Use innermost_loop_behavior for outer loop vectorisation

This patch replaces the individual stmt_vinfo dr_* fields with
an innermost_loop_behavior, so that the changes in later patches
get picked up automatically.  It also adds a helper function for
getting the behavior of a data reference wrt the vectorised loop.

2017-07-03  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* tree-vectorizer.h (_stmt_vec_info): Replace individual dr_*
	fields with dr_wrt_vec_loop.
	(STMT_VINFO_DR_BASE_ADDRESS, STMT_VINFO_DR_INIT, STMT_VINFO_DR_OFFSET)
	(STMT_VINFO_DR_STEP, STMT_VINFO_DR_ALIGNED_TO): Update accordingly.
	(STMT_VINFO_DR_WRT_VEC_LOOP): New macro.
	(vect_dr_behavior): New function.
	(vect_create_addr_base_for_vector_ref): Remove loop parameter.
	* tree-vect-data-refs.c (vect_compute_data_ref_alignment): Use
	vect_dr_behavior.  Use a step_preserves_misalignment_p boolean to
	track whether the step preserves the misalignment.
	(vect_create_addr_base_for_vector_ref): Remove loop parameter.
	Use vect_dr_behavior.
	(vect_setup_realignment): Update call accordingly.
	(vect_create_data_ref_ptr): Likewise.  Use vect_dr_behavior.
	* tree-vect-loop-manip.c (vect_gen_prolog_loop_niters): Update
	call to vect_create_addr_base_for_vector_ref.
	(vect_create_cond_for_align_checks): Likewise.
	* tree-vect-patterns.c (vect_recog_bool_pattern): Copy
	STMT_VINFO_DR_WRT_VEC_LOOP as a block.
	(vect_recog_mask_conversion_pattern): Likewise.
	* tree-vect-stmts.c (compare_step_with_zero): Use vect_dr_behavior.
	(new_stmt_vec_info): Remove redundant zeroing.

From-SVN: r249911

gcc/ChangeLog

+2017-07-03  Richard Sandiford  <richard.sandiford@linaro.org>
+
+	* tree-vectorizer.h (_stmt_vec_info): Replace individual dr_*
+	fields with dr_wrt_vec_loop.
+	(STMT_VINFO_DR_BASE_ADDRESS, STMT_VINFO_DR_INIT, STMT_VINFO_DR_OFFSET)
+	(STMT_VINFO_DR_STEP, STMT_VINFO_DR_ALIGNED_TO): Update accordingly.
+	(STMT_VINFO_DR_WRT_VEC_LOOP): New macro.
+	(vect_dr_behavior): New function.
+	(vect_create_addr_base_for_vector_ref): Remove loop parameter.
+	* tree-vect-data-refs.c (vect_compute_data_ref_alignment): Use
+	vect_dr_behavior.  Use a step_preserves_misalignment_p boolean to
+	track whether the step preserves the misalignment.
+	(vect_create_addr_base_for_vector_ref): Remove loop parameter.
+	Use vect_dr_behavior.
+	(vect_setup_realignment): Update call accordingly.
+	(vect_create_data_ref_ptr): Likewise.  Use vect_dr_behavior.
+	* tree-vect-loop-manip.c (vect_gen_prolog_loop_niters): Update
+	call to vect_create_addr_base_for_vector_ref.
+	(vect_create_cond_for_align_checks): Likewise.
+	* tree-vect-patterns.c (vect_recog_bool_pattern): Copy
+	STMT_VINFO_DR_WRT_VEC_LOOP as a block.
+	(vect_recog_mask_conversion_pattern): Likewise.
+	* tree-vect-stmts.c (compare_step_with_zero): Use vect_dr_behavior.
+	(new_stmt_vec_info): Remove redundant zeroing.
+
 2017-07-02  Richard Earnshaw  <rearnsha@arm.com>
 
 	* common/config/arm/arm-common.c (arm_be8_option): New function.

