[cairo] Cairo rendering on ARM

[Bob Murphy]

Hi,

I've been running some performance tests on SVG rendering using gdk  
on ARM without an FPU, and was surprised at the results.

I rendered three passes of over 250 SVG images into GdkPixbufs using  
Cairo 1.0.4, Cairo 1.4.4 with standard configure options, and Cairo  
1.4.4 built with --disable-some-floating-point defined for configure.

And to my considerable surprise, the results were identical on all  
three configurations, within three percent.

So here are some questions:

1. Does --disable-some-floating-point actually do anything? I saw a  
note that it had been added in an earlier version of Cairo (1.3.6?)  
for future use. And I tracked its effects through configure and so  
on, in both Cairo 1.4.4 and 1.4.6, and it looked to me like this  
option doesn't currently affect the compile or lin.

2. Are there any other ways to enable optional performance  
enhancements for devices without FPUs that I've missed?

3. Generally, what kinds of performance enhancements have been made  
for non-FPU devices? I'm wondering if perhaps they've all been done  
in areas that  simply don't affect SVG rendering.

Thanks,
Bob Murphy