Add a vect_get_num_copies helper routine

This patch adds a vectoriser helper routine to calculate how
many copies of a vector statement we need.  At present this
is always:

  LOOP_VINFO_VECT_FACTOR (loop_vinfo) / TYPE_VECTOR_SUBPARTS (vectype)

but later patches add other cases.  Another benefit of using
a helper routine is that it can assert that the division is
exact (which it must be).

2017-09-14  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* tree-vectorizer.h (vect_get_num_copies): New function.
	* tree-vect-data-refs.c (vect_get_data_access_cost): Use it.
	* tree-vect-loop.c (vectorizable_reduction): Likewise.
	(vectorizable_induction): Likewise.
	(vectorizable_live_operation): Likewise.
	* tree-vect-stmts.c (vectorizable_mask_load_store): Likewise.
	(vectorizable_bswap): Likewise.
	(vectorizable_call): Likewise.
	(vectorizable_conversion): Likewise.
	(vectorizable_assignment): Likewise.
	(vectorizable_shift): Likewise.
	(vectorizable_operation): Likewise.
	(vectorizable_store): Likewise.
	(vectorizable_load): Likewise.
	(vectorizable_condition): Likewise.
	(vectorizable_comparison): Likewise.
	(vect_analyze_stmt): Pass the slp node to vectorizable_live_operation.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r252764

gcc/ChangeLog

@@ -2,6 +2,28 @@
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood  <david.sherwood@arm.com>
 
+	* tree-vectorizer.h (vect_get_num_copies): New function.
+	* tree-vect-data-refs.c (vect_get_data_access_cost): Use it.
+	* tree-vect-loop.c (vectorizable_reduction): Likewise.
+	(vectorizable_induction): Likewise.
+	(vectorizable_live_operation): Likewise.
+	* tree-vect-stmts.c (vectorizable_mask_load_store): Likewise.
+	(vectorizable_bswap): Likewise.
+	(vectorizable_call): Likewise.
+	(vectorizable_conversion): Likewise.
+	(vectorizable_assignment): Likewise.
+	(vectorizable_shift): Likewise.
+	(vectorizable_operation): Likewise.
+	(vectorizable_store): Likewise.
+	(vectorizable_load): Likewise.
+	(vectorizable_condition): Likewise.
+	(vectorizable_comparison): Likewise.
+	(vect_analyze_stmt): Pass the slp node to vectorizable_live_operation.
+
+2017-09-14  Richard Sandiford  <richard.sandiford@linaro.org>
+	    Alan Hayward  <alan.hayward@arm.com>
+	    David Sherwood  <david.sherwood@arm.com>
+
 	* tree-vect-loop.c (vectorizable_induction): Use gimple_build instead
 	of vect_init_vector.
 

gcc/tree-vect-data-refs.c

@@ -1181,10 +1181,13 @@ vect_get_data_access_cost (struct data_reference *dr,
 {
   gimple *stmt = DR_STMT (dr);
   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
-  int nunits = TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info));
   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
-  int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
-  int ncopies = MAX (1, vf / nunits); /* TODO: Handle SLP properly  */
+  int ncopies;
+
+  if (PURE_SLP_STMT (stmt_info))
+    ncopies = 1;
+  else
+    ncopies = vect_get_num_copies (loop_vinfo, STMT_VINFO_VECTYPE (stmt_info));
 
   if (DR_IS_READ (dr))
     vect_get_load_cost (dr, ncopies, true, inside_cost, outside_cost,

gcc/tree-vect-loop.c

@@ -5683,8 +5683,7 @@ vectorizable_reduction (gimple *stmt, gimple_stmt_iterator *gsi,
       if (slp_node)
 	ncopies = 1;
       else
-	ncopies = (LOOP_VINFO_VECT_FACTOR (loop_vinfo)
-		   / TYPE_VECTOR_SUBPARTS (vectype_in));
+	ncopies = vect_get_num_copies (loop_vinfo, vectype_in);
 
       use_operand_p use_p;
       gimple *use_stmt;
@@ -5980,8 +5979,7 @@ vectorizable_reduction (gimple *stmt, gimple_stmt_iterator *gsi,
   if (slp_node)
     ncopies = 1;
   else
-    ncopies = (LOOP_VINFO_VECT_FACTOR (loop_vinfo)
-               / TYPE_VECTOR_SUBPARTS (vectype_in));
+    ncopies = vect_get_num_copies (loop_vinfo, vectype_in);
 
   gcc_assert (ncopies >= 1);
 
@@ -6550,7 +6548,7 @@ vectorizable_induction (gimple *phi,
   if (slp_node)
     ncopies = 1;
   else
-    ncopies = vf / nunits;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype);
   gcc_assert (ncopies >= 1);
 
   /* FORNOW. These restrictions should be relaxed.  */
@@ -7013,12 +7011,17 @@ vectorizable_live_operation (gimple *stmt,
   tree lhs, lhs_type, bitsize, vec_bitsize;
   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
   int nunits = TYPE_VECTOR_SUBPARTS (vectype);
-  int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
+  int ncopies;
   gimple *use_stmt;
   auto_vec<tree> vec_oprnds;
 
   gcc_assert (STMT_VINFO_LIVE_P (stmt_info));
 