gcc/tree-vect-data-refs.c

@@ -666,11 +666,8 @@ vect_compute_data_ref_alignment (struct data_reference *dr)
   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
   struct loop *loop = NULL;
   tree ref = DR_REF (dr);
-  tree vectype;
-  tree base, base_addr;
-  tree misalign = NULL_TREE;
-  tree aligned_to;
-  tree step;
+  tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+  tree base;
   unsigned HOST_WIDE_INT alignment;
 
   if (dump_enabled_p ())
@@ -683,11 +680,15 @@ vect_compute_data_ref_alignment (struct data_reference *dr)
   /* Initialize misalignment to unknown.  */
   SET_DR_MISALIGNMENT (dr, DR_MISALIGNMENT_UNKNOWN);
 
-  if (tree_fits_shwi_p (DR_STEP (dr)))
-    misalign = DR_INIT (dr);
-  aligned_to = DR_ALIGNED_TO (dr);
-  base_addr = DR_BASE_ADDRESS (dr);
-  vectype = STMT_VINFO_VECTYPE (stmt_info);
+  innermost_loop_behavior *drb = vect_dr_behavior (dr);
+  bool step_preserves_misalignment_p;
+
+  /* No step for BB vectorization.  */
+  if (!loop)
+    {
+      gcc_assert (integer_zerop (drb->step));
+      step_preserves_misalignment_p = true;
+    }
 
   /* In case the dataref is in an inner-loop of the loop that is being
      vectorized (LOOP), we use the base and misalignment information
@@ -695,26 +696,21 @@ vect_compute_data_ref_alignment (struct data_reference *dr)
      stays the same throughout the execution of the inner-loop, which is why
      we have to check that the stride of the dataref in the inner-loop evenly
      divides by the vector size.  */
-  if (loop && nested_in_vect_loop_p (loop, stmt))
+  else if (nested_in_vect_loop_p (loop, stmt))
     {
       tree step = DR_STEP (dr);
+      step_preserves_misalignment_p
+	= (tree_fits_shwi_p (step)
+	   && tree_to_shwi (step) % GET_MODE_SIZE (TYPE_MODE (vectype)) == 0);
 
-      if (tree_fits_shwi_p (step)
-	  && tree_to_shwi (step) % GET_MODE_SIZE (TYPE_MODE (vectype)) == 0)
-        {
-          if (dump_enabled_p ())
-            dump_printf_loc (MSG_NOTE, vect_location,
-                             "inner step divides the vector-size.\n");
-	  misalign = STMT_VINFO_DR_INIT (stmt_info);
-	  aligned_to = STMT_VINFO_DR_ALIGNED_TO (stmt_info);
-	  base_addr = STMT_VINFO_DR_BASE_ADDRESS (stmt_info);
-        }
-      else
+      if (dump_enabled_p ())
 	{
-	  if (dump_enabled_p ())
+	  if (step_preserves_misalignment_p)
+	    dump_printf_loc (MSG_NOTE, vect_location,
+			     "inner step divides the vector-size.\n");
+	  else
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-	                     "inner step doesn't divide the vector-size.\n");
-	  misalign = NULL_TREE;
+			     "inner step doesn't divide the vector-size.\n");
 	}
     }
 
@@ -725,18 +721,17 @@ vect_compute_data_ref_alignment (struct data_reference *dr)
   else
     {
       tree step = DR_STEP (dr);
-      unsigned vf = loop ? LOOP_VINFO_VECT_FACTOR (loop_vinfo) : 1;
+      unsigned vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
+      step_preserves_misalignment_p
+	= (tree_fits_shwi_p (step)
+	   && ((tree_to_shwi (step) * vf)
+	       % GET_MODE_SIZE (TYPE_MODE (vectype)) == 0));
 
