On 02/14/2012 10:52 AM, Jakub Jelinek wrote:
> /* Complex expressions should be the first, so decrease priority
> of objects. Prefer pointer objects over non pointer objects. */
> - if ((REG_P (op) && REG_POINTER (op))
> - || (MEM_P (op) && MEM_POINTER (op)))
> - return -1;
> - return -2;
> + if(REG_P(op))
> + return -1;
> + else if ((REG_P (op) && REG_POINTER (op))
> + || (MEM_P (op) && MEM_POINTER (op)))
> + return -2;
> + return -3;
The above is definitely wrong, I think it will penalize e.g. Power6/7 a lot.
Even if this was fixed, I'm not sure it is always the correct thing to
do, because it would override swap_commutative_operands_with_target. If
the target is memory, you'd want the memory to come first.
In other words, there is no right answer as to whether REG or MEM should
come first.
I think the register allocator will generate good code using % if you
make your predicate nonimmediate_operand in operand 1:
(define_insn "iorqi3"
[(set (match_operand:QI 0 "register_operand" "=c")
(ior:QI (match_operand:QI 1 "nonimmediate_operand" "%0")
(match_operand:QI 2 "general_operand" "cwmi")))
(clobber (reg:CC RCC))]
"register_operand(operands[1], QImode) ||
register_operand(operands[2], QImode)"
"or\\t%0,%f2")
Paolo
