If you've tried calling system functions from a Fortran program, you might have run into difficulties because these functions don't have a Fortran interface. For example, the following code will fail execution:
p = malloc(40)
if (p == 0) then
! malloc error. Print errno
print *, "malloc failed. errno=", errno()
x = [10.0, 5.0, 4.0, 7.0, 2.0, 1.0, 3.0, 6.0, 9.0, 8.0]
print *, x
The reason is that malloc , errno , exit , and free do not have an... [More]
When the compiler knows that an array occupies a contiguous block of memory, it can perform optimizations based on memory layout. Explicit shape arrays, assumed-size arrays and allocatable arrays occupy contiguous blocks of memory. For array pointers and assumed shape arrays, the compiler cannot determine at compile time if it is the case.
In the latest AIX XL Fortran compiler, -qassert=contiguous was introduced to allow the programmer to indicate to the compiler that: * all array pointers are pointer associated with contiguous... [More]
New and enhanced features in XL Fortran Version 14.1 include support of language
features that you can use to port code easily when moving to IBM Power Systems,
as well as improved compilation time at commonly used optimization levels. This
article for those who have some experience with previous versions of XL Fortran
gives the details and describes other highlights. Read more .
Check out new exercises in the Power sandbox. You can find them below.
You can learn about compiling with a list of options defined in a file, debugging optimized code, new OpenMP3.1 constructs, performance benefits of using F2008 CONTIGUOUS attribute and the F2008 BLOCK construct. Optimize server performance and programmer productivity with IBM
compilers Compile with a list of options defined in a file Debugging optimized XL Fortran code New and enhanced atomic constructs in OpenMP 3.1 The final clause in OpenMP 3.1... [More]
you know that the compiler you use can impact whether or not you
achieve optimal performance from all parts of your systems.
Organizations often overlook the importance of compilers, often running
new high-powered servers with outdated compilers that limit the servers’
potential. Or failing to update compilers that can improve the
efficiency of existing hardware investments as more advanced versions
are released. In practical terms,this translates into greater power
consumption, slower response times,numerous administrative... [More]
The July 2012 PTF for XL Fortran for AIX, V13.1 (VRMF: 184.108.40.206) is now available at the following links and on Fix Central . July 2012 PTF for XL Fortran for AIX, V13.1 July 2012 PTF for XL Fortran Runtime for AIX, V13.1 Can't find the updates for your compilers? Check out our Fortran compilers latest updates page here .
Check out this webinar by IBM Systems Magazine about Smart Tools on IBM i, AIX, and Linux for Faster Time to Market Get an early look at the next version of Rational's offerings for Power Systems. New advancements in compilers and significantly enhanced development tools will give your organization a competitive advantage! Listen to the replay .
Input / Output (I/O) performance can be a significant factor in overall program performance. The way you write I/O statements can make a big difference. Consider the following example:
subroutine sub(x, n) real x(n) do i = 1, n, 2 write (unit=11) x(i) enddo end subroutine
The I/O in sub might not be as fast as you'd like. This is due to the accumulation of the overhead for each write statement. The write statement above has to do some preparation work before it can actually write anything. It also has to do some... [More]
The June 2012 PTF for XL Fortran for AIX, V13.1 is now available at the following links and on Fix Central : June 2012 Update for XL Fortran for Linux, V13.1 June 2012 Update for XL Fortran Runtime for Linux, V13.1 Can't find the updates for your compilers? Check out our Fortran compilers latest updates page here .
Check out all the information about the latest release of XL Fortran for AIX, and XL Fortran for Linux. You can get a summary of
each release by product as well as all the announcement details. See
What's new in the release including enhancements to improve application
performance and programmer productivity. For all the details about the
XL Fortran announcements, see these resources. And don't forget our Webinar and Innovate2012 where you will hear lots more about the latest compilers. Webinar: Smart Tools on IBM i, AIX, and Linux... [More]
If you are using the Parallel Environment's (PE) mpi module with an older version of the XL Fortran compiler , you might hit this error message:
1514-220 (S) Module symbol file for module mpi is in a format not recognized by this compiler. Please compile the module with this
The mpi module was generated using XL Fortran 12.1, so it's incompatible with earlier versions of XL Fortran. We recently published a technote about this. Consider upgrading to take advantage of the extra type-checking offered by this module.
Fortran Compilers are
now live on the Request for Enhancement (RFE) Community. It is a great
place where you can collaborate with development teams and other product users.
Our development team will review your RFE and provide status updates throughout
Here is the link to the Community: Fortran RFE
Looking forward to
hearing from you.
The latest release of XL Fortran introduces new data types and intrinsic functions for the Vector Scalar eXtension (VSX) instruction set tuned for the POWER7 processor. With the VSX instruction set and the original Vector Multimedia eXtension (VMX) intrinsic functions; you can efficiently manipulate vector operations in your application. The Mathematical Acceleration Subsystem (MASS) libraries contain an accelerated set of frequently used mathematical intrinsic functions that provide improved performance over the corresponding standard system... [More]
Check out updated exercises in the Power sandbox. You can find them below.
You can learn about tracking compiler use, performance,
auto-vectorization, optimization, interoperability, and reporting Optimize server performance and programmer productivity with IBM
Learn about tracking IBM XL C/C++ and Fortran compiler utilization
Enhanced performance with new XL C/C++ and Fortran compilers
The February 2012 PTF for XL Fortran for AIX, V12.1 is now available at the following links and on Fix Central . February 2012 PTF for XL Fortran for AIX, V12.1 February 2012 PTF for XL Fortran for AIX, V12.1 Runtime Can't find the updates for your compilers? Check out our Fortran compilers latest updates page here .