DJ Delorie <[EMAIL PROTECTED]> writes: > In expmed.c I see code like this: > > if (REG_P (xop0) && GET_MODE (xop0) != op_mode) > xop0 = gen_rtx_SUBREG (op_mode, xop0, 0); > > However, this is wrong for big-endian targets (h8300-elf in my case) > because '0' is not the offset of the LSB of the register when it's a > pseudo and op_mode is smaller than xop0's mode. IIRC simplify_subreg > does endian adjustments where gen_rtx_SUBREG does not, however, > simplify_subreg may return NULL_RTX. > > What's the "right thing" to do here, these days? I've temporarily put > in a function to special case the failing case, but it seems... > inelegant. Is there a missing assumption somewhere?
One thing to do is to call simplify_gen_subreg. I don't know why this code still calls gen_rtx_SUBREG. It's pretty old code. But I don't think that will help. I think this code is simply incorrect. It seems to assume that op_mode is at least as large as GET_MODE (xop0), probably because that will be the case on the m68k. Ian
