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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug bootstrap/84402] [meta] GCC build system: parallelism
 bottleneck
Date: Tue, 28 Mar 2023 08:54:12 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D84402

--- 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 (=3D=3D 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 bef=
ore
emitting
the source, so don't know whether it is feasible.=