* cfgloop.c (flow_loop_entry_edges_find, flow_loop_exit_edges_find,

[pf3gnuchains/gcc-fork.git] / gcc / ifcvt.c

diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 5eea041..eb597d1 100644 (file)
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -1,5 +1,6 @@
 /* If-conversion support.
-   Copyright (C) 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005
+   Free Software Foundation, Inc.
 
    This file is part of GCC.
 
@@ -109,38 +110,7 @@ static int dead_or_predicable (basic_block, basic_block, basic_block,
                               basic_block, int);
 static void noce_emit_move_insn (rtx, rtx);
 static rtx block_has_only_trap (basic_block);
-static void mark_loop_exit_edges (void);
 \f
-/* Sets EDGE_LOOP_EXIT flag for all loop exits.  */
-static void
-mark_loop_exit_edges (void)
-{
-  struct loops loops;
-  basic_block bb;
-  edge e;
-  
-  flow_loops_find (&loops, LOOP_TREE);
-  free_dominance_info (CDI_DOMINATORS);
-  
-  if (loops.num > 1)
-    {
-      FOR_EACH_BB (bb)
-       {
-         edge_iterator ei;
-         FOR_EACH_EDGE (e, ei, bb->succs)
-           {
-             if (find_common_loop (bb->loop_father, e->dest->loop_father)
-                 != bb->loop_father)
-               e->flags |= EDGE_LOOP_EXIT;
-             else
-               e->flags &= ~EDGE_LOOP_EXIT;
-           }
-       }
-    }
-
-  flow_loops_free (&loops);
-}
-
 /* Count the number of non-jump active insns in BB.  */
 
 static int
@@ -1228,6 +1198,7 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
   rtx a = if_info->a;
   rtx b = if_info->b;
   rtx x = if_info->x;
+  rtx orig_a, orig_b;
   rtx insn_a, insn_b;
   rtx tmp, target;
   int is_mem = 0;
@@ -1303,6 +1274,9 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
 
   start_sequence ();
 
+  orig_a = a;
+  orig_b = b;
+
   /* If either operand is complex, load it into a register first.
      The best way to do this is to copy the original insn.  In this
      way we preserve any clobbers etc that the insn may have had.
@@ -1334,7 +1308,7 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
     }
   if (! general_operand (b, GET_MODE (b)))
     {
-      rtx set;
+      rtx set, last;
 
       if (no_new_pseudos)
        goto end_seq_and_fail;
@@ -1342,9 +1316,7 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
       if (is_mem)
        {
           tmp = gen_reg_rtx (GET_MODE (b));
-         tmp = emit_insn (gen_rtx_SET (VOIDmode,
-                                       tmp,
-                                       b));
+         tmp = gen_rtx_SET (VOIDmode, tmp, b);
        }
       else if (! insn_b)
        goto end_seq_and_fail;
@@ -1354,8 +1326,22 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
          tmp = copy_rtx (insn_b);
          set = single_set (tmp);
          SET_DEST (set) = b;
-         tmp = emit_insn (PATTERN (tmp));
+         tmp = PATTERN (tmp);
        }
+
+      /* If insn to set up A clobbers any registers B depends on, try to
+        swap insn that sets up A with the one that sets up B.  If even
+        that doesn't help, punt.  */
+      last = get_last_insn ();
+      if (last && modified_in_p (orig_b, last))
+       {
+         tmp = emit_insn_before (tmp, get_insns ());
+         if (modified_in_p (orig_a, tmp))
+           goto end_seq_and_fail;
+       }
+      else
+       tmp = emit_insn (tmp);
+
       if (recog_memoized (tmp) < 0)
        goto end_seq_and_fail;
     }
@@ -3339,7 +3325,14 @@ if_convert (int x_life_data_ok)
   if ((! targetm.cannot_modify_jumps_p ())
       && (!flag_reorder_blocks_and_partition || !no_new_pseudos
          || !targetm.have_named_sections))
-    mark_loop_exit_edges ();
+    {
+      struct loops loops;
+
+      flow_loops_find (&loops);
+      mark_loop_exit_edges (&loops);
+      flow_loops_free (&loops);
+      free_dominance_info (CDI_DOMINATORS);
+    }
 
   /* Compute postdominators if we think we'll use them.  */
   if (HAVE_conditional_execution || life_data_ok)