I Recursive Halving and Doubling Assume that each processor has formed the partial sum of the components of the vector that it has Step 1: Processor 2 sends its partial sum to processor 1 and processor 1 adds this partial sum to its own. Meanwhile, processor 4 sends its partial sum to processor 3 and processor 3 performs a similar summation Step 2: Processor 3 sends its partial sum, which is now the sum of the components on processors 3 and 4, to processor 1 and processor 1 adds it to its partial sum to get the final sum across all the components of the vector. At each stage of the process, the number of processes doing work is cut in half. The algorithm is depicted in the Figure 13.1 below, where the solid arrow denotes a send operation and the dotted line arrow denotes a receive operation followed by a summationRecursive Halving and Doubling • Assume that each processor has formed the partial sum of the components of the vector that it has. • Step 1: Processor 2 sends its partial sum to processor 1 and processor 1 adds this partial sum to its own. Meanwhile, processor 4 sends its partial sum to processor 3 and processor 3 performs a similar summation. • Step 2: Processor 3 sends its partial sum, which is now the sum of the components on processors 3 and 4, to processor 1 and processor 1 adds it to its partial sum to get the final sum across all the components of the vector. • At each stage of the process, the number of processes doing work is cut in half. The algorithm is depicted in the Figure 13.1 below, where the solid arrow denotes a send operation and the dotted line arrow denotes a receive operation followed by a summation