Segmentation fault in df-scan.c

[Paolo Bonzini]

> 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+1
> For 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