Adding fenv support for ARM
Eshan Dhawan
eshandhawan51 at gmail.com
Fri May 15 22:59:31 UTC 2020
On Fri, May 15, 2020 at 2:22 AM Eshan Dhawan <eshandhawan51 at gmail.com>
wrote:
>
>
> On Wed, May 13, 2020 at 7:40 PM Joel Sherrill <joel at rtems.org> wrote:
>
>> National free hint day!!!
>>
>> Look above the line that is reported. You will see __BEGIN_DECL. It isn't
>> defined. It is intended to expand to the __cplusplus wrapper.
>>
>> After you fix this, you will sequentially find 2 other things to change
>> in this file.
>>
>> I have made those changes when a new error occurs from the assembler in
> arm thumb mode
> There is no support for vfp instructions in arm thumb.
>
> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0471c/BABGHDBB.html
> So in which file will the compiler instructions given in the page
> <http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0471c/BABGHDBB.html>
> added?
>
FreeBSD has added file and architecture-specific flags in their
makefile.inc
https://github.com/freebsd/freebsd/blob/master/lib/msun/arm/Makefile.inc
How will it be added in newlib
I tried adding the flags -mfpu=vfp -mfloat-abi=softfp (used in FreeBSD) to
makefile.in but no effect.
thanks
-Eshan
> Errors :
>
> make[9]: Entering directory
> '/home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/thumb/newlib/libm/machine/arm'
> arm-rtems5-gcc
> -B/home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/thumb/newlib/
> -isystem
> /home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/thumb/newlib/targ-include
> -isystem /home/eshan/development/newlib/newlib-cygwin/newlib/libc/include
> -mthumb -DPACKAGE_NAME=\"newlib\" -DPACKAGE_TARNAME=\"newlib\"
> -DPACKAGE_VERSION=\"3.3.0\" -DPACKAGE_STRING=\"newlib\ 3.3.0\"
> -DPACKAGE_BUGREPORT=\"\" -DPACKAGE_URL=\"\" -I.
> -I../../../../../../../newlib-cygwin/newlib/libm/machine/arm -I
> ../../../../../../../newlib-cygwin/newlib/libm/machine/arm/../../../../newlib/libm/common
> -fno-builtin -mfpu=vfpv2 -ffunction-sections -fdata-sections
> -D_COMPILING_NEWLIB -DCLOCK_PROVIDED -DMALLOC_PROVIDED -DEXIT_PROVIDED
> -DSIGNAL_PROVIDED -DGETREENT_PROVIDED -DREENTRANT_SYSCALLS_PROVIDED
> -DHAVE_NANOSLEEP -DHAVE_BLKSIZE -DHAVE_FCNTL -DHAVE_ASSERT_FUNC
> -D_NO_GETLOGIN -D_NO_GETPWENT -D_NO_GETUT -D_NO_GETPASS -D_NO_SIGSET
> -D_NO_WORDEXP -D_NO_POPEN -D_NO_POSIX_SPAWN -DHAVE_INIT_FINI -g -O2
> -mthumb -c -o lib_a-fenv-vfp.o `test -f 'fenv-vfp.c' || echo
> '../../../../../../../newlib-cygwin/newlib/libm/machine/arm/'`fenv-vfp.c
> /tmp/ccEHiFws.s: Assembler messages:
> /tmp/ccEHiFws.s:37: Error: selected processor does not support `vmrs
> r3,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:48: Error: selected processor does not support `vmsr
> fpscr,r3' in Thumb mode
> /tmp/ccEHiFws.s:81: Error: selected processor does not support `vmrs
> r3,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:119: Error: selected processor does not support `vmrs
> r3,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:134: Error: selected processor does not support `vmsr
> fpscr,r3' in Thumb mode
> /tmp/ccEHiFws.s:169: Error: selected processor does not support `vmrs
> r3,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:182: Error: selected processor does not support `vmsr
> fpscr,r3' in Thumb mode
> /tmp/ccEHiFws.s:217: Error: selected processor does not support `vmrs
> r3,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:251: Error: selected processor does not support `vmrs
> r0,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:288: Error: selected processor does not support `vmrs
> r3,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:303: Error: selected processor does not support `vmsr
> fpscr,r0' in Thumb mode
> /tmp/ccEHiFws.s:340: Error: selected processor does not support `vmrs
> r3,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:374: Error: selected processor does not support `vmrs
> r3,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:390: Error: selected processor does not support `vmsr
> fpscr,r3' in Thumb mode
> /tmp/ccEHiFws.s:424: Error: selected processor does not support `vmsr
