qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH] target-arm: Move VLD/VST multiple into helper f


From: riku voipio
Subject: Re: [Qemu-devel] [PATCH] target-arm: Move VLD/VST multiple into helper functions
Date: Mon, 06 Jun 2011 10:18:09 +0300
User-agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110424 Thunderbird/3.1.10

On 06/03/2011 11:47 PM, Aurelien Jarno wrote:
On Mon, May 02, 2011 at 05:01:24PM +0100, Peter Maydell wrote:
On 20 April 2011 15:52, Peter Maydell<address@hidden>  wrote:
Move VLD/VST multiple into helper functions, as some cases can
generate more TCG ops than the maximum per-instruction limit
and certainly more than the recommended 20.

I've had a review comment in private email that this patch
slows down ffmpeg by a little over 4% (in a linux-user execution
run where about 5% of instructions were an affected vld/vst). So
perhaps the right approach is to increase the max-ops-per-insn limit
and update the guidance in tcg/README instead?

Does this patch fixes a real issue (ie most probably a crash), or it is
just to make the arm target compliant with the README?

Yes, it (or the similar patch in meego qemu) did fix an real issue. IIRC when running pixman code where vld4.8 variant of instruction was used.

Riku



reply via email to

[Prev in Thread] Current Thread [Next in Thread]