[PATCH] Fix PR58775

[Jakub Jelinek]

On Fri, Oct 18, 2013 at 06:36:44PM +0800, Zhenqiang Chen wrote:
--- a/gcc/tree-ssa-reassoc.c
+++ b/gcc/tree-ssa-reassoc.c
@@ -2861,6 +2861,19 @@ swap_ops_for_binary_stmt (vec<operand_entry_t> ops,
     }
 }
 
+/* Determine if stmt A is in th next list of stmt B.  */
+static inline bool
+next_stmt_of (gimple a, gimple b)
+{
+  gimple_stmt_iterator gsi;
+  for (gsi = gsi_for_stmt (b); !gsi_end_p (gsi); gsi_next (&gsi))
+    {
+      if (gsi_stmt (gsi) == a)
+	return true;
+    }
+  return false;
+}

How is that different from appears_later_in_bb?  More importantly,
not_dominated_by shouldn't be called with the same uid and basic block,
unless the stmts are the same, except for the is_gimple_debug case
(which looks like a bug).  And more importantly, if a stmt has zero uid,
we'd better set it from the previous or next non-zero uid stmt, so that
we don't lineary traverse the whole bb many times.

That said, I've lost track of the bugfixes for this, don't know if there is
any patch still pending or not.

	Jakub