[Vm-dev] Integer comparition primitive failures on Cog

[Nicolas Cellier]

OK, with SimpleCogit:
[1 to: 2000000 do: [:i |
   i < 2354.234.
   i <= 2354.234.
   i >= 2354.234.
    i > 2354.234.]] timeToRun 69

vs 4.2.5 VM:
[1 to: 2000000 do: [:i |
   i < 2354.234.
   i <= 2354.234.
   i >= 2354.234.
    i > 2354.234.]] timeToRun 299

StackToRegisterMappingCogit:
crash...

I don't get the x86 certification yet :(

Nicolas


2011/5/3 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
> Apart another declaration bug (FP missing in function name...) there
> is a killer :
>
> StackToRegisterMappingCogit inherits silently from
> SimpleStackBasedCogit>>#genSmallIntegerComparison:orDoubleComparison:
> though it does not share the stack structure. This is fatal...
>
> So an override StackToRegisterMappingCogit>>#genSmallIntegerComparison:orDoubleComparison:
> is mandatory
>
> Bad, bad inheritance...
>
> Now compiling the VM again...
>
> Nicolas
>
>
> 2011/5/3 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
>> Hem, some declaration were missing... and the argument for FP
>> comparison is tricky indeed...
>> Sorry for the noise, but this is a direct live
>>
>> Nicolas
>>
>> 2011/5/3 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
>>> And if  genSmallIntegerComparison:orDoubleComparison: is correct, then
>>> usage shall be quite straight forward
>>>
>>> Nicolas
>>>
>>> 2011/5/3 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
>>>> I always refused to learn x86 assembler, but by code imitation I can
>>>> give my own try in attachment.
>>>> Note that I did not use the trick to invert FP comparison operands
>>>> since this does not seem necessary.
>>>>
>>>> Nicolas
>>>>
>>>>
>>>> 2011/5/2 Eliot Miranda <eliot.miranda at gmail.com>:
>>>>>
>>>>> Hi Henrik,
>>>>>
>>>>> Eliot (phone)
>>>>>
>>>>> On May 2, 2011, at 3:12 AM, Henrik Sperre Johansen <henrik.s.johansen at veloxit.no> wrote:
>>>>>
>>>>>> As per my comment on the recent Morphic performance graphs,(http://blog.openinworld.com/2011/03/morphic-flavour-performance/#comment-59) on a Cog VM these primitives fail with a Float parameter, which leads to a huge performance hit when comparing Ints to Floats by doing silly things in the fallback code.
>>>>>>
>>>>>> Cog:
>>>>>> [1 to: 2000000 do: [:i |
>>>>>>    i < 2354.234.
>>>>>>    i <= 2354.234.
>>>>>>    i >= 2354.234.
>>>>>>     i > 2354.234.]] timeToRun 26594
>>>>>>
>>>>>> Trunk:
>>>>>> [1 to: 2000000 do: [:i |
>>>>>>    i < 2354.234.
>>>>>>    i <= 2354.234.
>>>>>>    i >= 2354.234.
>>>>>>     i > 2354.234.]] timeToRun 229
>>>>>>
>>>>>> Should this be changed in the VM,
>>>>>
>>>>> I think so.  When I first wrote the SmallInteger translated prims I hadn't yet written the JIT support for floats and so couldn't write int/float comparison.  Now all the support is there and it should be straight-forward.  Do you fancy trying to write this yourself?  Would be a fun exercise.  Let me know and I can hand-hold with using the simulator.
>>>>>
>>>>>
>>>>> Best
>>>>> Eliot (phone)
>>>>>
>>>>>
>>>>>> or is the difference for pure int/int comparition large enough that we should instead change
>>>>>> Float>>adaptToInteger: andCompare:
>>>>>> to use the corresponding comparitions with Float as receiver, which does work?
>>>>>> That's still slower than trunk in my image, but quite a bit better, above test takes about 1s.
>>>>>>
>>>>>> Cheers,
>>>>>> Henry
>>>>>
>>>>
>>>
>>
>