[Vm-dev] Small discrepancy in fileTimesInUTC between simulation & VM

Eliot Miranda eliot.miranda at gmail.com
Tue Dec 29 04:52:06 UTC 2020


Hi Nicolas,

On Sun, Dec 27, 2020 at 5:52 AM Nicolas Cellier <
nicolas.cellier.aka.nice at gmail.com> wrote:

>
> Hi all, Eliot,
>
> Simulation says:
>
>     ^(Smalltalk vmParameterAt: 48) anyMask: 128
>
> VM says:
>
>     ^imageHeaderFlags anyMask: 512
>
> Is the difference intentional?
>

It is, and it's a confusing mess for which I apologize.  The issue is that
the least significant two bits of the flags word are the full screen flag
and the "vm is big endian" flag.  Neither of these needs a setter since the
full screen flag is set via the toggle full screen primitive and the "vm is
big endian" is a constant depending on the VM.  Hence Smalltalk
vmParameterAt: 48 answers the flags bit shifted right 2 bits.  I get bit by
this all the time and wish I had not introduced the shift.  Back in early
October in VMMaker.oscog-eem.2837 I wrote completely incorrect code that
screwed up several flags until VMMaker.oscog-eem.2848 that I fixed a week
later.  But unfortunately the damage is done.  All we can do is comment the
situation, while I beg forgiveness and forbearance.

_,,,^..^,,,_
best, Eliot
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