1 files changed, 21 insertions, 55 deletions

diff --git a/gcc/combine.c b/gcc/combine.c
index af9cea2fe2a..129cd4dff39 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -2264,68 +2264,33 @@ cleanup_auto_inc_dec (rtx src, bool after, enum machine_mode mem_mode)
 
   return x;
 }
-#endif
 
 /* Auxiliary data structure for propagate_for_debug_stmt.  */
 
 struct rtx_subst_pair
 {
-  rtx from, to;
-  bool changed;
-#ifdef AUTO_INC_DEC
+  rtx to;
   bool adjusted;
   bool after;
-#endif
 };
 
-/* Clean up any auto-updates in PAIR->to the first time it is called
-   for a PAIR.  PAIR->adjusted is used to tell whether we've cleaned
-   up before.  */
+/* DATA points to an rtx_subst_pair.  Return the value that should be
+   substituted.  */
 
-static void
-auto_adjust_pair (struct rtx_subst_pair *pair ATTRIBUTE_UNUSED)
+static rtx
+propagate_for_debug_subst (rtx from ATTRIBUTE_UNUSED, void *data)
 {
-#ifdef AUTO_INC_DEC
+  struct rtx_subst_pair *pair = (struct rtx_subst_pair *)data;
+
   if (!pair->adjusted)
     {
       pair->adjusted = true;
       pair->to = cleanup_auto_inc_dec (pair->to, pair->after, VOIDmode);
+      return pair->to;
     }
-#endif
-}
-
-/* If *LOC is the same as FROM in the struct rtx_subst_pair passed as
-   DATA, replace it with a copy of TO.  Handle SUBREGs of *LOC as
-   well.  */
-
-static int
-propagate_for_debug_subst (rtx *loc, void *data)
-{
-  struct rtx_subst_pair *pair = (struct rtx_subst_pair *)data;
-  rtx from = pair->from, to = pair->to;
-  rtx x = *loc, s = x;
-
-  if (rtx_equal_p (x, from)
-      || (GET_CODE (x) == SUBREG && rtx_equal_p ((s = SUBREG_REG (x)), from)))
-    {
-      auto_adjust_pair (pair);
-      if (pair->to != to)
-	to = pair->to;
-      else
-	to = copy_rtx (to);
-      if (s != x)
-	{
-	  gcc_assert (GET_CODE (x) == SUBREG && SUBREG_REG (x) == s);
-	  to = simplify_gen_subreg (GET_MODE (x), to,
-				    GET_MODE (from), SUBREG_BYTE (x));
-	}
-      *loc = wrap_constant (GET_MODE (x), to);
-      pair->changed = true;
-      return -1;
-    }
-
-  return 0;
+  return copy_rtx (pair->to);
 }
+#endif
 
 /* Replace occurrences of DEST with SRC in DEBUG_INSNs between INSN
    and LAST.  If MOVE holds, debug insns must also be moved past
@@ -2334,14 +2299,11 @@ propagate_for_debug_subst (rtx *loc, void *data)
 static void
 propagate_for_debug (rtx insn, rtx last, rtx dest, rtx src, bool move)
 {
-  struct rtx_subst_pair p;
-  rtx next, move_pos = move ? last : NULL_RTX;
-
-  p.from = dest;
-  p.to = src;
-  p.changed = false;
+  rtx next, move_pos = move ? last : NULL_RTX, loc;
 
 #ifdef AUTO_INC_DEC
+  struct rtx_subst_pair p;
+  p.to = src;
   p.adjusted = false;
   p.after = move;
 #endif
@@ -2353,11 +2315,15 @@ propagate_for_debug (rtx insn, rtx last, rtx dest, rtx src, bool move)
       next = NEXT_INSN (insn);
       if (DEBUG_INSN_P (insn))
 	{
-	  for_each_rtx (&INSN_VAR_LOCATION_LOC (insn),
-			propagate_for_debug_subst, &p);
-	  if (!p.changed)
+#ifdef AUTO_INC_DEC
+	  loc = simplify_replace_fn_rtx (INSN_VAR_LOCATION_LOC (insn),
+					 dest, propagate_for_debug_subst, &p);
+#else
+	  loc = simplify_replace_rtx (INSN_VAR_LOCATION_LOC (insn), dest, src);
+#endif
+	  if (loc == INSN_VAR_LOCATION_LOC (insn))
 	    continue;
-	  p.changed = false;
+	  INSN_VAR_LOCATION_LOC (insn) = loc;
 	  if (move_pos)
 	    {
 	      remove_insn (insn);