sortix-mirror/libm/src/e_remainderf.c
Jonas 'Sortie' Termansen 5980be9b3c Add Sortix Math Library.
This work is based in part on code from NetBSD libm, libc and kernel.

The library is partly public domain and partly BSD-style licensed.
2013-12-17 14:30:39 +01:00

67 lines
1.5 KiB
C

/* e_remainderf.c -- float version of e_remainder.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 <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
__RCSID("$NetBSD: e_remainderf.c,v 1.7 2002/05/26 22:01:52 wiz Exp $");
#endif
#include "math.h"
#include "math_private.h"
static const float zero = 0.0;
float
__ieee754_remainderf(float x, float p)
{
int32_t hx,hp;
uint32_t sx;
float p_half;
GET_FLOAT_WORD(hx,x);
GET_FLOAT_WORD(hp,p);
sx = hx&0x80000000;
hp &= 0x7fffffff;
hx &= 0x7fffffff;
/* purge off exception values */
if(hp==0) return (x*p)/(x*p); /* p = 0 */
if((hx>=0x7f800000)|| /* x not finite */
((hp>0x7f800000))) /* p is NaN */
return (x*p)/(x*p);
if (hp<=0x7effffff) x = __ieee754_fmodf(x,p+p); /* now x < 2p */
if ((hx-hp)==0) return zero*x;
x = fabsf(x);
p = fabsf(p);
if (hp<0x01000000) {
if(x+x>p) {
x-=p;
if(x+x>=p) x -= p;
}
} else {
p_half = (float)0.5*p;
if(x>p_half) {
x-=p;
if(x>=p_half) x -= p;
}
}
GET_FLOAT_WORD(hx,x);
SET_FLOAT_WORD(x,hx^sx);
return x;
}