mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 20:51:11 +00:00
127 lines
3.0 KiB
C
127 lines
3.0 KiB
C
/* Copyright (C) 1997-2014 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library. If not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
#include "mathimpl.h"
|
|
|
|
#ifndef SUFF
|
|
#define SUFF
|
|
#endif
|
|
#ifndef float_type
|
|
#define float_type double
|
|
#endif
|
|
|
|
#define CONCATX(a,b) __CONCAT(a,b)
|
|
#define s(name) CONCATX(name,SUFF)
|
|
#define m81(func) __m81_u(s(func))
|
|
|
|
float_type
|
|
s(__ieee754_pow) (float_type x, float_type y)
|
|
{
|
|
float_type z;
|
|
float_type ax;
|
|
unsigned long x_cond, y_cond;
|
|
|
|
y_cond = __m81_test (y);
|
|
if (y_cond & __M81_COND_ZERO)
|
|
return 1.0;
|
|
if (y_cond & __M81_COND_NAN)
|
|
return x == 1.0 ? x : x + y;
|
|
|
|
x_cond = __m81_test (x);
|
|
if (x_cond & __M81_COND_NAN)
|
|
return x + y;
|
|
|
|
if (y_cond & __M81_COND_INF)
|
|
{
|
|
ax = s(fabs) (x);
|
|
if (ax == 1.0)
|
|
return ax;
|
|
if (ax > 1.0)
|
|
return y_cond & __M81_COND_NEG ? 0 : y;
|
|
else
|
|
return y_cond & __M81_COND_NEG ? -y : 0;
|
|
}
|
|
|
|
if (s(fabs) (y) == 1.0)
|
|
return y_cond & __M81_COND_NEG ? 1 / x : x;
|
|
|
|
if (y == 2)
|
|
return x * x;
|
|
if (y == 0.5 && !(x_cond & __M81_COND_NEG))
|
|
return m81(__ieee754_sqrt) (x);
|
|
|
|
if (x == 10.0)
|
|
{
|
|
__asm ("ftentox%.x %1, %0" : "=f" (z) : "f" (y));
|
|
return z;
|
|
}
|
|
if (x == 2.0)
|
|
{
|
|
__asm ("ftwotox%.x %1, %0" : "=f" (z) : "f" (y));
|
|
return z;
|
|
}
|
|
|
|
ax = s(fabs) (x);
|
|
if (x_cond & (__M81_COND_INF | __M81_COND_ZERO) || ax == 1.0)
|
|
{
|
|
z = ax;
|
|
if (y_cond & __M81_COND_NEG)
|
|
z = 1 / z;
|
|
if (x_cond & __M81_COND_NEG)
|
|
{
|
|
if (y != m81(__rint) (y))
|
|
{
|
|
if (x == -1)
|
|
z = (z - z) / (z - z);
|
|
}
|
|
else
|
|
goto maybe_negate;
|
|
}
|
|
return z;
|
|
}
|
|
|
|
if (x_cond & __M81_COND_NEG)
|
|
{
|
|
if (y == m81(__rint) (y))
|
|
{
|
|
z = m81(__ieee754_exp) (y * m81(__ieee754_log) (-x));
|
|
maybe_negate:
|
|
/* We always use the long double format, since y is already in
|
|
this format and rounding won't change the result. */
|
|
{
|
|
int32_t exponent;
|
|
u_int32_t i0, i1;
|
|
GET_LDOUBLE_WORDS (exponent, i0, i1, y);
|
|
exponent = (exponent & 0x7fff) - 0x3fff;
|
|
if (exponent <= 31
|
|
? i0 & (1 << (31 - exponent))
|
|
: (exponent <= 63
|
|
&& i1 & (1 << (63 - exponent))))
|
|
z = -z;
|
|
}
|
|
}
|
|
else
|
|
z = (y - y) / (y - y);
|
|
}
|
|
else
|
|
z = m81(__ieee754_exp) (y * m81(__ieee754_log) (x));
|
|
return z;
|
|
}
|
|
strong_alias (s(__ieee754_pow), CONCATX (s(__pow), _finite))
|