/* 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.

 * ====================================================

 */

#include <math.h>

#include <math_private.h>

static const float

two25   =  3.355443200e+07,	/* 0x4c000000 */

twom25  =  2.9802322388e-08,	/* 0x33000000 */

huge   = 1.0e+30,

tiny   = 1.0e-30;

float

__scalbnf (float x, int n)

{

	int32_t k,ix;

	GET_FLOAT_WORD(ix,x);

	k = (ix&0x7f800000)>>23;		/* extract exponent */

	if (__builtin_expect(k==0, 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 (__builtin_expect(k==0xff, 0)) return x+x;	/* NaN or Inf */

	if (__builtin_expect(n< -50000, 0))

	  return tiny*__copysignf(tiny,x);	/*underflow*/

	if (__builtin_expect(n> 50000 || k+n > 0xfe, 0))

	  return huge*__copysignf(huge,x); /* overflow  */

	/* Now k and n are bounded we know that k = k+n does not

	   overflow.  */

	k = k+n;

	if (__builtin_expect(k > 0, 1))		/* 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;

}