tree-eh.c (do_return_redirection): Remove return_value_p parameter.

	* tree-eh.c (do_return_redirection): Remove return_value_p
	parameter.  Change all callers.
	(lower_try_finally_nofallthru): Remove local return_val.
	(lower_try_finally_onedest): Likewise.
	(lower_try_finally_copy): Likewise.
	(lower_try_finally_switch): Likewise.

From-SVN: r180459

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 22b9514fc4db6bc3e0380abe3b6884c7c7f42f20..593ac816f25bb15d70d5fa636826315c7ed510ea 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2011-10-25  Ian Lance Taylor  <iant@google.com>
+
+       * tree-eh.c (do_return_redirection): Remove return_value_p
+       parameter.  Change all callers.
+       (lower_try_finally_nofallthru): Remove local return_val.
+       (lower_try_finally_onedest): Likewise.
+       (lower_try_finally_copy): Likewise.
+       (lower_try_finally_switch): Likewise.
+
 2011-10-25  H.J. Lu  <hongjiu.lu@intel.com>
 
        * config/i386/mmx.md (*mmx_maskmovq): Replace :SI with :P and

diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c
index c1896be228d2f87b13a3c01513416732325bd9e8..fbc444ca716146aca3f637459908e6e9e0ad69ec 100644 (file)
--- a/gcc/tree-eh.c
+++ b/gcc/tree-eh.c
@@ -711,66 +711,35 @@ verify_norecord_switch_expr (struct leh_state *state, gimple switch_expr)
 #define verify_norecord_switch_expr(state, switch_expr)
 #endif
 
-/* Redirect a RETURN_EXPR pointed to by STMT_P to FINLAB.  Place in CONT_P
-   whatever is needed to finish the return.  If MOD is non-null, insert it
-   before the new branch.  RETURN_VALUE_P is a cache containing a temporary
-   variable to be used in manipulating the value returned from the function.  */
+/* Redirect a RETURN_EXPR pointed to by Q to FINLAB.  If MOD is
+   non-null, insert it before the new branch.  */
 
 static void
-do_return_redirection (struct goto_queue_node *q, tree finlab, gimple_seq mod,
-                      tree *return_value_p)
+do_return_redirection (struct goto_queue_node *q, tree finlab, gimple_seq mod)
 {
-  tree ret_expr;
   gimple x;
 
-  /* In the case of a return, the queue node must be a gimple statement. */
+  /* In the case of a return, the queue node must be a gimple statement.  */
   gcc_assert (!q->is_label);
 
-  ret_expr = gimple_return_retval (q->stmt.g);
+  /* Note that the return value may have already been computed, e.g.,
 
-  if (ret_expr)
-    {
-      if (!*return_value_p)
-        *return_value_p = ret_expr;
-      else
-        gcc_assert (*return_value_p == ret_expr);
-      q->cont_stmt = q->stmt.g;
-      /* The nasty part about redirecting the return value is that the
-        return value itself is to be computed before the FINALLY block
-        is executed.  e.g.
-
-               int x;
-               int foo (void)
-               {
-                 x = 0;
-                 try {
-                   return x;
-                 } finally {
-                   x++;
-                 }
-               }
-
-         should return 0, not 1.  Arrange for this to happen by copying
-         computed the return value into a local temporary.  This also
-         allows us to redirect multiple return statements through the
-         same destination block; whether this is a net win or not really
-         depends, I guess, but it does make generation of the switch in
-         lower_try_finally_switch easier.  */
-
-      if (TREE_CODE (ret_expr) == RESULT_DECL)
+       int x;
+       int foo (void)
        {
-         if (!*return_value_p)
-           *return_value_p = ret_expr;
-         else
-           gcc_assert (*return_value_p == ret_expr);
-         q->cont_stmt = q->stmt.g;
+         x = 0;
+         try {
+           return x;
+         } finally {
+           x++;
+         }
        }
-      else
-         gcc_unreachable ();
-    }
-  else
-      /* If we don't return a value, all return statements are the same.  */
-      q->cont_stmt = q->stmt.g;
+
+     should return 0, not 1.  We don't have to do anything to make
+     this happens because the return value has been placed in the
+     RESULT_DECL already.  */
+
+  q->cont_stmt = q->stmt.g;
 
   if (!q->repl_stmt)
     q->repl_stmt = gimple_seq_alloc ();
@@ -1041,7 +1010,7 @@ static void
 lower_try_finally_nofallthru (struct leh_state *state,
                              struct leh_tf_state *tf)
 {
-  tree lab, return_val;
+  tree lab;
   gimple x;
   gimple_seq finally;
   struct goto_queue_node *q, *qe;
@@ -1055,12 +1024,11 @@ lower_try_finally_nofallthru (struct leh_state *state,
   x = gimple_build_label (lab);
   gimple_seq_add_stmt (&tf->top_p_seq, x);
 
-  return_val = NULL;
   q = tf->goto_queue;
   qe = q + tf->goto_queue_active;
   for (; q < qe; ++q)
     if (q->index < 0)
-      do_return_redirection (q, lab, NULL, &return_val);
+      do_return_redirection (q, lab, NULL);
     else
       do_goto_redirection (q, lab, NULL, tf);
 
@@ -1126,9 +1094,8 @@ lower_try_finally_onedest (struct leh_state *state, struct leh_tf_state *tf)
   if (tf->may_return)
     {
       /* Reachable by return expressions only.  Redirect them.  */
-      tree return_val = NULL;
       for (; q < qe; ++q)
-       do_return_redirection (q, finally_label, NULL, &return_val);
+       do_return_redirection (q, finally_label, NULL);
       replace_goto_queue (tf);
     }
   else
@@ -1197,7 +1164,6 @@ lower_try_finally_copy (struct leh_state *state, struct leh_tf_state *tf)
   if (tf->goto_queue)
     {
       struct goto_queue_node *q, *qe;
-      tree return_val = NULL;
       int return_index, index;
       struct labels_s
       {
@@ -1230,7 +1196,7 @@ lower_try_finally_copy (struct leh_state *state, struct leh_tf_state *tf)
            = create_artificial_label (tf_loc);
 
          if (index == return_index)
-           do_return_redirection (q, lab, NULL, &return_val);
+           do_return_redirection (q, lab, NULL);
          else
            do_goto_redirection (q, lab, NULL, tf);
 
@@ -1257,7 +1223,7 @@ lower_try_finally_copy (struct leh_state *state, struct leh_tf_state *tf)
          lab = labels[index].label;
 
          if (index == return_index)
-           do_return_redirection (q, lab, NULL, &return_val);
+           do_return_redirection (q, lab, NULL);
          else
            do_goto_redirection (q, lab, NULL, tf);
        }
@@ -1280,7 +1246,6 @@ static void
 lower_try_finally_switch (struct leh_state *state, struct leh_tf_state *tf)
 {
   struct goto_queue_node *q, *qe;
-  tree return_val = NULL;
   tree finally_tmp, finally_label;
   int return_index, eh_index, fallthru_index;
   int nlabels, ndests, j, last_case_index;
@@ -1401,7 +1366,7 @@ lower_try_finally_switch (struct leh_state *state, struct leh_tf_state *tf)
                                   build_int_cst (integer_type_node,
                                                  return_index));
          gimple_seq_add_stmt (&mod, x);
-         do_return_redirection (q, finally_label, mod, &return_val);
+         do_return_redirection (q, finally_label, mod);
          switch_id = return_index;
        }
       else