re PR tree-optimization/51721 (-Warray-bounds false positives and inconsistencies)

PR tree-optimization/51721
	* tree-vrp.c (register_edge_assert_for_2): Add asserts for unsvar
	if (int) unsvar cmp CST.

	* gcc.dg/tree-ssa/vrp64.c: New test.

From-SVN: r185222

gcc/ChangeLog

@@ -1,3 +1,9 @@
+2012-03-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/51721
+	* tree-vrp.c (register_edge_assert_for_2): Add asserts for unsvar
+	if (int) unsvar cmp CST.
+
 2012-03-12  Richard Guenther  <rguenther@suse.de>
 
         * tree-sra.c (create_access_replacement): Only rename the

gcc/testsuite/ChangeLog

@@ -1,5 +1,8 @@
 2012-03-12  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/51721
+	* gcc.dg/tree-ssa/vrp64.c: New test.
+
 	PR tree-optimization/52533
 	* gcc.c-torture/compile/pr52533.c: New test.
 

gcc/testsuite/gcc.dg/tree-ssa/vrp64.c

@@ -0,0 +1,152 @@
+/* PR tree-optimization/51721 */
+/* { dg-do link } */
+/* { dg-options "-O2" } */
+
+extern void link_error (void);
+
+#define BITSM1 (sizeof (int) * __CHAR_BIT__ - 1)
+
+void
+f1 (unsigned int s)
+{
+  if (s >> BITSM1 != 0)
+    {
+      if (s == 0 || s == 5 || s == __INT_MAX__)
+	link_error ();
+    }
+  else
+    {
+      if (s == 1U + __INT_MAX__ || s == 6U + __INT_MAX__ || s == -1U)
+	link_error ();
+    }
+}
+
+void
+f2 (int s)
+{
+  if (s >> BITSM1 == 0)
+    {
+      if (s == -1 || s == -5 || s == -__INT_MAX__ - 1)
+	link_error ();
+    }
+  else
+    {
+      if (s == 0 || s == 5 || s == __INT_MAX__)
+	link_error ();
+    }
+}
+
+void
+f3 (unsigned int s)
+{
+  if ((s & (1U << BITSM1)) != 0)
+    {
+      if (s == 0 || s == 5 || s == __INT_MAX__)
+	link_error ();
+    }
+  else
+    {
+      if (s == 1U + __INT_MAX__ || s == 6U + __INT_MAX__ || s == -1U)
+	link_error ();
+    }
+}
+
+void
+f4 (int s)
+{
+  if ((s & (1U << BITSM1)) == 0)
+    {
+      if (s == -1 || s == -5 || s == -__INT_MAX__ - 1)
+	link_error ();
+    }
+  else
+    {
+      if (s == 0 || s == 5 || s == __INT_MAX__)
+	link_error ();
+    }
+}
+
+void
+f5 (unsigned int s)
+{
+  if ((int) s < 0)
+    {
+      if (s == 0 || s == 5 || s == __INT_MAX__)
+	link_error ();
+    }
+  else
+    {
+      if (s == 1U + __INT_MAX__ || s == 6U + __INT_MAX__ || s == -1U)
+	link_error ();
+    }
+}
+
+void
+f6 (unsigned int s)
+{
+  if ((int) s < 4)
+    {
+      if (s == 4 || s == 6 || s == __INT_MAX__)
+	link_error ();
+    }
+  else
+    {
+      if (s == 1U + __INT_MAX__ || s == 6U + __INT_MAX__ || s == -1U
+	  || s == 3 || s == 0)
+	link_error ();
+    }
+}
+
+void
+f7 (unsigned int s)
+{
+  if ((int) s <= -7)
+    {
+      if (s == -6U || s == -1U || s == 0 || s == 4 || s == 6 || s == __INT_MAX__)
+	link_error ();
+    }
+  else
+    {
+      if (s == 1U + __INT_MAX__ || s == 6U + __INT_MAX__ || s == -9U
+	  || s == -7U)
+	link_error ();
+    }
+}
+
+void
+f8 (unsigned int s)
+{
+  if ((int) s >= 4)
+    {
+      if (s == 1U + __INT_MAX__ || s == 6U + __INT_MAX__ || s == -1U
+	  || s == 3 || s == 0)
+	link_error ();
+    }
+  else
+    {
+      if (s == 4 || s == 6 || s == __INT_MAX__)
+	link_error ();
+    }
+}
+
+void
+f9 (unsigned int s)
+{
+  if ((int) s > -7)
+    {
+      if (s == 1U + __INT_MAX__ || s == 6U + __INT_MAX__ || s == -9U
+	  || s == -7U)
+	link_error ();
+    }
+  else
+    {
+      if (s == -6U || s == -1U || s == 0 || s == 4 || s == 6 || s == __INT_MAX__)
+	link_error ();
+    }
+}
+
+int
+main ()
+{
+  return 0;
+}

