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Re: PATCH: Fix i8086 disassembler for 16bit displacements
- From: Bernd Jendrissek <berndj at prism dot co dot za>
- To: "H. J. Lu" <hjl at lucon dot org>
- Cc: binutils at sources dot redhat dot com
- Date: Mon, 5 Feb 2007 10:47:07 +0200
- Subject: Re: PATCH: Fix i8086 disassembler for 16bit displacements
- References: <20070203003737.GA6527@lucon.org>
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On Fri, Feb 02, 2007 at 04:37:37PM -0800, H. J. Lu wrote:
> 2076-02-02 H.J. Lu <hongjiu.lu@intel.com>
^^^^
May I borrow your time machine please?
> * i386-dis.c (OP_J): Only mask to 16bit if there is a data16
> prefix.
>
> --- binutils/ld/testsuite/ld-i386/pcrel16.d.disp 2006-01-18 13:07:49.000000000 -0800
> +++ binutils/ld/testsuite/ld-i386/pcrel16.d 2007-02-02 15:22:36.000000000 -0800
> @@ -12,4 +12,4 @@ Disassembly of section .text:
> 420: cd 42[ ]+int \$0x42
> 422: ca 02 00[ ]+lret \$0x2
> ...
> - f065: e9 b8 13[ ]+jmp 420 <_start\+0x420>
> + f065: e9 b8 13[ ]+jmp 10420 <__bss_start\+0x3b8>
^^^^^
What does a 16-bit processor, or a 32 or 64-bit one in 16-bit mode, know
of addresses greater than 0xffff?
I don't understand under which circumstances it is ever correct to
disassemble a jump target to greater than 0xffff if it is known to be a
16-bit displacement. Can you explain to me when this would be correct?
- --
Problems experienced downstream are symptoms of neglect upstream.
Upstream problems can only be solved upstream. - someone
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