summaryrefslogtreecommitdiffstats
path: root/js/src/jit/mips-shared/AtomicOperations-mips-shared.h
blob: 31e221ab20565f925e85275e77d3ad04b3c31246 (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
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sts=4 et sw=4 tw=99:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* For documentation, see jit/AtomicOperations.h */

#ifndef jit_mips_shared_AtomicOperations_mips_shared_h
#define jit_mips_shared_AtomicOperations_mips_shared_h

#include "mozilla/Assertions.h"
#include "mozilla/Types.h"

#if defined(__clang__) || defined(__GNUC__)

// The default implementation tactic for gcc/clang is to use the newer
// __atomic intrinsics added for use in C++11 <atomic>.  Where that
// isn't available, we use GCC's older __sync functions instead.
//
// ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS is kept as a backward
// compatible option for older compilers: enable this to use GCC's old
// __sync functions instead of the newer __atomic functions.  This
// will be required for GCC 4.6.x and earlier, and probably for Clang
// 3.1, should we need to use those versions.

//#define ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS

inline bool
js::jit::AtomicOperations::isLockfree8()
{
# ifndef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    MOZ_ASSERT(__atomic_always_lock_free(sizeof(int8_t), 0));
    MOZ_ASSERT(__atomic_always_lock_free(sizeof(int16_t), 0));
    MOZ_ASSERT(__atomic_always_lock_free(sizeof(int32_t), 0));
#  if _MIPS_SIM == _ABI64
    MOZ_ASSERT(__atomic_always_lock_free(sizeof(int64_t), 0));
#  endif
    return true;
# else
    return false;
# endif
}

inline void
js::jit::AtomicOperations::fenceSeqCst()
{
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    __sync_synchronize();
# else
    __atomic_thread_fence(__ATOMIC_SEQ_CST);
# endif
}

template<typename T>
inline T
js::jit::AtomicOperations::loadSeqCst(T* addr)
{
    MOZ_ASSERT(sizeof(T) < 8 || isLockfree8());
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    __sync_synchronize();
    T v = *addr;
    __sync_synchronize();
# else
    T v;
    __atomic_load(addr, &v, __ATOMIC_SEQ_CST);
# endif
    return v;
}

template<typename T>
inline void
js::jit::AtomicOperations::storeSeqCst(T* addr, T val)
{
    MOZ_ASSERT(sizeof(T) < 8 || isLockfree8());
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    __sync_synchronize();
    *addr = val;
    __sync_synchronize();
# else
    __atomic_store(addr, &val, __ATOMIC_SEQ_CST);
# endif
}

template<typename T>
inline T
js::jit::AtomicOperations::compareExchangeSeqCst(T* addr, T oldval, T newval)
{
    MOZ_ASSERT(sizeof(T) < 8 || isLockfree8());
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    return __sync_val_compare_and_swap(addr, oldval, newval);
# else
    __atomic_compare_exchange(addr, &oldval, &newval, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
    return oldval;
# endif
}

template<typename T>
inline T
js::jit::AtomicOperations::fetchAddSeqCst(T* addr, T val)
{
    static_assert(sizeof(T) <= 4, "not available for 8-byte values yet");
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    return __sync_fetch_and_add(addr, val);
# else
    return __atomic_fetch_add(addr, val, __ATOMIC_SEQ_CST);
# endif
}

template<typename T>
inline T
js::jit::AtomicOperations::fetchSubSeqCst(T* addr, T val)
{
    static_assert(sizeof(T) <= 4, "not available for 8-byte values yet");
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    return __sync_fetch_and_sub(addr, val);
# else
    return __atomic_fetch_sub(addr, val, __ATOMIC_SEQ_CST);
# endif
}

template<typename T>
inline T
js::jit::AtomicOperations::fetchAndSeqCst(T* addr, T val)
{
    static_assert(sizeof(T) <= 4, "not available for 8-byte values yet");
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    return __sync_fetch_and_and(addr, val);
# else
    return __atomic_fetch_and(addr, val, __ATOMIC_SEQ_CST);
# endif
}

template<typename T>
inline T
js::jit::AtomicOperations::fetchOrSeqCst(T* addr, T val)
{
    static_assert(sizeof(T) <= 4, "not available for 8-byte values yet");
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    return __sync_fetch_and_or(addr, val);
# else
    return __atomic_fetch_or(addr, val, __ATOMIC_SEQ_CST);
# endif
}

template<typename T>
inline T
js::jit::AtomicOperations::fetchXorSeqCst(T* addr, T val)
{
    static_assert(sizeof(T) <= 4, "not available for 8-byte values yet");
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    return __sync_fetch_and_xor(addr, val);
# else
    return __atomic_fetch_xor(addr, val, __ATOMIC_SEQ_CST);
# endif
}

template<typename T>
inline T
js::jit::AtomicOperations::loadSafeWhenRacy(T* addr)
{
    return *addr;               // FIXME (1208663): not yet safe
}

template<typename T>
inline void
js::jit::AtomicOperations::storeSafeWhenRacy(T* addr, T val)
{
    *addr = val;                // FIXME (1208663): not yet safe
}

inline void
js::jit::AtomicOperations::memcpySafeWhenRacy(void* dest, const void* src, size_t nbytes)
{
    ::memcpy(dest, src, nbytes); // FIXME (1208663): not yet safe
}

inline void
js::jit::AtomicOperations::memmoveSafeWhenRacy(void* dest, const void* src, size_t nbytes)
{
    ::memmove(dest, src, nbytes); // FIXME (1208663): not yet safe
}

template<typename T>
inline T
js::jit::AtomicOperations::exchangeSeqCst(T* addr, T val)
{
    MOZ_ASSERT(sizeof(T) < 8 || isLockfree8());
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    T v;
    __sync_synchronize();
    do {
	v = *addr;
    } while (__sync_val_compare_and_swap(addr, v, val) != v);
    return v;
# else
    T v;
    __atomic_exchange(addr, &val, &v, __ATOMIC_SEQ_CST);
    return v;
# endif
}

template<size_t nbytes>
inline void
js::jit::RegionLock::acquire(void* addr)
{
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    while (!__sync_bool_compare_and_swap(&spinlock, 0, 1))
        ;
# else
    uint32_t zero = 0;
    uint32_t one = 1;
    while (!__atomic_compare_exchange(&spinlock, &zero, &one, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE)) {
        zero = 0;
        continue;
    }
# endif
}

template<size_t nbytes>
inline void
js::jit::RegionLock::release(void* addr)
{
    MOZ_ASSERT(AtomicOperations::loadSeqCst(&spinlock) == 1, "releasing unlocked region lock");
# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
    __sync_sub_and_fetch(&spinlock, 1);
# else
    uint32_t zero = 0;
    __atomic_store(&spinlock, &zero, __ATOMIC_SEQ_CST);
# endif
}

# undef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS

#elif defined(ENABLE_SHARED_ARRAY_BUFFER)

# error "Either disable JS shared memory at compile time, use GCC or Clang, or add code here"

#endif

#endif // jit_mips_shared_AtomicOperations_mips_shared_h