However,making this simpler works: rtx tmp_reg_rtx = copy_to_mode_reg (QImode,gen_rtx_MEM (QImode, addr1)); emit_move_insn (addr1, gen_rtx_PLUS (Pmode, addr1, const1_rtx)); aka Rx=[Ry] Ry=Ry+1For now I have gone back to the second case, though the code is not quite as good.
When your patterns hit the trunk file a missed-optimization bug. auto-inc-dec should have synthesized the POST_INC. Or you can try a parallel of Rx=[Ry] and Ry=Ry+1.
Paolo