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

[rguenth at gcc dot gnu.org]

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

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |NEW
           Assignee|rguenth at gcc dot gnu.org         |unassigned at gcc dot gnu.org
            Summary|[6/7 Regression] wrong code |[6/7/8 Regression] wrong
                   |with -O -fno-tree-bit-ccp   |code with -O
                   |-fno-tree-coalesce-vars     |-fno-tree-bit-ccp
                   |-fno-tree-vrp               |-fno-tree-coalesce-vars
                   |                            |-fno-tree-vrp

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
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;?)