re PR sanitizer/60636 (ubsan doesn't instrument signed integer ABS_EXPR)

	PR sanitizer/60636
	* ubsan.c (instrument_si_overflow): Instrument ABS_EXPR.

	* c-c++-common/ubsan/pr60636.c: New test.

From-SVN: r208841

gcc/ChangeLog

 2014-03-26  Jakub Jelinek  <jakub@redhat.com>
 
+	PR sanitizer/60636
+	* ubsan.c (instrument_si_overflow): Instrument ABS_EXPR.
+
 	* tree-vrp.c (simplify_internal_call_using_ranges): If only
 	one range is range_int_cst_p, but not both, at least optimize
 	addition/subtraction of 0 and multiplication by 0 or 1.

gcc/testsuite/ChangeLog

+2014-03-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/60636
+	* c-c++-common/ubsan/pr60636.c: New test.
+
 2014-03-26  Andreas Schwab  <schwab@suse.de>
 
 	* g++.dg/torture/pr60315.C: Remove duplication.

gcc/testsuite/c-c++-common/ubsan/pr60636.c

+/* PR sanitizer/60636 */
+/* { dg-do run } */
+/* { dg-options "-fsanitize=undefined" } */
+
+volatile long long int a;
+
+int
+main ()
+{
+  long long int u = -__LONG_LONG_MAX__ - 1;
+  a = u > 0 ? u : -u;
+  return 0;
+}
+
+/* { dg-output "negation of -9223372036854775808 cannot be represented in type 'long long int'" } */

gcc/ubsan.c

@@ -737,6 +737,21 @@ instrument_si_overflow (gimple_stmt_iterator gsi)
       gimple_call_set_lhs (g, lhs);
       gsi_replace (&gsi, g, false);
       break;
+    case ABS_EXPR:
+      /* Transform i = ABS_EXPR<u>;
+	 into
+	 _N = UBSAN_CHECK_SUB (0, u);
+	 i = ABS_EXPR<_N>;  */
+      a = build_int_cst (lhstype, 0);
+      b = gimple_assign_rhs1 (stmt);
+      g = gimple_build_call_internal (IFN_UBSAN_CHECK_SUB, 2, a, b);
+      a = make_ssa_name (lhstype, NULL);
+      gimple_call_set_lhs (g, a);
+      gimple_set_location (g, gimple_location (stmt));
+      gsi_insert_before (&gsi, g, GSI_SAME_STMT);
+      gimple_assign_set_rhs1 (stmt, a);
+      update_stmt (stmt);
+      break;
     default:
       break;
     }