summaryrefslogtreecommitdiffstats
path: root/third_party/dav1d/src/arm/asm.S
blob: dc50415f1f1a3b589f7be6a9f291706bf03e9793 (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
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
/*
 * Copyright © 2018, VideoLAN and dav1d authors
 * Copyright © 2018, Janne Grunau
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef DAV1D_SRC_ARM_ASM_S
#define DAV1D_SRC_ARM_ASM_S

#include "config.h"

#if ARCH_AARCH64
#define x18 do_not_use_x18
#define w18 do_not_use_w18

/* Support macros for
 *   - Armv8.3-A Pointer Authentication and
 *   - Armv8.5-A Branch Target Identification
 * features which require emitting a .note.gnu.property section with the
 * appropriate architecture-dependent feature bits set.
 *
 * |AARCH64_SIGN_LINK_REGISTER| and |AARCH64_VALIDATE_LINK_REGISTER| expand to
 * PACIxSP and AUTIxSP, respectively. |AARCH64_SIGN_LINK_REGISTER| should be
 * used immediately before saving the LR register (x30) to the stack.
 * |AARCH64_VALIDATE_LINK_REGISTER| should be used immediately after restoring
 * it. Note |AARCH64_SIGN_LINK_REGISTER|'s modifications to LR must be undone
 * with |AARCH64_VALIDATE_LINK_REGISTER| before RET. The SP register must also
 * have the same value at the two points. For example:
 *
 *   .global f
 *   f:
 *     AARCH64_SIGN_LINK_REGISTER
 *     stp x29, x30, [sp, #-96]!
 *     mov x29, sp
 *     ...
 *     ldp x29, x30, [sp], #96
 *     AARCH64_VALIDATE_LINK_REGISTER
 *     ret
 *
 * |AARCH64_VALID_CALL_TARGET| expands to BTI 'c'. Either it, or
 * |AARCH64_SIGN_LINK_REGISTER|, must be used at every point that may be an
 * indirect call target. In particular, all symbols exported from a file must
 * begin with one of these macros. For example, a leaf function that does not
 * save LR can instead use |AARCH64_VALID_CALL_TARGET|:
 *
 *   .globl return_zero
 *   return_zero:
 *     AARCH64_VALID_CALL_TARGET
 *     mov x0, #0
 *     ret
 *
 * A non-leaf function which does not immediately save LR may need both macros
 * because |AARCH64_SIGN_LINK_REGISTER| appears late. For example, the function
 * may jump to an alternate implementation before setting up the stack:
 *
 *   .globl with_early_jump
 *   with_early_jump:
 *     AARCH64_VALID_CALL_TARGET
 *     cmp x0, #128
 *     b.lt .Lwith_early_jump_128
 *     AARCH64_SIGN_LINK_REGISTER
 *     stp x29, x30, [sp, #-96]!
 *     mov x29, sp
 *     ...
 *     ldp x29, x30, [sp], #96
 *     AARCH64_VALIDATE_LINK_REGISTER
 *     ret
 *
 *  .Lwith_early_jump_128:
 *     ...
 *     ret
 *
 * These annotations are only required with indirect calls. Private symbols that
 * are only the target of direct calls do not require annotations. Also note
 * that |AARCH64_VALID_CALL_TARGET| is only valid for indirect calls (BLR), not
 * indirect jumps (BR). Indirect jumps in assembly are supported through
 * |AARCH64_VALID_JUMP_TARGET|. Landing Pads which shall serve for jumps and
 * calls can be created using |AARCH64_VALID_JUMP_CALL_TARGET|.
 *
 * Although not necessary, it is safe to use these macros in 32-bit ARM
 * assembly. This may be used to simplify dual 32-bit and 64-bit files.
 *
 * References:
 * - "ELF for the Arm® 64-bit Architecture"
 *   https: *github.com/ARM-software/abi-aa/blob/master/aaelf64/aaelf64.rst
 * - "Providing protection for complex software"
 *   https://developer.arm.com/architectures/learn-the-architecture/providing-protection-for-complex-software
 */
#if defined(__ARM_FEATURE_BTI_DEFAULT) && (__ARM_FEATURE_BTI_DEFAULT == 1)
#define GNU_PROPERTY_AARCH64_BTI (1 << 0)   // Has Branch Target Identification
#define AARCH64_VALID_JUMP_CALL_TARGET hint #38  // BTI 'jc'
#define AARCH64_VALID_CALL_TARGET      hint #34  // BTI 'c'
#define AARCH64_VALID_JUMP_TARGET      hint #36  // BTI 'j'
#else
#define GNU_PROPERTY_AARCH64_BTI 0          // No Branch Target Identification
#define AARCH64_VALID_JUMP_CALL_TARGET
#define AARCH64_VALID_CALL_TARGET
#define AARCH64_VALID_JUMP_TARGET
#endif

#if defined(__ARM_FEATURE_PAC_DEFAULT)

