[MLton] cvs commit: decreasing liveness information in large SSA functions

[Matthew Fluet]

>   The big remaining problem is compile time.  It takes 8.6 hours to
>   compile HOL.  Here's the breakdown.
>
>         pre codegen finished in 456.25 + 260.84 (36% GC)
>         x86 code gen finished in 24579.91 + 5485.26 (18% GC)
>         Compile C and Assemble finished in 52.59 + 0.00 (0% GC)
>         Link finished in 204.34 + 0.00 (0% GC)
>
>   Matthew, if you can look into why the x86-codegen is taking so long
>   that would be great.  Let me know if you need any other data.

I'm working on a POPL submission, so I don't have many free cycles until
after July 16.  You can try -native-optimize 0 to turn off all the
x86-codegen optimizations.  The resulting code will be poorer, but you
should get it faster; if this doesn't finish in < 1hr, then there is a
serious problem somewhere.

If you system has nothing to do overnight, you could also try -verbose 3
so we can see the breakdown in the x86-codegen sub-passes.