Mike Lin wrote:
I have a bunch of biological sequence analysis stuff that could be interesting but I am already in x86-64 ("Wow! A 64 bit architecture!"). The above seems pretty clear but just to verify - I would not benefit from this new back-end, right?
Right. Sorry for not mentioning this. The x86-64 bit code generator for OCaml uses SSE2 floats, like all C compilers for this platform. The experimental back-end I announced is for x86-32 bit. Some more Q&A: Q: I have OCaml installed on my x86 machine, how do I know if it's 32 or 64 bits? A: Do: grep ^ARCH `ocamlopt -where`/Makefile.config If it says "amd64", it's 64 bits with SSE2 floats. If it says "i386", it's 32 bits with x87 floats. If if says "ia32", it's the experimental back-end: 32 bits with SSE2 floats. Q: If I compile from sources, which code generator is chosen by default? 32 or 64 bits? A: OCaml's configure script chooses whatever mode the C compiler defaults to. For instance, on a 32-bit Linux installation, the 32-bit generator is selected, and on 64-bit Linux installation, it's the 64-bit generator. Mac OS X is more tricky: 10.5 and earlier default to 32 bits, but 10.6 defaults to 64 bits... Will Farr wrote:
Oops. I just ran a bunch of tests on my Mac OS 10.6 system---does that mean that I compared two sse2 backends? The ocaml-sse2 branch definitely produced different code than the trunk, but that could easily be due to any small difference in the two compilers, and not due to a change of architecture.
It is quite possible you ended up with two 64-bit, SSE2-float back-ends. Oups. Sorry for your time loss. And, yes, unrelated changes between release 3.11.2 and the experimental sources I released (based on what will become 3.12.0) can account for small speed differences. - Xavier Leroy _______________________________________________ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
