mirror of
https://github.com/jart/cosmopolitan.git
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592f6ebc20
- Write some more unit tests - memcpy() on ARM is now faster - Address the Musl complex math FIXME comments - Some libm funcs like pow() now support setting errno - Import the latest and greatest math functions from ARM - Use more accurate atan2f() and log1pf() implementations - atoi() and atol() will no longer saturate or clobber errno
92 lines
3.7 KiB
C
92 lines
3.7 KiB
C
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│ vi: set noet ft=c ts=8 sw=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/runtime/fenv.h"
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#include "libc/tinymath/internal.h"
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__static_yoink("musl_libc_notice");
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#if FLT_EVAL_METHOD==0 || FLT_EVAL_METHOD==1
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#define EPS DBL_EPSILON
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#elif FLT_EVAL_METHOD==2
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#define EPS LDBL_EPSILON
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#endif
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static const double_t toint = 1/EPS;
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/**
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* Rounds 𝑥 to nearest integer, away from zero.
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*/
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double round(double x)
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{
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#ifdef __aarch64__
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asm("frinta\t%d0,%d1" : "=w"(x) : "w"(x));
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return x;
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#elif defined(__powerpc64__) && defined(_ARCH_PWR5X)
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asm("frin\t%0,%1" : "=d"(x) : "d"(x));
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return x;
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#elif defined(__s390x__) && (defined(__HTM__) || __ARCH__ >= 9)
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asm("fidbra\t%0,1,%1,4" : "=f"(x) : "f"(x));
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return x;
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#else
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union {double f; uint64_t i;} u = {x};
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int e = u.i >> 52 & 0x7ff;
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double_t y;
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if (e >= 0x3ff+52)
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return x;
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if (u.i >> 63)
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x = -x;
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if (e < 0x3ff-1) {
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/* raise inexact if x!=0 */
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FORCE_EVAL(x + toint);
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return 0*u.f;
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}
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y = x + toint - toint - x;
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if (y > 0.5)
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y = y + x - 1;
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else if (y <= -0.5)
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y = y + x + 1;
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else
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y = y + x;
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if (u.i >> 63)
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y = -y;
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return y;
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#endif /* __aarch64__ */
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}
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#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
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__weak_reference(round, roundl);
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#endif
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