[RFC PATCH 5/5] powerpc: sstep: Add selftests for addc[.] instruction

[Sandipan Das]

On 11/02/19 6:30 AM, Daniel Axtens wrote:
> Hi Sandipan,
> 
>> +			{
>> +				.descr = "RA = LONG_MIN | INT_MIN, RB = LONG_MIN | INT_MIN",
>> +				.instr = PPC_INST_ADDC | ___PPC_RT(20) | ___PPC_RA(21) | ___PPC_RB(22),
>> +				.regs =
>> +				{
>> +					.gpr[21] = LONG_MIN | (uint) INT_MIN,
>> +					.gpr[22] = LONG_MIN | (uint) INT_MIN,
>> +				}
>> +			}
> I don't know what this bit pattern is supposed to represent - is it
> supposed to be the smallest 32bit integer and the smallest 64bit
> integer 8000000080000000 - so you test 32 and 64 bit overflow at the
> same time? 
> 

Yes, exactly.

> 
> For the series:
> Tested-by: Daniel Axtens <dja at axtens.net> # Power8 LE
> 
> I notice the output is quite verbose, and doesn't include a line when it
> starts:
> 
> [    0.826181] Running code patching self-tests ...
> [    0.826607] Running feature fixup self-tests ...
> [    0.826615] nop     : R0 = LONG_MAX                                      [PASS]
> [    0.826617] add     : RA = LONG_MIN, RB = LONG_MIN                       [PASS]
> 
> Maybe it would be good to include a line saying "Running single-step
> emulation self-tests" and perhaps by default on printing when there is a
> failure.
> 

That makes sense. Will include it in the next revision.

> Finally, I think you might be able to squash patches 1 and 2 and patches
> 4 and 5, but that's just my personal preference.
> 
> Regards,
> Daniel
>