[PATCH 1/2] powerpc/sstep: Add emulation support for ‘setb’ instruction

[Michael Ellerman]

"Naveen N. Rao" <naveen.n.rao at linux.ibm.com> writes:
> Daniel Axtens wrote:
>> Sathvika Vasireddy <sathvika at linux.vnet.ibm.com> writes:
>> 
>>> This adds emulation support for the following instruction:
>>>    * Set Boolean (setb)
>>>
>>> Signed-off-by: Sathvika Vasireddy <sathvika at linux.vnet.ibm.com>
...
>> 
>> If you do end up respinning the patch, I think it would be good to make
>> the maths a bit clearer. I think it works because a left shift of 2 is
>> the same as multiplying by 4, but it would be easier to follow if you
>> used a temporary variable for btf.
>
> Indeed. I wonder if it is better to follow the ISA itself. Per the ISA, 
> the bit we are interested in is:
> 	4 x BFA + 32
>
> So, if we use that along with the PPC_BIT() macro, we get:
> 	if (regs->ccr & PPC_BIT(ra + 32))

Use of PPC_BIT risks annoying your maintainer :)

cheers