New blog location

This will be my last blog entry here. I'm leaving Oracle after 16 amazing years. I've had a fantastic time, and I'm glad to have been able share some of that with you. If you wish to read about my continuing adventures please head along to http://www.darrylgove.com/. All the best, Darryl.

Tuesday, August 11, 2015 | Personal | Read More

Where does misaligned data come from?

A good question about data (mis)alignment is "Where did it come from?". So here's a reasonably detailed answer to that... If the compiler has generated the code for you and you've not done anything "weird" then the data should be correctly aligned. So most apps don't have misaligned data, and most of the time you (as a developer) don't have to worry about it. For example, if you allocate a local variable, or a global variable, then the compiler will correctly align it. If you...

Thursday, May 28, 2015 | Personal | Read More

Misaligned loads profiled (again)

A long time ago I described how misaligned loads appeared in profiles of 32-bit applications. Since then we've changed the level of detail presented in the Performance Analyzer. When I wrote the article the time spent on-cpu that wasn't User time was grouped as System time. We've now started showing more detail - and more detail is good. Here's a similar bit of code: #include <stdio.h>static int i,j;volatile double *d;void main (){ char a[10]; d=(double*)&a[1]; j=100000000; ...

Wednesday, May 27, 2015 | Work | Read More

Misaligned loads in 64-bit apps

A while back I wrote up how to use dtrace to identify misaligned loads in 32-bit apps. Here's a script to do the same for 64-bit apps: #!/usr/sbin/dtrace -spid$1::__do_misaligned_ldst_instr:entry{ @p[ustack()]=count();} Run it as './script '

Wednesday, May 13, 2015 | Personal | Read More

C++ rules enforced in Studio 12.4

Studio 12.4 has improved adherence to the C++ standard, so some codes which were accepted by 12.3 might get reported as errors with the new compiler. The compiler documentation has a list of the improvements and examples of how to modify problem code to make it standard compliant.

Tuesday, May 5, 2015 | Work | Read More

SPARC processor documentation

The documentation for older SPARC processors has been put up on the web!

Tuesday, April 28, 2015 | Personal | Read More
 

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