tree-optimization/106521 - unroll-and-jam LC SSA rewrite

The LC SSA rewrite performs SSA verification at start but the VN
run performed on the unrolled-and-jammed body can leave us with
invalid SSA form until CFG cleanup is run.  So make sure we do that
before rewriting into LC SSA.

	PR tree-optimization/106521
	* gimple-loop-jam.cc (tree_loop_unroll_and_jam): Perform
	CFG cleanup manually before rewriting into LC SSA.

	* gcc.dg/torture/pr106521.c: New testcase.

1 files changed, 9 insertions, 1 deletions

diff --git a/gcc/gimple-loop-jam.cc b/gcc/gimple-loop-jam.cc
index 8cde6c7..a8a57d3 100644
--- a/gcc/gimple-loop-jam.cc
+++ b/gcc/gimple-loop-jam.cc
@@ -39,6 +39,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-loop-ivopts.h"
 #include "tree-vectorizer.h"
 #include "tree-ssa-sccvn.h"
+#include "tree-cfgcleanup.h"
 
 /* Unroll and Jam transformation
    
@@ -609,9 +610,16 @@ tree_loop_unroll_and_jam (void)
 
   if (todo)
     {
+      free_dominance_info (CDI_DOMINATORS);
+      /* We need to cleanup the CFG first since otherwise SSA form can
+	 be not up-to-date from the VN run.  */
+      if (todo & TODO_cleanup_cfg)
+	{
+	  cleanup_tree_cfg ();
+	  todo &= ~TODO_cleanup_cfg;
+	}
       rewrite_into_loop_closed_ssa (NULL, 0);
       scev_reset ();
-      free_dominance_info (CDI_DOMINATORS);
     }
   return todo;
 }