[PATCH 2/6] Andes nds32: machine description of nds32 porting (3).

[Richard Sandiford]

Chung-Ju Wu <jasonwucj@gmail.com> writes:
>>> +mno-ctor-dtor
>>> +Target Report RejectNegative
>>> +Disable constructor/destructor feature.
>> 
>> How is this option used?
>> 
>
> It effects how we link crt stuff.  Refer to nds32.h:
>
> /* The option -mno-ctor-dtor can disable constructor/destructor feature
>    by applying different crt stuff.  In the convention, crt0.o is the
>    startup file without constructor/destructor;
>    crt1.o, crti.o, crtbegin.o, crtend.o, and crtn.o are the
>    startup files with constructor/destructor.
>    Note that crt0.o, crt1.o, crti.o, and crtn.o are provided
>    by newlib/mculib/glibc/ublic, while crtbegin.o and crtend.o are
>    currently provided by GCC for nds32 target.
>
>    For nds32 target so far:
>    If -mno-ctor-dtor, we are going to link
>    "crt0.o [user objects]".
>    If general cases, we are going to link
>    "crt1.o crtbegin1.o [user objects] crtend1.o".  */
> #define STARTFILE_SPEC \
>   " %{!mno-ctor-dtor:crt1.o%s;:crt0.o%s}" \
>   " %{!mno-ctor-dtor:crtbegin1.o%s}"
> #define ENDFILE_SPEC \
>   " %{!mno-ctor-dtor:crtend1.o%s}"

Oops, sorry, I forgot to check the specs.

> +mforce-fp-as-gp
> +Target Report Mask(FORCE_FP_AS_GP)
> +Prevent $fp being allocated during register allocation so that compiler is able to force performing fp-as-gp optimization.

Maybe:

  Prevent $fp from being used by the register allocator, so that it is always available for the fp-as-gp optimization.

Looks good otherwise, thanks.

Richard