vrs4_expf: Four-valued single precision exponential function

• C Prototype:
  • __m128 __vrs4_expf(__m128 x);

  • Inputs:
    • __m128 x - the four single precision input values.
      
  • Outputs:
    • e raised to the power x (exponential of x) for each input value x.
      __m128 y - the four single precision exponent results, returned in xmm0.
• Notes:
  • __vrs4_expf computes the double precision exponential function of four input arguments.
    
    This routine accepts four single precision input values passed as a __m128 value. The result is the single precision exponent of the four values, returned as a __m128 value. This is a relaxed version of exp, 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.
• Special case return values:

  • Input	Output
    QNaN	same QNaN
    SNaN	same NaN converted to QNaN
    < -87.5	0
    > 88	+infinity

• Performance:
  • 91 cycles for most valid inputs (23 cycles per value).