diff options
Diffstat (limited to 'libm/src/s_ilogbf.c')
-rw-r--r-- | libm/src/s_ilogbf.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/libm/src/s_ilogbf.c b/libm/src/s_ilogbf.c new file mode 100644 index 0000000..3c9c4de --- /dev/null +++ b/libm/src/s_ilogbf.c @@ -0,0 +1,41 @@ +/* s_ilogbf.c -- float version of s_ilogb.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. + * ==================================================== + */ + +#ifndef lint +static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_ilogbf.c,v 1.7 2004/10/09 17:14:28 stefanf Exp $"; +#endif + +#include <limits.h> + +#include "math.h" +#include "math_private.h" + + int ilogbf(float x) +{ + int32_t hx,ix; + + GET_FLOAT_WORD(hx,x); + hx &= 0x7fffffff; + if(hx<0x00800000) { + if(hx==0) + return FP_ILOGB0; + else /* subnormal x */ + for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1; + return ix; + } + else if (hx<0x7f800000) return (hx>>23)-127; + else if (hx>0x7f800000) return FP_ILOGBNAN; + else return INT_MAX; +} |