ercs50@castle.ed.ac.uk (gerry weir) (03/15/91)
Does anybody know how many of the VMS Fortran Extensions are incorporated in DEC'S Ultrix Fortran compiler. Does it have records and unions? Are there any significant features missing? Are any of the VMS system calls supported?
peterson@fman.enet.dec.com (Bob Peterson) (03/20/91)
Attached is an excerpt from the online release notes and it describes
what the differences are. The changes are mainly due to VMS features
not found in U*IX as well. As we ported the VAX FORTRAN front end
(parser) only, and not the back end, the syntax is largely the same.
\bob peterson peterson@tle.enet.dec.com
DEC Fortran
Digital Equipment Corp.
1.6.1.2 VAX FORTRAN Features Not in DEC Fortran
In general, VAX FORTRAN features that are not available
in DEC Fortran are flagged with error messages at compile
time. VAX FORTRAN command line options or OPEN keywords
or keyword values that are not available in DEC Fortran
usually generate warning messages (not errors) and are
ignored.
The following VAX FORTRAN features are not available in
DEC Fortran:
o Vectorization and directed decomposition features (in
VAX FORTRAN HPO)
o The CPAR$ manual decomposition directives
o The DICTIONARY statement
o Support for multi-key ISAM indexed files
o The REAL*16 data type (and Q* intrinsic functions)
RISC hardware does not support 128-bit floating point.
FORTRAN for RISC accepted the syntax and used the first
64 bits as a double precision value.
o Certain OPEN and INQUIRE keywords and keyword values
Certain OPEN and INQUIRE keywords and keyword values
are not available in DEC Fortran for ULTRIX RISC
Systems Version 3.0 or have meanings or defaults that
differ from VAX FORTRAN for VMS systems. For more
information, see the DEC Fortran Language Reference
Manual.
DEC Fortran does not support the OPEN keyword
USEROPEN, and it ignores the OPEN keywords EXTENDSIZE,
INITIALSIZE, NOSPANBLOCKS, and SHARED.
o Run-time default I/O units that are spelled FOR0nn.DAT
and SYS$INPUT, and so forth
In DEC Fortran, these are spelled fort.n, stdin, and so
forth, as on ULTRIX. You can set the FORTn environment
variable to the file name to be opened on unit n. For
more information, see the DEC Fortran for ULTRIX RISC
Systems User Manual.
o FORSYSDEF symbol definitions for VMS systems
o Certain subroutines that VAX FORTRAN provides for
PDP-11 compatibility
For more information, see the DEC Fortran for ULTRIX
RISC Systems User Manual.
o The "07 octal notation for integer constants (by
default)
[Reenabled with a command line option. -bob]
o The ability to include text from text libraries
o Radix-50 constants
o The %DESCR built-in function
However, DEC Fortran supports the built-in functions
%LOC, %VAL, and %REF.
o Calling a function that is a CHARACTER*(*) dummy
argument
This is an extension to FORTRAN-77 that the RISC ULTRIX
calling convention does not support.
o The option /[NO]G_FLOATING (either in an OPTIONS
statement or on the command line)