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46 lines
2.4 KiB
C
46 lines
2.4 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2021 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/bits/bits.h"
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#include "libc/macros.internal.h"
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#include "libc/str/str.h"
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/**
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* Atomically stores value.
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*
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* This macro is intended to prevent things like compiler store tearing
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* optimizations.
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*/
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intptr_t(atomic_store)(void *p, intptr_t x, size_t n) {
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switch (n) {
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case 1:
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__builtin_memcpy(p, &x, 1);
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return x;
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case 2:
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__builtin_memcpy(p, &x, 2);
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return x;
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case 4:
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__builtin_memcpy(p, &x, 4);
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return x;
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case 8:
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__builtin_memcpy(p, &x, 8);
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return x;
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default:
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return 0;
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}
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}
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