github-actions[bot] commented on issue #6377:
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alexcrichton commented on issue #6377:
I've done some further investigation of this with @elliottt. We've got a clif function which before this commit took 15 seconds to codegen and after this commit took ~3 seconds. Profiling showed that virtually all time was spent in this loop. We worked together to develop a better means of merging sets there which reduced the compilation time of the test case in question, both before and after this commit, to ~0.2s. It turns out though that this new means isn't actually necessary since the code has already changed on
main
! This means that relanding this should be a "simple" matter of updating regalloc2 first and then this can re-land.This bodes well in my mind in that we were pretty surprised that this was the root cause of the regression. Tickling regalloc2 slightly different though makes a lot of sense and it made what was arguably already a pathological case even worse. Fixing the underlying pathology should provide some nice benefits!
Last updated: Nov 22 2024 at 16:03 UTC