1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/ossrv/genericopenlibs/cstdlib/LMATH/S_MODF.C	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,132 @@
     1.4 +/* S_MODF.C
     1.5 + * 
     1.6 + * Portions Copyright (c) 1993-1999 Nokia Corporation and/or its subsidiary(-ies).
     1.7 + * All rights reserved.
     1.8 + */
     1.9 +
    1.10 +
    1.11 +/* @(#)s_modf.c 5.1 93/09/24 */
    1.12 +/*
    1.13 + * ====================================================
    1.14 + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
    1.15 + *
    1.16 + * Developed at SunPro, a Sun Microsystems, Inc. business.
    1.17 + * Permission to use, copy, modify, and distribute this
    1.18 + * software is freely granted, provided that this notice 
    1.19 + * is preserved.
    1.20 + * ====================================================
    1.21 + */
    1.22 +
    1.23 +/*
    1.24 +FUNCTION
    1.25 +       <<modf>>, <<modff>>---split fractional and integer parts
    1.26 +
    1.27 +INDEX
    1.28 +	modf
    1.29 +INDEX
    1.30 +	modff
    1.31 +
    1.32 +ANSI_SYNOPSIS
    1.33 +	#include <math.h>
    1.34 +	double modf(double <[val]>, double *<[ipart]>);
    1.35 +        float modff(float <[val]>, float *<[ipart]>);
    1.36 +
    1.37 +TRAD_SYNOPSIS
    1.38 +	#include <math.h>
    1.39 +	double modf(<[val]>, <[ipart]>)
    1.40 +        double <[val]>;
    1.41 +        double *<[ipart]>;
    1.42 +
    1.43 +	float modff(<[val]>, <[ipart]>)
    1.44 +	float <[val]>;
    1.45 +        float *<[ipart]>;
    1.46 +
    1.47 +DESCRIPTION
    1.48 +	<<modf>> splits the double <[val]> apart into an integer part
    1.49 +	and a fractional part, returning the fractional part and
    1.50 +	storing the integer part in <<*<[ipart]>>>.  No rounding
    1.51 +	whatsoever is done; the sum of the integer and fractional
    1.52 +	parts is guaranteed to be exactly  equal to <[val]>.   That
    1.53 +	is, if . <[realpart]> = modf(<[val]>, &<[intpart]>); then
    1.54 +	`<<<[realpart]>+<[intpart]>>>' is the same as <[val]>.
    1.55 +	<<modff>> is identical, save that it takes and returns
    1.56 +	<<float>> rather than <<double>> values. 
    1.57 +
    1.58 +RETURNS
    1.59 +	The fractional part is returned.  Each result has the same
    1.60 +	sign as the supplied argument <[val]>.
    1.61 +
    1.62 +PORTABILITY
    1.63 +	<<modf>> is ANSI C. <<modff>> is an extension.
    1.64 +
    1.65 +QUICKREF
    1.66 +	modf  ansi pure 
    1.67 +	modff - pure
    1.68 +
    1.69 +*/
    1.70 +
    1.71 +/*
    1.72 + * modf(double x, double *iptr) 
    1.73 + * return fraction part of x, and return x's integral part in *iptr.
    1.74 + * Method:
    1.75 + *	Bit twiddling.
    1.76 + *
    1.77 + * Exception:
    1.78 + *	No exception.
    1.79 + */
    1.80 +
    1.81 +#include "FDLIBM.H"
    1.82 +
    1.83 +static const double one = 1.0;
    1.84 +
    1.85 +/**
    1.86 +Split floating-point value into fractional and integer parts.
    1.87 +Breaks x in two parts: the integer (stored in location pointed by iptr)
    1.88 +and the fraction (return value).
    1.89 +@return Fractional part of x
    1.90 +@param x Floating point value. 
    1.91 +@param iptr Location where the integer part of x will be stored.
    1.92 +*/	
    1.93 +EXPORT_C double modf(double x, double *iptr) __SOFTFP
    1.94 +{
    1.95 +	__int32_t i0,i1,j0;
    1.96 +	__uint32_t i;
    1.97 +	EXTRACT_WORDS(i0,i1,x);
    1.98 +	j0 = ((i0>>20)&0x7ff)-0x3ff;	/* exponent of x */
    1.99 +	if(j0<20) {			/* integer part in high x */
   1.100 +	    if(j0<0) {			/* |x|<1 */
   1.101 +	        INSERT_WORDS(*iptr,i0&0x80000000,0);	/* *iptr = +-0 */
   1.102 +		return x;
   1.103 +	    } else {
   1.104 +		i = (0x000fffff)>>j0;
   1.105 +		if(((i0&i)|i1)==0) {		/* x is integral */
   1.106 +		    __uint32_t high;
   1.107 +		    *iptr = x;
   1.108 +		    GET_HIGH_WORD(high,x);
   1.109 +		    INSERT_WORDS(x,high&0x80000000,0);	/* return +-0 */
   1.110 +		    return x;
   1.111 +		} else {
   1.112 +		    INSERT_WORDS(*iptr,i0&(~i),0);
   1.113 +		    return x - *iptr;
   1.114 +		}
   1.115 +	    }
   1.116 +	} else if (j0>51) {		/* no fraction part */
   1.117 +	    __uint32_t high;
   1.118 +	    *iptr = x*one;
   1.119 +	    GET_HIGH_WORD(high,x);
   1.120 +	    INSERT_WORDS(x,high&0x80000000,0);	/* return +-0 */
   1.121 +	    return x;
   1.122 +	} else {			/* fraction part in low x */
   1.123 +	    i = ((__uint32_t)(0xffffffff))>>(j0-20);
   1.124 +	    if((i1&i)==0) { 		/* x is integral */
   1.125 +	        __uint32_t high;
   1.126 +		*iptr = x;
   1.127 +		GET_HIGH_WORD(high,x);
   1.128 +		INSERT_WORDS(x,high&0x80000000,0);	/* return +-0 */
   1.129 +		return x;
   1.130 +	    } else {
   1.131 +	        INSERT_WORDS(*iptr,i0,i1&(~i));
   1.132 +		return x - *iptr;
   1.133 +	    }
   1.134 +	}
   1.135 +}