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Re: getting rid of ggc_push_context
On Fri, Oct 01, 2004 at 01:16:40PM -0700, Richard Henderson wrote:
> Until we get rid of cse-follow-jumps, I don't see that much has
> changed in how CSE operates.
Yes, but a lot has changed in its input. Like Zack said: "with the
three optimizers in place, it probably isn't generating nearly as much
garbage as it used to".
I instrumented cc1-i-files to measure CSE memory use, and the most cse
ever allocated for any function was 800K. I didn't try the referenced
test from Plum Hall, but that would be easy to do next week...
On Fri, Oct 01, 2004 at 08:28:02AM -0700, Zack Weinberg wrote:
> All else being equal, it is highly desirable to get rid of this
> machinery. In ggc-page, it's expensive and it ruins memory locality.
> In ggc-zone, I'm not sure if it works at all. Dan Jacobowitz would
> know, but he's out of town.
It doesn't work at all. No one (of the very few people who have played
with the zone allocator) ever encountered a problem, because we never
collect at a pushed context depth.
--
Daniel Jacobowitz