for  gcc/ChangeLog
from  Alexandre Oliva  <aoliva@redhat.com>

	PR debug/50869
	* cselib.c (cfa_base_preserved_regno): Initialize.
	(cselib_expand_value_rtx_1): Don't expand it.
	* var-tracking.c (vt_expand_var_loc_chain): Initialize depth.
	Check it's only zero if result is NULL.

Index: gcc/cselib.c
===================================================================
--- gcc/cselib.c.orig	2011-10-27 18:32:20.137366314 -0200
+++ gcc/cselib.c	2011-10-27 18:27:05.387597000 -0200
@@ -185,7 +185,7 @@ static cselib_val dummy_val;
    that is constant through the whole function and should never be
    eliminated.  */
 static cselib_val *cfa_base_preserved_val;
-static unsigned int cfa_base_preserved_regno;
+static unsigned int cfa_base_preserved_regno = INVALID_REGNUM;
 
 /* Used to list all values that contain memory reference.
    May or may not contain the useless values - the list is compacted
@@ -1451,7 +1451,7 @@ cselib_expand_value_rtx_1 (rtx orig, str
 	  if (GET_MODE (l->elt->val_rtx) == GET_MODE (orig))
 	    {
 	      rtx result;
-	      int regno = REGNO (orig);
+	      unsigned regno = REGNO (orig);
 
 	      /* The only thing that we are not willing to do (this
 		 is requirement of dse and if others potential uses
@@ -1471,7 +1471,8 @@ cselib_expand_value_rtx_1 (rtx orig, str
 		 make the frame assumptions.  */
 	      if (regno == STACK_POINTER_REGNUM
 		  || regno == FRAME_POINTER_REGNUM
-		  || regno == HARD_FRAME_POINTER_REGNUM)
+		  || regno == HARD_FRAME_POINTER_REGNUM
+		  || regno == cfa_base_preserved_regno)
 		return orig;
 
 	      bitmap_set_bit (evd->regs_active, regno);
Index: gcc/var-tracking.c
===================================================================
--- gcc/var-tracking.c.orig	2011-10-27 18:32:20.141366261 -0200
+++ gcc/var-tracking.c	2011-10-27 18:28:03.823813000 -0200
@@ -7764,7 +7764,7 @@ vt_expand_var_loc_chain (variable var, b
   bool pending_recursion;
   rtx loc_from = NULL;
   struct elt_loc_list *cloc = NULL;
-  int depth, saved_depth = elcd->depth;
+  int depth = 0, saved_depth = elcd->depth;
 
   /* Clear all backlinks pointing at this, so that we're not notified
      while we're active.  */
@@ -7842,6 +7842,8 @@ vt_expand_var_loc_chain (variable var, b
   VAR_LOC_FROM (var) = loc_from;
   VAR_LOC_DEPTH (var) = depth;
 
+  gcc_checking_assert (!depth == !result);
+
   elcd->depth = update_depth (saved_depth, depth);
 
   /* Indicate whether any of the dependencies are pending recursion