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PATCH: New c-torture test
- To: gcc-patches at gcc dot gnu dot org
- Subject: PATCH: New c-torture test
- From: Greg McGary <greg at mcgary dot org>
- Date: Wed, 6 Sep 2000 01:27:44 -0700
I just committed this:
2000-09-06 Greg McGary <greg@mcgary.org>
* gcc.c-torture/20000906.c: New test.
* gcc.c-torture/20000906.x: Expect failure for ix86 at `-O2'.
Index: gcc/testsuite/gcc.c-torture/execute/20000906-1.c
===================================================================
RCS file: 20000906-1.c
diff -N 20000906-1.c
--- /dev/null Tue May 5 13:32:27 1998
+++ 20000906-1.c Wed Sep 6 01:24:33 2000
@@ -0,0 +1,76 @@
+/* Testcase distilled from glibc's nss_parse_service_list in nss/nsswitch.c
+ It can't be distilled further. Fails with `-O2' for i[3456]86. */
+
+/* this simulates a bounded-pointer type. */
+struct ucharp { unsigned char *v, *l, *h; };
+
+/* this simulates bounded-pointer check prior to pointer dereference. */
+#define AREF(var, idx) ((((((((var).v+(idx)) < (var).l) \
+ || (((var).v+(idx)+1) > (var).h))) \
+ && (__builtin_trap (), 0)), \
+ (var).v)[(idx)])
+
+struct list
+{
+ struct list *next;
+};
+
+struct list *
+alloc_list (void)
+{
+ static struct list l;
+ return &l;
+}
+
+int one = 1;
+
+void
+foo (struct ucharp cp, struct ucharp lp, struct list **nextp)
+{
+ while (1)
+ {
+ struct list *list;
+ while (AREF (lp, 0) && AREF (cp, AREF (lp, 0)))
+ ++lp.v;
+ list = alloc_list ();
+ while (AREF (cp, AREF (lp, 0)))
+ ++lp.v;
+ if (AREF (lp, 0) == one)
+ do
+ ++lp.v;
+ while (AREF (lp, 0) && AREF (cp, AREF (lp, 0)));
+ /* The above AREF (cp, ...) fails because the pseudo created to
+ hold cp.v holds garbage, having never been set.
+ The easiest way to see the problem is to compile wiht `-O2 -da'
+ then look at *.09.loop. Search for something like this:
+
+ Hoisted regno 183 r/o from (mem/s:SI (reg:SI 16 argp) 10)
+ Replaced reg 91, deleting init_insn (213).
+
+ Now, look for the use of reg 91, which has no set. */
+
+ *nextp = list;
+ nextp = &list->next;
+ if (!*lp.v)
+ break;
+ }
+}
+
+extern void exit (int);
+
+int
+main (void)
+{
+ static unsigned char cp0[] = "\0\0\0\0";
+ struct ucharp cp = { cp0, cp0, cp0 + sizeof (cp0) };
+
+ static unsigned char lp0[] = "\1\1\0\0";
+ struct ucharp lp = { lp0, lp0, lp0 + sizeof (lp0) };
+
+ struct list list;
+ struct list *nextp = &list;
+
+ foo (cp, lp, &nextp);
+
+ exit (0);
+}
Index: gcc/testsuite/gcc.c-torture/execute/20000906-1.x
===================================================================
RCS file: 20000906-1.x
diff -N 20000906-1.x
--- /dev/null Tue May 5 13:32:27 1998
+++ 20000906-1.x Wed Sep 6 01:24:33 2000
@@ -0,0 +1,14 @@
+# This only fails for `-O2', but not `-O3' or `-Os'
+# as I had expected. See clues in testcase source file.
+
+set torture_eval_before_execute {
+
+ set compiler_conditional_xfail_data {
+ "loop optimizer leaves dangling pseudo" \
+ "i?86-*-*" \
+ { "-O2" } \
+ { "" }
+ }
+}
+
+return 0