[Bug tree-optimization/77856] [7 Regression] wrong code at -O2 on x86_64-linux-gnu in 32-bit mode

[vmakarov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77856

--- Comment #3 from Vladimir Makarov <vmakarov at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #2)

> So, %ebx doesn't hold 1 as it is supposed to, but 1 << %ecx (64).
> Vlad, could you please have a look?

It is a bug in a new optimization (invariant inheritance) which I added this
summer.

The optimization is important for PPC.  So it will take more time to fix it
than usual.  Still ETA is the next week.