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https://github.com/jart/cosmopolitan.git
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1422e96b4e
There's a new program named ape/ape-m1.c which will be used to build an embeddable binary that can load ape and elf executables. The support is mostly working so far, but still chasing down ABI issues.
79 lines
3.5 KiB
C
79 lines
3.5 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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│ Musl Libc │
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│ Copyright © 2005-2014 Rich Felker, et al. │
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│ │
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│ Permission is hereby granted, free of charge, to any person obtaining │
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│ a copy of this software and associated documentation files (the │
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│ "Software"), to deal in the Software without restriction, including │
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│ without limitation the rights to use, copy, modify, merge, publish, │
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│ distribute, sublicense, and/or sell copies of the Software, and to │
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│ permit persons to whom the Software is furnished to do so, subject to │
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│ the following conditions: │
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│ │
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│ The above copyright notice and this permission notice shall be │
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│ included in all copies or substantial portions of the Software. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
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│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
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│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
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│ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY │
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│ CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, │
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│ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE │
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│ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
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│ │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/math.h"
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#include "libc/tinymath/internal.h"
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asm(".ident\t\"\\n\\n\
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Musl libc (MIT License)\\n\
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Copyright 2005-2014 Rich Felker, et. al.\"");
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asm(".include \"libc/disclaimer.inc\"");
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// clang-format off
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/**
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* Returns hyperbolic tangent of 𝑥.
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*
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* @define `tanhf(x)=(expf(x)-expf(-x))/(expf(x)+expf(-x))`
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* @define `tanhf(x)=(expf(2.f*x)-1.f)/(expf(2.f*x)-1.f+2.f)`
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*/
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float tanhf(float x)
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{
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union {float f; uint32_t i;} u = {.f = x};
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uint32_t w;
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int sign;
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float t;
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/* x = |x| */
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sign = u.i >> 31;
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u.i &= 0x7fffffff;
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x = u.f;
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w = u.i;
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if (w > 0x3f0c9f54) {
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/* |x| > log(3)/2 ~= 0.5493 or nan */
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if (w > 0x41200000) {
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/* |x| > 10 */
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t = 1 + 0/x;
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} else {
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t = expm1f(2*x);
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t = 1 - 2/(t+2);
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}
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} else if (w > 0x3e82c578) {
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/* |x| > log(5/3)/2 ~= 0.2554 */
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t = expm1f(2*x);
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t = t/(t+2);
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} else if (w >= 0x00800000) {
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/* |x| >= 0x1p-126 */
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t = expm1f(-2*x);
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t = -t/(t+2);
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} else {
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/* |x| is subnormal */
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FORCE_EVAL(x*x);
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t = x;
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}
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return sign ? -t : t;
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}
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