diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_modfl.c')
| -rw-r--r-- | sysdeps/libm-ieee754/s_modfl.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_modfl.c b/sysdeps/libm-ieee754/s_modfl.c new file mode 100644 index 0000000000..433c936240 --- /dev/null +++ b/sysdeps/libm-ieee754/s_modfl.c @@ -0,0 +1,88 @@ +/* s_modfl.c -- long double version of s_modf.c. + * Conversion to long double by Ulrich Drepper, + * Cygnus Support, drepper@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. + * ==================================================== + */ + +#if defined(LIBM_SCCS) && !defined(lint) +static char rcsid[] = "$NetBSD: $"; +#endif + +/* + * modfl(long double x, long double *iptr) + * return fraction part of x, and return x's integral part in *iptr. + * Method: + * Bit twiddling. + * + * Exception: + * No exception. + */ + +#include "math.h" +#include "math_private.h" + +#ifdef __STDC__ +static const long double one = 1.0; +#else +static long double one = 1.0; +#endif + +#ifdef __STDC__ + long double __modfl(long double x, long double *iptr) +#else + long double __modfl(x, iptr) + long double x,*iptr; +#endif +{ + int32_t i0,i1,j0; + u_int32_t i,se; + GET_LDOUBLE_WORDS(se,i0,i1,x); + j0 = (se&0x7fff)-0x3fff; /* exponent of x */ + if(j0<32) { /* integer part in high x */ + if(j0<0) { /* |x|<1 */ + SET_LDOUBLE_WORDS(*iptr,se&0x8000,0,0); /* *iptr = +-0 */ + return x; + } else { + i = (0xffffffff)>>j0; + if(((i0&i)|i1)==0) { /* x is integral */ + u_int32_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>63) { /* no fraction part */ + u_int32_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 = ((u_int32_t)(0xffffffff))>>(j0-20); + if((i1&i)==0) { /* x is integral */ + u_int32_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; + } + } +} +weak_alias (__modfl, modfl) |