match.pd: Revert a * (1 << b) relaxation.

2016-08-31  Marc Glisse  <marc.glisse@inria.fr>

	PR tree-optimization/73714
gcc/
	* match.pd (a * (1 << b)): Revert change from 2016-05-23.
gcc/testsuite/
	* gcc.dg/tree-ssa/pr73714.c: New test.

From-SVN: r239902

gcc/ChangeLog

+2016-08-31  Marc Glisse  <marc.glisse@inria.fr>
+
+	PR tree-optimization/73714
+	* match.pd (a * (1 << b)): Revert change from 2016-05-23.
+
 2016-08-31  David Malcolm  <dmalcolm@redhat.com>
 
 	* selftest.c: Move "namespace selftest {" to top of file,

gcc/match.pd

@@ -468,8 +468,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 (simplify
  (mult:c @0 (convert? (lshift integer_onep@1 @2)))
   (if (! FLOAT_TYPE_P (type)
-       && (element_precision (type) <= element_precision (TREE_TYPE (@1))
-	   || TYPE_UNSIGNED (TREE_TYPE (@1))))
+       && tree_nop_conversion_p (type, TREE_TYPE (@1)))
    (lshift @0 @2)))
 
 /* Fold (C1/X)*C2 into (C1*C2)/X.  */

gcc/testsuite/ChangeLog

+2016-08-31  Marc Glisse  <marc.glisse@inria.fr>
+
+	PR tree-optimization/73714
+	* gcc.dg/tree-ssa/pr73714.c: New test.
+
 2016-08-31  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR libgfortran/77393

gcc/testsuite/gcc.dg/tree-ssa/pr73714.c

+/* { dg-do compile { target lp64 } } */
+/* { dg-options "-O2 -fdump-tree-optimized-raw" } */
+
+int f(int a, int b){
+  return a * (int)(1L << b);
+}
+
+/* { dg-final { scan-tree-dump "mult_expr" "optimized" } } */