+  if (slp_node)
+    ncopies = 1;
+  else
+    ncopies = vect_get_num_copies (loop_vinfo, vectype);
+
   if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def)
     return false;
 

gcc/tree-vect-stmts.c

@@ -2038,7 +2038,7 @@ vectorizable_mask_load_store (gimple *stmt, gimple_stmt_iterator *gsi,
   if (slp_node != NULL)
     return false;
 
-  ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
+  ncopies = vect_get_num_copies (loop_vinfo, vectype);
   gcc_assert (ncopies >= 1);
 
   mask = gimple_call_arg (stmt, 2);
@@ -2472,7 +2472,7 @@ vectorizable_bswap (gimple *stmt, gimple_stmt_iterator *gsi,
   if (slp_node)
     ncopies = 1;
   else
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype);
 
   gcc_assert (ncopies >= 1);
 
@@ -2805,9 +2805,9 @@ vectorizable_call (gimple *gs, gimple_stmt_iterator *gsi, gimple **vec_stmt,
   if (slp_node)
     ncopies = 1;
   else if (modifier == NARROW && ifn == IFN_LAST)
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_out;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype_out);
   else
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_in;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype_in);
 
   /* Sanity check: make sure that at least one copy of the vectorized stmt
      needs to be generated.  */
@@ -4204,9 +4204,9 @@ vectorizable_conversion (gimple *stmt, gimple_stmt_iterator *gsi,
   if (slp_node)
     ncopies = 1;
   else if (modifier == NARROW)
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_out;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype_out);
   else
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_in;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype_in);
 
   /* Sanity check: make sure that at least one copy of the vectorized stmt
      needs to be generated.  */
@@ -4690,7 +4690,7 @@ vectorizable_assignment (gimple *stmt, gimple_stmt_iterator *gsi,
   if (slp_node)
     ncopies = 1;
   else
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype);
 
   gcc_assert (ncopies >= 1);
 
@@ -4948,7 +4948,7 @@ vectorizable_shift (gimple *stmt, gimple_stmt_iterator *gsi,
   if (slp_node)
     ncopies = 1;
   else
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_in;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype);
 
   gcc_assert (ncopies >= 1);
 
@@ -5379,7 +5379,7 @@ vectorizable_operation (gimple *stmt, gimple_stmt_iterator *gsi,
   if (slp_node)
     ncopies = 1;
   else
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_in;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype);
 
   gcc_assert (ncopies >= 1);
 
@@ -5718,7 +5718,7 @@ vectorizable_store (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt,
   if (slp)
     ncopies = 1;
   else
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype);
 
   gcc_assert (ncopies >= 1);
 
@@ -6713,7 +6713,7 @@ vectorizable_load (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt,
   if (slp)
     ncopies = 1;
   else
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype);
 
   gcc_assert (ncopies >= 1);
 
@@ -7926,13 +7926,12 @@ vectorizable_condition (gimple *stmt, gimple_stmt_iterator *gsi,
     return false;
 
   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
-  int nunits = TYPE_VECTOR_SUBPARTS (vectype);
   tree vectype1 = NULL_TREE, vectype2 = NULL_TREE;
 
   if (slp_node)
     ncopies = 1;
   else
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype);
 
   gcc_assert (ncopies >= 1);
   if (reduc_index && ncopies > 1)
@@ -8269,7 +8268,7 @@ vectorizable_comparison (gimple *stmt, gimple_stmt_iterator *gsi,
   if (slp_node)
     ncopies = 1;
   else
-    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
+    ncopies = vect_get_num_copies (loop_vinfo, vectype);
 
   gcc_assert (ncopies >= 1);
   if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def
@@ -8700,7 +8699,7 @@ vect_analyze_stmt (gimple *stmt, bool *need_to_vectorize, slp_tree node,
       need extra handling, except for vectorizable reductions.  */
   if (STMT_VINFO_LIVE_P (stmt_info)
       && STMT_VINFO_TYPE (stmt_info) != reduc_vec_info_type)
-    ok = vectorizable_live_operation (stmt, NULL, NULL, -1, NULL);
+    ok = vectorizable_live_operation (stmt, NULL, node, -1, NULL);
 
   if (!ok)
     {

gcc/tree-vectorizer.h

@@ -1076,6 +1076,20 @@ unlimited_cost_model (loop_p loop)
   return (flag_vect_cost_model == VECT_COST_MODEL_UNLIMITED);
 }
 
+/* Return the number of copies needed for loop vectorization when
+   a statement operates on vectors of type VECTYPE.  This is the
+   vectorization factor divided by the number of elements in
+   VECTYPE and is always known at compile time.  */
+
+static inline unsigned int
+vect_get_num_copies (loop_vec_info loop_vinfo, tree vectype)
+{
+  gcc_checking_assert (LOOP_VINFO_VECT_FACTOR (loop_vinfo)
+		       % TYPE_VECTOR_SUBPARTS (vectype) == 0);
+  return (LOOP_VINFO_VECT_FACTOR (loop_vinfo)
+	  / TYPE_VECTOR_SUBPARTS (vectype));
+}
+
 /* Source location */
 extern source_location vect_location;