| /* s_logbl.c -- long double version of s_logb.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. |
| * ==================================================== |
| */ |
| |
| /* |
| * 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> |
| |
| long double |
| __logbl (long double x) |
| { |
| int32_t es, lx, ix; |
| |
| GET_LDOUBLE_WORDS (es, ix, lx, x); |
| es &= 0x7fff; /* exponent */ |
| if ((es | ix | lx) == 0) |
| return -1.0 / fabsl (x); |
| if (es == 0x7fff) |
| return x * x; |
| if (es == 0) /* IEEE 754 logb */ |
| { |
| /* POSIX specifies that denormal number is treated as |
| though it were normalized. */ |
| if (ix == 0) |
| es = -(__builtin_clz (lx) + 32); |
| else |
| es = -__builtin_clz (ix); |
| } |
| return (long double) (es - 16383); |
| } |
| |
| weak_alias (__logbl, logbl) |
