tree.def: Document restriction on {L|R}SHIFT_EXPR's second argument.

2001-07-19  Toon Moene  <toon@moene.indiv.nluug.nl>

	* tree.def: Document restriction on {L|R}SHIFT_EXPR's second argument.
	* doc/tree.texi: Ditto.
	* f/com.c (ffecom_expr_intrinsic_): Cope with it.

From-SVN: r44156

gcc/ChangeLog

+2001-07-19  Toon Moene  <toon@moene.indiv.nluug.nl>
+
+	* tree.def: Document restriction on {L|R}SHIFT_EXPR's second argument.
+	* doc/tree.texi: Ditto.
+
 2001-07-19  Mark Kettenis  <kettenis@wins.uva.nl>
 	    Jakub Jelinek  <jakub@redhat.com>
 

gcc/doc/c-tree.texi

@@ -2003,6 +2003,9 @@ second operand is an expression for the number of bits by which to
 shift.  Right shift should be treated as arithmetic, i.e., the
 high-order bits should be zero-filled when the expression has unsigned
 type and filled with the sign bit when the expression has signed type.
+Note that the result is undefined if the second operand is larger
+than the first operand's type size.
+
 
 @item BIT_IOR_EXPR
 @itemx BIT_XOR_EXPR

gcc/f/ChangeLog

+2001-07-19  Toon Moene  <toon@moene.indiv.nluug.nl>
+
+	* f/com.c (ffecom_expr_intrinsic_): Deal (correctly) with
+	{L|R}SHIFT_EXPR not working when shift > size of type.
+
 2001-07-17  Toon Moene  <toon@moene.indiv.nluug.nl>
 
 	* com.c (lang_print_error_function): Argument context

gcc/f/com.c

@@ -4573,8 +4573,10 @@ ffecom_expr_intrinsic_ (ffebld expr, tree dest_tree,
 	expr_tree
 	  = ffecom_3 (COND_EXPR, tree_type,
 		      ffecom_truth_value
-		      (ffecom_2 (NE_EXPR, integer_type_node,
-				 arg2_tree,
+		      (ffecom_2 (LT_EXPR, integer_type_node,
+				 ffecom_1 (ABS_EXPR,
+					   integer_type_node,
+					   arg2_tree),
 				 TYPE_SIZE (uns_type))),
 		      expr_tree,
 		      convert (tree_type, integer_zero_node));

gcc/tree.def

@@ -617,7 +617,9 @@ DEFTREECODE (FFS_EXPR, "ffs_expr", '1', 1)
    Shift means logical shift if done on an
    unsigned type, arithmetic shift if done on a signed type.
    The second operand is the number of bits to
-   shift by; it need not be the same type as the first operand and result.  */
+   shift by; it need not be the same type as the first operand and result.
+   Note that the result is undefined if the second operand is larger
+   than the first operand's type size.  */
 DEFTREECODE (LSHIFT_EXPR, "lshift_expr", '2', 2)
 DEFTREECODE (RSHIFT_EXPR, "rshift_expr", '2', 2)
 DEFTREECODE (LROTATE_EXPR, "lrotate_expr", '2', 2)