-      if (tree_fits_shwi_p (step)
-	  && ((tree_to_shwi (step) * vf)
-	      % GET_MODE_SIZE (TYPE_MODE (vectype)) != 0))
-	{
-	  if (dump_enabled_p ())
-	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-	                     "step doesn't divide the vector-size.\n");
-	  misalign = NULL_TREE;
-	}
+      if (!step_preserves_misalignment_p && dump_enabled_p ())
+	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			 "step doesn't divide the vector-size.\n");
     }
+  tree base_addr = drb->base_address;
 
   /* To look at alignment of the base we have to preserve an inner MEM_REF
      as that carries alignment information of the actual access.  */
@@ -777,8 +772,8 @@ vect_compute_data_ref_alignment (struct data_reference *dr)
 
   alignment = TYPE_ALIGN_UNIT (vectype);
 
-  if ((compare_tree_int (aligned_to, alignment) < 0)
-      || !misalign)
+  if ((compare_tree_int (drb->aligned_to, alignment) < 0)
+      || !step_preserves_misalignment_p)
     {
       if (dump_enabled_p ())
 	{
@@ -835,19 +830,16 @@ vect_compute_data_ref_alignment (struct data_reference *dr)
       DR_VECT_AUX (dr)->base_element_aligned = true;
     }
 
-  if (loop && nested_in_vect_loop_p (loop, stmt))
-    step = STMT_VINFO_DR_STEP (stmt_info);
-  else
-    step = DR_STEP (dr);
   /* If this is a backward running DR then first access in the larger
      vectype actually is N-1 elements before the address in the DR.
      Adjust misalign accordingly.  */
-  if (tree_int_cst_sgn (step) < 0)
+  tree misalign = drb->init;
+  if (tree_int_cst_sgn (drb->step) < 0)
     {
       tree offset = ssize_int (TYPE_VECTOR_SUBPARTS (vectype) - 1);
       /* DR_STEP(dr) is the same as -TYPE_SIZE of the scalar type,
 	 otherwise we wouldn't be here.  */
-      offset = fold_build2 (MULT_EXPR, ssizetype, offset, step);
+      offset = fold_build2 (MULT_EXPR, ssizetype, offset, drb->step);
       /* PLUS because STEP was negative.  */
       misalign = size_binop (PLUS_EXPR, misalign, offset);
     }
@@ -3973,38 +3965,22 @@ tree
 vect_create_addr_base_for_vector_ref (gimple *stmt,
 				      gimple_seq *new_stmt_list,
 				      tree offset,
-				      struct loop *loop,
 				      tree byte_offset)
 {
   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
   struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
-  tree data_ref_base;
   const char *base_name;
   tree addr_base;
   tree dest;
   gimple_seq seq = NULL;
-  tree base_offset;
-  tree init;
   tree vect_ptr_type;
   tree step = TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr)));
   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+  innermost_loop_behavior *drb = vect_dr_behavior (dr);
 
-  if (loop_vinfo && loop && loop != (gimple_bb (stmt))->loop_father)
-    {
-      struct loop *outer_loop = LOOP_VINFO_LOOP (loop_vinfo);
-
-      gcc_assert (nested_in_vect_loop_p (outer_loop, stmt));
-
-      data_ref_base = unshare_expr (STMT_VINFO_DR_BASE_ADDRESS (stmt_info));
-      base_offset = unshare_expr (STMT_VINFO_DR_OFFSET (stmt_info));
-      init = unshare_expr (STMT_VINFO_DR_INIT (stmt_info));
-    }
-  else
-    {
-      data_ref_base = unshare_expr (DR_BASE_ADDRESS (dr));
-      base_offset = unshare_expr (DR_OFFSET (dr));
-      init = unshare_expr (DR_INIT (dr));
-    }
+  tree data_ref_base = unshare_expr (drb->base_address);
+  tree base_offset = unshare_expr (drb->offset);
+  tree init = unshare_expr (drb->init);
 
   if (loop_vinfo)
     base_name = get_name (data_ref_base);
@@ -4169,11 +4145,7 @@ vect_create_data_ref_ptr (gimple *stmt, tree aggr_type, struct loop *at_loop,
 
