On 10/13/2011 06:35 PM, Richard Kenner wrote:
It never calls make_extraction. There are several cases handled for AND operation. But(and:DI (plus:DI (subreg:DI (mult:SI (reg/v:SI 85 [ i ]) (const_int 4 [0x4])) 0) (subreg:DI (reg:SI 106) 0)) (const_int 4294967292 [0xfffffffc])) isn't one of them.Yes, clearly. Otherwise it would work! The correct fix for this problem is to make it to do that. That's where this needs to be fixed: in make_compound_operation.
An and:DI is cheaper than a zero_extend:DI of an and:SI. So GCC is correct in not doing this transformation. I think adding a case to make_compound_operation that simply undoes the transformation (without calling make_extraction) is fine if you guard it with if (in_code == MEM).
Paolo