> fpscr,r3' in Thumb mode
> /tmp/ccEHiFws.s:457: Error: selected processor does not support `vmrs
> r1,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:466: Error: selected processor does not support `vmsr
> fpscr,r3' in Thumb mode
> /tmp/ccEHiFws.s:478: Error: selected processor does not support `vmrs
> r2,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:503: Error: selected processor does not support `vmsr
> fpscr,r3' in Thumb mode
> /tmp/ccEHiFws.s:543: Error: selected processor does not support `vmrs
> r0,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:559: Error: selected processor does not support `vmsr
> fpscr,r3' in Thumb mode
> /tmp/ccEHiFws.s:595: Error: selected processor does not support `vmrs
> r3,fpscr' in Thumb mode
> /tmp/ccEHiFws.s:612: Error: selected processor does not support `vmsr
> fpscr,r2' in Thumb mode
> /tmp/ccEHiFws.s:647: Error: selected processor does not support `vmrs
> r3,fpscr' in Thumb mode
> Makefile:476: recipe for target 'lib_a-fenv-vfp.o' failed
> make[9]: *** [lib_a-fenv-vfp.o] Error 1
> make[9]: Leaving directory
> '/home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/thumb/newlib/libm/machine/arm'
> Makefile:324: recipe for target 'all-recursive' failed
> make[8]: *** [all-recursive] Error 1
> make[8]: Leaving directory
> '/home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/thumb/newlib/libm/machine'
> Makefile:553: recipe for target 'all-recursive' failed
> make[7]: *** [all-recursive] Error 1
> make[7]: Leaving directory
> '/home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/thumb/newlib/libm'
> Makefile:641: recipe for target 'all-recursive' failed
> make[6]: *** [all-recursive] Error 1
> make[6]: Leaving directory
> '/home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/thumb/newlib'
> Makefile:452: recipe for target 'all' failed
> make[5]: *** [all] Error 2
> make[5]: Leaving directory
> '/home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/thumb/newlib'
> Makefile:1260: recipe for target 'multi-do' failed
> make[4]: *** [multi-do] Error 1
> make[4]: Leaving directory
> '/home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/newlib'
> Makefile:1176: recipe for target 'all-multi' failed
> make[3]: *** [all-multi] Error 2
> make[3]: Leaving directory
> '/home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/newlib'
> Makefile:452: recipe for target 'all' failed
> make[2]: *** [all] Error 2
> make[2]: Leaving directory
> '/home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/newlib'
> Makefile:8491: recipe for target 'all-target-newlib' failed
> make[1]: *** [all-target-newlib] Error 2
> make[1]: Leaving directory
> '/home/eshan/development/newlib/c-arm-rtems5-newlib'
> Makefile:878: recipe for target 'all' failed
> make: *** [all] Error 2
>
> -Eshan
>
>> Then we need to make a decision whether the static inline versions of the
>> methods in sys/fenv.h are appropriate for newlib or not.
>>
>> --joel
>>
>> On Tue, May 12, 2020 at 5:20 PM Joel Sherrill <joel at rtems.org> wrote:
>>
>>> Gedare is right but one more piece of information is needed. When newlib
>>> is being built, it lays target dependent files on top of generic ones. So
>>> the default sys/fenv.h is replaced with something like
>>> libc/machine/arm/sys/fenv.h. Make sure that
>>> /home/eshan/development/newlib/newlib-cygwin/newlib/libc/include/fenv.h is
>>> in fact the file you think it should be.
>>>
>>> Also look at what is supposed to be in the generic fenv.h and
>>> <sys/fenv.h>. You will probably have to tweak it some.
>>>
>>> Check out what is in x86_64/fenv.h and riscv/fenv.h with respect to the
>>> default environment variable. It looks to be declared differently in the
>>> other ports so you may have to make it match.
>>>
>>> But more output does help.
>>>
>>> --joel
>>>
>>>
>>>
>>> On Tue, May 12, 2020 at 4:53 PM Gedare Bloom <gedare at rtems.org> wrote:
>>>
>>>> Take the first error reported, and show what is being compiled. You've
>>>> trimmed off too much preceding this to know what is being compiled and
>>>> how this might be influencing your error.
