rtx compare_from_rtx (rtx op0, rtx op1, enum rtx_code code, int unsignedp, enum machine_mode mode, rtx size) { enum rtx_code ucode; rtx tem; /* If one operand is constant, make it the second one. Only do this if the other operand is not constant as well. */ if (swap_commutative_operands_p (op0, op1)) { tem = op0; op0 = op1; op1 = tem; code = swap_condition (code); } if (flag_force_mem) { op0 = force_not_mem (op0); op1 = force_not_mem (op1); } do_pending_stack_adjust (); ucode = unsignedp ? unsigned_condition (code) : code; if ((tem = simplify_relational_operation (ucode, mode, op0, op1)) != 0) return tem; #if 0 /* There's no need to do this now that combine.c can eliminate lots of sign extensions. This can be less efficient in certain cases on other machines. */ /* If this is a signed equality comparison, we can do it as an unsigned comparison since zero-extension is cheaper than sign extension and comparisons with zero are done as unsigned. This is the case even on machines that can do fast sign extension, since zero-extension is easier to combine with other operations than sign-extension is. If we are comparing against a constant, we must convert it to what it would look like unsigned. */ if ((code == EQ || code == NE) && ! unsignedp && GET_MODE_BITSIZE (GET_MODE (op0)) <= HOST_BITS_PER_WIDE_INT) { if (GET_CODE (op1) == CONST_INT && (INTVAL (op1) & GET_MODE_MASK (GET_MODE (op0))) != INTVAL (op1)) op1 = GEN_INT (INTVAL (op1) & GET_MODE_MASK (GET_MODE (op0))); unsignedp = 1; } #endif emit_cmp_insn (op0, op1, code, size, mode, unsignedp); #if HAVE_cc0 return gen_rtx_fmt_ee (code, VOIDmode, cc0_rtx, const0_rtx); #else return gen_rtx_fmt_ee (code, VOIDmode, op0, op1); #endif }
rtx compare_from_rtx (rtx op0, rtx op1, enum rtx_code code, int unsignedp, enum machine_mode mode, rtx size) { rtx tem; /* If one operand is constant, make it the second one. Only do this if the other operand is not constant as well. */ if (swap_commutative_operands_p (op0, op1)) { tem = op0; op0 = op1; op1 = tem; code = swap_condition (code); } do_pending_stack_adjust (); code = unsignedp ? unsigned_condition (code) : code; tem = simplify_relational_operation (code, VOIDmode, mode, op0, op1); if (tem) { if (CONSTANT_P (tem)) return tem; if (COMPARISON_P (tem)) { code = GET_CODE (tem); op0 = XEXP (tem, 0); op1 = XEXP (tem, 1); mode = GET_MODE (op0); unsignedp = (code == GTU || code == LTU || code == GEU || code == LEU); } } emit_cmp_insn (op0, op1, code, size, mode, unsignedp); #if HAVE_cc0 return gen_rtx_fmt_ee (code, VOIDmode, cc0_rtx, const0_rtx); #else return gen_rtx_fmt_ee (code, VOIDmode, op0, op1); #endif }