Entity#a(AxisAlignedBB) attempts to fix the AABB given to it. This forces the cretaion of a new AABB every time the method is invoked (which is quite often).

This patch skips many AABB allocations on my test server and reduced their allocation count by 16% (many entities on that server)

public void a(AxisAlignedBB axisalignedbb) {
// Changes start - block invalid bounding boxes
// Fix: Do not allocate if not required.
double a = axisalignedbb.a,
b = axisalignedbb.b,
c = axisalignedbb.c,
d = axisalignedbb.d,
e = axisalignedbb.e,
f = axisalignedbb.f;
if (d - a > 64 || d - a < 0 || e - b > 64 || e - b < 0 || f - c > 64 || f - c < 0)

else

// Changes end
}

// Changes start - block invalid bounding boxes
private void assignFixedAABB(double a, double b, double c, double d, double e,
double f)

private double clamp(double d, double min, double max)

// Changes end