From: "H . J . Lu" <hjl@lucon.org>
To: cgd@broadcom.com
Cc: ica2_ts@csv.ica.uni-stuttgart.de, binutils@sources.redhat.com
Subject: Re: [PATCH] Fix distinction of 32/64bit addresses in MIPS gas
Date: Fri, 31 Aug 2001 14:31:00 -0000 [thread overview]
Message-ID: <20010831143107.A4532@lucon.org> (raw)
In-Reply-To: <yov5ofow585q.fsf@highland.sibyte.com>
On Fri, Aug 31, 2001 at 12:41:37PM -0700, cgd@broadcom.com wrote:
> ica2_ts@csv.ica.uni-stuttgart.de ("Thiemo Seufer") writes:
> > Can you give a example where R_MIPS_64 is actually needed instead
> > of R_MIPS_32? If the output is truncated I can't see why R_MIPS_32
> > (possibly with tweaked content) insn't enough.
>
> cat > foo.c << __EOF__
> extern int foo;
>
> int *bar = &foo;
> __EOF
> mips-elf-gcc -mips4 -mlong64 -c foo.c
>
>
> i believe that should be sufficient. (certainly, it does the trick
> here with both our mips-linux tools and mips-elf-variant tools... 8-)
>
> yes, i know that the pointer is going to be constrainted to being a
> sign-extended 32-bit value, but neither the compiler or any assembly
> code that uses it needs to know that (or should). As far as they're
> concerned, pointers are 64-bit values and they're loaded with ld, etc.
Why do you need R_MIPS_64 for that?
>
> yes, there's code that actually uses this. why? it's really nice to
> have code that is linked into a 32-bit address space, but can have
> 'usable' 64-bit pointers in C code. e.g. code that lives at the boot
> vector, but wants to address data in xkphys... One could use 64-bit
> ELF for these programs, but that support is really new (does it even
> work completely yet?), and, really, there's no reason for people doing
> this to _want_ to switch to 64-bit ELF so why do it?
What is the 32bit address of `foo'?
H.J.
next prev parent reply other threads:[~2001-08-31 14:31 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-08-24 18:26 Thiemo Seufer
2001-08-31 8:02 ` Richard Sandiford
2001-08-31 8:28 ` H . J . Lu
2001-08-31 9:17 ` Thiemo Seufer
2001-08-31 9:53 ` Geoff Keating
2001-08-31 10:31 ` Thiemo Seufer
[not found] ` <mailpost.999279120.2469@postal.sibyte.com>
2001-08-31 10:37 ` cgd
2001-08-31 11:46 ` Thiemo Seufer
2001-08-31 11:49 ` Ian Lance Taylor
2001-08-31 11:50 ` Ian Lance Taylor
[not found] ` <mailpost.999283589.5294@postal.sibyte.com>
2001-08-31 12:41 ` cgd
2001-08-31 14:31 ` H . J . Lu [this message]
2001-09-03 23:07 ` cgd
2001-09-06 10:50 ` H . J . Lu
2001-09-06 10:59 ` cgd
2001-09-06 11:07 ` H . J . Lu
2001-09-06 11:35 ` Thiemo Seufer
2001-09-06 11:39 ` cgd
2001-09-06 11:40 ` cgd
2001-09-08 12:03 ` Andrew Cagney
2001-09-08 16:38 ` Thiemo Seufer
2001-09-08 16:56 ` Thiemo Seufer
2001-09-06 11:57 ` Richard Sandiford
2001-09-06 20:53 ` Thiemo Seufer
2001-09-06 21:09 ` Thiemo Seufer
2001-09-06 21:12 ` Thiemo Seufer
2001-09-06 22:38 ` H . J . Lu
2001-09-06 23:11 ` Thiemo Seufer
2001-09-07 4:10 ` Richard Sandiford
2001-09-07 6:22 ` Thiemo Seufer
2001-09-07 7:02 ` Richard Sandiford
2001-09-07 8:11 ` Thiemo Seufer
2001-09-07 9:20 ` Richard Sandiford
2001-09-07 9:49 ` Thiemo Seufer
2001-09-06 11:14 ` Thiemo Seufer
2001-09-06 11:08 ` Thiemo Seufer
2001-08-31 18:22 ` Thiemo Seufer
2001-09-03 2:57 ` Richard Sandiford
2001-09-03 15:00 ` Thiemo Seufer
2001-08-31 14:49 ` Andrew Cagney
2001-08-31 15:00 ` H . J . Lu
2001-08-31 16:30 ` Eric Christopher
2001-08-31 16:41 ` Andrew Cagney
2001-08-31 16:46 ` H . J . Lu
2001-08-31 17:45 ` matthew green
2001-09-02 19:25 ` J Grant
2001-08-31 16:44 ` H . J . Lu
2001-08-31 17:42 ` matthew green
2001-08-31 19:06 ` H . J . Lu
2001-08-31 19:11 ` matthew green
[not found] ` <mailpost.999310274.17560@postal.sibyte.com>
2001-09-03 23:18 ` cgd
2001-09-06 11:00 ` H . J . Lu
2001-09-06 11:38 ` cgd
2001-09-06 12:09 ` H . J . Lu
2001-08-31 18:49 ` Thiemo Seufer
2001-08-31 17:35 ` matthew green
2001-08-31 19:05 ` H . J . Lu
2001-08-31 18:25 ` Thiemo Seufer
2001-08-31 20:46 ` Ian Lance Taylor
2001-08-31 21:04 ` Thiemo Seufer
2001-08-31 10:04 ` Richard Sandiford
2001-08-31 10:41 ` Thiemo Seufer
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