[Bug target/64851] New: [SH] Add atomic not

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64851

            Bug ID: 64851
           Summary: [SH] Add atomic not
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: olegendo at gcc dot gnu.org
            Target: sh*-*-*

Although the __atomic builtins cover only add,sub,or,xor,and,nand, an atomic
not operation can be implicitly done by
- xor (val, -1)
- nand (val, -1)

Combine is already trying to simplify such patterns into a not inside the
atomic patterns.