Intel® Fortran Compiler 17.0 Developer Guide and Reference
Elemental Intrinsic Function (Specific): Produces a higher precision product. This is a specific function that has no generic function associated with it.
result = DPROD (x, y)
x |
(Input) Must be of type REAL(4) or REAL(8). |
y |
(Input) Must have the same type and kind parameters as x. |
If x and y are of type REAL(4), the result type is double-precision real (REAL(8) or REAL*8). If x and y are of type REAL(8), the result type is REAL(16). The result value is equal to x* y.
The setting of compiler options specifying real size can affect this function.
DPROD (2.0, -4.0) has the value -8.00D0.
DPROD (5.0D0, 3.0D0) has the value 15.00Q0.
The following shows another example:
REAL(4) e
REAL(8) d
e = 123456.7
d = 123456.7D0
! DPROD (e,e) returns 15241557546.4944
! DPROD (d,d) returns 15241556774.8899992813874268904328