match.pd ((convert (op:s (convert@2 @0) (convert?@3 @1)))): Add support for…

match.pd ((convert (op:s (convert@2 @0) (convert?@3 @1)))): Add support for constant operand for OP.

	* match.pd ((convert (op:s (convert@2 @0) (convert?@3 @1)))): Add
	support for constant operand for OP.

	gcc/testsuite
	* gcc.dg/fold-narrowbopcst-1.c: New test.

From-SVN: r241624

gcc/ChangeLog

+2016-10-27  Bin Cheng  <bin.cheng@arm.com>
+
+	* match.pd ((convert (op:s (convert@2 @0) (convert?@3 @1)))): Add
+	support for constant operand for OP.
+
 2016-10-27  Jakub Jelinek  <jakub@redhat.com>
 
 	* dwarf2out.c (gen_member_die): Only reparent_child instead of

gcc/match.pd

@@ -3277,7 +3277,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
    operation and convert the result to the desired type.  */
 (for op (plus minus)
   (simplify
-    (convert (op:s (convert@2 @0) (convert@3 @1)))
+    (convert (op:s (convert@2 @0) (convert?@3 @1)))
     (if (INTEGRAL_TYPE_P (type)
 	 /* We check for type compatibility between @0 and @1 below,
 	    so there's no need to check that @1/@3 are integral types.  */
@@ -3293,12 +3293,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 	 && TYPE_PRECISION (type) == GET_MODE_PRECISION (TYPE_MODE (type))
 	 /* The inner conversion must be a widening conversion.  */
 	 && TYPE_PRECISION (TREE_TYPE (@2)) > TYPE_PRECISION (TREE_TYPE (@0))
-	 && types_match (@0, @1)
-	 && types_match (@0, type))
+	 && types_match (@0, type)
+	 && (types_match (@0, @1)
+	     /* Or the second operand is const integer or converted const
+		integer from valueize.  */
+	     || TREE_CODE (@1) == INTEGER_CST))
       (if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0)))
-	(convert (op @0 @1))
+	(op @0 (convert @1))
 	(with { tree utype = unsigned_type_for (TREE_TYPE (@0)); }
-	 (convert (op (convert:utype @0) (convert:utype @1))))))))
+	 (convert (op (convert:utype @0)
+		      (convert:utype @1))))))))
 
 /* This is another case of narrowing, specifically when there's an outer
    BIT_AND_EXPR which masks off bits outside the type of the innermost

gcc/testsuite/ChangeLog

+2016-10-27  Bin Cheng  <bin.cheng@arm.com>
+
+	* gcc.dg/fold-narrowbopcst-1.c: New test.
+
 2016-10-27  Fritz Reese <fritzoreese@gmail.com>
 
 	* gfortran.dg/dec_io_5.f90: Don't use "test.txt", and use

gcc/testsuite/gcc.dg/fold-narrowbopcst-1.c

+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-optimized" } */
+
+int foo1 (unsigned char a[], unsigned int x)
+{
+  unsigned int i;
+  for (i = 0; i < 1000; i++)
+    {
+      x = a[i];
+      a[i] = (unsigned char)(x >= 100 ? x - 100 : 0);
+    }
+  return x;
+}
+/* { dg-final { scan-tree-dump " = _.* \\+ 156" "optimized" } } */