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
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
|
/* Assembler macros for ARM.
Copyright (C) 1997-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<https://www.gnu.org/licenses/>. */
#include <sysdeps/generic/sysdep.h>
#include <features.h>
#ifndef __ASSEMBLER__
# include <stdint.h>
#else
# include <arm-features.h>
#endif
/* The __ARM_ARCH define is provided by gcc 4.8. Construct it otherwise. */
#ifndef __ARM_ARCH
# ifdef __ARM_ARCH_2__
# define __ARM_ARCH 2
# elif defined (__ARM_ARCH_3__) || defined (__ARM_ARCH_3M__)
# define __ARM_ARCH 3
# elif defined (__ARM_ARCH_4__) || defined (__ARM_ARCH_4T__)
# define __ARM_ARCH 4
# elif defined (__ARM_ARCH_5__) || defined (__ARM_ARCH_5E__) \
|| defined(__ARM_ARCH_5T__) || defined(__ARM_ARCH_5TE__) \
|| defined(__ARM_ARCH_5TEJ__)
# define __ARM_ARCH 5
# elif defined (__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \
|| defined (__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) \
|| defined (__ARM_ARCH_6K__) || defined(__ARM_ARCH_6T2__)
# define __ARM_ARCH 6
# elif defined (__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \
|| defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \
|| defined(__ARM_ARCH_7EM__)
# define __ARM_ARCH 7
# else
# error unknown arm architecture
# endif
#endif
#if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__)
# define ARCH_HAS_BX
#endif
#if __ARM_ARCH > 4
# define ARCH_HAS_BLX
#endif
#if __ARM_ARCH > 6 || defined (__ARM_ARCH_6K__) || defined (__ARM_ARCH_6ZK__)
# define ARCH_HAS_HARD_TP
#endif
#if __ARM_ARCH > 6 || defined (__ARM_ARCH_6T2__)
# define ARCH_HAS_T2
#endif
#ifdef __ASSEMBLER__
/* Syntactic details of assembler. */
#define ALIGNARG(log2) log2
#define ASM_SIZE_DIRECTIVE(name) .size name,.-name
#define PLTJMP(_x) _x##(PLT)
#ifdef ARCH_HAS_BX
# define BX(R) bx R
# define BXC(C, R) bx##C R
# ifdef ARCH_HAS_BLX
# define BLX(R) blx R
# else
# define BLX(R) mov lr, pc; bx R
# endif
#else
# define BX(R) mov pc, R
# define BXC(C, R) mov##C pc, R
# define BLX(R) mov lr, pc; mov pc, R
#endif
#define DO_RET(R) BX(R)
#define RETINSTR(C, R) BXC(C, R)
/* Define an entry point visible from C. */
#define ENTRY(name) \
.globl C_SYMBOL_NAME(name); \
.type C_SYMBOL_NAME(name),%function; \
.align ALIGNARG(4); \
C_LABEL(name) \
CFI_SECTIONS; \
cfi_startproc; \
CALL_MCOUNT
#define CFI_SECTIONS \
.cfi_sections .debug_frame
#undef END
#define END(name) \
cfi_endproc; \
ASM_SIZE_DIRECTIVE(name)
/* If compiled for profiling, call `mcount' at the start of each function. */
#ifdef PROF
/* Call __gnu_mcount_nc (GCC >= 4.4). */
#define CALL_MCOUNT \
push {lr}; \
cfi_adjust_cfa_offset (4); \
cfi_rel_offset (lr, 0); \
bl PLTJMP(mcount); \
cfi_adjust_cfa_offset (-4); \
cfi_restore (lr)
#else
#define CALL_MCOUNT /* Do nothing. */
#endif
/* Since C identifiers are not normally prefixed with an underscore
on this system, the asm identifier `syscall_error' intrudes on the
C name space. Make sure we use an innocuous name. */
#define syscall_error __syscall_error
#define mcount __gnu_mcount_nc
/* Tag_ABI_align8_preserved: This code preserves 8-byte
alignment in any callee. */
.eabi_attribute 25, 1
/* Tag_ABI_align8_needed: This code may require 8-byte alignment from
the caller. */
.eabi_attribute 24, 1
/* The thumb2 encoding is reasonably complete. Unless suppressed, use it. */
.syntax unified
# if defined(__thumb2__) && !defined(NO_THUMB)
.thumb
#else
# undef __thumb__
# undef __thumb2__
.arm
# endif
/* Load or store to/from address X + Y into/from R, (maybe) using T.
