* lcm.c: Move all mode-switching related functions from here...

	* mode-switching.c: ...to this new file.
	* doc/passes.texi: Update accordingly.

	* basic-block.h (label_value_list): Remove extern decl.
	* cfgrtl.c (label_value_list): Remove.
	(can_delete_label_p): Don't look at it.
	* cfgcleanup.c (cleanup_cfg): Don't free it.

	* common.opt: Don't refer to non-existing flag_alias_check.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@100591 138bc75d-0d04-0410-961f-82ee72b054a4

9 files changed, 732 insertions, 690 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5c3ad3551d8..ad10c835cc3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,16 @@
+2005-06-04  Steven Bosscher  <stevenb@suse.de>
+
+	* lcm.c: Move all mode-switching related functions from here...
+	* mode-switching.c: ...to this new file.
+	* doc/passes.texi: Update accordingly.
+
+	* basic-block.h (label_value_list): Remove extern decl.
+	* cfgrtl.c (label_value_list): Remove.
+	(can_delete_label_p): Don't look at it.
+	* cfgcleanup.c (cleanup_cfg): Don't free it.
+
+	* common.opt: Don't refer to non-existing flag_alias_check.
+
 2005-06-04  David Edelsohn  <edelsohn@gnu.org>
 
 	* config/rs6000/aix52.h (ASM_CPU_SPEC): Add power5.
@@ -62,7 +75,7 @@
 2005-06-03  Eric Christopher  <echristo@redhat.com>
 
 	* config/mips/mips.opt: Add RejectNegative to divide-breaks and
-        divide-traps.
+	divide-traps.
 
 2005-06-03  Jan Hubicka  <jh@suse.cz>
 
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 30bdf4fc6d1..9be640ebf26 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -949,7 +949,7 @@ OBJS-common = \
  haifa-sched.o hooks.o ifcvt.o insn-attrtab.o insn-emit.o insn-modes.o	   \
  insn-extract.o insn-opinit.o insn-output.o insn-peep.o insn-recog.o	   \
  integrate.o intl.o jump.o  langhooks.o lcm.o lists.o local-alloc.o  	   \
- loop.o modulo-sched.o optabs.o options.o opts.o			   \
+ loop.o mode-switching.o modulo-sched.o optabs.o options.o opts.o	   \
  params.o postreload.o postreload-gcse.o predict.o			   \
  insn-preds.o pointer-set.o postreload.o				   \
  print-rtl.o print-tree.o profile.o value-prof.o var-tracking.o		   \
@@ -2099,6 +2099,9 @@ resource.o : resource.c $(CONFIG_H) $(RTL_H) hard-reg-set.h $(SYSTEM_H) \
 lcm.o : lcm.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) $(REGS_H) \
    hard-reg-set.h $(FLAGS_H) real.h insn-config.h $(INSN_ATTR_H) $(RECOG_H) \
    $(BASIC_BLOCK_H) $(TM_P_H) function.h output.h
+mode-switching.o : mode-switching.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) \
+   $(RTL_H) $(REGS_H) hard-reg-set.h $(FLAGS_H) real.h insn-config.h \
+   $(INSN_ATTR_H) $(RECOG_H) $(BASIC_BLOCK_H) $(TM_P_H) function.h output.h
 tree-ssa-dce.o : tree-ssa-dce.c $(CONFIG_H) $(SYSTEM_H) $(TREE_H) \
     $(RTL_H) $(TM_P_H) $(TREE_FLOW_H) $(DIAGNOSTIC_H) $(TIMEVAR_H) $(TM_H) \
     coretypes.h $(TREE_DUMP_H) tree-pass.h $(FLAGS_H) $(BASIC_BLOCK_H) \
diff --git a/gcc/basic-block.h b/gcc/basic-block.h
index 5c033dfbd4b..2979e01a3ea 100644
--- a/gcc/basic-block.h
+++ b/gcc/basic-block.h
@@ -446,10 +446,6 @@ extern bool rediscover_loops_after_threading;
 #define FOR_ALL_BB_FN(BB, FN) \
   for (BB = ENTRY_BLOCK_PTR_FOR_FUNCTION (FN); BB; BB = BB->next_bb)
 
