Thanks. I still have some qns and some answers to
qns that you had asked.
> Yes, the instruction set has been implemented, but
> only those instructions
> needed for supporting Jikes RVM.
> R> 1)So how do i add it ?
> Well, adding the instruction is one thing, but
> presumably you want to be
> able to get at it, no? How do you propose to have
> the system generate it?
Yes, I wanted to insert it because there seemed to
no suitably equivalent PPC_DCBTST (like there is for
PPC_DCBST) in OperatorList.dat. I propose to introduce
the prefetch instructions after HIR optimizations.
Ideally, I would like to insert the DCBTST
instructions at the HIR stage itself.
> You may want to take a look at the use of dcbst, for
> example. (See
> VM_Magic.java and
> This would be if you want to express it in source
> If you want to generate it in an optimization, then
> you can just create the
> necessary instructions at the right places.
Yes, I want to generate it during an optimization.
Currently u can insert a PPC_DCBST and PPC_DCBF (and
not DCBTST) using CacheOp.create(PPC_DCBST/PPC_DCBF,
..,..,..,..) and not worry about how it gets
translated to actual machine code. I would like to do
something so that this same method (CacheOp.create())
can be used for PPC_DCBTST as well. Alternately, any
other idea that you have for doing the same thing in a
simpler fashion would be most welcome :-).
> R> 2)I noticed that the difference between dcbst
> R> dcbtst is that the bits 21-30 contain 54 for
> dcbst and
> R> 246 for dcbtst. If i make the change from 54
> to 246 in
> R> OperatorList.dat : line no 1537
> R> ####################
> R> PPC_DCBST
> R> MIR_CacheOp
> R> memAsLoad | memAsStore
> R> (31<<26 | 54<<1)
> R> will the rvm insert dcbtst instead of DCBST
> or will
> R> there be any trouble?
> You may need an HIR or LIR instruction, _and_ you
> need eventual bit-pattern
> stuff for emitting it as machine code.
> I don't claim to be an expert in this :-) ...
> -- EM
> Jikesrvm-researchers mailing list
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