   /* Check the step (evolution) of the load in LOOP, and record
      whether it's invariant.  */
-  if (nested_in_vect_loop)
-    step = STMT_VINFO_DR_STEP (stmt_info);
-  else
-    step = DR_STEP (STMT_VINFO_DATA_REF (stmt_info));
-
+  step = vect_dr_behavior (dr)->step;
   if (integer_zerop (step))
     *inv_p = true;
   else
@@ -4271,7 +4243,7 @@ vect_create_data_ref_ptr (gimple *stmt, tree aggr_type, struct loop *at_loop,
   /* Create: (&(base[init_val+offset]+byte_offset) in the loop preheader.  */
 
   new_temp = vect_create_addr_base_for_vector_ref (stmt, &new_stmt_list,
-						   offset, loop, byte_offset);
+						   offset, byte_offset);
   if (new_stmt_list)
     {
       if (pe)
@@ -4985,7 +4957,7 @@ vect_setup_realignment (gimple *stmt, gimple_stmt_iterator *gsi,
 	{
 	  /* Generate the INIT_ADDR computation outside LOOP.  */
 	  init_addr = vect_create_addr_base_for_vector_ref (stmt, &stmts,
-							NULL_TREE, loop);
+							    NULL_TREE);
           if (loop)
             {
    	      pe = loop_preheader_edge (loop);

gcc/tree-vect-loop-manip.c

@@ -949,7 +949,6 @@ vect_gen_prolog_loop_niters (loop_vec_info loop_vinfo,
 			     basic_block bb, int *bound)
 {
   struct data_reference *dr = LOOP_VINFO_UNALIGNED_DR (loop_vinfo);
-  struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
   tree var;
   tree niters_type = TREE_TYPE (LOOP_VINFO_NITERS (loop_vinfo));
   gimple_seq stmts = NULL, new_stmts = NULL;
@@ -977,7 +976,7 @@ vect_gen_prolog_loop_niters (loop_vec_info loop_vinfo,
       tree offset = negative
 	  ? size_int (-TYPE_VECTOR_SUBPARTS (vectype) + 1) : size_zero_node;
       tree start_addr = vect_create_addr_base_for_vector_ref (dr_stmt,
-						&stmts, offset, loop);
+							      &stmts, offset);
       tree type = unsigned_type_for (TREE_TYPE (start_addr));
       tree vectype_align_minus_1 = build_int_cst (type, vectype_align - 1);
       HOST_WIDE_INT elem_size =
@@ -1975,7 +1974,6 @@ vect_create_cond_for_align_checks (loop_vec_info loop_vinfo,
                                    tree *cond_expr,
 				   gimple_seq *cond_expr_stmt_list)
 {
-  struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
   vec<gimple *> may_misalign_stmts
     = LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo);
   gimple *ref_stmt;
@@ -2016,7 +2014,7 @@ vect_create_cond_for_align_checks (loop_vec_info loop_vinfo,
       /* create: addr_tmp = (int)(address_of_first_vector) */
       addr_base =
 	vect_create_addr_base_for_vector_ref (ref_stmt, &new_stmt_list,
-					      offset, loop);
+					      offset);
       if (new_stmt_list != NULL)
 	gimple_seq_add_seq (cond_expr_stmt_list, new_stmt_list);
 

