By Darryl Gove-Oracle on May 28, 2008
An updated version of my article on compiler options has been put up. I think I last refreshed this a couple of years back. It's interesting to see what difference a couple of years makes. I'd started the update with the expectation that things would have become much simpler, although this is true, there's still some complexity left. The major changes were:
- More focus on
-xtarget=generic. Really that's the best option to start with and to use when possible. But there are exceptions....
- For x86 it's a good plan to use
-xarch=sse2 -xvector=simdto get the compiler to use the SSE2 instruction set which is common on all recent x86 processors.
- For SPARC the SPARC64 VI processor supports floating point multiply accumulate instructions. These are a boost for floating point codes, and are generated under the flags
- The compiler is pretty good at generating prefetch instructions by default, so there's no real need to emphasise the prefetch flags.
- Profile feedback and crossfile optimisation are pretty common options, and should be considered for all applications.