From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] x86 emulated hardware : which make.conf options ?
Date: Fri, 1 Apr 2005 19:04:07 +0100 [thread overview]
Message-ID: <200504011904.12228.paul@codesourcery.com> (raw)
In-Reply-To: <a88cb668c069e1bca6074c6af8befc14@teleline.es>
On Friday 01 April 2005 18:26, Natalia Portillo wrote:
> Use the same optimizations you should use in a real Pentium II.
> You can also enable SSE and SSE2 (but not Pentium III or Pentium 4), as
> QEMU emulates them.
Do you have any facts to substatiate this statement?
The pentium 2, 3, and 4 all support the same core instruction set, the only
difference being sse and sse2. From the qemu point of view a pentuim3/4 is
just a pentium2 with sse/sse2.
Qemu emulates the x86 instruction set. It does not implement the
microarchitecture of a particular implementation. I haven't done any tests,
but I'd expect the performance characteristics of qemu are significantly
different to those of a real CPU.
-Os optimizes for code size, not speed. This may be faster than -O2 in some
cases, but I'd be surprised if that was true in general.
Paul
next prev parent reply other threads:[~2005-04-01 18:21 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-07 20:55 [Qemu-devel] gentoo disk image for QEmu Jérôme Bouat
2005-03-07 21:26 ` Magnus Damm
2005-03-08 1:51 ` [Qemu-devel] ESC key problems & keyboard problems Paulo R. Dallan
2005-03-09 11:16 ` Oliver Gerlich
2005-03-09 18:44 ` Paulo R. Dallan
2005-03-10 22:52 ` [Qemu-devel] Still some keyboard problems (was: ESC key problems & keyboard problems) Paulo R. Dallan
2005-03-12 21:33 ` [Qemu-devel] Still some keyboard problems Oliver Gerlich
2005-03-12 9:55 ` [Qemu-devel] gentoo disk image for QEmu Jérôme Bouat
2005-03-12 10:31 ` Magnus Damm
2005-04-01 13:05 ` [Qemu-devel] x86 emulated hardware : which make.conf options ? Jérôme Bouat
2005-04-01 13:14 ` Karel Gardas
2005-04-01 17:26 ` Natalia Portillo
2005-04-01 18:04 ` Paul Brook [this message]
2005-04-02 16:38 ` Natalia Portillo
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