I see, thanks very much :) I googled it and found some useful definitions in a paper [0]: "the parallel programming community has developed a deep understandi

I see, thanks very much :) I googled it and found some useful definitions in a paper [0]: "the parallel programming community has developed a deep understanding of the opportunities for exploiting parallelism in regular programs organized around dense vectors and matrices, such as matrix factorizations and stencil computations. ... we understand relatively little about the patterns of parallelism and locality in irregular programs, which are organized around pointer-based data structures such as trees and graphs." [0] How Much Parallelism is There in Irregular Applications? : https://iss.oden.utexas.edu/Publications/Papers/ppopp2009.pdf https://iss.oden.utexas.edu/Publications/Papers/ppopp2009.pd...