Sources to port fenv.h to ARM and AARCH64

[Aditya Upadhyay]

On Sun, Mar 22, 2020 at 1:56 AM Joel Sherrill <joel at rtems.org> wrote:
>
>
>
> On Sat, Mar 21, 2020, 3:16 PM Aditya Upadhyay <aadit0402 at gmail.com> wrote:
>>
>> On Sun, Mar 22, 2020 at 1:30 AM Joel Sherrill <joel at rtems.org> wrote:
>> >
>> >
>> >
>> > On Sat, Mar 21, 2020 at 3:03 AM Aditya Upadhyay <aadit0402 at gmail.com> wrote:
>> >>
>> >>
>> >>
>> >> On Sat, 21 Mar 2020, 10:29 Eshan Dhawan, <eshandhawan51 at gmail.com> wrote:
>> >>>
>> >>> I went through the FreeBSD and NetBSD sources for implementation
>> >>> In FreeBSD there is an architecture-specific implementation with different header file for each architecture it supports .
>> >>> Whereas in NetBSD there is a single fenv.h defined but each architecture has its own C file to implement the functions.
>> >>> Also FreeBSD has soft-float for ARM
>> >>> So, I think FreeBSD would be a better option.
>> >>
>> >>
>> >> Look into this discussion on mail thread:
>> >> https://sourceware.org/legacy-ml/newlib/2017/msg00818.html
>> >>
>> >> and this patch series on newlib mailing list.
>> >>
>> >> https://sourceware.org/legacy-ml/newlib/2019/msg00418.html .
>> >>
>> >> It will help to understand the fenv-stub code.
>> >
>> >
>> > I am having trouble finding the implementation of any fenv method in the NetBSD code. I only am finding the weak alias mappings. Where is an example of the body of one of the methods in any architecture?
>> >
>>
>> I have cloned this NetBSD Sources. As I can see those
>> architecture-specific implemented methods here. Please correct me if I
>> am looking into different than what you are looking for.
>>
>> ./lib/libm/arch/powerpc/fenv.c
>> ./lib/libm/arch/sh/fenv.c
>> ./lib/libm/arch/mips64/fenv.c
>> ./lib/libm/arch/amd64/fenv.c
>> ./lib/libm/arch/arm/fenv.c
>> ./lib/libm/arch/i387/fenv.c
>> ./lib/libm/arch/hppa/fenv.c
>> ./lib/libm/arch/m88k/fenv.c
>> ./lib/libm/arch/alpha/fenv.c
>> ./lib/libm/arch/sparc64/fenv.c
>> ./lib/libm/arch/aarch64/fenv.c
>> ./regress/lib/libm/fenv/fenv.c
>
>
> That's what I see browsing the repo.
>
> The single file NetBSD looks easy to integrate. Would be similar to the x86_64 or i386 there now on file layout.
>
> Does the freebsd support more hardware variants?

FreeBSD does not have fenv support for some architecture like RISCV,
M88k, alpha architecture, I can see netbsd support more
hardware variants. NetBSD includes fenv support for these architecture also.

>>
>>
>> > --joel
>> >>
>> >>
>> >>
>> >>>
>> >>> On Sat, Mar 21, 2020 at 2:37 AM Joel Sherrill <joel at rtems.org> wrote:
>> >>>>
>> >>>>
>> >>>>
>> >>>> On Fri, Mar 20, 2020 at 3:33 PM Eshan Dhawan <eshandhawan51 at gmail.com> wrote:
>> >>>>>
>> >>>>> thanks, dr Joel
>> >>>>>
>> >>>>> I had gone through the musl-libc library but it doesn't have much architecture specific support for ARM as well as AARCH64
>> >>>>> It has support for s390x, m68k, powerpc64
>> >>>>
>> >>>>
>> >>>> This type of evaluation is important.  The architecture may be supported in only one implementation or one may be more complete than another.
>> >>>>
>> >>>> Ignoring the license requirements of course.
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>> On Sat, Mar 21, 2020 at 1:32 AM Joel Sherrill <joel at rtems.org> wrote:
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>> On Fri, Mar 20, 2020 at 2:43 PM Eshan Dhawan <eshandhawan51 at gmail.com> wrote:
>> >>>>>>>
>> >>>>>>> What would be the preferred source to port fenv.h to ARM and AARCH64
>> >>>>>>> its implementation is present in both FreeBSD as well AS NetBSD
>> >>>>>>> -> ARM
>> >>>>>>> ---FreeBSD Source
>> >>>>>>> # https://github.com/freebsd/freebsd/tree/master/lib/msun/arm
>> >>>>>>> ---NetBSD Source
>> >>>>>>> # https://github.com/NetBSD/src/tree/trunk/lib/libm/arch/arm
>> >>>>>>>
>> >>>>>>> ->AARCH64
>> >>>>>>> ---FreeBSD Source
>> >>>>>>> # https://github.com/freebsd/freebsd/tree/master/lib/msun/aarch64
>> >>>>>>> ---NetBSD Source
>> >>>>>>> # https://github.com/NetBSD/src/tree/trunk/lib/libm/arch/aarch64
>> >>>>>>
>> >>>>>>
>> >>>>>> Don't forget MUSL-C Library which has a lot of architectures and
>> >>>>>> is appropriately licensed.
>> >>>>>>
>> >>>>>> https://git.musl-libc.org/cgit/musl/tree/src/fenv
>> >>>>>>
>> >>>>>> I think our the order is going to be FreeBSD, NetBSD, then other places.
>> >>>>>>
>> >>>>>> The code drops into newlib's libm in a particular way which may require
>> >>>>>> some refactoring. fenv.h is shared across all ports and machine/fenv.h is
>> >>>>>> where port code goes. There must be an architecture specific file for each
>> >>>>>> method. But the entire implementation could go in one file and the others
>> >>>>>> be stubs. The i386 does this.
>> >>>>>>
>> >>>>>> --joel
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>
>> >>>>>>> Thanks
>> >>>>>>> -Eshan
>> >>>>>>> _______________________________________________
>> >>>>>>> devel mailing list
>> >>>>>>> devel at rtems.org
>> >>>>>>> http://lists.rtems.org/mailman/listinfo/devel
>> >>>
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>> >>
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