mirror of
https://github.com/jart/cosmopolitan.git
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f7ae50462a
- Fix unused local variable errors - Remove yoinks from sigaction() header - Add nox87 and aarch64 to github actions - Fix cosmocc -fportcosmo in linking mode - It's now possible to build `make m=llvm o/llvm/libc`
45 lines
2.3 KiB
C
45 lines
2.3 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 "dsp/core/core.h"
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/**
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* Compresses 16-bit signed linear audio sample with a-Law.
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*
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* @param x is clamped to 16-bits of which the top 14 are considered
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* @return coded number in range [0..255]
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* @see ITU G.711
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*/
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int alaw(int x) {
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int a, b, i;
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if ((a = x) < 0) a = ~a;
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a >>= 4;
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if (a > 15) {
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if ((i = a >> 5)) {
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b = (__builtin_clz(i) ^ 31) + 1;
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a >>= b;
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a -= 16;
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a += (b + 1) << 4;
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} else {
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a -= 16;
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a += 16;
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}
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}
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if (x >= 0) a |= 128;
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return a ^ 85;
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}
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