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[Qemu-devel] Re: branches are expensive
From: |
Steffen Liebergeld |
Subject: |
[Qemu-devel] Re: branches are expensive |
Date: |
Thu, 19 Mar 2009 10:39:01 +0000 (UTC) |
User-agent: |
slrn/pre0.9.9-111 (Linux) |
Laurent Desnogues <address@hidden> schrieb:
> On Thu, Mar 19, 2009 at 11:07 AM, Steffen Liebergeld <address@hidden> wrote:
>>
>> I've tested Qemu 0.10.0 and with i386-softmmu on a i386 host I get the
>> following numbers:
>> direct jump count 70%, 2 jumps 54%
>>
>> For qemu-system-arm on an ARM host, the numbers look like this:
>> direct jump count 47%, 2 jumps 40%
>>
>> For completeness I tested qemu-system-arm on a i386 host as well:
>> direct jump count 44%, 2 jumps 37%
>>
>> So it looks like the chaining on ARM targets is not as effective as on i386
>> targets (regardless of the guest, I used the same guest setup, compiled for
>> different architectures, on all tests). Do you have any ideas why this is the
>> case?
>
> Different instruction sets, different compilers. You'd better compare
> guest code before drawing any conclusion.
The qemu-system-arm on ARM and i386 were compiled by the same compiler.
Greetings, Steffen
- [Qemu-devel] branches are expensive, Steffen Liebergeld, 2009/03/17
- Re: [Qemu-devel] branches are expensive, Avi Kivity, 2009/03/17
- [Qemu-devel] Re: branches are expensive, Jan Kiszka, 2009/03/17
- [Qemu-devel] Re: branches are expensive, Steffen Liebergeld, 2009/03/17
- Re: [Qemu-devel] Re: branches are expensive, Paul Brook, 2009/03/17
- Re: [Qemu-devel] Re: branches are expensive, Avi Kivity, 2009/03/17
- [Qemu-devel] Re: branches are expensive, Steffen Liebergeld, 2009/03/19
- Re: [Qemu-devel] Re: branches are expensive, Laurent Desnogues, 2009/03/19
- [Qemu-devel] Re: branches are expensive,
Steffen Liebergeld <=
- Re: [Qemu-devel] Re: branches are expensive, Laurent Desnogues, 2009/03/19
- Re: [Qemu-devel] Re: branches are expensive, Avi Kivity, 2009/03/19
- Re: [Qemu-devel] Re: branches are expensive, Paul Brook, 2009/03/19
[Qemu-devel] Re: branches are expensive, Steffen Liebergeld, 2009/03/17
Re: [Qemu-devel] branches are expensive, Laurent Desnogues, 2009/03/17