:
if (! MEM_READONLY_P (x))
{
bitmap_iterator bi;
unsigned bb_index;
rtx x_addr;
x_addr = get_addr (XEXP (x, 0));
x_addr = canon_rtx (x_addr);
/* First handle all the blocks with calls. We don't need to
do any list walking for them. */
EXECUTE_IF_SET_IN_BITMAP (blocks_with_calls, 0, bb_index, bi)
{
bitmap_clear_bit (bmap[bb_index], indx);
}
/* Now iterate over the blocks which have memory modifications
but which do not have any calls. */
EXECUTE_IF_AND_COMPL_IN_BITMAP (modify_mem_list_set,
blocks_with_calls,
0, bb_index, bi)
{
vec<modify_pair> list
= canon_modify_mem_list[bb_index];
modify_pair *pair;
unsigned ix;
FOR_EACH_VEC_ELT_REVERSE (list, ix, pair)
{
rtx dest = pair->dest;
rtx dest_addr = pair->dest_addr;
if (canon_true_dependence (dest, GET_MODE (dest),
dest_addr, x, x_addr))
{
bitmap_clear_bit (bmap[bb_index], indx);
break;
}
}
}
}
x = XEXP (x, 0);
goto repeat;
case PC:
case CC0: /*FIXME*/
case CONST:
CASE_CONST_ANY:
case SYMBOL_REF:
case LABEL_REF:
case ADDR_VEC:
case ADDR_DIFF_VEC:
return;
default:
break;
}
for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--)
{
if (fmt[i] == 'e')
{
/* If we are about to do the last recursive call
needed at this level, change it into iteration.
This function is called enough to be worth it. */
if (i == 0)
{
x = XEXP (x, i);
goto repeat;
}
compute_transp (XEXP (x, i), indx, bmap, blocks_with_calls,
modify_mem_list_set, canon_modify_mem_list);
}
else if (fmt[i] == 'E')
for (j = 0; j < XVECLEN (x, i); j++)
compute_transp (XVECEXP (x, i, j), indx, bmap, blocks_with_calls,
modify_mem_list_set, canon_modify_mem_list);
}
}
|
