diff options
Diffstat (limited to 'REORG.TODO/sysdeps/ieee754/ldbl-128/s_logbl.c')
| -rw-r--r-- | REORG.TODO/sysdeps/ieee754/ldbl-128/s_logbl.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/ieee754/ldbl-128/s_logbl.c b/REORG.TODO/sysdeps/ieee754/ldbl-128/s_logbl.c new file mode 100644 index 0000000000..24baae64fa --- /dev/null +++ b/REORG.TODO/sysdeps/ieee754/ldbl-128/s_logbl.c @@ -0,0 +1,54 @@ +/* s_logbl.c -- long double version of s_logb.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 + +/* + * long double logbl(x) + * IEEE 754 logb. Included to pass IEEE test suite. Not recommend. + * Use ilogb instead. + */ + +#include <math.h> +#include <math_private.h> + +_Float128 +__logbl (_Float128 x) +{ + int64_t lx, hx, ex; + + GET_LDOUBLE_WORDS64 (hx, lx, x); + hx &= 0x7fffffffffffffffLL; /* high |x| */ + if ((hx | lx) == 0) + return -1.0 / fabsl (x); + if (hx >= 0x7fff000000000000LL) + return x * x; + if ((ex = hx >> 48) == 0) /* IEEE 754 logb */ + { + /* POSIX specifies that denormal number is treated as + though it were normalized. */ + int ma; + if (hx == 0) + ma = __builtin_clzll (lx) + 64; + else + ma = __builtin_clzll (hx); + ex -= ma - 16; + } + return (_Float128) (ex - 16383); +} + +weak_alias (__logbl, logbl) |