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/*
* ====================================================
* Copyright (C) 1998, 2002 by Red Hat Inc. All rights reserved.
*
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#if !defined(_SOFT_FLOAT)
/*
Fast version of exp using Intel float instructions.
float _f_expf (float x);
Function computes e ** x. The following special cases exist:
1. if x is 0.0 ==> return 1.0
2. if x is infinity ==> return infinity
3. if x is -infinity ==> return 0.0
4. if x is NaN ==> return x
There is no error checking or setting of errno.
*/
#include <math.h>
#include <ieeefp.h>
#include "f_math.h"
float _f_expf (float x)
{
if (check_finitef(x))
{
float result;
asm ("fldl2e; fmulp; fld %%st; frndint; fsub %%st,%%st(1); fxch;" \
"fchs; f2xm1; fld1; faddp; fxch; fld1; fscale; fstp %%st(1); fmulp" :
"=t"(result) : "0"(x));
return result;
}
else if (x == -infinityf())
return 0.0;
return x;
}
#endif
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