source: trunk/libs/newlib/src/newlib/libm/math/ef_remainder.c @ 444

/* ef_remainder.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 "fdlibm.h"

#ifdef __STDC__
static const float zero = 0.0;
#else
static float zero = 0.0;
#endif


#ifdef __STDC__
        float __ieee754_remainderf(float x, float p)
#else
        float __ieee754_remainderf(x,p)
        float x,p;
#endif
{
        __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(FLT_UWORD_IS_ZERO(hp)||
           !FLT_UWORD_IS_FINITE(hx)||
           FLT_UWORD_IS_NAN(hp))
            return (x*p)/(x*p);


        if (hp<=FLT_UWORD_HALF_MAX) 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;
}