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Date: Wed, 7 Nov 2018 20:10:07 +0100
From: Fredrik Noring <noring@nocrew.org>
Message-ID: <20181107191007.GA31580@sx9>
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Subject: Re: [Qemu-devel] [PATCH v2 12/12] disas/mips: Disassemble R5900
 DIV[U]1, M{F, T}{LO, HI}1 and MULT[U]1
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To: Aleksandar Markovic <amarkovic@wavecomp.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>, Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= <f4bug@amsat.org>, =?utf-8?Q?J=C3=BCrgen?= Urban <JuergenUrban@gmx.de>, "Maciej W. Rozycki" <macro@linux-mips.org>, qemu-devel@nongnu.org

Hi Aleksandar,

> I am glad that you want to include QEMU disas support for R5900 - this
> area usually gets forgotten.
> 
> But, as you can see, this MIPS feature is partially broken - it doesn't
> handle well overlapping opcodes, and the field "membership" is not taken
> into account at all. I think the feature should be fixed first, and then
> R5900 support added. In fact, the disassembler support in QEMU is almost
> independent on the emulation support (for the corresponding instructions)
> - so, we could add disassembler support for all R5900 instructions in one
> clean sweep, instead dividing that in "million" pieces.
> 
> The key to the successful solution would be detecting what CPU is
> currently being emulated, and making disassembling decision based on that.
> 
> Let's talk about that later.

Yes, the current disassembly table needs to be reworked, so let's postpone
the opcodes for the R5900.

> P.S. Sorry for misspelling your name on several occasions.

No problem!

Fredrik