47 lines
570 B
C
47 lines
570 B
C
/*
|
|
* $Source$
|
|
* $State$
|
|
* $Revision$
|
|
*/
|
|
|
|
/* no headers allowed! */
|
|
|
|
/* Given a double, calculates the mantissa and exponent.
|
|
*
|
|
* This function is intended to be called internally by the code generator,
|
|
* so the calling convention is odd.
|
|
*/
|
|
|
|
int __fef8(double* fp)
|
|
{
|
|
double f = *fp;
|
|
int exponent, sign;
|
|
|
|
if (f == 0.0)
|
|
return 0;
|
|
|
|
if (f < 0.0)
|
|
{
|
|
sign = -1;
|
|
f = -f;
|
|
}
|
|
else
|
|
sign = 0;
|
|
|
|
exponent = 0;
|
|
while (f >= 1.0)
|
|
{
|
|
f /= 2.0;
|
|
exponent++;
|
|
}
|
|
|
|
while (f < 0.5)
|
|
{
|
|
f *= 2.0;
|
|
exponent--;
|
|
}
|
|
|
|
*fp = (sign) ? -f : f;
|
|
return exponent;
|
|
}
|