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/* @(#)z_powf.c 1.0 98/08/13 */
#include <float.h>
#include "fdlibm.h"
#include "zmath.h"
float powf (float x, float y)
{
float d, t, r = 1.0;
int n, k, sign = 0;
__int32_t px;
GET_FLOAT_WORD (px, x);
k = modff (y, &d);
if (k == 0.0)
{
if (modff (ldexpf (y, -1), &t))
sign = 0;
else
sign = 1;
}
if (x == 0.0 && y <= 0.0)
errno = EDOM;
else if ((t = y * log (fabsf (x))) >= BIGX)
{
errno = ERANGE;
if (px & 0x80000000)
{
if (!k)
{
errno = EDOM;
x = 0.0;
}
else if (sign)
x = -z_infinity_f.f;
else
x = z_infinity_f.f;
}
else
x = z_infinity_f.f;
}
else if (t < SMALLX)
{
errno = ERANGE;
x = 0.0;
}
else
{
if ( k && fabsf (d) <= 32767 )
{
n = (int) d;
if (sign = (n < 0))
n = -n;
while ( n > 0 )
{
if ((unsigned int) n % 2)
r *= x;
x *= x;
n = (unsigned int) n / 2;
}
if (sign)
r = 1.0 / r;
return r;
}
else
{
if ( px & 0x80000000 )
{
if ( !k )
{
errno = EDOM;
return 0.0;
}
}
x = exp (t);
if ( sign )
{
px ^= 0x80000000;
SET_FLOAT_WORD (x, px);
}
}
}
return x;
}
#ifdef _DOUBLE_IS_32BITS
double pow (double x, double y)
{
return (double) powf ((float) x, (float) y);
}
#endif /* defined(_DOUBLE_IS_32BITS) */
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