diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_frexpl.c')
-rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_frexpl.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_frexpl.c b/sysdeps/ieee754/ldbl-128ibm/s_frexpl.c new file mode 100644 index 0000000000..fab566da3b --- /dev/null +++ b/sysdeps/ieee754/ldbl-128ibm/s_frexpl.c @@ -0,0 +1,92 @@ +/* s_frexpl.c -- long double version of s_frexp.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 + +/* + * for non-zero x + * x = frexpl(arg,&exp); + * return a long double fp quantity x such that 0.5 <= |x| <1.0 + * and the corresponding binary exponent "exp". That is + * arg = x*2^exp. + * If arg is inf, 0.0, or NaN, then frexpl(arg,&exp) returns arg + * with *exp=0. + */ + +#include "math.h" +#include "math_private.h" +#include <math_ldbl_opt.h> + +#ifdef __STDC__ +static const long double +#else +static long double +#endif +two107 = 162259276829213363391578010288128.0; /* 0x4670000000000000, 0 */ + +#ifdef __STDC__ + long double __frexpl(long double x, int *eptr) +#else + long double __frexpl(x, eptr) + long double x; int *eptr; +#endif +{ + u_int64_t hx, lx, ix, ixl; + int64_t explo; + GET_LDOUBLE_WORDS64(hx,lx,x); + ixl = 0x7fffffffffffffffULL&lx; + ix = 0x7fffffffffffffffULL&hx; + *eptr = 0; + if(ix>=0x7ff0000000000000ULL||((ix|ixl)==0)) return x; /* 0,inf,nan */ + if (ix<0x0010000000000000ULL) { /* subnormal */ + x *= two107; + GET_LDOUBLE_MSW64(hx,x); + ix = hx&0x7fffffffffffffffULL; + *eptr = -107; + } + *eptr += (ix>>52)-1022; + + if (ixl != 0ULL) { + explo = (ixl>>52) - (ix>>52) + 0x3fe; + if ((ixl&0x7ff0000000000000ULL) == 0LL) { + /* the lower double is a denomal so we need to correct its + mantissa and perhaps its exponent. */ + int cnt; + + if (sizeof (ixl) == sizeof (long)) + cnt = __builtin_clzl (ixl); + else if ((ixl >> 32) != 0) + cnt = __builtin_clzl ((long) (ixl >> 32)); + else + cnt = __builtin_clzl ((long) ixl) + 32; + cnt = cnt - 12; + lx = (lx&0x8000000000000000ULL) | ((explo-cnt)<<52) + | ((ixl<<(cnt+1))&0x000fffffffffffffULL); + } else + lx = (lx&0x800fffffffffffffULL) | (explo<<52); + } else + lx = 0ULL; + + hx = (hx&0x800fffffffffffffULL) | 0x3fe0000000000000ULL; + SET_LDOUBLE_WORDS64(x,hx,lx); + return x; +} +#ifdef IS_IN_libm +long_double_symbol (libm, __frexpl, frexpl); +#else +long_double_symbol (libc, __frexpl, frexpl); +#endif |