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/* sf_scalbn.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 "fdlibm.h"
#include <limits.h>
#include <float.h>
#if INT_MAX > 50000
#define OVERFLOW_INT 50000
#else
#define OVERFLOW_INT 30000
#endif
static const float
two25 = 3.355443200e+07, /* 0x4c000000 */
twom25 = 2.9802322388e-08; /* 0x33000000 */
float scalbnf (float x, int n)
{
__int32_t k,ix;
__uint32_t hx;
GET_FLOAT_WORD(ix,x);
hx = ix&0x7fffffff;
k = hx>>23; /* extract exponent */
if (k == 0) {
if (hx == 0) return x;
x *= two25;
GET_FLOAT_WORD(ix,x);
k = ((ix&0x7f800000)>>23) - 25;
#if __SIZEOF_INT__ > 2
if (n< -50000)
return __math_uflowf(ix<0); /*underflow*/
#endif
}
if (k == 0xff) return x + x; /* NaN or Inf */
if (n > OVERFLOW_INT) /* in case integer overflow in n+k */
return __math_oflowf(ix<0); /*overflow*/
k = k+n;
if (k > FLT_LARGEST_EXP)
return __math_oflowf(ix<0); /* overflow */
if (k > 0) /* normal result */
{SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;}
if (k < -25)
return __math_uflowf(ix<0); /*underflow*/
k += 25; /* subnormal result */
SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23));
return check_uflowf(x*twom25);
}
#if defined(_HAVE_ALIAS_ATTRIBUTE)
#ifndef __clang__
#pragma GCC diagnostic ignored "-Wmissing-attributes"
#endif
__strong_reference(scalbnf, ldexpf);
#else
float
ldexpf(float value, int exp)
{
return scalbnf(value, exp);
}
#endif
_MATH_ALIAS_f_fi(scalbn)
_MATH_ALIAS_f_fi(ldexp)
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