2013/4/10 Terry Guo <flameroc@xxxxxxxxx>:
> Hi there,
>
> For define_peephole2, one can use (match_scratch:SI 2 "r") to require an
> extra scratch register. I am wondering whether it is possible to require an
> extra register for define_split?
>
> I am trying to split following RTL into more than one RTLs and thus need an
> extra register.
>
> (define_split
> [(set (match_operand:SF 0 "register_operand")
> (match_operand:SF 1 "const_double_operand"))]
> .................
> )
>
> The above define_split can match its targets, but following will fail to
> match:
>
> (define_split
> [(set (match_operand:SF 0 "register_operand")
> (match_operand:SF 1 "const_double_operand"))
> (clobber (match_scratch:SI 2 "register_operand"))]
> ............
> )
>
> Could some one please help? Thanks in advance.
>
> BR,
> Terry
Hi, Terry,
The split may happen before/after reload phase.
You can use reload_completed or can_create_pseudo_p()
to check whether you can create a new register.
A sample can be refered in arm.md:
(define_split
[(set (match_operand:SI 0 "register_operand" "")
(match_operand:SI 1 "const_int_operand" ""))]
"TARGET_THUMB1 && satisfies_constraint_J (operands[1])"
[(set (match_dup 2) (match_dup 1))
(set (match_dup 0) (neg:SI (match_dup 2)))]
"
{
operands[1] = GEN_INT (- INTVAL (operands[1]));
operands[2] = can_create_pseudo_p () ? gen_reg_rtx (SImode) : operands[0];
}"
)
Also I think you can add more statement in your
(define_expand "movsf"
...
...)
to process const_double earlier.
Best regards,
jasonwucj
