>
> While it's neat to think about where these calls are coming from, IMHO
> it doesn't seem valuable to try and remove them. If you want to speed
> things up, try reducing the number of redundent things that get redrawn
> for common operations in Morphic. :)
>
>
> Lex
>

Well it's idle curiosity, and fiddling with Apple's new set of hardware  
analysis tools.
That pointed to the fact we were doing a millisecond clock check every  
2ish milliseconds from
the Smalltalk code when the system is IDLE. If it's idle why is it so  
busy....


PS part of this was discovering how to tune the Mpeg plugin to take a  
test case from
49.38 to  69.67 frames per second, that is quite a major change (gcc  
3.3 & some code changes) it was
not at all obvious from earlier codewarrior based tuning tools.  So  
it's not all wasted effort.
and I did learn for the mpeg plugin the number of syscalls required to  
do disk io is low, a
question in the  past which requires no further thought.

Funny you should mention Morphic drawing

As part of my work I did insert a Transcript print into the ioprocess  
loop. That results in a slowdown
of the entire drawing cycle and you get to observe some *very  
interesting* drawing behaviour.

I've also noted that in
BitBltSimulation>>copyLoop you've got.

				2 to: nWords-1 do:
					[ :word |  "Note loop starts with prevWord loaded (due to preload)"
					self dstLongAt: destIndex put: prevWord.
					destIndex _ destIndex + hInc.
					prevWord _ self srcLongAt: sourceIndex.
					sourceIndex _ sourceIndex + hInc]]]

This resolves  (with my previous copyloop code change to)
					for (word = 2; word <= nWordsMinusOne; word += 1) {
						longAtput(destIndexLocal, prevWord);
						destIndexLocal += hInc;
						prevWord = longAt(sourceIndexLocal);
						sourceIndexLocal += hInc;
					}

mmm which really implies you want to move a bunch of words from  
sourceIndexLocal to destIndexLocal assuming hInc is 4 with special care  
for the first and last words based on masking bits.  So with the above  
C, does
your compiler really optimize the assembler instructions correctly to  
make it happy?

--
======================================================================== 
===
John M. McIntosh <johnmci at smalltalkconsulting.com> 1-800-477-2659
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
======================================================================== 
===