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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/87744] Some valid instantiations of
 linear_congruential_engine produce compiler errors when __int128 isn't
 available
Date: Tue, 06 Feb 2024 21:28:11 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D87744

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Based on that, I'm not sure what libc++ does is actually better than what
libstdc++ does today (i.e. refuse to compile if the results would be wrong).

I think the patch above would make sense though. I'm sure it could be
optimized, I was more concerned with getting the results right than with
performance.

The first loop in operator% could just be a single left shift by the differ=
ence
in the number of leading zeros between __l and __x. And halve() should just=
 be
a right shift (and "halve" isn't a reserved name).=