c-common.c (warn_logical_operator): Use tree_int_cst_equal when comparing INTEGER_CSTs.

	* c-common.c (warn_logical_operator): Use tree_int_cst_equal
	when comparing INTEGER_CSTs.

	* c-c++-common/Wlogical-op-3.c: New test.

From-SVN: r224853

gcc/c-family/ChangeLog

+2015-06-23  Marek Polacek  <polacek@redhat.com>
+
+	* c-common.c (warn_logical_operator): Use tree_int_cst_equal
+	when comparing INTEGER_CSTs.
+
 2015-06-22  Pierre-Marie de Rodat  <derodat@adacore.com>
 
 	* c-ada-spec.h (cpp_operation): Add HAS_DEPENDENT_TEMPLATE_ARGS.

gcc/c-family/c-common.c

@@ -1838,7 +1838,8 @@ warn_logical_operator (location_t location, enum tree_code code, tree type,
 	}
       /* Or warn if the operands have exactly the same range, e.g.
 	 A > 0 && A > 0.  */
-      else if (low0 == low1 && high0 == high1)
+      else if (tree_int_cst_equal (low0, low1)
+	       && tree_int_cst_equal (high0, high1))
 	{
 	  if (or_op)
 	    warning_at (location, OPT_Wlogical_op,

gcc/testsuite/ChangeLog

+2015-06-23  Marek Polacek  <polacek@redhat.com>
+
+	* c-c++-common/Wlogical-op-3.c: New test.
+
 2015-06-23  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/66254

gcc/testsuite/c-c++-common/Wlogical-op-3.c

+/* { dg-do compile } */
+/* { dg-options "-Wlogical-op" } */
+
+void
+fn1 (int a)
+{
+  const int x = a;
+  if (x && x) {} /* { dg-warning "logical .and. of equal expressions" } */
+  if (x && (int) x) {} /* { dg-warning "logical .and. of equal expressions" } */
+  if ((int) x && x) {} /* { dg-warning "logical .and. of equal expressions" } */
+  if ((int) x && (int) x) {} /* { dg-warning "logical .and. of equal expressions" } */
+}
+
+void
+fn2 (int a)
+{
+  const int x = a;
+  if (x || x) {} /* { dg-warning "logical .or. of equal expressions" } */
+  if (x || (int) x) {} /* { dg-warning "logical .or. of equal expressions" } */
+  if ((int) x || x) {} /* { dg-warning "logical .or. of equal expressions" } */
+  if ((int) x || (int) x) {} /* { dg-warning "logical .or. of equal expressions" } */
+}