mirror of
https://github.com/reactos/reactos.git
synced 2024-05-31 17:51:49 +00:00
152 lines
4.6 KiB
C
152 lines
4.6 KiB
C
|
|
/*******************************************************************************
|
|
MIT License
|
|
-----------
|
|
|
|
Copyright (c) 2002-2019 Advanced Micro Devices, Inc.
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
of this Software and associated documentaon files (the "Software"), to deal
|
|
in the Software without restriction, including without limitation the rights
|
|
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
copies of the Software, and to permit persons to whom the Software is
|
|
furnished to do so, subject to the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be included in
|
|
all copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
THE SOFTWARE.
|
|
*******************************************************************************/
|
|
|
|
#include "libm.h"
|
|
#include "libm_util.h"
|
|
|
|
#define USE_VALF_WITH_FLAGS
|
|
#define USE_NANF_WITH_FLAGS
|
|
#define USE_HANDLE_ERRORF
|
|
#include "libm_inlines.h"
|
|
#undef USE_NANF_WITH_FLAGS
|
|
#undef USE_VALF_WITH_FLAGS
|
|
#undef USE_HANDLE_ERRORF
|
|
|
|
#include "libm_errno.h"
|
|
|
|
// Disable "C4163: not available as intrinsic function" warning that older
|
|
// compilers may issue here.
|
|
#pragma warning(disable:4163)
|
|
#pragma function(asinf)
|
|
|
|
|
|
float FN_PROTOTYPE(asinf)(float x)
|
|
{
|
|
/* Computes arcsin(x).
|
|
The argument is first reduced by noting that arcsin(x)
|
|
is invalid for abs(x) > 1 and arcsin(-x) = -arcsin(x).
|
|
For denormal and small arguments arcsin(x) = x to machine
|
|
accuracy. Remaining argument ranges are handled as follows.
|
|
For abs(x) <= 0.5 use
|
|
arcsin(x) = x + x^3*R(x^2)
|
|
where R(x^2) is a rational minimax approximation to
|
|
(arcsin(x) - x)/x^3.
|
|
For abs(x) > 0.5 exploit the identity:
|
|
arcsin(x) = pi/2 - 2*arcsin(sqrt(1-x)/2)
|
|
together with the above rational approximation, and
|
|
reconstruct the terms carefully.
|
|
*/
|
|
|
|
/* Some constants and split constants. */
|
|
|
|
static const float
|
|
piby2_tail = 7.5497894159e-08F, /* 0x33a22168 */
|
|
hpiby2_head = 7.8539812565e-01F, /* 0x3f490fda */
|
|
piby2 = 1.5707963705e+00F; /* 0x3fc90fdb */
|
|
float u, v, y, s = 0.0F, r;
|
|
int xexp, xnan, transform = 0;
|
|
|
|
unsigned int ux, aux, xneg;
|
|
GET_BITS_SP32(x, ux);
|
|
aux = ux & ~SIGNBIT_SP32;
|
|
xneg = (ux & SIGNBIT_SP32);
|
|
xnan = (aux > PINFBITPATT_SP32);
|
|
xexp = (int)((ux & EXPBITS_SP32) >> EXPSHIFTBITS_SP32) - EXPBIAS_SP32;
|
|
|
|
/* Special cases */
|
|
|
|
if (xnan)
|
|
{
|
|
return _handle_errorf("asinf", OP_ASIN, ux|0x00400000, _DOMAIN, 0,
|
|
EDOM, x, 0.0F, 1);
|
|
}
|
|
else if (xexp < -14)
|
|
/* y small enough that arcsin(x) = x */
|
|
return valf_with_flags(x, AMD_F_INEXACT);
|
|
else if (xexp >= 0)
|
|
{
|
|
/* abs(x) >= 1.0 */
|
|
if (x == 1.0F)
|
|
return valf_with_flags(piby2, AMD_F_INEXACT);
|
|
else if (x == -1.0F)
|
|
return valf_with_flags(-piby2, AMD_F_INEXACT);
|
|
else
|
|
return _handle_errorf("asinf", OP_ASIN, INDEFBITPATT_SP32, _DOMAIN,
|
|
AMD_F_INVALID, EDOM, x, 0.0F, 1);
|
|
}
|
|
|
|
if (xneg) y = -x;
|
|
else y = x;
|
|
|
|
transform = (xexp >= -1); /* abs(x) >= 0.5 */
|
|
|
|
if (transform)
|
|
{ /* Transform y into the range [0,0.5) */
|
|
r = 0.5F*(1.0F - y);
|
|
/* VC++ intrinsic call */
|
|
_mm_store_ss(&s, _mm_sqrt_ss(_mm_load_ss(&r)));
|
|
y = s;
|
|
}
|
|
else
|
|
r = y*y;
|
|
|
|
/* Use a rational approximation for [0.0, 0.5] */
|
|
|
|
u=r*(0.184161606965100694821398249421F +
|
|
(-0.0565298683201845211985026327361F +
|
|
(-0.0133819288943925804214011424456F -
|
|
0.00396137437848476485201154797087F*r)*r)*r)/
|
|
(1.10496961524520294485512696706F -
|
|
0.836411276854206731913362287293F*r);
|
|
|
|
if (transform)
|
|
{
|
|
/* Reconstruct asin carefully in transformed region */
|
|
float c, s1, p, q;
|
|
unsigned int us;
|
|
GET_BITS_SP32(s, us);
|
|
PUT_BITS_SP32(0xffff0000 & us, s1);
|
|
c = (r-s1*s1)/(s+s1);
|
|
p = 2.0F*s*u - (piby2_tail-2.0F*c);
|
|
q = hpiby2_head - 2.0F*s1;
|
|
v = hpiby2_head - (p-q);
|
|
}
|
|
else
|
|
{
|
|
/* Use a temporary variable to prevent VC++ rearranging
|
|
y + y*u
|
|
into
|
|
y * (1 + u)
|
|
and getting an incorrectly rounded result */
|
|
float tmp;
|
|
tmp = y * u;
|
|
v = y + tmp;
|
|
}
|
|
|
|
if (xneg) return -v;
|
|
else return v;
|
|
}
|