Parallel Computer Architecture

11.4 Block Data Transfer in a Shared Address Space 853

for i<r-0 to n-l do

A[i]<-...;

end for

put (A[0..n-1] to

tmp[0..n-l]);

flag <- 1; while (¡flag) {}; /*spin~wait*/

for i^O to n-l do for i<-l to n-l do

compute

f(C[i]);

use

tmp[i];

end for compute

g(B[i]);

end for

FIGURE 11.9 Using block transfer in a shared address space for the example of

Figure

11.1.

The array A is allocated in processor P^'s local memory and the array tmp in

processor P#'s local memory.

11.4 BLOCK DATA TRANSFER IN A SHARED ADDRESS SPACE

In a shared address space, coalescing data to make messages larger (called block data

transfer) and initiating the block transfers ca ...