From: Brian Inglis <Brian.Inglis@SystematicSw.ab.ca>
To: newlib@sourceware.org
Subject: Re: Soft Floating Point Exceptions
Date: Mon, 25 May 2020 15:43:05 -0600 [thread overview]
Message-ID: <c66308f9-5138-c732-940e-da4fc4045bfa@SystematicSw.ab.ca> (raw)
In-Reply-To: <CAF9ehCXiAdHbbYDLhata9MZdz9jQ15D9fmnNUt7Cy7GwF5gkpA@mail.gmail.com>
On 2020-05-25 11:17, Joel Sherrill wrote:
> An RTEMS GSoC student (Eshan Dhawan) has almost completed porting the
> FreeBSD fenv code to newlib. Unfortunately, the software floating point
> code calls __softfloat_float_raise which has a couple of issues. First, he
> can't find the code which probably indicates an issue in the BSD world but
> no one likely cares because I doubt there is a BSD install on an ARM with
> soft floating point.
>
> Second, to use this in newlib, we will be relying on GCC's soft float
> implementation which means something different has to happen. Is there an
> equivalent routine in GCC? What should happen for
> __softfloat_float_raise()?
You will have to look at these to see what is relevant to your issue.
Interface:
$ info gccint libgcc soft
implementation:
https://gcc.gnu.org/git?p=gcc.git;a=blob_plain;f=libgcc/config/arm/sfp-machine.h;hb=HEAD
https://gcc.gnu.org/git?p=gcc.git;a=blob_plain;f=libgcc/config/arm/ieee754-sf.S;hb=HEAD
https://gcc.gnu.org/git?p=gcc.git;a=blob_plain;f=libgcc/config/arm/ieee754-df.S;hb=HEAD
https://gcc.gnu.org/git?p=gcc.git;a=blob_plain;f=libgcc/config/arm/fp16.c;hb=HEAD
implementation:
https://github.com/freebsd/freebsd/commit/85aab3336e0d6172ddd5fe3cde38389abd612728
https://github.com/freebsd/freebsd/tree/master/lib/libc/softfloat
https://github.com/freebsd/freebsd/blob/master/lib/libc/softfloat/softfloat.txt#L357
https://github.com/freebsd/freebsd/blob/master/lib/libc/softfloat/softfloat-for-gcc.h
https://github.com/freebsd/freebsd/blob/master/lib/libc/softfloat/softfloat-specialize#L67
alternative:
http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/arch/arm/softfloat/
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
This email may be disturbing to some readers as it contains
too much technical detail. Reader discretion is advised.
[Data in IEC units and prefixes, physical quantities in SI.]
next prev parent reply other threads:[~2020-05-25 21:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-25 17:17 Joel Sherrill
2020-05-25 21:43 ` Brian Inglis [this message]
2020-05-26 4:01 ` Brian Inglis
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