[Bug tree-optimization/105820] [13 Regression] ICE in invert, at value-range.cc:1971

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105820

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |13.0
                 CC|                            |amacleod at redhat dot com

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
#1  0x0000000001ced6a0 in irange::invert (this=0x7fffffff1f30)
    at /space/rguenther/src/gcc/gcc/value-range.cc:2166
2166      gcc_checking_assert (!undefined_p () && !varying_p ());

well, invert(undefined) = varying, invert(varying) = undefined - not sure
why we assert here.

(undefined is another name for 'empty')

I've wondered of several places checking for undefined/varying before
calling .invert () ...