[RFA] Fix pr67830, another type narrowing problem

	PR tree-optimization/67830
	* match.pd ((bit_and (plus/minus (convert @0) (convert @1)) mask)):
	Explicitly verify the mask has no bits outside the type of
	the innermost operands.

	PR tree-optimization/67830
	* gcc.dg/pr67830.c: New test.

From-SVN: r229267

gcc/ChangeLog

+2015-10-23  Jeff Law  <law@redhat.com>
+
+	PR tree-optimization/67830
+	* match.pd ((bit_and (plus/minus (convert @0) (convert @1)) mask)):
+	Explicitly verify the mask has no bits outside the type of
+	the innermost operands.
+
 2015-10-23  Gregor Richards  <gregor.richards@uwaterloo.ca>
 	    Szabolcs Nagy  <szabolcs.nagy@arm.com>
 

gcc/match.pd

@@ -2719,8 +2719,8 @@ along with GCC; see the file COPYING3.  If not see
        && types_match (@0, @1)
        && (tree_int_cst_min_precision (@4, TYPE_SIGN (TREE_TYPE (@0)))
 	   <= TYPE_PRECISION (TREE_TYPE (@0)))
-       && (TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))
-	   || tree_int_cst_sgn (@4) >= 0))
+       && (wi::bit_and (@4, wi::mask (TYPE_PRECISION (TREE_TYPE (@0)),
+			true, TYPE_PRECISION (type))) == 0))
    (if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0)))
     (with { tree ntype = TREE_TYPE (@0); }
      (convert (bit_and (op @0 @1) (convert:ntype @4))))

gcc/testsuite/ChangeLog

+2015-10-23  Jeff Law  <law@redhat.com>
+
+	PR tree-optimization/67830
+	* gcc.dg/pr67830.c: New test.
+
 2015-10-23  Jan Hubicka  <hubicka@ucw.cz>
 
 	* gcc.dg/tree-ssa/operand-equal-2.c: New testcase.

gcc/testsuite/gcc.dg/pr67830.c

+/* PR tree-optimization/67830 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+int a, b, *g, h;
+unsigned char c, d;
+
+int
+main ()
+{
+  int f, e = -2;
+  b = e;
+  g = &b;
+  h = c = a + 1;
+  f = d - h;
+  *g &= f;
+
+  if (b != -2)
+    __builtin_abort ();
+
+  return 0;
+}