tree-vect-loop.c (vectorizable_reduction): Remember reduction PHI.

2019-11-06  Richard Biener  <rguenther@suse.de>

	* tree-vect-loop.c (vectorizable_reduction): Remember reduction
	PHI.  Use STMT_VINFO_REDUC_IDX to skip the reduction operand.
	Simplify single_defuse_cycle condition.

From-SVN: r277882

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d04b6bea18bcf44817c5dff2386a7028eb8c23c9..bc3d23842a4e91e181d3b2315734982068476200 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-11-06  Richard Biener  <rguenther@suse.de>
+
+       * tree-vect-loop.c (vectorizable_reduction): Remember reduction
+       PHI.  Use STMT_VINFO_REDUC_IDX to skip the reduction operand.
+       Simplify single_defuse_cycle condition.
+
 2019-11-06  Richard Sandiford  <richard.sandiford@arm.com>
 
        * tree-vect-loop.c (vect_analyze_loop_2): When vectorizing an

diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index ec0bd2c3875a5d9ec5e7522b01c325ac0ab3c369..d982e1aea771c9482869177ad605d88adcd2a9e3 100644 (file)
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -5734,6 +5734,7 @@ vectorizable_reduction (stmt_vec_info stmt_info, slp_tree slp_node,
     }
 
   stmt_vec_info orig_stmt_of_analysis = stmt_info;
+  stmt_vec_info phi_info = stmt_info;
   if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def
       || STMT_VINFO_DEF_TYPE (stmt_info) == vect_double_reduction_def)
     {
@@ -5758,8 +5759,8 @@ vectorizable_reduction (stmt_vec_info stmt_info, slp_tree slp_node,
          bool res = single_imm_use (gimple_phi_result (stmt_info->stmt),
                                     &use_p, &use_stmt);
          gcc_assert (res);
-         stmt_info = loop_vinfo->lookup_stmt (use_stmt);
-         stmt_info = vect_stmt_to_vectorize (STMT_VINFO_REDUC_DEF (stmt_info));
+         phi_info = loop_vinfo->lookup_stmt (use_stmt);
+         stmt_info = vect_stmt_to_vectorize (STMT_VINFO_REDUC_DEF (phi_info));
        }
       /* STMT_VINFO_REDUC_DEF doesn't point to the first but the last
          element.  */
@@ -5769,6 +5770,8 @@ vectorizable_reduction (stmt_vec_info stmt_info, slp_tree slp_node,
          stmt_info = REDUC_GROUP_FIRST_ELEMENT (stmt_info);
        }
     }
+  /* PHIs should not participate in patterns.  */
+  gcc_assert (!STMT_VINFO_RELATED_STMT (phi_info));
 
   if (nested_in_vect_loop_p (loop, stmt_info))
     {
@@ -5831,9 +5834,6 @@ vectorizable_reduction (stmt_vec_info stmt_info, slp_tree slp_node,
      The last use is the reduction variable.  In case of nested cycle this
      assumption is not true: we use reduc_index to record the index of the
      reduction variable.  */
-  stmt_vec_info phi_info = STMT_VINFO_REDUC_DEF (vect_orig_stmt (stmt_info));
-  /* PHIs should not participate in patterns.  */
-  gcc_assert (!STMT_VINFO_RELATED_STMT (phi_info));
   gphi *reduc_def_phi = as_a <gphi *> (phi_info->stmt);
 
   /* Verify following REDUC_IDX from the latch def leads us back to the PHI
@@ -5882,11 +5882,8 @@ vectorizable_reduction (stmt_vec_info stmt_info, slp_tree slp_node,
                             "use not simple.\n");
          return false;
        }
-      if ((dt == vect_reduction_def || dt == vect_nested_cycle)
-         && op == reduc_def)
-       {
-         continue;
-       }
+      if (i == STMT_VINFO_REDUC_IDX (stmt_info))
+       continue;
 
       /* There should be only one cycle def in the stmt, the one
          leading to reduc_def.  */
@@ -6347,14 +6344,9 @@ vectorizable_reduction (stmt_vec_info stmt_info, slp_tree slp_node,
    This only works when we see both the reduction PHI and its only consumer
    in vectorizable_reduction and there are no intermediate stmts
    participating.  */
-  stmt_vec_info use_stmt_info;
-  tree reduc_phi_result = gimple_phi_result (reduc_def_phi);
   if (ncopies > 1
       && (STMT_VINFO_RELEVANT (stmt_info) <= vect_used_only_live)
-      && (use_stmt_info = loop_vinfo->lookup_single_use (reduc_phi_result))
-      && (!STMT_VINFO_IN_PATTERN_P (use_stmt_info)
-         || !STMT_VINFO_PATTERN_DEF_SEQ (use_stmt_info))
-      && vect_stmt_to_vectorize (use_stmt_info) == stmt_info)
+      && reduc_chain_length == 1)
     single_defuse_cycle = true;
 
   if (single_defuse_cycle || lane_reduc_code_p)