The string concat optimization happens in the interpreter dispatch for INPLACE_ADD
On Fri, Sep 1, 2017 at 9:10 PM, Greg Ewing <greg.ew...@canterbury.ac.nz> wrote: > Chris Angelico wrote: > >> This particular example is safe, because the arguments get passed >> individually - so 'args' has one reference, plus there's one more for >> the actual function call >> > > However, that's also true when you use the += operator, > so if the optimisation is to trigger at all in any useful > case, the refcount threshold needs to be set higher than > 1. > > Some experiments I did suggest that if you set it high > enough for x += y to trigger it, then it will also be > triggered in Joe's case. > > BTW, isn't there already a similar optimisation somewhere > for concatenating strings? Does it still exist? How does > it avoid this issue? > > -- > Greg > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: https://mail.python.org/mailman/options/python-dev/joe% > 40quantopian.com >
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