> I know that the T2000 is binary compatible with sparc > software, and infact I already tested my installer on > a T2000, and the software works fine. > I was wondering if I should consider rebuilding all > the native softwares of my bundle on T1 processor, so > having a separate installer for this platform. > Will I have any performance gain? Will I have to > specify flags or something to have optimized binaries > for T1?
For any different SPARC CPU, there may be different instruction scheduling optimizations that are ideal. But unless you run into a real problem, it's usually more maintainable and good enough to compile it with flags that result in something that's decent on all SPARC CPUs. Also, gcc may not have options giving as fine-grained control of that as the Studio C compiler has. I think the typical behavior of current Studio is to select a default that would be reasonable on any UltraSPARC CPU, i.e. v8plus (SPARC v8 plus 32-bit compatible v9 extensions); if you want compilation optimized for the compiling system, that would be -xtarget=native (or maybe -fast, depending on whether the other unusual behavior that it might imply is ok). The real issue with the T1000/T2000 (i.e. UltraSPARC T1 chip) is that it has a certain configuration of cores and threads per core, and more than that, that it only has one floating-point unit for the entire chip. So integer-intensive code might benefit from some tweaks for scheduling, but would probably be ok; but floating-point intensive code (esp. with more than one app running floating-point intensive code at once) would be at least as much a problem as that situation would be on a single-core system; indeed probably a worse problem, given more competition for the FPU (in that there would be plenty of parallelism for non-floating-point activity across threads, but that they'd stand in line when they needed the FPU). The upcoming T2 chip is said to have one FPU per core, which should be a much better situation (although for reasons I don't entirely understand, it's seems to not be marketed as being as general purpose as other present or future UltraSPARC CPUs). This message posted from opensolaris.org _______________________________________________ opensolaris-discuss mailing list [email protected]
