[Bug rtl-optimization/81020] [6/7/8 Regression] wrong code with -O -fno-tree-bit-ccp -fno-tree-coalesce-vars -fno-tree-vrp

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81020

--- Comment #11 from ktkachov at gcc dot gnu.org ---
(In reply to Richard Biener from comment #10)
> There's nothing wrong with the GIMPLE (looked at aarch64) so it must be some
> other RTL optimization issue.
> 
> aarch64 assembler is
> 
> foo:
>         adrp    x1, .LANCHOR0
>         ldr     w1, [x1, #:lo12:.LANCHOR0]
>         orr     w0, w1, w0
>         ret
> 
> that looks indeed bogus (just does return v | x;?)

Indeed, bisection points to the combine.c commit at r255384