re PR c/44828 (possible integer wrong code bug)

2010-07-06  Richard Guenther  <rguenther@suse.de>

	PR middle-end/44828
	* convert.c (convert_to_integer): Watch out for overflowing
	MULT_EXPR as well.

	* gcc.c-torture/execute/pr44828.c: New testcase.

From-SVN: r161869

gcc/ChangeLog

+2010-07-06  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/44828
+	* convert.c (convert_to_integer): Watch out for overflowing
+	MULT_EXPR as well.
+
 2010-07-05  Jan Hubicka  <jh@suse.cz>
 
 	* lto-streamer.c (write_symbol_vec): Rename to ...

gcc/convert.c

@@ -768,13 +768,19 @@ convert_to_integer (tree type, tree expr)
 			|| ex_form == LSHIFT_EXPR
 			/* If we have !flag_wrapv, and either ARG0 or
 			   ARG1 is of a signed type, we have to do
-			   PLUS_EXPR or MINUS_EXPR in an unsigned
-			   type.  Otherwise, we would introduce
+			   PLUS_EXPR, MINUS_EXPR or MULT_EXPR in an unsigned
+			   type in case the operation in outprec precision
+			   could overflow.  Otherwise, we would introduce
 			   signed-overflow undefinedness.  */
 			|| ((!TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0))
 			     || !TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1)))
+			    && ((TYPE_PRECISION (TREE_TYPE (arg0)) * 2u
+				 > outprec)
+				|| (TYPE_PRECISION (TREE_TYPE (arg1)) * 2u
+				    > outprec))
 			    && (ex_form == PLUS_EXPR
-				|| ex_form == MINUS_EXPR)))
+				|| ex_form == MINUS_EXPR
+				|| ex_form == MULT_EXPR)))
 		      typex = unsigned_type_for (typex);
 		    else
 		      typex = signed_type_for (typex);

gcc/testsuite/ChangeLog

+2010-07-06  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/44828
+	* gcc.c-torture/execute/pr44828.c: New testcase.
+
 2010-07-06  Shujing Zhao  <pearly.zhao@oracle.com>
 
 	* g++.dg/warn/noeffect2.C: Adjust expected warning.

gcc/testsuite/gcc.c-torture/execute/pr44828.c

+extern void abort (void);
+
+static char
+foo (char si1, char si2)
+{
+  return si1 * si2;
+}
+
+int a = 0x105F61CA;
+
+int
+main (void)
+{
+  int b = 0x0332F5C8;
+  if (foo (b, a) > 0)
+    abort ();
+  return 0;
+}
+