mirror of
https://github.com/jart/cosmopolitan.git
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550b52abf6
- Introduce epoll_pwait() - Rewrite -ftrapv and ffs() libraries in C code - Use more FreeBSD code in math function library - Get significantly more tests passing on qemu-aarch64 - Fix many Musl long double functions that were broken on AARCH64
88 lines
4.6 KiB
C
88 lines
4.6 KiB
C
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi│
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╚──────────────────────────────────────────────────────────────────────────────╝
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│ │
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│ FreeBSD lib/msun/src/s_tanhf.c │
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│ Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. │
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│ │
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│ Copyright (c) 1992-2023 The FreeBSD Project. │
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│ │
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│ Redistribution and use in source and binary forms, with or without │
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│ modification, are permitted provided that the following conditions │
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│ are met: │
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│ 1. Redistributions of source code must retain the above copyright │
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│ notice, this list of conditions and the following disclaimer. │
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│ 2. Redistributions in binary form must reproduce the above copyright │
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│ notice, this list of conditions and the following disclaimer in the │
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│ documentation and/or other materials provided with the distribution. │
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│ │
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│ THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND │
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│ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE │
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│ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE │
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│ ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE │
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│ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL │
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│ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS │
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│ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) │
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│ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT │
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│ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY │
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│ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF │
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│ SUCH DAMAGE. │
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│ │
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│ Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. │
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│ Developed at SunPro, a Sun Microsystems, Inc. business. │
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│ Permission to use, copy, modify, and distribute this │
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│ software is freely granted, provided that this notice │
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│ is preserved. │
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│ │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/math.h"
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#include "libc/tinymath/freebsd.internal.h"
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asm(".ident\t\"\\n\\n\
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FreeBSD libm (BSD-2 License)\\n\
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Copyright (c) 2005-2011, Bruce D. Evans, Steven G. Kargl, David Schultz.\"");
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asm(".ident\t\"\\n\\n\
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fdlibm (fdlibm license)\\n\
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Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.\"");
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asm(".include \"libc/disclaimer.inc\"");
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// clang-format off
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static const volatile float tiny = 1.0e-30;
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static const float one=1.0, two=2.0, huge = 1.0e30;
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/**
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* Returns hyperbolic tangent of 𝑥.
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*/
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float
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tanhf(float x)
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{
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float t,z;
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int32_t jx,ix;
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GET_FLOAT_WORD(jx,x);
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ix = jx&0x7fffffff;
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/* x is INF or NaN */
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if(ix>=0x7f800000) {
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if (jx>=0) return one/x+one; /* tanh(+-inf)=+-1 */
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else return one/x-one; /* tanh(NaN) = NaN */
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}
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/* |x| < 9 */
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if (ix < 0x41100000) { /* |x|<9 */
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if (ix<0x39800000) { /* |x|<2**-12 */
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if(huge+x>one) return x; /* tanh(tiny) = tiny with inexact */
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}
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if (ix>=0x3f800000) { /* |x|>=1 */
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t = expm1f(two*fabsf(x));
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z = one - two/(t+two);
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} else {
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t = expm1f(-two*fabsf(x));
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z= -t/(t+two);
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}
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/* |x| >= 9, return +-1 */
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} else {
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z = one - tiny; /* raise inexact flag */
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}
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return (jx>=0)? z: -z;
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}
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