[MLton] Re: Cross compile on ARM successful
fluet at tti-c.org
Wed Jun 27 07:21:00 PDT 2007
Ryan Newton wrote:
> I cross compiled the MLton runtime for ARM-linux and it's currently
> running fine on some embedded devices. It was a bit tough because I had
> to manually go through and do the steps in "add-cross" (the embedded
> machines don't have gcc!) and I had to apply a few hacks to the code,
> but it works fine.
Wow, that's awesome! Please send any patches that you needed to apply;
it would be great to make it easier for others to target ARM-linux.
> By the way, are there any incantations that can turn off all
> optimizations in the compiler and simply maximize compilation speed?
> Maybe most people simply use SML/nj for prototyping, but I'm now
> dependent on the MLton FFI...
There is an undocumented compiler option:
That should turn off a fair number of the compiler optimizations.
However, it should be noted that for most programs, the time in gcc with
the C codegen is where a lot of the time takes, and on ARM, you're stuck
using the C codegen. And, for small programs, the time to type-check
the whole program (including the Basis Library) can be a significant
portion of compile time. Unfortunately, you can't skip either of these
phases of the compiler.
If you turn off the compiler optimizations, you end up sending even more
code to gcc, which in turn slows things down further. We had an
experimental bytecode codegen, which was supposed to mitigate this sort
of behavior: a very fast codegen (that could be combined with turning
off compiler optimizations for fast compile times), but a somewhat
Unfortunately, the bytecode codegen wasn't used very much (certainly, no
one has ever had anything good or bad to say about it), and it is
currently broken after merging in the x86-64 changes.
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