tree-ssa-threadupdate.c (thread_through_all_blocks): Do not clobber the loop structur...

	* tree-ssa-threadupdate.c (thread_through_all_blocks): Do not
	clobber the loop structure thread_block was unsuccessful.  If
	thread_block was unsuccessful, cleanup appropriately.

From-SVN: r205459

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 404d785..ad6468e 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2013-11-27  Jeff Law  <law@redhat.com>
+
+       * tree-ssa-threadupdate.c (thread_through_all_blocks): Do not
+       clobber the loop structure thread_block was unsuccessful.  If
+       thread_block was unsuccessful, cleanup appropriately.
+
 2013-11-27  Chen Liqin <liqin.gcc@gmail.com>
 
        * config/score/score.h (REG_CLASS_FROM_LETTER): Delete.

diff --git a/gcc/tree-ssa-threadupdate.c b/gcc/tree-ssa-threadupdate.c
index 1a52e47..24d0f42 100644 (file)
--- a/gcc/tree-ssa-threadupdate.c
+++ b/gcc/tree-ssa-threadupdate.c
@@ -1676,13 +1676,20 @@ thread_through_all_blocks (bool may_peel_loop_headers)
                  {
                    struct loop *loop = (*path)[0]->e->dest->loop_father;
 
-                   retval |= thread_block ((*path)[0]->e->dest, false);
-                   e->aux = NULL;
-
-                   /* This jump thread likely totally scrambled this loop.
-                      So arrange for it to be fixed up.  */
-                   loop->header = NULL;
-                   loop->latch = NULL;
+                   if (thread_block ((*path)[0]->e->dest, false))
+                     {
+                       /* This jump thread likely totally scrambled this loop.
+                          So arrange for it to be fixed up.  */
+                       loop->header = NULL;
+                       loop->latch = NULL;
+                       e->aux = NULL;
+                     }
+                   else
+                     {
+                       delete_jump_thread_path (path);
+                       e->aux = NULL;
+                       ei_next (&ei);
+                     }
                  }
              }
           else