1 /* { dg-do compile } */ 2 /* { dg-options "-O -ftree-loop-vectorize -fdump-tree-vect-details -fno-tree-loop-im -mavx2 -mprefer-vector-width=256" } */ 3 4 double x[1024][1024], red[1024]; foo(void)5void foo (void) 6 { 7 for (int i = 0; i < 1024; ++i) 8 for (int j = 0; j < 1024; ++j) 9 { 10 double v = i == 0 ? 0.0 : red[j]; 11 v = v + x[i][j]; 12 red[j] = v; 13 } 14 } 15 16 /* { dg-final { scan-tree-dump "vectorization factor = 4" "vect" } } */ 17