https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89049
Segher Boessenkool <segher at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |segher at gcc dot gnu.org
--- Comment #8 from Segher Boessenkool <segher at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #5)
> So combine can see
[ snip, 11 ]
> with its uses
[ snip, 13 and 25 ]
> but somehow it only tries 11 -> 13:
combine only tries to combine something with its first use. Trying second (or
third, etc.) uses as well would easily take exponential time complexity.
I do however want combine to try to combine an insn together with its first two
uses. That is just as linear as even simple 1+1 combinations, and it is likely
to succeed (in fact there is at least one other PR where I wanted this).
