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From: Rich Felker <dalias@aerifal.cx>
To: musl@lists.openwall.com
Cc: David Wuertele <dave+gmane@wuertele.com>
Subject: Re: Re: arm softfp compatibility arch/fpu in gcc-4.8.2
Date: Thu, 7 Nov 2013 18:16:26 -0500	[thread overview]
Message-ID: <20131107231626.GX24286@brightrain.aerifal.cx> (raw)
In-Reply-To: <527C1842.1000300@barfooze.de>

On Thu, Nov 07, 2013 at 11:46:26PM +0100, John Spencer wrote:
> >If I omit the "--with-fpu", will it just default to use soft float all the time?
> 
> not sure what the default is, but afaik vfp is the most compatible
> one (only needed when you want to create binaries that work on way
> less decent arm chips).

VFP is the only one which gives IEEE conforming behavior and the only
one which is explicitly supported by musl (which requires/provides
IEEE floating point semantics). Anything else might blow up (for
example, crashing or wrong results in strtod or printf) so I would not
recommend using them for compiling musl. If you want to use them in
application code linked to musl (with the standard EABI, i.e. "arm")
that doesn't depend on IEEE semantics, that shouldn't hurt anything.

Fortunately, at least as I understand it, the other ARM fpu options
were never widely available, and are pretty much deprecated.

Rich


      reply	other threads:[~2013-11-07 23:16 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-07 20:12 David Wuertele
2013-11-07 22:21 ` John Spencer
2013-11-07 22:26   ` Rich Felker
2013-11-07 22:35   ` David Wuertele
2013-11-07 22:46     ` John Spencer
2013-11-07 23:16       ` Rich Felker [this message]

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