PR rtl-optimization/21330

	* loop-unswitch.c (may_unswitch_on): Set *cinsn only when
	returning non-NULL.
	(unswitch_single_loop): Clear cinsn when retrying.

	* gcc.c-torture/execute/20050502-1.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@99157 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 3 insertions, 2 deletions

diff --git a/gcc/loop-unswitch.c b/gcc/loop-unswitch.c
index 96d80c39477..ef4e5b8c2d4 100644
--- a/gcc/loop-unswitch.c
+++ b/gcc/loop-unswitch.c
@@ -223,11 +223,11 @@ may_unswitch_on (basic_block bb, struct loop *loop, rtx *cinsn)
       if (at != BB_END (bb))
 	return NULL_RTX;
 
-      *cinsn = BB_END (bb);
       if (!rtx_equal_p (op[0], XEXP (test, 0))
 	  || !rtx_equal_p (op[1], XEXP (test, 1)))
 	return NULL_RTX;
 
+      *cinsn = BB_END (bb);
       return test;
     }
 
@@ -266,7 +266,7 @@ unswitch_single_loop (struct loops *loops, struct loop *loop,
   basic_block *bbs;
   struct loop *nloop;
   unsigned i;
-  rtx cond, rcond = NULL_RTX, conds, rconds, acond, cinsn = NULL_RTX;
+  rtx cond, rcond = NULL_RTX, conds, rconds, acond, cinsn;
   int repeat;
   edge e;
 
@@ -321,6 +321,7 @@ unswitch_single_loop (struct loops *loops, struct loop *loop,
   do
     {
       repeat = 0;
+      cinsn = NULL_RTX;
 
       /* Find a bb to unswitch on.  */
       bbs = get_loop_body (loop);