glibc/sysdeps/ieee754/flt-32/k_sinf.c
Joseph Myers ad39cce0da Fix sin, sincos missing underflows (bug 16526, bug 16538).
Similar to various other bugs in this area, some sin and sincos
implementations do not raise the underflow exception for subnormal
arguments, when the result is tiny and inexact.  This patch forces the
exception in a similar way to previous fixes.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #16526]
	[BZ #16538]
	* sysdeps/ieee754/dbl-64/s_sin.c: Include <float.h>.
	(__sin): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/flt-32/k_sinf.c: Include <float.h>.
	(__kernel_sinf): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128/k_sincosl.c: Include <float.h>.
	(__kernel_sincosl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128/k_sinl.c: Include <float.h>.
	(__kernel_sinl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128ibm/k_sincosl.c: Include <float.h>.
	(__kernel_sincosl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128ibm/k_sinl.c: Include <float.h>.
	(__kernel_sinl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-96/k_sinl.c: Include <float.h>.
	(__kernel_sinl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/powerpc/fpu/k_sinf.c: Include <float.h>.
	(__kernel_sinf): Force underflow exception for arguments with
	small absolute value.
	* math/auto-libm-test-in: Add more tests of sin and sincos.
	* math/auto-libm-test-out: Regenerated.
2015-06-23 22:24:20 +00:00

55 lines
1.5 KiB
C

/* k_sinf.c -- float version of k_sin.c
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: k_sinf.c,v 1.4 1995/05/10 20:46:33 jtc Exp $";
#endif
#include <float.h>
#include <math.h>
#include <math_private.h>
static const float
half = 5.0000000000e-01,/* 0x3f000000 */
S1 = -1.6666667163e-01, /* 0xbe2aaaab */
S2 = 8.3333337680e-03, /* 0x3c088889 */
S3 = -1.9841270114e-04, /* 0xb9500d01 */
S4 = 2.7557314297e-06, /* 0x3638ef1b */
S5 = -2.5050759689e-08, /* 0xb2d72f34 */
S6 = 1.5896910177e-10; /* 0x2f2ec9d3 */
float __kernel_sinf(float x, float y, int iy)
{
float z,r,v;
int32_t ix;
GET_FLOAT_WORD(ix,x);
ix &= 0x7fffffff; /* high word of x */
if(ix<0x32000000) /* |x| < 2**-27 */
{
if (fabsf (x) < FLT_MIN)
{
float force_underflow = x * x;
math_force_eval (force_underflow);
}
if ((int) x == 0)
return x; /* generate inexact */
}
z = x*x;
v = z*x;
r = S2+z*(S3+z*(S4+z*(S5+z*S6)));
if(iy==0) return x+v*(S1+z*r);
else return x-((z*(half*y-v*r)-y)-v*S1);
}