[Bug tree-optimization/98474] [8/9/10/11 Regression] incorrect results using __uint128_t

[jeffhurchalla at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98474

--- Comment #4 from Jeff Hurchalla <jeffhurchalla at gmail dot com> ---
Thanks for your fix.
I built/installed gcc from the latest git sources, and prior to applying your
patch, as expected the test cases in this report produced incorrect results. 
After I applied your patch, all my tests passed.  This includes the test case
in my first post here, the two godbolt tests I mentioned, and my unit tests for
my github library where I first ran into the problem.

Since it's not quick for me to understand the patched code, could you let me
know if there is a way to avoid the regression with __uint128_t in gcc versions
prior to this patch?  Right now I'm just making the pessimistic assumption that
__uint128_t can't be safely used with gcc versions between 5.1 and the upcoming
version with the patch.  Is that assumption really necessary?