diff options
Diffstat (limited to 'ports/sysdeps/m68k/m680x0/fpu/s_logbl.c')
| -rw-r--r-- | ports/sysdeps/m68k/m680x0/fpu/s_logbl.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/ports/sysdeps/m68k/m680x0/fpu/s_logbl.c b/ports/sysdeps/m68k/m680x0/fpu/s_logbl.c new file mode 100644 index 0000000000..2586622bf7 --- /dev/null +++ b/ports/sysdeps/m68k/m680x0/fpu/s_logbl.c @@ -0,0 +1,49 @@ +/* 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) |