re PR tree-optimization/53773 (Vectorizer generates non-canonical multiplies)

gcc:

2012-07-31  Bill Schmidt  <wschmidt@linux.ibm.com>

	PR tree-optimization/53773
	* tree-vectorizer.h (struct _loop_vec_info): Add operands_swapped.
	(LOOP_VINFO_OPERANDS_SWAPPED): New macro.
	* tree-vect-loop.c (new_loop_vec_info): Initialize
	LOOP_VINFO_OPERANDS_SWAPPED field.
	(destroy_loop_vec_info): Restore canonical form.
	(vect_is_slp_reduction): Set LOOP_VINFO_OPERANDS_SWAPPED field.
	(vect_is_simple_reduction_1): Likewise.

gcc/testsuite:

2012-07-31  Bill Schmidt  <wschmidt@linux.ibm.com>

	PR tree-optimization/53773
	* testsuite/gcc.dg/vect/pr53773.c: New test.

From-SVN: r190007

gcc/ChangeLog

@@ -1,3 +1,14 @@
+2012-07-31  Bill Schmidt  <wschmidt@linux.ibm.com>
+
+	PR tree-optimization/53773
+	* tree-vectorizer.h (struct _loop_vec_info): Add operands_swapped.
+	(LOOP_VINFO_OPERANDS_SWAPPED): New macro.
+	* tree-vect-loop.c (new_loop_vec_info): Initialize
+	LOOP_VINFO_OPERANDS_SWAPPED field.
+	(destroy_loop_vec_info): Restore canonical form.
+	(vect_is_slp_reduction): Set LOOP_VINFO_OPERANDS_SWAPPED field.
+	(vect_is_simple_reduction_1): Likewise.
+
 2012-07-31  Steven Bosscher  <steven@gcc.gnu.org>
 
 	* sched-vis.c (dump_insn_slim): Print print_rtx_head at the

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2012-07-31  Bill Schmidt  <wschmidt@linux.ibm.com>
+
+	PR tree-optimization/53773
+	* testsuite/gcc.dg/vect/pr53773.c: New test.
+
 2012-07-31  Nick Clifton  <nickc@redhat.com>
 
 	* gcc.dg/stack-usage-1.c (SIZE): Define for FRV.

gcc/testsuite/gcc.dg/vect/pr53773.c

@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+
+int
+foo (int integral, int decimal, int power_ten)
+{
+  while (power_ten > 0)
+    {
+      integral *= 10;
+      decimal *= 10;
+      power_ten--;
+    }
+
+  return integral+decimal;
+}
+
+/* Two occurrences in annotations, two in code.  */
+/* { dg-final { scan-tree-dump-times "\\* 10" 4 "vect" } } */
+/* { dg-final { cleanup-tree-dump "vect" } } */
+

gcc/tree-vect-loop.c

@@ -853,6 +853,7 @@ new_loop_vec_info (struct loop *loop)
   LOOP_VINFO_PEELING_HTAB (res) = NULL;
   LOOP_VINFO_TARGET_COST_DATA (res) = init_cost (loop);
   LOOP_VINFO_PEELING_FOR_GAPS (res) = false;
+  LOOP_VINFO_OPERANDS_SWAPPED (res) = false;
 
   return res;
 }
@@ -873,6 +874,7 @@ destroy_loop_vec_info (loop_vec_info loop_vinfo, bool clean_stmts)
   int j;
   VEC (slp_instance, heap) *slp_instances;
   slp_instance instance;
+  bool swapped;
 
   if (!loop_vinfo)
     return;
@@ -881,6 +883,7 @@ destroy_loop_vec_info (loop_vec_info loop_vinfo, bool clean_stmts)
 
   bbs = LOOP_VINFO_BBS (loop_vinfo);
   nbbs = loop->num_nodes;
+  swapped = LOOP_VINFO_OPERANDS_SWAPPED (loop_vinfo);
 
   if (!clean_stmts)
     {
@@ -905,6 +908,22 @@ destroy_loop_vec_info (loop_vec_info loop_vinfo, bool clean_stmts)
       for (si = gsi_start_bb (bb); !gsi_end_p (si); )
         {
           gimple stmt = gsi_stmt (si);
+
+	  /* We may have broken canonical form by moving a constant
+	     into RHS1 of a commutative op.  Fix such occurrences.  */
+	  if (swapped && is_gimple_assign (stmt))
+	    {
+	      enum tree_code code = gimple_assign_rhs_code (stmt);
+
+	      if ((code == PLUS_EXPR
+		   || code == POINTER_PLUS_EXPR
+		   || code == MULT_EXPR)
+		  && CONSTANT_CLASS_P (gimple_assign_rhs1 (stmt)))
+		swap_tree_operands (stmt,
+				    gimple_assign_rhs1_ptr (stmt),
+				    gimple_assign_rhs2_ptr (stmt));
+	    }
+
 	  /* Free stmt_vec_info.  */
 	  free_stmt_vec_info (stmt);
           gsi_next (&si);
@@ -1920,6 +1939,9 @@ vect_is_slp_reduction (loop_vec_info loop_info, gimple phi, gimple first_stmt)
 	 		          gimple_assign_rhs1_ptr (next_stmt),
                                   gimple_assign_rhs2_ptr (next_stmt));
 	      update_stmt (next_stmt);
+
+	      if (CONSTANT_CLASS_P (gimple_assign_rhs1 (next_stmt)))
+		LOOP_VINFO_OPERANDS_SWAPPED (loop_info) = true;
 	    }
 	  else
 	    return false;
@@ -2324,6 +2346,9 @@ vect_is_simple_reduction_1 (loop_vec_info loop_info, gimple phi,
 
           swap_tree_operands (def_stmt, gimple_assign_rhs1_ptr (def_stmt),
  			      gimple_assign_rhs2_ptr (def_stmt));
+
+	  if (CONSTANT_CLASS_P (gimple_assign_rhs1 (def_stmt)))
+	    LOOP_VINFO_OPERANDS_SWAPPED (loop_info) = true;
         }
       else
         {

gcc/tree-vectorizer.h

@@ -296,6 +296,12 @@ typedef struct _loop_vec_info {
      this.  */
   bool peeling_for_gaps;
 
+  /* Reductions are canonicalized so that the last operand is the reduction
+     operand.  If this places a constant into RHS1, this decanonicalizes
+     GIMPLE for other phases, so we must track when this has occurred and
+     fix it up.  */
+  bool operands_swapped;
+
 } *loop_vec_info;
 
 /* Access Functions.  */
@@ -326,6 +332,7 @@ typedef struct _loop_vec_info {
 #define LOOP_VINFO_PEELING_HTAB(L)         (L)->peeling_htab
 #define LOOP_VINFO_TARGET_COST_DATA(L)     (L)->target_cost_data
 #define LOOP_VINFO_PEELING_FOR_GAPS(L)     (L)->peeling_for_gaps
+#define LOOP_VINFO_OPERANDS_SWAPPED(L)     (L)->operands_swapped
 
 #define LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT(L) \
 VEC_length (gimple, (L)->may_misalign_stmts) > 0