Instead of calculating a^2, b^2, (a+b)^2 and (a-b)^2, calculate only
a^2, b^2 and 2*a*b in each iteration and derive the latter parts from
these three at the end.
Before and after:
A78
ac3_sum_square_bufferfly_int32_neon: 484.8 ( 2.00x)
ac3_sum_square_bufferfly_int32_neon: 468.2 ( 2.08x)
A72
ac3_sum_square_bufferfly_int32_neon: 793.6 ( 1.26x)
ac3_sum_square_bufferfly_int32_neon: 527.3 ( 1.92x)
Signed-off-by: Martin Storsjö <martin@martin.st>
Krzysztof Pyrkosz
e8d4c55987