[darcs-users] darcs patch: add exception to haskell_policy.sh for D... (and 61 more)
droundy at darcs.net
Fri Oct 31 11:55:28 UTC 2008
On Thu, Oct 30, 2008 at 08:26:37PM -0700, Jason Dagit wrote:
> On Thu, Oct 30, 2008 at 2:20 PM, David Roundy <droundy at darcs.net> wrote:
> > I suspect there are significant regressions from the
> > OldFastPackedstring code mixed with major improvements elsewhere. I'd
> > rather not add these significant regressions to the repository, but
> > since the first thing he did was to remove the older, faster code, it's
> > very hard to track them down. It's very frustrating...
> We have no reason to believe that the indirection layer we added to
> make the BS api compatible with OldFastPackedStrings was efficient.
> Actually, since that was never really profiled (as far as I know) it
> makes sense that that layer of indirection is a cause of slow down. I
> guess I'm arguing that the regression is already in darcs and it's
> what you called "old" in your timings.
Except that we *know* that the new code without that indirection layer is
still slower than OldFastPackedString in some tests. Which means that
there's an unresolved performance problem with bytestrings. Or perhaps
it's a new regression, rather than a remaining regression.
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