gcc/tree-vect-patterns.c

@@ -3789,14 +3789,8 @@ vect_recog_bool_pattern (vec<gimple *> *stmts, tree *type_in,
       set_vinfo_for_stmt (pattern_stmt, pattern_stmt_info);
       STMT_VINFO_DATA_REF (pattern_stmt_info)
 	= STMT_VINFO_DATA_REF (stmt_vinfo);
-      STMT_VINFO_DR_BASE_ADDRESS (pattern_stmt_info)
-	= STMT_VINFO_DR_BASE_ADDRESS (stmt_vinfo);
-      STMT_VINFO_DR_INIT (pattern_stmt_info) = STMT_VINFO_DR_INIT (stmt_vinfo);
-      STMT_VINFO_DR_OFFSET (pattern_stmt_info)
-	= STMT_VINFO_DR_OFFSET (stmt_vinfo);
-      STMT_VINFO_DR_STEP (pattern_stmt_info) = STMT_VINFO_DR_STEP (stmt_vinfo);
-      STMT_VINFO_DR_ALIGNED_TO (pattern_stmt_info)
-	= STMT_VINFO_DR_ALIGNED_TO (stmt_vinfo);
+      STMT_VINFO_DR_WRT_VEC_LOOP (pattern_stmt_info)
+	= STMT_VINFO_DR_WRT_VEC_LOOP (stmt_vinfo);
       DR_STMT (STMT_VINFO_DATA_REF (stmt_vinfo)) = pattern_stmt;
       *type_out = vectype;
       *type_in = vectype;
@@ -3930,14 +3924,8 @@ vect_recog_mask_conversion_pattern (vec<gimple *> *stmts, tree *type_in,
       set_vinfo_for_stmt (pattern_stmt, pattern_stmt_info);
       STMT_VINFO_DATA_REF (pattern_stmt_info)
 	= STMT_VINFO_DATA_REF (stmt_vinfo);
-      STMT_VINFO_DR_BASE_ADDRESS (pattern_stmt_info)
-	= STMT_VINFO_DR_BASE_ADDRESS (stmt_vinfo);
-      STMT_VINFO_DR_INIT (pattern_stmt_info) = STMT_VINFO_DR_INIT (stmt_vinfo);
-      STMT_VINFO_DR_OFFSET (pattern_stmt_info)
-	= STMT_VINFO_DR_OFFSET (stmt_vinfo);
-      STMT_VINFO_DR_STEP (pattern_stmt_info) = STMT_VINFO_DR_STEP (stmt_vinfo);
-      STMT_VINFO_DR_ALIGNED_TO (pattern_stmt_info)
-	= STMT_VINFO_DR_ALIGNED_TO (stmt_vinfo);
+      STMT_VINFO_DR_WRT_VEC_LOOP (pattern_stmt_info)
+	= STMT_VINFO_DR_WRT_VEC_LOOP (stmt_vinfo);
       DR_STMT (STMT_VINFO_DATA_REF (stmt_vinfo)) = pattern_stmt;
 
       *type_out = vectype1;

gcc/tree-vect-stmts.c

@@ -1692,13 +1692,9 @@ static int
 compare_step_with_zero (gimple *stmt)
 {
   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
-  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
-  tree step;
-  if (loop_vinfo && nested_in_vect_loop_p (LOOP_VINFO_LOOP (loop_vinfo), stmt))
-    step = STMT_VINFO_DR_STEP (stmt_info);
-  else
-    step = DR_STEP (STMT_VINFO_DATA_REF (stmt_info));
-  return tree_int_cst_compare (step, size_zero_node);
+  data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
+  return tree_int_cst_compare (vect_dr_behavior (dr)->step,
+			       size_zero_node);
 }
 
 /* If the target supports a permute mask that reverses the elements in
@@ -8845,12 +8841,6 @@ new_stmt_vec_info (gimple *stmt, vec_info *vinfo)
   STMT_VINFO_VEC_REDUCTION_TYPE (res) = TREE_CODE_REDUCTION;
   STMT_VINFO_VEC_CONST_COND_REDUC_CODE (res) = ERROR_MARK;
 
