[Bug target/121794] New: [avr] Use zero_reg less

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121794

            Bug ID: 121794
           Summary: [avr] Use zero_reg less
           Product: gcc
           Version: 15.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gjl at gcc dot gnu.org
  Target Milestone: ---

Using zero_reg less can improve small ISRs.  For example it may turn out that,
SBCI Rx,0 is better than SBC Rx,__zero_reg__ since it doesn't invoke zero_reg.