[Vm-dev] VM Maker: VMMaker.oscog-dtl.3123.mcz

David T. Lewis lewis at mail.msen.com
Thu Apr 7 23:42:48 UTC 2022

On Thu, Apr 07, 2022 at 04:22:51AM -0700, Eliot Miranda wrote:
> Hi Marcel,
> > On Apr 7, 2022, at 4:17 AM, Marcel Taeumel <marcel.taeumel at hpi.de> wrote:
> > 
> > ???
> > Hi Dave, hi Eliot, hi all --
> > 
> > I think we can still merge this into the next VM release.
> > 
> > For Squeak 6.0, I only then have to figure out how to produce that new (base) image for the bundles. :-) Probably something in the area of SystemTracer... or I just hack the image header directly? xD
> I don???t think you need to anything to the image.  This is a vm property, ie does the vm support multiple bytecode sets or not?  One should be able to run an image that uses only one bytecode set on a vm that supports two.

Right. On the image side the only thing to be aware of is this:

CompiledCode class>>multipleBytecodeSetsActive: aBoolean
	"Inform the VM when multiple bytecode sets, typically the Sista bytecodes
	in addition to the traditional V3 bytecode set, are now in use in this image.
	The VM may use this information to update the image format number when
	saving the image to the file system."

	<primitive: 'primitiveMultipleBytecodeSetsActive'>

So for the Squeak 6.0 release, if we are confident that most users
of the new release will be using the release VM, and if we are
releasing with Sista activated, then we just need to make sure that
this method is called in the update stream and/or ReleaseBuilder.

See also the convenience method CompiledCode class>>useSista:


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