> Does it look OK? No.
If I understand your code correctly, there's essentially the same code as you have a bit above that: /* If the constant is one less than a power of two, this might be representable by an extraction even if no shift is present. If it doesn't end up being a ZERO_EXTEND, we will ignore it unless we are in a COMPARE. */ else if ((i = exact_log2 (INTVAL (XEXP (x, 1)) + 1)) >= 0) new_rtx = make_extraction (mode, make_compound_operation (XEXP (x, 0), next_code), 0, NULL_RTX, i, 1, 0, in_code == COMPARE); So you need to understand why your code "fires" and it doesn't.