X or Y can use T freely; T can be R if OP is a load. The first
version eschews the two-register addressing mode, while the
second version uses it. */
# define LDST_INDEXED_NOINDEX(OP, R, T, X, Y) \
add T, X, Y; \
OP R, [T]
# define LDST_INDEXED_INDEX(OP, R, X, Y) \
OP R, [X, Y]
# ifdef ARM_NO_INDEX_REGISTER
/* We're never using the two-register addressing mode, so this
always uses an intermediate add. */
# define LDST_INDEXED(OP, R, T, X, Y) LDST_INDEXED_NOINDEX (OP, R, T, X, Y)
# define LDST_PC_INDEXED(OP, R, T, X) LDST_INDEXED_NOINDEX (OP, R, T, pc, X)
# else
/* The two-register addressing mode is OK, except on Thumb with pc. */
# define LDST_INDEXED(OP, R, T, X, Y) LDST_INDEXED_INDEX (OP, R, X, Y)
# ifdef __thumb2__
# define LDST_PC_INDEXED(OP, R, T, X) LDST_INDEXED_NOINDEX (OP, R, T, pc, X)
# else
# define LDST_PC_INDEXED(OP, R, T, X) LDST_INDEXED_INDEX (OP, R, pc, X)
# endif
# endif
/* Load or store to/from a pc-relative EXPR into/from R, using T. */
# ifdef __thumb2__
# define LDST_PCREL(OP, R, T, EXPR) \
ldr T, 98f; \
.subsection 2; \
98: .word EXPR - 99f - PC_OFS; \
.previous; \
99: add T, T, pc; \
OP R, [T]
# elif defined (ARCH_HAS_T2) && ARM_PCREL_MOVW_OK
# define LDST_PCREL(OP, R, T, EXPR) \
movw T, #:lower16:EXPR - 99f - PC_OFS; \
movt T, #:upper16:EXPR - 99f - PC_OFS; \
99: LDST_PC_INDEXED (OP, R, T, T)
# else
# define LDST_PCREL(OP, R, T, EXPR) \
ldr T, 98f; \
.subsection 2; \
98: .word EXPR - 99f - PC_OFS; \
.previous; \
99: OP R, [pc, T]
# endif
/* Load from a global SYMBOL + CONSTANT into R, using T. */
# if defined (ARCH_HAS_T2) && !defined (PIC)
# define LDR_GLOBAL(R, T, SYMBOL, CONSTANT) \
movw T, #:lower16:SYMBOL; \
movt T, #:upper16:SYMBOL; \
ldr R, [T, $CONSTANT]
# elif defined (ARCH_HAS_T2) && defined (PIC) && ARM_PCREL_MOVW_OK
# define LDR_GLOBAL(R, T, SYMBOL, CONSTANT) \
movw R, #:lower16:_GLOBAL_OFFSET_TABLE_ - 97f - PC_OFS; \
movw T, #:lower16:99f - 98f - PC_OFS; \
movt R, #:upper16:_GLOBAL_OFFSET_TABLE_ - 97f - PC_OFS; \
movt T, #:upper16:99f - 98f - PC_OFS; \
.pushsection .rodata.cst4, "aM", %progbits, 4; \
.balign 4; \
99: .word SYMBOL##(GOT); \
.popsection; \
97: add R, R, pc; \
98: LDST_PC_INDEXED (ldr, T, T, T); \
LDST_INDEXED (ldr, R, T, R, T); \
ldr R, [R, $CONSTANT]
# else
# define LDR_GLOBAL(R, T, SYMBOL, CONSTANT) \
ldr T, 99f; \
ldr R, 100f; \
98: add T, T, pc; \
ldr T, [T, R]; \
.subsection 2; \
99: .word _GLOBAL_OFFSET_TABLE_ - 98b - PC_OFS; \
100: .word SYMBOL##(GOT); \
.previous; \
ldr R, [T, $CONSTANT]
# endif
/* This is the same as LDR_GLOBAL, but for a SYMBOL that is known to
be in the same linked object (as for one with hidden visibility).
We can avoid the GOT indirection in the PIC case. For the pure
static case, LDR_GLOBAL is already optimal. */
# ifdef PIC
# define LDR_HIDDEN(R, T, SYMBOL, CONSTANT) \
LDST_PCREL (ldr, R, T, SYMBOL + CONSTANT)
# else
# define LDR_HIDDEN(R, T, SYMBOL, CONSTANT) \
LDR_GLOBAL (R, T, SYMBOL, CONSTANT)
# endif
/* Cope with negative memory offsets, which thumb can't encode.
Use NEGOFF_ADJ_BASE to (conditionally) alter the base register,
and then NEGOFF_OFF1 to use 0 for thumb and the offset for arm,
or NEGOFF_OFF2 to use A-B for thumb and A for arm. */
# ifdef __thumb2__
# define NEGOFF_ADJ_BASE(R, OFF) add R, R, $OFF
# define NEGOFF_ADJ_BASE2(D, S, OFF) add D, S, $OFF
# define NEGOFF_OFF1(R, OFF) [R]
# define NEGOFF_OFF2(R, OFFA, OFFB) [R, $((OFFA) - (OFFB))]
# else
# define NEGOFF_ADJ_BASE(R, OFF)
# define NEGOFF_ADJ_BASE2(D, S, OFF) mov D, S
# define NEGOFF_OFF1(R, OFF) [R, $OFF]
# define NEGOFF_OFF2(R, OFFA, OFFB) [R, $OFFA]
# endif
/* Helper to get the TLS base pointer. The interface is that TMP is a
register that may be used to hold the LR, if necessary. TMP may be
LR itself to indicate that LR need not be saved. The base pointer
is returned in R0. Only R0 and TMP are modified. */
# ifdef ARCH_HAS_HARD_TP
/* If the cpu has cp15 available, use it. */
# define GET_TLS(TMP) mrc p15, 0, r0, c13, c0, 3
# else
/* At this generic level we have no tricks to pull. Call the ABI routine. */
# define GET_TLS(TMP) \
push { r1, r2, r3, lr }; \
cfi_remember_state; \
cfi_adjust_cfa_offset (16); \
cfi_rel_offset (r1, 0); \
cfi_rel_offset (r2, 4); \
cfi_rel_offset (r3, 8); \
cfi_rel_offset (lr, 12); \
bl __aeabi_read_tp; \
pop { r1, r2, r3, lr }; \
cfi_restore_state
# endif /* ARCH_HAS_HARD_TP */
/* These are the directives used for EABI unwind info.
Wrap them in macros so another configuration's sysdep.h
file can define them away if it doesn't use EABI unwind info. */
# define eabi_fnstart .fnstart
# define eabi_fnend .fnend
# define eabi_save(...) .save __VA_ARGS__
# define eabi_cantunwind .cantunwind
# define eabi_pad(n) .pad n
#endif /* __ASSEMBLER__ */
/* This number is the offset from the pc at the current location. */
#ifdef __thumb__
# define PC_OFS 4
#else
# define PC_OFS 8
#endif
|
