Re: [Gems-users] Ruby magic instructions interference: Warning: in fn void magic_instruction_callback

["Thomas De Schampheleire" <patrickdepinguin@xxxxxxxxx>]

Hi,

When I execute for example
sethi 5031 %g0

then by having the following (python) handler:

def magic_callback(user_arg, cpu, n):
   print n

I get the value 5031, and not 5031 << 16 (as seems to be what you
expect in the ruby handler). I'm not sure if this is due Simics
version differences, but based on the behavior I see I don't
understand the shift in your code.

Anyway, as you suggested I will modify the commands.C handler to
ignore the '0' value.

Thanks, Thomas

On 5/16/07, Dan Gibson <degibson@xxxxxxxx> wrote:
> The shift has been a subject of much confusion internally and among our
> users, as some versions of ruby use shifted magic numbers and others do
> not -- since the magic number is provided by a sethi instruction, the
> original intent was to have "sethi 4 $g0" correspond to magic number 4,
> for readability.
>
> Nonetheless, the end result is the same. 6000 >> 16 is still 0, so Ruby
> is still treating the value as unhandled, which is, inevitably, what you
> probably want.
>
> Regards,
> Dan
>
>
> Thomas De Schampheleire wrote:
> > Hi,
> >
> > Thanks for the quick reply. See below:
> >
> > On 5/16/07, Dan Gibson <degibson@xxxxxxxx> wrote:
> >
> >> Ruby handles assumes magic instructions are directives passed to Ruby to
> >> perform various tasks (eg. begin_transaction, etc.). Its actually a
> >> *good* thing that you're seeing warnings -- its because Ruby doesn't
> >> know how to interpret the magic number, and therefore isn't doing anything.
> >>
> >> You should have a look at commands.C to see what values Ruby associates
> >> with various actions. So long as you don't use Ruby's magic numbers, you
> >> will not incur any Ruby-strangeness due to magic calls.
> >>
> >> Since you're using magic number 0, you can safely ignore these warnings.
> >> You can trivially modify commands.C to recognize "0" as a null command
> >> and not print the warning at all.
> >>
> >
> > Well, actually I'm using magic numbers in the range of 1000 upto 6000
> > or something. However, I noticed that in the magic ruby code in
> > commands.C, there is a right shift:
> >   val = val >> 16;
> > which effectively makes my magic numbers appear to be zero.
> >
> > Is there a particular reason why this shift takes place?
> > Due to the shift, it seems that Ruby only uses magic numbers above
> > 2^16 = 65 536.
> >
> > Thanks, thomas
> >
> >
> >> Regards,
> >> Dan
> >>
> >> Thomas De Schampheleire wrote:
> >>
> >>> Hi,
> >>>
> >>> I am using Simics 2.2.19 and Ruby release 1.2.
> >>> I have added some magic instructions to the OpenSolaris kernel
> >>> (UltraSPARC architecture), which are handled by my own callback
> >>> function. This works as I expect.
> >>>
> >>> However, when adding Ruby to the simulation, I get warnings on every
> >>> magic instruction:
> >>>
> >>> cpu0 [ cycle 56876262505L ]: [ magic 1021 ] disp_getwork()
> >>> Warning: in fn void magic_instruction_callback(void*, void*,
> >>> integer_t) in simics/commands.C:158: val is 0
> >>> Warning: in fn void magic_instruction_callback(void*, void*,
> >>> integer_t) in simics/commands.C:158: val is 0
> >>> Warning: in fn void magic_instruction_callback(void*, void*,
> >>> integer_t) in simics/commands.C:159: Unexpected magic call
> >>> Warning: in fn void magic_instruction_callback(void*, void*,
> >>> integer_t) in simics/commands.C:159: Unexpected magic call
> >>>
> >>> The first line is the line that is printed out by my own handler, and
> >>> the subsequent four lines seem to come from Ruby code.
> >>>
> >>> Can I avoid having these warnings by using other numbers for my magic
> >>> instructions? (which range of magic instructions is used by Ruby?)
> >>> Can my magic instructions interfere with Ruby?
> >>> Can I possibly turn off these warnings?
> >>>
> >>> Thank you,
> >>> Thomas
> >>> _______________________________________________
> >>> Gems-users mailing list
> >>> Gems-users@xxxxxxxxxxx
> >>> https://lists.cs.wisc.edu/mailman/listinfo/gems-users
> >>> Use Google to search the GEMS Users mailing list by adding "site:https://lists.cs.wisc.edu/archive/gems-users/"; to your search.
> >>>
> >>>
> >>>
> >> --
> >> http://www.cs.wisc.edu/~gibson [esc]:wq!
> >>
> >> _______________________________________________
> >> Gems-users mailing list
> >> Gems-users@xxxxxxxxxxx
> >> https://lists.cs.wisc.edu/mailman/listinfo/gems-users
> >> Use Google to search the GEMS Users mailing list by adding "site:https://lists.cs.wisc.edu/archive/gems-users/"; to your search.
> >>
> >>
> >>
> > _______________________________________________
> > Gems-users mailing list
> > Gems-users@xxxxxxxxxxx
> > https://lists.cs.wisc.edu/mailman/listinfo/gems-users
> > Use Google to search the GEMS Users mailing list by adding "site:https://lists.cs.wisc.edu/archive/gems-users/"; to your search.
> >
> >
>
> --
> http://www.cs.wisc.edu/~gibson [esc]:wq!
>
> _______________________________________________
> Gems-users mailing list
> Gems-users@xxxxxxxxxxx
> https://lists.cs.wisc.edu/mailman/listinfo/gems-users
> Use Google to search the GEMS Users mailing list by adding "site:https://lists.cs.wisc.edu/archive/gems-users/"; to your search.