Merge in trunk.

[thirdparty/gcc.git] / gcc / tree-vect-loop.c

diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 9c12a42d80226166653bfa3658d0344cc118349b..f959da6232068fedcb2b00ccf94b98651752ef67 100644 (file)
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -1968,10 +1968,8 @@ vect_is_slp_reduction (loop_vec_info loop_info, gimple phi, gimple first_stmt)
       FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
         {
          gimple use_stmt = USE_STMT (use_p);
-          if (is_gimple_debug (use_stmt))
-            continue;
-
-         use_stmt = USE_STMT (use_p);
+         if (is_gimple_debug (use_stmt))
+           continue;
 
           /* Check if we got back to the reduction phi.  */
          if (use_stmt == phi)
@@ -2195,6 +2193,12 @@ vect_is_simple_reduction_1 (loop_vec_info loop_info, gimple phi,
               || (!check_reduction && flow_loop_nested_p (vect_loop, loop)));
 
   name = PHI_RESULT (phi);
+  /* ???  If there are no uses of the PHI result the inner loop reduction
+     won't be detected as possibly double-reduction by vectorizable_reduction
+     because that tries to walk the PHI arg from the preheader edge which
+     can be constant.  See PR60382.  */
+  if (has_zero_uses (name))
+    return NULL;
   nloop_uses = 0;
   FOR_EACH_IMM_USE_FAST (use_p, imm_iter, name)
     {
@@ -3507,9 +3511,13 @@ get_initial_def_for_induction (gimple iv_phi)
       exit_phi = NULL;
       FOR_EACH_IMM_USE_FAST (use_p, imm_iter, loop_arg)
         {
-         if (!flow_bb_inside_loop_p (iv_loop, gimple_bb (USE_STMT (use_p))))
+         gimple use_stmt = USE_STMT (use_p);
+         if (is_gimple_debug (use_stmt))
+           continue;
+
+         if (!flow_bb_inside_loop_p (iv_loop, gimple_bb (use_stmt)))
            {
-             exit_phi = USE_STMT (use_p);
+             exit_phi = use_stmt;
              break;
            }
         }
@@ -5413,10 +5421,13 @@ vectorizable_induction (gimple phi, gimple_stmt_iterator *gsi ATTRIBUTE_UNUSED,
       loop_arg = PHI_ARG_DEF_FROM_EDGE (phi, latch_e);
       FOR_EACH_IMM_USE_FAST (use_p, imm_iter, loop_arg)
        {
-         if (!flow_bb_inside_loop_p (loop->inner,
-                                     gimple_bb (USE_STMT (use_p))))
+         gimple use_stmt = USE_STMT (use_p);
+         if (is_gimple_debug (use_stmt))
+           continue;
+
+         if (!flow_bb_inside_loop_p (loop->inner, gimple_bb (use_stmt)))
            {
-             exit_phi = USE_STMT (use_p);
+             exit_phi = use_stmt;
              break;
            }
        }
@@ -5514,7 +5525,7 @@ vectorizable_live_operation (gimple stmt,
            {
              gimple use_stmt = USE_STMT (use_p);
              if (gimple_code (use_stmt) == GIMPLE_PHI
-                 || gimple_bb (use_stmt) == merge_bb)
+                 && gimple_bb (use_stmt) == merge_bb)
                {
                  if (vec_stmt)
                    {