https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110088
--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Georg-Johann Lay <g...@gcc.gnu.org>: https://gcc.gnu.org/g:7bf89a919fdab9e18b7ad3efaa1a79f1d7520ddf commit r14-1492-g7bf89a919fdab9e18b7ad3efaa1a79f1d7520ddf Author: Georg-Johann Lay <a...@gjlay.de> Date: Fri Jun 2 12:41:07 2023 +0200 target/110088: Improve operation of l-reg with const after move from d-reg. After reload, there may be sequences like lreg = dreg lreg = lreg <op> const with an LD_REGS dreg, non-LD_REGS lreg, and <op> in PLUS, IOR, AND. If dreg dies after the first insn, it is possible to use dreg = dreg <op> const lreg = dreg instead which is more efficient. gcc/ PR target/110088 * config/avr/avr.md: Add an RTL peephole to optimize operations on non-LD_REGS after a move from LD_REGS. (piaop): New code iterator.