gcc for ppc code quality

Andreas Raab Andreas.Raab at gmx.de
Wed Dec 12 22:12:41 UTC 2001


John,

> But under Mach-O the clock call becomes a real unix call which of all
> the choices for clock is *very* expensive when call a zillion times
> per second.

Yes, I noticed the same when ioLowResMSecs was first introduced. It
defaulted to clock() which is on Windows implemented in heavy-duty 64 bit
arithmetic (can you spell Y2K?! ;-) I measured the effects with both
Time>>benchmarkMillisecondClock and Time>>benchmarkPrimitiveResponseDelay to
find out about these effects.

> So change the ioLowResMSClock to use TickCount. Which actually uses
> the nanosecond clock under Mach-o! This then produces a VM with
> similar performance to the CW Classic Carbon PEF one!!!!!!!!!!!
>
> Yes...

Excellent!

Cheers,
  - Andreas





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