Paul Koning <paul_kon...@dell.com> writes:
>> I assume you by 'instruction' here mean a define_insn and not a single
>> RTL or assembler instruction.
>>
>> So, assume I have two classes M_REGS and Y_REGS and I cannot move
>> between them except if I go through an intermediary in C_REGS.
>> Do I need a secondary reload?
>
> Yes
>>
>> I wouldn't expect so cause I could write a rule that has a scratch from
>> C_REGS. Then I move the value from SOURCE to C_REGS and from C_REGS to
>> DEST. Have I misunderstood what you said?
>>
What about the above case?
Couldn't you have something like I described above:
(define_insn "transfer"
[
(set (match_operand 0 "register_operand" "m")
(match_operand 1 "register_operand" "y"))
(clobber (match_scratch 2 "c"))
]
""
{
move from 1 to 2;
move from 2 to 0;
})
Why would something like this not work and force you to have a secondary
reload hook?
--
PMatos
