I am using Halide, and trying to generate a simplified version of the inner kernel in a GEMM operation, similar to this. Basically it multiplies a 12x1 column vector with a 1x4 row vector and updates an accumulator cell of size 12x4. I am targeting 32-bit ARM NEON.
Ideally, all the accumulators and operands should fit in the q registers, without spilling to the stack. However, the generated ARM assembly uses the registers in a sub-optimal way, and keeps spilling registers onto the stack and reloading them.
Any help to how to solve this, or what might be causing it, will be greatly appreciated.
Thanks a lot,