tree-ssa-sccvn.c (ao_ref_init_from_vn_reference): Use offset_int for offset and…

tree-ssa-sccvn.c (ao_ref_init_from_vn_reference): Use offset_int for offset and size computations instead of HOST_WIDE_INT.

	* tree-ssa-sccvn.c (ao_ref_init_from_vn_reference): Use offset_int for
	offset and size computations instead of HOST_WIDE_INT.

From-SVN: r227819

gcc/ChangeLog

+2015-09-16  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* tree-ssa-sccvn.c (ao_ref_init_from_vn_reference): Use offset_int for
+	offset and size computations instead of HOST_WIDE_INT.
+
 2015-09-16  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/67442

gcc/testsuite/ChangeLog

+2015-09-16  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/opt49.adb: New test.
+
 2015-09-16  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/67442

gcc/testsuite/gnat.dg/opt49.adb

+-- { dg-do run }
+-- { dg-options "-O -fstack-check" }
+
+procedure Opt49 is
+
+   function Ident (I : Integer) return Integer;
+   pragma No_Inline (Ident);
+
+   function Ident (I : Integer) return Integer is
+   begin
+     return I;
+   end;
+
+   Int_0 : Integer := Ident (0);
+   Int_4 : Integer := Ident (4);
+
+   A : array (-4 .. Int_4) of Integer;
+
+begin
+   A := (-4 , -3 , -2 , -1 , 100 , 1 , 2 , 3 , 4);
+   A (-4 .. Int_0) :=  A (Int_0 .. 4); 
+   if A /= (100 ,  1 ,  2 ,  3 ,  4  , 1 , 2 , 3 , 4) then
+      raise Program_Error;
+   end if;
+
+   A := (-4 , -3 , -2 , -1 , 100 ,  1 ,  2 ,  3 ,  4);
+   A (Int_0 .. 4) := A (-4 .. Int_0); 
+   if A /= (-4 , -3 , -2 , -1 , -4  , -3 , -2 , -1 , 100) then
+      raise Program_Error;
+   end if;
+end;

gcc/tree-ssa-sccvn.c

@@ -953,9 +953,9 @@ ao_ref_init_from_vn_reference (ao_ref *ref,
   unsigned i;
   tree base = NULL_TREE;
   tree *op0_p = &base;
-  HOST_WIDE_INT offset = 0;
-  HOST_WIDE_INT max_size;
-  HOST_WIDE_INT size = -1;
+  offset_int offset = 0;
+  offset_int max_size;
+  offset_int size = -1;
   tree size_tree = NULL_TREE;
   alias_set_type base_alias_set = -1;
 
@@ -971,15 +971,11 @@ ao_ref_init_from_vn_reference (ao_ref *ref,
       if (mode == BLKmode)
 	size_tree = TYPE_SIZE (type);
       else
-        size = GET_MODE_BITSIZE (mode);
-    }
-  if (size_tree != NULL_TREE)
-    {
-      if (!tree_fits_uhwi_p (size_tree))
-	size = -1;
-      else
-	size = tree_to_uhwi (size_tree);
+	size = int (GET_MODE_BITSIZE (mode));
     }
+  if (size_tree != NULL_TREE
+      && TREE_CODE (size_tree) == INTEGER_CST)
+    size = wi::to_offset (size_tree);
 
   /* Initially, maxsize is the same as the accessed element size.
      In the following it will only grow (or become -1).  */
@@ -1034,7 +1030,7 @@ ao_ref_init_from_vn_reference (ao_ref *ref,
 
 	/* And now the usual component-reference style ops.  */
 	case BIT_FIELD_REF:
-	  offset += tree_to_shwi (op->op1);
+	  offset += wi::to_offset (op->op1);
 	  break;
 
 	case COMPONENT_REF:
@@ -1043,15 +1039,16 @@ ao_ref_init_from_vn_reference (ao_ref *ref,
 	    /* We do not have a complete COMPONENT_REF tree here so we
 	       cannot use component_ref_field_offset.  Do the interesting
 	       parts manually.  */
+	    tree this_offset = DECL_FIELD_OFFSET (field);
 
-	    if (op->op1
-		|| !tree_fits_uhwi_p (DECL_FIELD_OFFSET (field)))
+	    if (op->op1 || TREE_CODE (this_offset) != INTEGER_CST)
 	      max_size = -1;
 	    else
 	      {
-		offset += (tree_to_uhwi (DECL_FIELD_OFFSET (field))
-			   * BITS_PER_UNIT);
-		offset += TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field));
+		offset_int woffset = wi::lshift (wi::to_offset (this_offset),
+						 LOG2_BITS_PER_UNIT);
+		woffset += wi::to_offset (DECL_FIELD_BIT_OFFSET (field));
+		offset += woffset;
 	      }
 	    break;
 	  }
@@ -1059,17 +1056,18 @@ ao_ref_init_from_vn_reference (ao_ref *ref,
 	case ARRAY_RANGE_REF:
 	case ARRAY_REF:
 	  /* We recorded the lower bound and the element size.  */
-	  if (!tree_fits_shwi_p (op->op0)
-	      || !tree_fits_shwi_p (op->op1)
-	      || !tree_fits_shwi_p (op->op2))
+	  if (TREE_CODE (op->op0) != INTEGER_CST
+	      || TREE_CODE (op->op1) != INTEGER_CST
+	      || TREE_CODE (op->op2) != INTEGER_CST)
 	    max_size = -1;
 	  else
 	    {
-	      HOST_WIDE_INT hindex = tree_to_shwi (op->op0);
-	      hindex -= tree_to_shwi (op->op1);
-	      hindex *= tree_to_shwi (op->op2);
-	      hindex *= BITS_PER_UNIT;
-	      offset += hindex;
+	      offset_int woffset
+		= wi::sext (wi::to_offset (op->op0) - wi::to_offset (op->op1),
+			    TYPE_PRECISION (TREE_TYPE (op->op0)));
+	      woffset *= wi::to_offset (op->op2);
+	      woffset = wi::lshift (woffset, LOG2_BITS_PER_UNIT);
+	      offset += woffset;
 	    }
 	  break;
 
@@ -1102,9 +1100,6 @@ ao_ref_init_from_vn_reference (ao_ref *ref,
 
   ref->ref = NULL_TREE;
   ref->base = base;
-  ref->offset = offset;
-  ref->size = size;
-  ref->max_size = max_size;
   ref->ref_alias_set = set;
   if (base_alias_set != -1)
     ref->base_alias_set = base_alias_set;
@@ -1113,6 +1108,30 @@ ao_ref_init_from_vn_reference (ao_ref *ref,
   /* We discount volatiles from value-numbering elsewhere.  */
   ref->volatile_p = false;
 
+  if (!wi::fits_shwi_p (size) || wi::neg_p (size))
+    {
+      ref->offset = 0;
+      ref->size = -1;
+      ref->max_size = -1;
+      return true;
+    }
+
+  ref->size = size.to_shwi ();
+
+  if (!wi::fits_shwi_p (offset))
+    {
+      ref->offset = 0;
+      ref->max_size = -1;
+      return true;
+    }
+
+  ref->offset = offset.to_shwi ();
+
+  if (!wi::fits_shwi_p (max_size) || wi::neg_p (max_size))
+    ref->max_size = -1;
+  else
+    ref->max_size = max_size.to_shwi ();
+
   return true;
 }