diff options
| -rw-r--r-- | gcc/testsuite/gcc.dg/vect/pr97838.c | 11 | ||||
| -rw-r--r-- | gcc/tree-vect-slp.c | 22 |
2 files changed, 28 insertions, 5 deletions
diff --git a/gcc/testsuite/gcc.dg/vect/pr97838.c b/gcc/testsuite/gcc.dg/vect/pr97838.c new file mode 100644 index 0000000..06ec035 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/pr97838.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ + +int a, b, c, d; + +void f() { + while (c++) { + int e = -1; + d = a ? e / a : e; + b ^= ~d; + } +} diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c index e4c2aa4..b98d5db 100644 --- a/gcc/tree-vect-slp.c +++ b/gcc/tree-vect-slp.c @@ -2629,8 +2629,18 @@ vect_slp_build_vertices (vec_info *info, vec<slp_tree> &vertices, unsigned i; slp_instance instance; FOR_EACH_VEC_ELT (info->slp_instances, i, instance) - vect_slp_build_vertices (visited, SLP_INSTANCE_TREE (instance), vertices, - leafs); + { + unsigned n_v = vertices.length (); + unsigned n_l = leafs.length (); + vect_slp_build_vertices (visited, SLP_INSTANCE_TREE (instance), vertices, + leafs); + /* If we added vertices but no entries to the reverse graph we've + added a cycle that is not backwards-reachable. Push the entry + to mimic as leaf then. */ + if (vertices.length () > n_v + && leafs.length () == n_l) + leafs.safe_push (SLP_INSTANCE_TREE (instance)->vertex); + } } /* Apply (reverse) bijectite PERM to VEC. */ @@ -2724,9 +2734,11 @@ vect_optimize_slp (vec_info *vinfo) || SLP_TREE_DEF_TYPE (node) == vect_constant_def) continue; - /* Loads are the only thing generating permutes and leafs do not - change across iterations. */ - bitmap_set_bit (n_visited, idx); + /* Leafs do not change across iterations. Note leafs also double + as entries to the reverse graph. */ + if (!slpg->vertices[idx].succ) + bitmap_set_bit (n_visited, idx); + /* Loads are the only thing generating permutes. */ if (!SLP_TREE_LOAD_PERMUTATION (node).exists ()) continue; |