(gcc-4.4.1) Hi, I found out some strange behavior of simplify_relational_operation. Apparently it assumes QImode is signed even though this could not be deduced from the EQ operator. Here is an example:
rtx reg = gen_reg_rtx(QImode); ... rtx test = simplify_relational_operation(EQ, VOIDmode, QImode, reg, GEN_INT(129)); In this case simplify_relational_operation returns const_int 0 because of comparisons optimization with upper and lower bounds performed on simplify_const_relational_operation. The problem with this behavior was the removal of a "case 129:" in a switch during cse pass (proprietary target and backend). Perhaps EQ and NE could be treated as unsigned, like the GEU,LEU,GTU,LTU operators? Amir
