[Bug tree-optimization/99296] [11 Regression] ICE:in irange_set_anti_range, at value-range.cc:205 with "-Os -fno-toplevel-reorder -fno-tree-bit-ccp" since r11-5105-ga5f9c27bfc441722

[aldyh at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99296

--- Comment #5 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
Created attachment 50420
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50420&action=edit
proposed patch

As Jakub has mentioned, this is a problem with signed 1-bit precision.

Legacy anti-ranges has special cased this scenario, so I've adapted out some
common logic both alternatives can use.

Testing in progress.