One of the problem I foresee is this one:

1.0e17 >= 100000000000000001

indeed, the (generated) primitive currently convert the SmallInteger to double, and this one is true:

1.0e17 >= 100000000000000001 asFloat

In 32 bit Spur/COG with 30 bit max magnitude, it was OK because every conversion SmallInteger -> Double was exact - like all integer in the range [-2^53,2^53] - see Float class>>maxExactInteger

In 64 bits Spur, this might not be the case anymore since some SmallInteger exceed this range...

So the (generated) primitive must be protected with some range test.