fix armeabi-v7a

[bostick]

Fix #813

Emulate vzip1q_f32 for 32-bit

[erincatto]

Thanks for this fix! Are you able to do any performance comparisons versus SIMD disabled on this platform? Just curious.

[bostick]

I have a 32-bit arm7 device I can test on. What comparisons would be good to do?

[erincatto]

If you can run the benchmark app that would be great.

box2d/CMakeLists.txt

Line 72 in 2dbb681

option(BOX2D_BENCHMARKS "Build the Box2D benchmarks" OFF)

[bostick]

OK, I will setup a simple Android app for running the benchmark.

[bostick]

OK @erincatto , I put up a repo with the results of running the benchmark:
https://github.com/bostick/Box2DAndroidBenchmark

I have not interpreted the results. Let me know if you'd like anything else

[erincatto]

It seems SIMD optimizations are not helping on this CPU. I've heard 32-bit Neon is not very good. I see good results on 64-bit Neon though. This CPU is also quite slow in general. But it does make sense to use around 4 threads on this.

Thanks a lot for running these tests!

[erincatto]

Fixed the formatting. You can see other benchmark results here: https://box2d.org/files/benchmark_results.html

[bostick]

Ah, I messed up the formatting when I stripped the \n in the fprintf calls when I was replacing all of printf calls with Android logging. Fixed in the repo now.