Today we continue to discuss the WRL research report on Swift Java compiler. We were discussing  Trace scheduling and block layout. We saw that this involves a greedy algorithm where the most frequently executed block that is not yet placed in the trace is taken as the first block in the new trace.
The trace is then extended upwards and downwards in the control flow graph. The algorithm  proceeds until there are no more blocks to place in the trace. The instruction scheduler operates on one trace at a time. It adds dependence to make sure that a value is scheduled early enough to dominate all its users who are not in the trace. The scheduler also includes a model of the alpha 21164 and 21264 pipelines. This let's the scheduler decide when the result of an operation will be ready based on the latency of the operation  and the state of the pipelines. Given this dependence and latency information, the scheduler decides at each point to schedule the value whose dependence have all been satisfied and whose inputs are ready or available at the earliest. If a value is chosen that is a control flow or an exception, the current basic block is ended. when a value is scheduled, the finite state automata is updated to reflect it's execution . Swift uses the profile information to determine the best layout for the trace
#codingexercise
GetAllNumberRangeProductCubeRootSquares) (Double [] A)
{
if (A == null) return 0;

Return A.AllNumberRangeProductCubeRootSquares();


}