diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_scalblnf.c')
-rw-r--r-- | sysdeps/libm-ieee754/s_scalblnf.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_scalblnf.c b/sysdeps/libm-ieee754/s_scalblnf.c new file mode 100644 index 0000000000..4ed48733cf --- /dev/null +++ b/sysdeps/libm-ieee754/s_scalblnf.c @@ -0,0 +1,63 @@ +/* s_scalbnf.c -- float version of s_scalbn.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. + * ==================================================== + */ + +#if defined(LIBM_SCCS) && !defined(lint) +static char rcsid[] = "$NetBSD: s_scalbnf.c,v 1.4 1995/05/10 20:48:10 jtc Exp $"; +#endif + +#include "math.h" +#include "math_private.h" + +#ifdef __STDC__ +static const float +#else +static float +#endif +two25 = 3.355443200e+07, /* 0x4c000000 */ +twom25 = 2.9802322388e-08, /* 0x33000000 */ +huge = 1.0e+30, +tiny = 1.0e-30; + +#ifdef __STDC__ + float __scalblnf (float x, long int n) +#else + float __scalblnf (x,n) + float x; long int n; +#endif +{ + int32_t k,ix; + GET_FLOAT_WORD(ix,x); + k = (ix&0x7f800000)>>23; /* extract exponent */ + if (k==0) { /* 0 or subnormal x */ + if ((ix&0x7fffffff)==0) return x; /* +-0 */ + x *= two25; + GET_FLOAT_WORD(ix,x); + k = ((ix&0x7f800000)>>23) - 25; + } + if (k==0xff) return x+x; /* NaN or Inf */ + k = k+n; + if (n> 50000 || k > 0xfe) + return huge*copysignf(huge,x); /* overflow */ + if (n< -50000) + return tiny*copysignf(tiny,x); /*underflow*/ + if (k > 0) /* normal result */ + {SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;} + if (k <= -25) + return tiny*copysignf(tiny,x); /*underflow*/ + k += 25; /* subnormal result */ + SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); + return x*twom25; +} +weak_alias (__scalblnf, scalblnf) |