From: "Joseph S. Myers" <joseph@codesourcery.com>
To: Thiemo Seufer <ths@networkno.de>
Cc: binutils@sourceware.org
Subject: Re: [PATCH] MIPS: Add a GNU attribute for -mips32 -mfp64 objects
Date: Thu, 15 Nov 2007 00:03:00 -0000 [thread overview]
Message-ID: <Pine.LNX.4.64.0711142351410.26948@digraph.polyomino.org.uk> (raw)
In-Reply-To: <20071114202400.GT8363@networkno.de>
On Wed, 14 Nov 2007, Thiemo Seufer wrote:
> While I wrote this patch I noticed that the tagging takes only place
> when the respective gnu_attribute is found in the source code. This
> leaves objects created from assembly untagged. I wonder if it is a good
> idea to generally add a FP ABI attribute, derived from the assembler's
> command line flags, unless this is overridden by a gnu_attribute
> directive in the source. Is there a backward compatibility issue I fail
> to see, or some other effect which makes this a bad idea?
I didn't think the compiler passed the -msoft-float/-mhard-float ABI
information to the assembler, so this could cause problems with incorrect
tagging when older compilers are used with newer assemblers. The ABI is a
separate matter from what instructions are enabled, and a valid ABI is
being compatible with both hard and soft float; a file with purely integer
instructions could be a soft-float file if the functions are taking
floating-point parameters, or a file compatible with both if they are
taking integer parameters. How would you deduce the C language function
call compatibility of an object (which is what the attributes describe)
from the assembler source and command line options?
--
Joseph S. Myers
joseph@codesourcery.com
next prev parent reply other threads:[~2007-11-15 0:03 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-14 20:24 Thiemo Seufer
2007-11-15 0:03 ` Joseph S. Myers [this message]
2007-11-15 0:45 ` Thiemo Seufer
2007-11-15 0:55 ` Joseph S. Myers
2007-11-15 20:25 ` Richard Sandiford
2007-11-15 20:32 ` Paul Koning
2007-11-15 20:45 ` Richard Sandiford
2007-11-15 23:12 ` Thiemo Seufer
2007-11-16 9:31 ` Richard Sandiford
2007-11-15 0:04 ` Joseph S. Myers
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