#if ((__ARM_FEATURE_PAC_DEFAULT & (1 << 0)) != 0) // authentication using key A
#define AARCH64_SIGN_LINK_REGISTER      paciasp
#define AARCH64_VALIDATE_LINK_REGISTER  autiasp
#elif ((__ARM_FEATURE_PAC_DEFAULT & (1 << 1)) != 0) // authentication using key B
#define AARCH64_SIGN_LINK_REGISTER      pacibsp
#define AARCH64_VALIDATE_LINK_REGISTER  autibsp
#else
#error Pointer authentication defines no valid key!
#endif
#if ((__ARM_FEATURE_PAC_DEFAULT & (1 << 2)) != 0) // authentication of leaf functions
#error Authentication of leaf functions is enabled but not supported in dav1d!
#endif
#define GNU_PROPERTY_AARCH64_PAC (1 << 1)

#elif defined(__APPLE__) && defined(__arm64e__)

#define GNU_PROPERTY_AARCH64_PAC 0
#define AARCH64_SIGN_LINK_REGISTER      pacibsp
#define AARCH64_VALIDATE_LINK_REGISTER  autibsp

#else /* __ARM_FEATURE_PAC_DEFAULT */

#define GNU_PROPERTY_AARCH64_PAC 0
#define AARCH64_SIGN_LINK_REGISTER
#define AARCH64_VALIDATE_LINK_REGISTER

#endif /* !__ARM_FEATURE_PAC_DEFAULT */


#if (GNU_PROPERTY_AARCH64_BTI != 0 || GNU_PROPERTY_AARCH64_PAC != 0) && defined(__ELF__)
        .pushsection .note.gnu.property, "a"
        .balign 8
        .long 4
        .long 0x10
        .long 0x5
        .asciz "GNU"
        .long 0xc0000000 /* GNU_PROPERTY_AARCH64_FEATURE_1_AND */
        .long 4
        .long (GNU_PROPERTY_AARCH64_BTI | GNU_PROPERTY_AARCH64_PAC)
        .long 0
        .popsection
#endif /* (GNU_PROPERTY_AARCH64_BTI != 0 || GNU_PROPERTY_AARCH64_PAC != 0) && defined(__ELF__) */
#endif /* ARCH_AARCH64 */

#if ARCH_ARM
        .syntax unified
#ifdef __ELF__
        .arch armv7-a
        .fpu neon
        .eabi_attribute 10, 0           // suppress Tag_FP_arch
        .eabi_attribute 12, 0           // suppress Tag_Advanced_SIMD_arch
        .section .note.GNU-stack,"",%progbits // Mark stack as non-executable
#endif /* __ELF__ */

#ifdef _WIN32
#define CONFIG_THUMB 1
#else
#define CONFIG_THUMB 0
#endif

#if CONFIG_THUMB
        .thumb
#define A @
#define T
#else
#define A
#define T @
#endif /* CONFIG_THUMB */
#endif /* ARCH_ARM */

#if !defined(PIC)
#if defined(__PIC__)
#define PIC __PIC__
#elif defined(__pic__)
#define PIC __pic__
#endif
#endif

#ifndef PRIVATE_PREFIX
#define PRIVATE_PREFIX dav1d_
#endif

#define PASTE(a,b) a ## b
#define CONCAT(a,b) PASTE(a,b)

#ifdef PREFIX
#define EXTERN CONCAT(_,PRIVATE_PREFIX)
#else
#define EXTERN PRIVATE_PREFIX
#endif

.macro function name, export=0, align=2
    .macro endfunc
#ifdef __ELF__
        .size   \name, . - \name
#endif
#if HAVE_AS_FUNC
        .endfunc
#endif
        .purgem endfunc
    .endm
        .text
        .align \align
    .if \export
        .global EXTERN\name
#ifdef __ELF__
        .type   EXTERN\name, %function
        .hidden EXTERN\name
#elif defined(__MACH__)
        .private_extern EXTERN\name
#endif
#if HAVE_AS_FUNC
        .func   EXTERN\name
#endif
EXTERN\name:
    .else
#ifdef __ELF__
        .type \name, %function
#endif
#if HAVE_AS_FUNC
        .func \name
#endif
    .endif
\name:
#if ARCH_AARCH64
    .if \export
         AARCH64_VALID_CALL_TARGET
    .endif
#endif
.endm

.macro  const   name, export=0, align=2
    .macro endconst
#ifdef __ELF__
        .size   \name, . - \name
#endif
        .purgem endconst
    .endm
#if defined(_WIN32)
        .section        .rdata
#elif !defined(__MACH__)
        .section        .rodata
#else
        .const_data
#endif
        .align          \align
    .if \export
        .global EXTERN\name
#ifdef __ELF__
        .hidden EXTERN\name
#elif defined(__MACH__)
        .private_extern EXTERN\name
#endif
EXTERN\name:
    .endif
\name:
.endm

#ifdef __APPLE__
#define L(x) L ## x
#else
#define L(x) .L ## x
#endif

#define X(x) CONCAT(EXTERN, x)


#endif /* DAV1D_SRC_ARM_ASM_S */