diff options
Diffstat (limited to 'newlib/libm/common/sf_ilogb.c')
| -rw-r--r-- | newlib/libm/common/sf_ilogb.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/newlib/libm/common/sf_ilogb.c b/newlib/libm/common/sf_ilogb.c new file mode 100644 index 00000000000..ee65594b152 --- /dev/null +++ b/newlib/libm/common/sf_ilogb.c @@ -0,0 +1,53 @@ +/* sf_ilogb.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. + * ==================================================== + */ + +#include "fdlibm.h" +#include <limits.h> + +#ifdef __STDC__ + int ilogbf(float x) +#else + int ilogbf(x) + float x; +#endif +{ + __int32_t hx,ix; + + GET_FLOAT_WORD(hx,x); + hx &= 0x7fffffff; + if(hx<0x00800000) { + if(hx==0) + return - INT_MAX; /* ilogb(0) = 0x80000001 */ + 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 return INT_MAX; +} + +#ifdef _DOUBLE_IS_32BITS + +#ifdef __STDC__ + int ilogb(double x) +#else + int ilogb(x) + double x; +#endif +{ + return ilogbf((float) x); +} + +#endif /* defined(_DOUBLE_IS_32BITS) */ |