ITEM: CG3146L
What is the difference between Fortran V4 and V3
What is the difference between Fortran V4 and V3.
XL Fortran for AIX Version 4:
o Supports file sizes larger than 2GB under AIX Version 4.2
o Supports selected features from Fortran 95 (F95)
o Provides better performance for array language
o Provides enhanced optimization technologies to improve
execution time
o Supports Unicode under AIX Version 4.2 on RISC System/6000
o Supports full Fortran 90 and FORTRAN 77 (F77) standards
o Supports source code compatibility of existing FORTRAN
applications written with existing versions of XL Fortran
for AIX
IBM's XL Fortran for AIX (R) Version 4 is a follow-on product
to XL Fortran for AIX Version 3.2. It supports file sizes greater
than 2GB under AIX Version 4.2, supports selected Fortran 95 features
and improves array language execution time. Additionally, you are
given the option of whether to use the licensing management tool with
the product or not, based on your business and system environment.
ENHANCEMENTS
Enhancements available to F90 and F77 programs are:
o Aggressive inlining of F90 array language to achieve performance
comparable to F77 by eliminating unnecessary generation and
copying of array temporaries
o Transforms loop structure for improved data locality
XL Fortran for AIX Version 4 is designed to exploit the POWER,
POWER2, and PowerPC architectures by incorporating a state-of-the-art
optimizing backend. Compile options let programmers generate
executables targeting specific processor architectures to achieve
better performance at execution time.
LARGE FILE SUPPORT
To support Fortran users on AIX Version 4.2, XL Fortran for AIX V4
will support large files in the following ways:
- Larger than 2GB file size
- Larger than 2GB record number (not record size)
o File Size greater than or equal to 2GB (Up to 2 to the power of
63 minus 1)
Applications using large files (greater than 2GB file
size) can be addressed without being changed to get the benefit
of larger files. Large files are no longer needed to be
partitioned into smaller files for processing.
Fortran applications compiled with XL Fortran for AIX
Version 3.2 or XL F Fortran for AIX Version 4 on AIX Version 4.1
do not need to be recompiled on AIX Version 4.2 in order to take
advantage of the large file support. This is assuming that the
larger file enabled file system is created under AIX Version 4.2.
o Record Numbers up to 2 to the power of 63 minus 1.
Applications can now address record numbers less than
2**31-1 by declaring the record number or the variable holding
the record number to be INTEGER(8) in their programs.
Applications need to be recompiled with the XL Fortran for
AIX Version 4 and run with XL Fortran RTE for AIX Version 4.
SELECTED FORTRAN 95 FEATURES
o FORALL CONSTRUCT
FORALL Construct has been used in the parallel programming
language such as High Performance Fortran(HPF). Using this
construct in the F95 language allows the application to port to
parallel systems with less effort.
o PURE PROCEDURES
FORTRAN programmers can take advantage of PURE procedures
in their application. When procedures are declared to be PURE,
unnecessary setup code will not be generated by XL Fortran for
AIX Version 4, hence the execution time of the procedures may
reduced.
o MAXLOC/MINLOC Extensions (Optional DIM argument)
LICENSE MANAGEMENT TOOL
Existing XL Fortran for AIX Version 3.2 uses iFOR/LS as the licensing
management tool in the product. In XL Fortran for AIX Version 4, the
same tool is available to the user to track and manage the usage of
the compiler. XL Fortran for AIX Version 4 is iFOR/LS enabled. The
customer is required to call IBM key center for iFOR/LS keys.
o Fortran 95 (drafted International Standard for Fortran from WG5
committee dated: November 29, 1995).
- Supported Features
-- FORALL Construct
-- PURE Procedures
-- MAXLOC and MINLOC with DIM optional argument
Support Line: What is the difference between Fortran V4 and V3 ITEM: CG3146L
Dated: October 1996 Category: N/A
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