diff -r 000000000000 -r bde4ae8d615e os/ossrv/genericopenlibs/cstdlib/LMATH/S_MODF.C --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/os/ossrv/genericopenlibs/cstdlib/LMATH/S_MODF.C Fri Jun 15 03:10:57 2012 +0200 @@ -0,0 +1,132 @@ +/* S_MODF.C + * + * Portions Copyright (c) 1993-1999 Nokia Corporation and/or its subsidiary(-ies). + * All rights reserved. + */ + + +/* @(#)s_modf.c 5.1 93/09/24 */ +/* + * ==================================================== + * 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. + * ==================================================== + */ + +/* +FUNCTION + <<modf>>, <<modff>>---split fractional and integer parts + +INDEX + modf +INDEX + modff + +ANSI_SYNOPSIS + #include <math.h> + double modf(double <[val]>, double *<[ipart]>); + float modff(float <[val]>, float *<[ipart]>); + +TRAD_SYNOPSIS + #include <math.h> + double modf(<[val]>, <[ipart]>) + double <[val]>; + double *<[ipart]>; + + float modff(<[val]>, <[ipart]>) + float <[val]>; + float *<[ipart]>; + +DESCRIPTION + <<modf>> splits the double <[val]> apart into an integer part + and a fractional part, returning the fractional part and + storing the integer part in <<*<[ipart]>>>. No rounding + whatsoever is done; the sum of the integer and fractional + parts is guaranteed to be exactly equal to <[val]>. That + is, if . <[realpart]> = modf(<[val]>, &<[intpart]>); then + `<<<[realpart]>+<[intpart]>>>' is the same as <[val]>. + <<modff>> is identical, save that it takes and returns + <<float>> rather than <<double>> values. + +RETURNS + The fractional part is returned. Each result has the same + sign as the supplied argument <[val]>. + +PORTABILITY + <<modf>> is ANSI C. <<modff>> is an extension. + +QUICKREF + modf ansi pure + modff - pure + +*/ + +/* + * modf(double x, double *iptr) + * return fraction part of x, and return x's integral part in *iptr. + * Method: + * Bit twiddling. + * + * Exception: + * No exception. + */ + +#include "FDLIBM.H" + +static const double one = 1.0; + +/** +Split floating-point value into fractional and integer parts. +Breaks x in two parts: the integer (stored in location pointed by iptr) +and the fraction (return value). +@return Fractional part of x +@param x Floating point value. +@param iptr Location where the integer part of x will be stored. +*/ +EXPORT_C double modf(double x, double *iptr) __SOFTFP +{ + __int32_t i0,i1,j0; + __uint32_t i; + EXTRACT_WORDS(i0,i1,x); + j0 = ((i0>>20)&0x7ff)-0x3ff; /* exponent of x */ + if(j0<20) { /* integer part in high x */ + if(j0<0) { /* |x|<1 */ + INSERT_WORDS(*iptr,i0&0x80000000,0); /* *iptr = +-0 */ + return x; + } else { + i = (0x000fffff)>>j0; + if(((i0&i)|i1)==0) { /* x is integral */ + __uint32_t high; + *iptr = x; + GET_HIGH_WORD(high,x); + INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */ + return x; + } else { + INSERT_WORDS(*iptr,i0&(~i),0); + return x - *iptr; + } + } + } else if (j0>51) { /* no fraction part */ + __uint32_t high; + *iptr = x*one; + GET_HIGH_WORD(high,x); + INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */ + return x; + } else { /* fraction part in low x */ + i = ((__uint32_t)(0xffffffff))>>(j0-20); + if((i1&i)==0) { /* x is integral */ + __uint32_t high; + *iptr = x; + GET_HIGH_WORD(high,x); + INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */ + return x; + } else { + INSERT_WORDS(*iptr,i0,i1&(~i)); + return x - *iptr; + } + } +}