| /* s_logbf.c -- float version of s_logb.c. |
| * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@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. |
| * ==================================================== |
| */ |
| |
| #include <math.h> |
| #include <math_private.h> |
| #include <libm-alias-float.h> |
| #include <fix-int-fp-convert-zero.h> |
| |
| float |
| __logbf (float x) |
| { |
| int32_t ix, rix; |
| |
| GET_FLOAT_WORD (ix, x); |
| ix &= 0x7fffffff; /* high |x| */ |
| if (ix == 0) |
| return (float) -1.0 / fabsf (x); |
| if (ix >= 0x7f800000) |
| return x * x; |
| if (__glibc_unlikely ((rix = ix >> 23) == 0)) |
| { |
| /* POSIX specifies that denormal number is treated as |
| though it were normalized. */ |
| rix -= __builtin_clz (ix) - 9; |
| } |
| if (FIX_INT_FP_CONVERT_ZERO && rix == 127) |
| return 0.0f; |
| return (float) (rix - 127); |
| } |
| libm_alias_float (__logb, logb) |
