diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_modfl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_modfl.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_modfl.c b/sysdeps/ieee754/ldbl-128ibm/s_modfl.c new file mode 100644 index 0000000000..f2e65f0c44 --- /dev/null +++ b/sysdeps/ieee754/ldbl-128ibm/s_modfl.c @@ -0,0 +1,94 @@ +/* s_modfl.c -- long double version of s_modf.c. + * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz. + */ + +/* + * ==================================================== + * 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" +#include <math_ldbl_opt.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 +{ + int64_t i0,i1,j0; + u_int64_t i; + GET_LDOUBLE_WORDS64(i0,i1,x); + i1 &= 0x000fffffffffffffLL; + j0 = ((i0>>52)&0x7ff)-0x3ff; /* exponent of x */ + if(j0<52) { /* integer part in high x */ + if(j0<0) { /* |x|<1 */ + /* *iptr = +-0 */ + SET_LDOUBLE_WORDS64(*iptr,i0&0x8000000000000000ULL,0); + return x; + } else { + i = (0x000fffffffffffffLL)>>j0; + if(((i0&i)|(i1&0x7fffffffffffffffLL))==0) { /* x is integral */ + *iptr = x; + /* return +-0 */ + SET_LDOUBLE_WORDS64(x,i0&0x8000000000000000ULL,0); + return x; + } else { + SET_LDOUBLE_WORDS64(*iptr,i0&(~i),0); + return x - *iptr; + } + } + } else if (j0>103) { /* no fraction part */ + *iptr = x*one; + /* We must handle NaNs separately. */ + if (j0 == 0x400 && ((i0 & 0x000fffffffffffffLL) | i1)) + return x*one; + /* return +-0 */ + SET_LDOUBLE_WORDS64(x,i0&0x8000000000000000ULL,0); + return x; + } else { /* fraction part in low x */ + i = -1ULL>>(j0-52); + if((i1&i)==0) { /* x is integral */ + *iptr = x; + /* return +-0 */ + SET_LDOUBLE_WORDS64(x,i0&0x8000000000000000ULL,0); + return x; + } else { + SET_LDOUBLE_WORDS64(*iptr,i0,i1&(~i)); + return x - *iptr; + } + } +} +#ifdef IS_IN_libm +long_double_symbol (libm, __modfl, modfl); +#else +long_double_symbol (libc, __modfl, modfl); +#endif |