I made a mistake in my earlier benching -- one image was Spur the
other was Cog, oops!

Still, there is a > 5% speed loss in byteAt:put:, which is strange
unless that prim is failing...

|ba| ba:= ByteArray new: 1.
[ba byteAt: 1 put: 200] bench

bf-612:  '92,700,000 per second. 10.8 nanoseconds per run.'
tfel.613:   '87,900,000 per second. 11.4 nanoseconds per run.'

What also is not so elegant is the inconsistency with ByteString.

     ByteString>>#byteAt:put:  ---> coercion on prim fail
     ByteArray>>#byteAt:put:   ---> no-coercion on prim fail

     ByteString>>#at:put:  ----> no-coercion on prim fail
     ByteArray>>#at:put:   ----> coercion on prim fail

IMHO, #at:put: should fail if the wrong type of argument is passed.

Also, I don't understand the change to ByteArray>>#byteAt:.  Since
there is no #at: implementation in ByteArray, isn't the change to call
super unnecessary..?

On Thu, Apr 9, 2015 at 11:19 AM, Bert Freudenberg <bert at freudenbergs.de> wrote:
> On 09.04.2015, at 17:16, Chris Muller <asqueaker at gmail.com> wrote:
>>
>> On Thu, Apr 9, 2015 at 10:11 AM, Bert Freudenberg <bert at freudenbergs.de> wrote:
>>>>
>>>> Egads!  This is a performance critical method that has now been slowed by half!
>>>>
>>>>    old version:    '94,500,000 per second. 10.6 nanoseconds per run.'
>>>>  new version:     '49,400,000 per second. 20.3 nanoseconds per run.'
>>>
>>> What exactly are you testing?
>>
>> |ba| ba:= ByteArray new: 1.
>> [ba byteAt: 1 put: 200] bench
>>
>> and
>>
>> |ba| ba:= ByteArray new: 1.
>> [ba at: 1 put: 200] bench
>
> These two are not equivalent. #at:put: is optimized by the VM.
>
> I would be very surprised if Tim's changes have any effect on performance one way or other. They're purely about correctness.
>
> To test, you would have to run the exact same code before and after updating.
>
> - Bert -
>
>
>
>