Re: [MIT-Scheme-devel] [commit acae7a5] svm: Port to 64 bit words.

[Matt Birkholz]

> From: Taylor R Campbell <address@hidden>
> Date: Sun, 4 Mar 2012 18:51:39 +0000
> 
> [...]
> 
> What I'm wondering about is whether SVM code is independent of the
> word size of the Scheme system you load it into.

Yes.  With an upcoming patch, the exact same instructions will be
assembled for all word sizes.

> In the C back end [...] you can load the same C code into a 32-bit
> Scheme and a 64-bit Scheme, by way of a C compiler fit for the
> target Scheme's system characteristics.

The C back end includes its own special "fasdump" that produces a
whack of opcodes that re-construct the constants.

> So, if I build an SVM cross-compiler on my ancient and decrepit
> 32-bit MacBook , and use that to compile some Scheme to SVM code,
> can I [...] then load that SVM code into Scheme on a 64-bit system,
> and vice versa?

I believe the only remaining trick is the 32<->64bit fasloader.