GNU bug report logs - #11087
vector limitation in compiling to bytecode

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Message #10 received at 11087-done <at> debbugs.gnu.org (full text, mbox):

From: Andy Wingo <wingo <at> pobox.com>
To: Ian Price <ianprice90 <at> googlemail.com>
Cc: 11087-done <at> debbugs.gnu.org
Subject: Re: bug#11087: vector limitation in compiling to bytecode
Date: Thu, 05 Jul 2012 23:01:42 +0200

On Sat 24 Mar 2012 21:09, Ian Price <ianprice90 <at> googlemail.com> writes:

> ;;; ERROR: In procedure bytevector-u8-set!: Value out of range: 390
> vector constant containing 100000 values
>
> This limitation is documented, and somewhat reasonable, but on IRC mark
> weaver asked me to file a bug anyway, since he thinks the assembler
> should have a fall back plan.

I agree with Mark.

For what it's worth, if the vector is really constant (e.g. just
composed of immediates), the RTL VM will emit the whole thing
statically.  Otherwise it will emit code to allocate a vector
of the right size at init time, initializing its elements with
individual instructions.   This latter strategy is probably the right
thing to do with the Guile 2.0 VM.

In the mean time, I added a check for the vector-length to
glil/compile-assembly.scm.  If the vector is too big, it hits the array
case, which has a 24-bit range.  It seems to hit some other problem
after that, but I gave it the ole college try, right?

Cheers,

Andy
-- 
http://wingolog.org/

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