https://community.arm.com/tools/f/discussions/555/neon-vs-vfp-usage
Note: This was originally posted on 30th August 2011 at http://forums.arm.com
Could I use NEON and VFP at the same time in my application?
What would be the downsides of that?
You can there is no technical problem.
But don't believe you'll able to optimize a code. Mixing NEON and VPf instructions will give you poor performance. (On cortex A8! On Cortex A9 I don't know)
VPf do not have instruction queue like NEON, so every VPf instruction need to wait for the NEON queue to be empty.
So this is most of case not a good idea to use both together.
