https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65505
--- Comment #1 from Oleg Endo <olegendo at gcc dot gnu.org> --- Created attachment 35084 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35084&action=edit possible patch The problem here is that sh_disp_addr_displacement gets an address that looks like: (plus:SI (subreg:SI (reg:DI ...) ..) (const_int ...) The predicates displacement_mem_operand and simple_mem_operand use arith_reg_operand to match the register operand. This also matches sign_extend and subreg, which is not handled by constraints such as Sdd. This is a latent problem, although it seems it never triggered on 4.8 and 4.9. If we allow subregs for the register operand of address expressions, things get a bit hairy. Additional checks need to be added everywhere to make sure that the subreg is indeed a register operand and not e.g. subreg (mem ...). Disallowing subregs in address expressions seems easier in this case. The attached patch fixes the problem.
