re PR rtl-optimization/46878 (V850 ICE in in maybe_add_or_update_dep_1, at sched-deps.c:854)

PR rtl-optimization/46878
* combine.c (insn_a_feeds_b): Check for the implicit cc0
setter/user dependency as well.

* gcc.dg/pr46878-1.c: New test.

From-SVN: r169307

gcc/ChangeLog

+2011-01-26  DJ Delorie  <dj@redhat.com>
+
+	PR rtl-optimization/46878
+	* combine.c (insn_a_feeds_b): Check for the implicit cc0
+	setter/user dependency as well.
+
 2011-01-26  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR rtl-optimization/44469

gcc/combine.c

@@ -1032,7 +1032,9 @@ clear_log_links (void)
 /* Walk the LOG_LINKS of insn B to see if we find a reference to A.  Return
    true if we found a LOG_LINK that proves that A feeds B.  This only works
    if there are no instructions between A and B which could have a link
-   depending on A, since in that case we would not record a link for B.  */
+   depending on A, since in that case we would not record a link for B.
+   We also check the implicit dependency created by a cc0 setter/user
+   pair.  */
 
 static bool
 insn_a_feeds_b (rtx a, rtx b)
@@ -1041,6 +1043,10 @@ insn_a_feeds_b (rtx a, rtx b)
   for (links = LOG_LINKS (b); links; links = XEXP (links, 1))
     if (XEXP (links, 0) == a)
       return true;
+#ifdef HAVE_cc0
+  if (sets_cc0_p (a))
+    return true;
+#endif
   return false;
 }
 

gcc/testsuite/ChangeLog

+2011-01-26  DJ Delorie  <dj@redhat.com>
+
+	PR rtl-optimization/46878
+	* gcc.dg/pr46878-1.c: New test.
+
 2011-01-26  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/47476

gcc/testsuite/gcc.dg/pr46878-1.c

+/* PR rtl-optimization/46878 */
+/* Make sure this doesn't ICE.  */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+struct baz
+{
+  int *newp;
+};
+
+int
+get_ice (int *op, struct baz *ret)
+{
+  int *tmpp;
+  int c;
+  c = (__foo () != 1);
+  if (__bar ())
+    {
+      return (1);
+    }
+  if (c)
+    tmpp = op;
+  if (tmpp)
+    {
+    }
+  else if (c)
+    {
+      ret->newp = tmpp;
+    }
+}