[Bug target/119421] New: [avr] Better optimize some operations involving bits

[gjl at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119421

            Bug ID: 119421
           Summary: [avr] Better optimize some operations involving bits
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gjl at gcc dot gnu.org
  Target Milestone: ---

There are occasions where knowledge about nonzero bits makes some
optimizations possible.  For example,

   Rd |= Rn << Off

can be implemented as

   SBRC Rn, 0
   ORI  Rd, 1 << Off

when Rn in { 0, 1 }, i.e. nonzero_bits (Rn) == 1.