-  STMT_VINFO_DR_BASE_ADDRESS (res) = NULL;
-  STMT_VINFO_DR_OFFSET (res) = NULL;
-  STMT_VINFO_DR_INIT (res) = NULL;
-  STMT_VINFO_DR_STEP (res) = NULL;
-  STMT_VINFO_DR_ALIGNED_TO (res) = NULL;
-
   if (gimple_code (stmt) == GIMPLE_PHI
       && is_loop_header_bb_p (gimple_bb (stmt)))
     STMT_VINFO_DEF_TYPE (res) = vect_unknown_def_type;

gcc/tree-vectorizer.h

@@ -554,11 +554,7 @@ typedef struct _stmt_vec_info {
 
   /* Information about the data-ref relative to this loop
      nest (the loop that is being considered for vectorization).  */
-  tree dr_base_address;
-  tree dr_init;
-  tree dr_offset;
-  tree dr_step;
-  tree dr_aligned_to;
+  innermost_loop_behavior dr_wrt_vec_loop;
 
   /* For loop PHI nodes, the base and evolution part of it.  This makes sure
      this information is still available in vect_update_ivs_after_vectorizer
@@ -708,11 +704,12 @@ STMT_VINFO_BB_VINFO (stmt_vec_info stmt_vinfo)
 #define STMT_VINFO_VEC_REDUCTION_TYPE(S)   (S)->v_reduc_type
 #define STMT_VINFO_VEC_CONST_COND_REDUC_CODE(S) (S)->const_cond_reduc_code
 
-#define STMT_VINFO_DR_BASE_ADDRESS(S)      (S)->dr_base_address
-#define STMT_VINFO_DR_INIT(S)              (S)->dr_init
-#define STMT_VINFO_DR_OFFSET(S)            (S)->dr_offset
-#define STMT_VINFO_DR_STEP(S)              (S)->dr_step
-#define STMT_VINFO_DR_ALIGNED_TO(S)        (S)->dr_aligned_to
+#define STMT_VINFO_DR_WRT_VEC_LOOP(S)      (S)->dr_wrt_vec_loop
+#define STMT_VINFO_DR_BASE_ADDRESS(S)      (S)->dr_wrt_vec_loop.base_address
+#define STMT_VINFO_DR_INIT(S)              (S)->dr_wrt_vec_loop.init
+#define STMT_VINFO_DR_OFFSET(S)            (S)->dr_wrt_vec_loop.offset
+#define STMT_VINFO_DR_STEP(S)              (S)->dr_wrt_vec_loop.step
+#define STMT_VINFO_DR_ALIGNED_TO(S)        (S)->dr_wrt_vec_loop.aligned_to
 
 #define STMT_VINFO_IN_PATTERN_P(S)         (S)->in_pattern_p
 #define STMT_VINFO_RELATED_STMT(S)         (S)->related_stmt
@@ -1014,6 +1011,22 @@ known_alignment_for_access_p (struct data_reference *data_ref_info)
   return (DR_MISALIGNMENT (data_ref_info) != DR_MISALIGNMENT_UNKNOWN);
 }
 
+/* Return the behavior of DR with respect to the vectorization context
+   (which for outer loop vectorization might not be the behavior recorded
+   in DR itself).  */
+
+static inline innermost_loop_behavior *
+vect_dr_behavior (data_reference *dr)
+{
+  gimple *stmt = DR_STMT (dr);
+  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+  if (loop_vinfo == NULL
+      || !nested_in_vect_loop_p (LOOP_VINFO_LOOP (loop_vinfo), stmt))
+    return &DR_INNERMOST (dr);
+  else
+    return &STMT_VINFO_DR_WRT_VEC_LOOP (stmt_info);
+}
 
 /* Return true if the vect cost model is unlimited.  */
 static inline bool
@@ -1144,8 +1157,7 @@ extern tree vect_get_new_vect_var (tree, enum vect_var_kind, const char *);
 extern tree vect_get_new_ssa_name (tree, enum vect_var_kind,
 				   const char * = NULL);
 extern tree vect_create_addr_base_for_vector_ref (gimple *, gimple_seq *,
-						  tree, struct loop *,
-						  tree = NULL_TREE);
+						  tree, tree = NULL_TREE);
 
 /* In tree-vect-loop.c.  */
 /* FORNOW: Used in tree-parloops.c.  */