Re: PATCH: stfiwx implementation for PowerPC gdb simulator

[Tom Marn <tom.marn@telargo.com>]

Daniel Jacobowitz wrote:
> I would review this patch, except that I have no idea whether it's
> correct.  I hope someone more familiar with PowerPC is able to look
> at it.
>

Thank you Daniel

The instruction is the same as stfdx except that the stfiwx has effect only on lower 4 bytes instead of full 8 (as stfdx)
My reference for that instruction:

http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.aixassem/doc/alangref/stfiwx.htm

and also:
the code for stfdx in gdb/sim/ppc/ppc-instructions file

> I'd recommend not moving the instruction; I believe the comments are
> section references to the manual from which the pseudocode came
> originally.
>

I agree not moving the location of implementation but: At first, I did implement the instruction on comment out section but I had a problems with dynamic code generator (i don't know why there is not appropriate place), code just won't compile. If someone has a better knowledge about code locations inside ppc-instructions also this could be corrected.

It is also strange that only this instruction is left out (or forgotten), all others "optional PowerPC instructions" are implemented. Instead of this instruction the illegal instruction exception is raised, but also in linux kernel there is no implementation. I think that the problem becomes more and more obvious (this year i think) when GCC starts to generate the binaries with this instruction. The same thing is in the QEMU, guess what, also this instruction is missing, where I'm also trying to implement stfiwx instruction. But this is for QEMU mailing list, where i also saw your contributions, maybe we could fix this problem together.

Tom Marn