tree-scalar-evolution (interpret_rhs_expr): generate chrec for array reference…

tree-scalar-evolution (interpret_rhs_expr): generate chrec for array reference and component reference.

2012-03-09  Jiangning Liu  <jiangning.liu@arm.com>                                                        

	* tree-scalar-evolution (interpret_rhs_expr): generate chrec for
	array reference and component reference.
	(analyze_scalar_evolution_for_address_of): New.

2012-03-09  Jiangning Liu  <jiangning.liu@arm.com>                                                        

	* gcc.dg/tree-ssa/scev-3.c: New.
	* gcc.dg/tree-ssa/scev-4.c: New.

From-SVN: r185129

gcc/ChangeLog

+2012-03-09  Jiangning Liu  <jiangning.liu@arm.com>
+
+	* tree-scalar-evolution (interpret_rhs_expr): generate chrec for
+	array reference and component reference.
+	(analyze_scalar_evolution_for_address_of): New.
+
 2012-03-08  Jie Zhang  <jzhang918@gmail.com>
 
 	PR target/49862

gcc/testsuite/ChangeLog

+2012-03-09  Jiangning Liu  <jiangning.liu@arm.com>
+
+	* gcc.dg/tree-ssa/scev-3.c: New.
+	* gcc.dg/tree-ssa/scev-4.c: New.
+
 2012-03-08  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/52469

gcc/testsuite/gcc.dg/tree-ssa/scev-3.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+int *a_p;
+int a[1000];
+
+f(int k)
+{
+	int i;
+
+	for (i=k; i<1000; i+=k) {
+		a_p = &a[i];
+		*a_p = 100;
+        }
+}
+
+/* { dg-final { scan-tree-dump-times "&a" 1 "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/testsuite/gcc.dg/tree-ssa/scev-4.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+typedef struct {
+	int x;
+	int y;
+} S;
+
+int *a_p;
+S a[1000];
+
+f(int k)
+{
+	int i;
+
+	for (i=k; i<1000; i+=k) {
+		a_p = &a[i].y;
+		*a_p = 100;
+        }
+}
+
+/* { dg-final { scan-tree-dump-times "&a" 1 "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/tree-scalar-evolution.c

@@ -266,6 +266,8 @@ along with GCC; see the file COPYING3.  If not see
 #include "params.h"
 
 static tree analyze_scalar_evolution_1 (struct loop *, tree, tree);
+static tree analyze_scalar_evolution_for_address_of (struct loop *loop,
+						     tree var);
 
 /* The cached information about an SSA name VAR, claiming that below
    basic block INSTANTIATED_BELOW, the value of VAR can be expressed
@@ -1712,16 +1714,59 @@ interpret_rhs_expr (struct loop *loop, gimple at_stmt,
   switch (code)
     {
     case ADDR_EXPR:
-      /* Handle &MEM[ptr + CST] which is equivalent to POINTER_PLUS_EXPR.  */
-      if (TREE_CODE (TREE_OPERAND (rhs1, 0)) != MEM_REF)
-	{
-	  res = chrec_dont_know;
-	  break;
-	}
+      if (TREE_CODE (TREE_OPERAND (rhs1, 0)) == MEM_REF
+	  || handled_component_p (TREE_OPERAND (rhs1, 0)))
+        {
+	  enum machine_mode mode;
+	  HOST_WIDE_INT bitsize, bitpos;
+	  int unsignedp;
+	  int volatilep = 0;
+	  tree base, offset;
+	  tree chrec3;
+	  tree unitpos;
+
+	  base = get_inner_reference (TREE_OPERAND (rhs1, 0),
+				      &bitsize, &bitpos, &offset,
+				      &mode, &unsignedp, &volatilep, false);
+
+	  if (TREE_CODE (base) == MEM_REF)
+	    {
+	      rhs2 = TREE_OPERAND (base, 1);
+	      rhs1 = TREE_OPERAND (base, 0);
+
+	      chrec1 = analyze_scalar_evolution (loop, rhs1);
+	      chrec2 = analyze_scalar_evolution (loop, rhs2);
+	      chrec1 = chrec_convert (type, chrec1, at_stmt);
+	      chrec2 = chrec_convert (TREE_TYPE (rhs2), chrec2, at_stmt);
+	      res = chrec_fold_plus (type, chrec1, chrec2);
+	    }
+	  else
+	    {
+	      chrec1 = analyze_scalar_evolution_for_address_of (loop, base);
+	      chrec1 = chrec_convert (type, chrec1, at_stmt);
+	      res = chrec1;
+	    }
+
+	  if (offset != NULL_TREE)
+	    {
+	      chrec2 = analyze_scalar_evolution (loop, offset);
+	      chrec2 = chrec_convert (TREE_TYPE (offset), chrec2, at_stmt);
+	      res = chrec_fold_plus (type, res, chrec2);
+	    }
+
+	  if (bitpos != 0)
+	    {
+	      gcc_assert ((bitpos % BITS_PER_UNIT) == 0);
 
-      rhs2 = TREE_OPERAND (TREE_OPERAND (rhs1, 0), 1);
-      rhs1 = TREE_OPERAND (TREE_OPERAND (rhs1, 0), 0);
-      /* Fall through.  */
+	      unitpos = size_int_kind (bitpos / BITS_PER_UNIT, SIZETYPE);
+	      chrec3 = analyze_scalar_evolution (loop, unitpos);
+	      chrec3 = chrec_convert (TREE_TYPE (unitpos), chrec3, at_stmt);
+	      res = chrec_fold_plus (type, res, chrec3);
+	    }
+        }
+      else
+	res = chrec_dont_know;
+      break;
 
     case POINTER_PLUS_EXPR:
       chrec1 = analyze_scalar_evolution (loop, rhs1);
@@ -1961,6 +2006,14 @@ analyze_scalar_evolution (struct loop *loop, tree var)
   return res;
 }
 
+/* Analyzes and returns the scalar evolution of VAR address in LOOP.  */
+
+static tree
+analyze_scalar_evolution_for_address_of (struct loop *loop, tree var)
+{
+  return analyze_scalar_evolution (loop, build_fold_addr_expr (var));
+}
+
 /* Analyze scalar evolution of use of VERSION in USE_LOOP with respect to
    WRTO_LOOP (which should be a superloop of USE_LOOP)