Dave Anderson wrote:
> You omit the frame pointer because it takes an extra register
> on x86 systems, which can slow the machine down tremendously
> (it has to do more with fewer registers)
>
> BTW, what do you consider "tremendously"? Has anybody
> every published any hard numbers on this? In any rough
> testing we've done, the loss in performance is neglible,
> i.e., in the low single-digit percentiles, if that.
Some of our tests when I was at SGI showed measurements of 10%
to 20%, depending on the code loops. One of my former co-workers
found cases of up to 25%, but I didn't see the code to prove it
myself.
> Just wondering,
> Dave Anderson
That's the reason why it's fantastic that lcrash can work
without requiring frame pointers. If they exist, great, but
they aren't necessary.
--Matt
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