vrda_sincos: Array double precision Sine and Cosine

void __vrda_sincos (int n, double *x, double *ys, double *yc)

• C Prototype:
  • void __vrda_sincos (int n, double *x, double *ys, double *yc)
    

• Inputs:

  • int	n	- the number of values in both the input and output arrays.
    double	*x	- pointer to the array of input values.
    double	*ys	- pointer to the array of sin output values.
    double	*yc	- pointer to the array of cos output values.

• Outputs:
  • Sine for each x value, filled into the ys array.$* Cosine for each x value, filled into the yc array.$*
• Notes:
  • __vrda_sincos computes the Sine and Cosine functions for each element of an array of input arguments.
    

    This routine accepts an array of double precision input values, computes sincos(x) for each input value, and stores the results in the arrays pointed to by the ys and yc pointer inputs. It is the responsibility of the calling program to allocate/deallocate enough storage for the output array. This is a relaxed version of sincos, suitable for use with fastmath compiler flags or applications not requiring full error handling. Denormal inputs may produce unpredictable results. Special case inputs produce C99 return values. The routine is accurate to better than 1 ulp over the valid input range. This routine may return slightly worse than 1 ulp for very large values between 4e5 and 5e5.

• Special case return values:

  • Input	Output
    QNaN	same QNaN
    SNaN	same NaN converted to QNaN
    +infinity	QNaN
    -infinity	QNaN

• Performance:
  • 180 cycles for most valid inputs < 5e5 (43 cycles per Sin and Cos of a value), n = 24.