[Bug bootstrap/84402] [meta] GCC build system: parallelism bottleneck

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84402

--- Comment #62 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Looking at gimple-match.cc, the case CFN_BUILT_IN_ATOMIC_FETCH_OR_{1,2,4,8,16}:
etc. blocks are identical there, except for the numbers in next_after_fail*
label numbers.
So, could we perhaps expand everything the way we do and just when emitting a
switch
hash the subtree of the cases to be emitted and if the hashes are equal also
compare
and if the subtrees are the same (== would result in the same text being
emitted into
the output except for the label numbers) emit multiple cases with the same
block?
Admittedly I haven't looked yet at the data structures genmatch.cc uses before
emitting
the source, so don't know whether it is feasible.