In the CortexA9 MPE TRM document, it states that a feature of the ARM CortexA9, is that it has independent pipelines for the VFPv3 and Advanced SIMD instructions. Does this mean that you can run VFPv3 and Advanced SIMD instructions in parallel because of their own independent pipeline?
The Cortex-A9 NEON MPE features are:
- ...
- independent pipelines for VFPv3 and Advanced SIMD instructions
- ...
However, here it later states that the units cannot execute concurrently.
The VFP and Advanced-SIMD units can not execute concurrently. All instructions targeting either the Advanced-SIMD or VFP units complete >before later instructions are issued on the other unit.
So, what is the case for the CortexA9?
If it is not possible to execute these instructions in parallel, I do not see how the independent pipelines are a useful feature.
FWIW, this question has been answered already for the CortexA8 here.
