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From: Richard Henderson <richard.henderson@linaro.org>
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Date: Wed, 24 Jan 2018 16:09:00 -0800
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Subject: Re: [Qemu-devel] [PATCH v3 00/22] re-factor softfloat and add fp16
 functions
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To: Howard Spoelstra <hsp.cat7@gmail.com>, =?UTF-8?Q?Alex_Benn=c3=a9e?= <alex.bennee@linaro.org>
Cc: qemu-devel qemu-devel <qemu-devel@nongnu.org>

On 01/24/2018 01:49 PM, Howard Spoelstra wrote:
> Hi,
> 
> I built qemu-system-ppc for OSX and Windows from
> https://github.com/stsquad/qemu/tree/softfloat-refactor-and-fp16-v3
> and noticed a considerable drop in floating point performance on both
> hosts.
> Running Mac OS 9.2 in OSX, using MacBench 3.0, the score for the
> floating point performance dropped from ~60 to ~42.
> 
> Recent tcg optimisations had improved processor and floating point
> performance considerably, but that gain seems to be more than lost for
> the floating point performance.
> 
> Any idea what is causing this?

Is this a 64-bit or a 32-bit build?

We made a conscious choice to share code and use all 64-bit operations, under
the assumption that x86_64 is the most common host.

Otherwise we have not really done extensive benchmarking.


r~