>>>>
>>>> The specific error you're getting is often due to some syntax errors
>>>> preceding the line shown.
>>>>
>>>> On Tue, May 12, 2020 at 2:59 PM Eshan Dhawan <eshandhawan51 at gmail.com>
>>>> wrote:
>>>> >
>>>> > Hello everyone,
>>>> > After adding the files and compiling. I am
>>>> > getting a few errors which I am not able to rectify.
>>>> > If you could take a look and tell how to sort them.
>>>> >
>>>> > link to newlib's git repo:
>>>> https://github.com/eshandhawan51/newlib-cygwin/tree/add_fenv_support
>>>> >
>>>> > errors :
>>>> >
>>>> > In file included from
>>>> /home/eshan/development/newlib/newlib-cygwin/newlib/libc/include/fenv.h:15:0,
>>>> > from
>>>> ../../../../../../newlib-cygwin/newlib/libm/fenv/feclearexcept.c:57:
>>>> >
>>>> /home/eshan/development/newlib/c-arm-rtems5-newlib/arm-rtems5/thumb/newlib/targ-include/sys/fenv.h:82:1:
>>>> error: expected '=', ',', ';', 'asm' or '__attribute__' before 'extern'
>>>> > extern const fenv_t *_fe_dfl_env;
>>>> > ^~~~~~
>>>> > In file included from
>>>> ../../../../../../newlib-cygwin/newlib/libm/fenv/feclearexcept.c:57:0:
>>>> >
>>>> /home/eshan/development/newlib/newlib-cygwin/newlib/libc/include/fenv.h:22:1:
>>>> error: expected '=', ',', ';', 'asm' or '__attribute__' before 'int'
>>>> > int feclearexcept(int excepts);
>>>> > ^~~
>>>> >
>>>> > thanks
>>>> > -Eshan
>>>> > On Sat, May 9, 2020 at 2:53 AM Joel Sherrill <joel at rtems.org> wrote:
>>>> >>
>>>> >>
>>>> >>
>>>> >> On Thu, May 7, 2020 at 1:33 PM Eshan Dhawan <eshandhawan51 at gmail.com>
>>>> wrote:
>>>> >>>
>>>> >>> Hello everyone,
>>>> >>> This the tread to discuss adding fenv support for ARM architecture
>>>> in newlib.
>>>> >>>
>>>> >>> Link to previous thread:
>>>> https://lists.rtems.org/pipermail/devel/2020-March/058473.html
>>>> >>>
>>>> >>> ---FreeBSD Source
>>>> >>> # https://github.com/freebsd/freebsd/tree/master/lib/msun/arm
>>>> >>> #
>>>> https://github.com/freebsd/freebsd/blob/master/sys/arm/include/ieeefp.h
>>>> >>> ---NetBSD Source
>>>> >>> # https://github.com/NetBSD/src/tree/trunk/lib/libm/arch/arm
>>>> >>>
>>>> >>> --- Musl has no implementation for fenv support for ARM in it
>>>> >>>
>>>> >>> After going through the implementations both FreeBSD and NetBSD
>>>> have a stub implementation.
>>>> >>> But then FreeBSD implementation seems to be more portable compared
>>>> to that in NetBSD.
>>>> >>>
>>>> >>> Should I start porting it from FreeBSD?
>>>> >>> And which ARM BSP should I use for testing the changes?
>>>> >>> Currently, I have xilinx_zynq_a9_qemu build
>>>> >>
>>>> >>
>>>> >> I think the FreeBSD implementation is the one to use. It looks to
>>>> support hard and soft floating point implementations.
>>>> >>
>>>> >> I think the fenv.h file there will have to be worked on so some of
>>>> the contents go into sys or machine/fenv.h. There is a portable fenv.h.
>>>> >>
>>>> >>>
>>>> >>>
>>>> >>> There would also be a requirement to discuss where to place the
>>>> files in Newlib.
>>>> >>
>>>> >>
>>>> >> Not much to discuss. It should go into
>>>> newlib-cygwin/newlib/libm/machine/arm.
>>>> >>>
>>>> >>>
>>>> >>> Thanks
>>>> >>> -Eshan
>>>> >>>
>>>> > _______________________________________________
>>>> > devel mailing list
>>>> > devel at rtems.org
>>>> > http://lists.rtems.org/mailman/listinfo/devel
>>>>
>>>
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