Tech Tip: NAG Fortran Library and Absoft Pro Fortran Version 9.0

The NAG DLLs may be used in many environments. Our Users' Note contains detailed descriptions of how the DLLs may be used in these situations and often a set of examples is given, together with supporting information.

The Absoft F77 compiler provides one such environment. When the Mark 20 DLLs were released the current Absoft compiler was version 7.0 and so our description and example gave details of use with this compiler. The example was a modified example program for D02CJF. This routine solves an ordinary differential equation, initial value problem using a variable order, variable step Adams method.

The integration proceeds until a user-specified function is zero. The user is required to provide this function, G(T,Y) in the form of a FUNCTION. Since the DLLs are DOUBLE PRECISION and are compiled using the STDCALL calling convention, at Absoft version 7 the following convention is used:

STDCALL DOUBLE PRECISION FUNCTION G(T,Y)

With the latest, version 9.0, release of the Absoft F77 compiler this syntax is no longer recognised and gives rise to a compiler error. At version 9 one of the following syntaxes is required:

STDCALL FUNCTION G(T,Y)
DOUBLE PRECISION G

or

DOUBLE PRECISION FUNCTION G(T,Y)
STDCALL G

To summarise, in version 9.0 of the Absoft F77 Compiler the STDCALL statement cannot be followed by the function type.

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