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From: Thiemo Seufer <ths@networkno.de>
To: Karl Magdsick <kmagnum@gmail.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH, RFC] More than 2G of memory on 64-bit hosts
Date: Tue, 26 Jun 2007 09:00:36 +0100	[thread overview]
Message-ID: <20070626080036.GE3665@networkno.de> (raw)
In-Reply-To: <cd8ecdef0706251903v6b15eb44r6045452fe271bd13@mail.gmail.com>

Karl Magdsick wrote:
[snip]
> With proper support from the compiler, it's theoretically possible on
> x86-64 systems to use 32-bit pointers in long mode (16 general purpose
> 64-bit registers).  (There's an instruction prefix that will cause the
> CPU to perform 32-bit pointer calculations in the 64-bit address
> space.) I'm not aware of any systems that use this, however.  (Getting
> the speed boost from fewer register spills while not paying the space
> cost of 64-bit pointers sounds very attractive in many applications,
> though.)

FYI, the MIPS N32 ABI does that (64bit wide registers, 32bit address
space, data type sizes compatible to pure 32bit programs).


Thiemo

  reply	other threads:[~2007-06-26  8:08 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-25 20:16 [Qemu-devel] [PATCH, RFC] More than 2G of memory on 64-bit hosts Blue Swirl
2007-06-25 20:26 ` Michal Schulz
2007-06-25 20:52   ` Blue Swirl
2007-06-25 21:08     ` Michal Schulz
2007-06-26  2:03     ` Karl Magdsick
2007-06-26  8:00       ` Thiemo Seufer [this message]
2007-06-26 13:54       ` Paul Brook
2007-06-27 10:26         ` Blue Swirl
2007-06-27 10:32           ` Julian Seward
2007-06-27 11:10             ` Thiemo Seufer
2007-06-27 11:20               ` Julian Seward
2007-06-27 12:18                 ` Marius Groeger
2007-06-27 12:32                   ` Thiemo Seufer
2007-07-06 19:20           ` Rob Landley
2007-06-29 14:26       ` Gwenole Beauchesne
2007-06-25 20:28 ` Thiemo Seufer
2007-06-25 20:53   ` Blue Swirl

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