2008-05-16 Kenneth Zadeck <zadeck@naturalbridge.com>

	* ifcvt.c (dead_or_predicable): Rename
	df_simulate_one_insn_backwards to df_simulate_one_insn.
	* recog.c (peephole2_optimize): Ditto.
	* rtl-factoring.c (collect_pattern_seqs, clear_regs_live_in_seq): 
	Ditto.
	* df.h: Rename df_simulate_one_insn_backwards to
	df_simulate_one_insn.  and delete df_simulate_one_insn_forwards.
	* df-problems.c (df_simulate_artificial_refs_at_top) Reversed
	scanning of defs and uses.
	(df_simulate_one_insn_backwards): Renamed to df_simulate_one_insn.
	(df_simulate_one_insn_forwards): Removed.

	


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@135422 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 38 insertions, 38 deletions

diff --git a/gcc/df-problems.c b/gcc/df-problems.c
index f7288c78e8e..682cca857a7 100644
--- a/gcc/df-problems.c
+++ b/gcc/df-problems.c
@@ -3682,7 +3682,6 @@ df_note_add_problem (void)
    DF_LR_IN.  If you start at the bottom of the block use one of
    DF_LIVE_OUT or DF_LR_OUT.  BE SURE TO PASS A COPY OF THESE SETS,
    THEY WILL BE DESTROYED.
-
 ----------------------------------------------------------------------------*/
 
 
@@ -3757,87 +3756,88 @@ df_simulate_fixup_sets (basic_block bb, bitmap live)
 }
 
 
-/* Apply the artificial uses and defs at the top of BB in a forwards
+/*----------------------------------------------------------------------------
+   The following three functions are used only for BACKWARDS scanning:
+   i.e. they process the defs before the uses.
+
+   df_simulate_artificial_refs_at_end should be called first with a
+   bitvector copyied from the DF_LIVE_OUT or DF_LR_OUT.  Then
+   df_simulate_one_insn should be called for each insn in the block,
+   starting with the last on.  Finally,
+   df_simulate_artificial_refs_at_top can be called to get a new value
+   of the sets at the top of the block (this is rarely used).
+
+   It would be trivial to define a similar set of functions that work
+   in the forwards direction.  The only changes would be to process
+   the uses before the defs and properly rename the functions.  This
+   has so far not been necessary.
+----------------------------------------------------------------------------*/
+
+/* Apply the artificial uses and defs at the end of BB in a backwards
    direction.  */
 
 void 
-df_simulate_artificial_refs_at_top (basic_block bb, bitmap live)
+df_simulate_artificial_refs_at_end (basic_block bb, bitmap live)
 {
   struct df_ref **def_rec;
-#ifdef EH_USES
   struct df_ref **use_rec;
-#endif
   int bb_index = bb->index;
   
-#ifdef EH_USES
-  for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
-    {
-      struct df_ref *use = *use_rec;
-      if (DF_REF_FLAGS (use) & DF_REF_AT_TOP)
-	bitmap_set_bit (live, DF_REF_REGNO (use));
-    }
-#endif
-
   for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
     {
       struct df_ref *def = *def_rec;
-      if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
+      if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0)
 	bitmap_clear_bit (live, DF_REF_REGNO (def));
     }
+
+  for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
+    {
+      struct df_ref *use = *use_rec;
+      if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0)
+	bitmap_set_bit (live, DF_REF_REGNO (use));
+    }
 }
 
 
-/* Simulate the forwards effects of INSN on the bitmap LIVE.  */
+/* Simulate the backwards effects of INSN on the bitmap LIVE.  */
 
 void 
-df_simulate_one_insn_forwards (basic_block bb, rtx insn, bitmap live)
+df_simulate_one_insn (basic_block bb, rtx insn, bitmap live)
 {
   if (! INSN_P (insn))
     return;	
   
-  df_simulate_uses (insn, live);
   df_simulate_defs (insn, live);
+  df_simulate_uses (insn, live);
   df_simulate_fixup_sets (bb, live);
 }
 
 
-/* Apply the artificial uses and defs at the end of BB in a backwards
+/* Apply the artificial uses and defs at the top of BB in a backwards
    direction.  */
 
 void 
-df_simulate_artificial_refs_at_end (basic_block bb, bitmap live)
+df_simulate_artificial_refs_at_top (basic_block bb, bitmap live)
 {
   struct df_ref **def_rec;
+#ifdef EH_USES
   struct df_ref **use_rec;
+#endif
   int bb_index = bb->index;
   
   for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
     {
       struct df_ref *def = *def_rec;
-      if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0)
+      if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
 	bitmap_clear_bit (live, DF_REF_REGNO (def));
     }
 
+#ifdef EH_USES
   for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
     {
       struct df_ref *use = *use_rec;
-      if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0)
+      if (DF_REF_FLAGS (use) & DF_REF_AT_TOP)
 	bitmap_set_bit (live, DF_REF_REGNO (use));
     }
+#endif
 }
-
-
-/* Simulate the backwards effects of INSN on the bitmap LIVE.  */
-
-void 
-df_simulate_one_insn_backwards (basic_block bb, rtx insn, bitmap live)
-{
-  if (! INSN_P (insn))
-    return;	
-  
-  df_simulate_defs (insn, live);
-  df_simulate_uses (insn, live);
-  df_simulate_fixup_sets (bb, live);
-}
-
-