gcc/tree-vrp.c

@@ -4462,8 +4462,6 @@ register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi,
 	}
     }
 
-  /* Similarly add asserts for NAME == CST and NAME being defined as
-     NAME = NAME2 >> CST2.  */
   if (TREE_CODE_CLASS (comp_code) == tcc_comparison
       && TREE_CODE (val) == INTEGER_CST)
     {
@@ -4473,7 +4471,60 @@ register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi,
       double_int mask = double_int_zero;
       unsigned int prec = TYPE_PRECISION (TREE_TYPE (val));
 
-      /* Extract CST2 from the right shift.  */
+      /* Add asserts for NAME cmp CST and NAME being defined
+	 as NAME = (int) NAME2.  */
+      if (!TYPE_UNSIGNED (TREE_TYPE (val))
+	  && (comp_code == LE_EXPR || comp_code == LT_EXPR
+	      || comp_code == GT_EXPR || comp_code == GE_EXPR)
+	  && gimple_assign_cast_p (def_stmt))
+	{
+	  name2 = gimple_assign_rhs1 (def_stmt);
+	  if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))
+	      && INTEGRAL_TYPE_P (TREE_TYPE (name2))
+	      && TYPE_UNSIGNED (TREE_TYPE (name2))
+	      && prec == TYPE_PRECISION (TREE_TYPE (name2))
+	      && (comp_code == LE_EXPR || comp_code == GT_EXPR
+		  || !tree_int_cst_equal (val,
+					  TYPE_MIN_VALUE (TREE_TYPE (val))))
+	      && live_on_edge (e, name2)
+	      && !has_single_use (name2))
+	    {
+	      tree tmp, cst;
+	      enum tree_code new_comp_code = comp_code;
+
+	      cst = fold_convert (TREE_TYPE (name2),
+				  TYPE_MIN_VALUE (TREE_TYPE (val)));
+	      /* Build an expression for the range test.  */
+	      tmp = build2 (PLUS_EXPR, TREE_TYPE (name2), name2, cst);
+	      cst = fold_build2 (PLUS_EXPR, TREE_TYPE (name2), cst,
+				 fold_convert (TREE_TYPE (name2), val));
+	      if (comp_code == LT_EXPR || comp_code == GE_EXPR)
+		{
+		  new_comp_code = comp_code == LT_EXPR ? LE_EXPR : GT_EXPR;
+		  cst = fold_build2 (MINUS_EXPR, TREE_TYPE (name2), cst,
+				     build_int_cst (TREE_TYPE (name2), 1));
+		}
+
+	      if (dump_file)
+		{
+		  fprintf (dump_file, "Adding assert for ");
+		  print_generic_expr (dump_file, name2, 0);
+		  fprintf (dump_file, " from ");
+		  print_generic_expr (dump_file, tmp, 0);
+		  fprintf (dump_file, "\n");
+		}
+
+	      register_new_assert_for (name2, tmp, new_comp_code, cst, NULL,
+				       e, bsi);
+
+	      retval = true;
+	    }
+	}
+
+      /* Add asserts for NAME cmp CST and NAME being defined as
+	 NAME = NAME2 >> CST2.
+
+	 Extract CST2 from the right shift.  */
       if (is_gimple_assign (def_stmt)
 	  && gimple_assign_rhs_code (def_stmt) == RSHIFT_EXPR)
 	{
@@ -4491,7 +4542,6 @@ register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi,
 	      val2 = fold_binary (LSHIFT_EXPR, TREE_TYPE (val), val, cst2);
 	    }
 	}
-
       if (val2 != NULL_TREE
 	  && TREE_CODE (val2) == INTEGER_CST
 	  && simple_cst_equal (fold_build2 (RSHIFT_EXPR,