diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1412a6ac87a..7e955d4c9e6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,16 @@
+2013-04-05  Steven Bosscher  <steven@gcc.gnu.org>
+
+	* bb-reorder.c (fix_crossing_unconditional_branches): Remove a
+	set-but-unused variable.
+
+	* cgraph.c (cgraph_release_function_body): Clear cfun->cfg to make
+	basic blocks of released function bodies garbage-collectable.
+
+	* ree.c (find_and_remove_re): Do not call df_finish_pass here.
+	(struct rtl_opt_pass): Add TODO_df_finish.
+
+	* rtl.def (DEFINE_SUBST, DEFINE_SUBST_ATTR): Add documentation.
+
 2013-04-05  Greta Yorsh  <Greta.Yorsh@arm.com>
 
 	* config/arm/constraints.md (q): New constraint.
diff --git a/gcc/bb-reorder.c b/gcc/bb-reorder.c
index 48d43a63dde..7605e17e7ef 100644
--- a/gcc/bb-reorder.c
+++ b/gcc/bb-reorder.c
@@ -1998,14 +1998,12 @@ fix_crossing_unconditional_branches (void)
       if (JUMP_P (last_insn)
 	  && (succ->flags & EDGE_CROSSING))
 	{
-	  rtx label2;
-
 	  gcc_assert (!any_condjump_p (last_insn));
 
 	  /* Make sure the jump is not already an indirect or table jump.  */
 
 	  if (!computed_jump_p (last_insn)
-	      && !tablejump_p (last_insn, &label2, NULL))
+	      && !tablejump_p (last_insn, NULL, NULL))
 	    {
 	      /* We have found a "crossing" unconditional branch.  Now
 		 we must convert it to an indirect jump.  First create
diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index 930ccd862fe..693d4db9014 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -1260,7 +1260,10 @@ cgraph_node_remove_callers (struct cgraph_node *node)
   node->callers = NULL;
 }
 
-/* Release memory used to represent body of function NODE.  */
+/* Release memory used to represent body of function NODE.
+   Use this only for functions that are released before being translated to
+   target code (i.e. RTL).  Functions that are compiled to RTL and beyond
+   are free'd in final.c via free_after_compilation().  */
 
 void
 cgraph_release_function_body (struct cgraph_node *node)
@@ -1285,6 +1288,7 @@ cgraph_release_function_body (struct cgraph_node *node)
 	  gcc_assert (dom_computed[0] == DOM_NONE);
 	  gcc_assert (dom_computed[1] == DOM_NONE);
 	  clear_edges ();
+	  cfun->cfg = NULL;
 	}
       if (cfun->value_histograms)
 	free_histograms ();
diff --git a/gcc/ree.c b/gcc/ree.c
index ff96df8a016..c60921239a7 100644
--- a/gcc/ree.c
+++ b/gcc/ree.c
@@ -919,8 +919,6 @@ find_and_remove_re (void)
   if (dump_file && num_re_opportunities > 0)
     fprintf (dump_file, "Elimination opportunities = %d realized = %d\n",
 	     num_re_opportunities, num_realized);
-
-  df_finish_pass (false);
 }
 
 /* Find and remove redundant extensions.  */
@@ -958,7 +956,8 @@ struct rtl_opt_pass pass_ree =
   0,                                    /* properties_provided */
   0,                                    /* properties_destroyed */
   0,                                    /* todo_flags_start */
-  TODO_ggc_collect |
-  TODO_verify_rtl_sharing,              /* todo_flags_finish */
+  TODO_df_finish
+    | TODO_ggc_collect
+    | TODO_verify_rtl_sharing,          /* todo_flags_finish */
  }
 };
diff --git a/gcc/rtl.def b/gcc/rtl.def
index 47a37623c6d..5da3dd3ec00 100644
--- a/gcc/rtl.def
+++ b/gcc/rtl.def
@@ -1290,8 +1290,41 @@ DEF_RTL_EXPR (ATTR_FLAG, "attr_flag", "s", RTX_EXTRA)
    true, the second operand will be used as the value of the conditional.  */
 DEF_RTL_EXPR(COND, "cond", "Ee", RTX_EXTRA)
 
+/* Definition of a pattern substitution meta operation on a DEFINE_EXPAND
+   or a DEFINE_INSN.  Automatically generates new instances of DEFINE_INSNs
+   that match the substitution pattern.
+
+   Operand:
+   0: The name of the substitition template.
+   1: Input template to match to see if a substitution is applicable.
+   2: A C expression giving an additional condition for the generated
+      new define_expand or define_insn.
+   3: Output tempalate to generate via substitution.
+
+   Within a DEFINE_SUBST template, the meaning of some RTL expressions is
+   different from their usual interpretation: a MATCH_OPERAND matches any
+   expression tree with matching machine mode or with VOIDmode.  Likewise,
+   MATCH_OP_DUP and MATCH_DUP match more liberally in a DEFINE_SUBST than
+   in other RTL expressions.  MATCH_OPERATOR matches all common operators
+   but also UNSPEC, UNSPEC_VOLATILE, and MATCH_OPERATORS from the input
+   DEFINE_EXPAND or DEFINE_INSN.  */
 DEF_RTL_EXPR(DEFINE_SUBST, "define_subst", "sEsE", RTX_EXTRA)
+
+/* Substitution attribute to apply a DEFINE_SUBST to a pattern.
+
+   Operand:
+   0: The name of the subst-attribute.
+   1: The name of the DEFINE_SUBST to be applied for this attribute.
+   2: String to substitute for the subst-attribute name in the pattern
+      name, for the case that the DEFINE_SUBST is not applied (i.e. the
+      unmodified version of the pattern).
+   3: String to substitute for the subst-attribute name in the pattern
+      name, for the case that the DEFINE_SUBST is applied to the patten.
+      
+   The use of DEFINE_SUBST and DEFINE_SUBST_ATTR is explained in the
+   GCC internals manual, under "RTL Templates Transformations".  */
 DEF_RTL_EXPR(DEFINE_SUBST_ATTR, "define_subst_attr", "ssss", RTX_EXTRA)
+
 #endif /* GENERATOR_FILE */
 
 /*