glibc/sysdeps/ieee754/flt-32/e_hypotf.c
David S. Miller 7c10fd3515 Fix hypotf overflow/underflow by using double precision instead of scaling.
[BZ #13840]
	* sysdeps/ieee754/flt-32/e_hypotf.c (__ieee754_hypotf): Rewrite to use
	double-precision for the calculation instead of scaling.
2012-03-13 18:08:58 -07:00

54 lines
1.2 KiB
C

/* e_hypotf.c -- float version of e_hypot.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.
* ====================================================
*/
#include <math.h>
#include <math_private.h>
float
__ieee754_hypotf(float x, float y)
{
double d_x, d_y;
int32_t ha, hb;
GET_FLOAT_WORD(ha,x);
ha &= 0x7fffffff;
GET_FLOAT_WORD(hb,y);
hb &= 0x7fffffff;
if (ha == 0x7f800000)
{
if (x == y)
return fabsf(y);
return fabsf(x);
}
else if (hb == 0x7f800000)
{
if (x == y)
return fabsf(x);
return fabsf(y);
}
else if (ha > 0x7f800000 || hb > 0x7f800000)
return fabsf(x) * fabsf(y);
else if (ha == 0)
return fabsf(y);
else if (hb == 0)
return fabsf(x);
d_x = (double) x;
d_y = (double) y;
return (float) __ieee754_sqrt(d_x * d_x + d_y * d_y);
}
strong_alias (__ieee754_hypotf, __hypotf_finite)