# # Example 1 in "Generating Efficient Tiled Code for Distributed Memory # Machines", Peiyi Tang and Jingling Xue. # # for (int i = 1; i <= 9; i++) { # for (int j = 1; j <= 4; j++) { # A[i,2*j] = A[i,2*j-2] + A[i-1,2*j-2]; # } # } # # We tile it with a tiling matrix H = [1/2 0] # [-1/2 1/2] # # We get: # # for (int i = 0; i <= 9; i += 2) { # for (int j = max(-1, -9 + i); j <= min(4, 3 + i); j++) { # for (int k = max(1, i, i-j); k <= min(4 + i -j, 1 + i, 9); k++) { # for (int l = max(-i + j + k, 1); l <= min(4, 1 -i + j + k); l++) { # if (i % 2 == 0) { # if ((i + j) % 2 == 0) { # A[k, 2 * l] = A[k, -2 + 2 * l] + A[-1 + k, -2 + 2 * l]; # } # } # } # } # } # } # # language: C c # parameter (none) 1 2 # 1 1 1 0 1 # number of statements 1 # -2i-2j -l +4 >= 0 # -k +l >= 0 # -2i -k +9 >= 0 # k >= 0 # 2i +k -1 >= 0 # k -l +1 >= 0 # -k +1 >= 0 # 2i+2j +l-1 >= 0 8 6 # i j k l 1 1 -2 -2 0 -1 4 1 0 0 -1 1 0 1 -2 0 -1 0 9 1 0 0 1 0 0 1 2 0 1 0 -1 1 0 0 1 -1 1 1 0 0 -1 0 1 1 2 2 0 1 -1 0 0 0 0 1 # Scattering functions 9 15 # alpha=[2i, 2i+2j, 2i+k, 2i+2j+l] gamma=[0, 0, 0, 0] beta=[0, 0, 0, 0, 0, 0] # c1 c2 c3 c4 c5 c6 c7 c8 c9 i j k l 1 0 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 0 0 0 0 0 2 2 0 0 0 0 0 0 0 0 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 0 0 0 2 0 1 0 0 0 0 0 0 0 0 0 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 0 2 2 0 1 0 0 0 0 0 0 0 0 0 0 -1 0 0 0 0 0 0