-/* Special labels found during CFG build.  */
-
-extern GTY(()) rtx label_value_list;
-
 extern bitmap_obstack reg_obstack;
 
 /* Indexed by n, gives number of basic block that  (REG n) is used in.
diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c
index 10e6f101eed..98c82452ca3 100644
--- a/gcc/cfgcleanup.c
+++ b/gcc/cfgcleanup.c
@@ -2132,8 +2132,6 @@ cleanup_cfg (int mode)
       delete_dead_jumptables ();
     }
 
-  /* Kill the data we won't maintain.  */
-  free_EXPR_LIST_list (&label_value_list);
   timevar_pop (TV_CLEANUP_CFG);
 
   return changed;
diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c
index 86b2435c30a..2571d4d65dc 100644
--- a/gcc/cfgrtl.c
+++ b/gcc/cfgrtl.c
@@ -59,11 +59,6 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "target.h"
 #include "cfgloop.h"
 
-/* The labels mentioned in non-jump rtl.  Valid during find_basic_blocks.  */
-/* ??? Should probably be using LABEL_NUSES instead.  It would take a
-   bit of surgery to be able to use or co-opt the routines in jump.  */
-rtx label_value_list;
-
 static int can_delete_note_p (rtx);
 static int can_delete_label_p (rtx);
 static void commit_one_edge_insertion (edge, int);
@@ -103,8 +98,7 @@ can_delete_label_p (rtx label)
   return (!LABEL_PRESERVE_P (label)
 	  /* User declared labels must be preserved.  */
 	  && LABEL_NAME (label) == 0
-	  && !in_expr_list_p (forced_labels, label)
-	  && !in_expr_list_p (label_value_list, label));
+	  && !in_expr_list_p (forced_labels, label));
 }
 
 /* Delete INSN by patching it out.  Return the next insn.  */
diff --git a/gcc/common.opt b/gcc/common.opt
index a603707508a..f54eabce8a1 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -234,7 +234,6 @@ Common RejectNegative Joined UInteger
 ;   global variables.
 ; 2 if pointer arguments may not alias each other and may not
 ;   alias global variables.  True in Fortran.
-;   The value is ignored if flag_alias_check is 0.
 fargument-alias
 Common Report Var(flag_argument_noalias,0)
 Specify that arguments may alias each other and globals
diff --git a/gcc/doc/passes.texi b/gcc/doc/passes.texi
index ad6110e7312..e2fcc7a5d02 100644
--- a/gcc/doc/passes.texi
+++ b/gcc/doc/passes.texi
@@ -639,7 +639,8 @@ The pass is located in @file{regmove.c}.
 This pass looks for instructions that require the processor to be in a
 specific ``mode'' and minimizes the number of mode changes required to
 satisfy all users.  What these modes are, and what they apply to are
-completely target-specific.  The source is located in @file{lcm.c}.
+completely target-specific.
+The source is located in @file{mode-switching.c}.
 
 @cindex modulo scheduling
 @cindex sms, swing, software pipelining
diff --git a/gcc/lcm.c b/gcc/lcm.c
index 210e4d600b1..330068e7d61 100644
--- a/gcc/lcm.c
+++ b/gcc/lcm.c
@@ -809,676 +809,3 @@ pre_edge_rev_lcm (FILE *file ATTRIBUTE_UNUSED, int n_exprs, sbitmap *transp,
   return edge_list;
 }
 
-/* Mode switching:
-
-   The algorithm for setting the modes consists of scanning the insn list
-   and finding all the insns which require a specific mode.  Each insn gets
-   a unique struct seginfo element.  These structures are inserted into a list
-   for each basic block.  For each entity, there is an array of bb_info over
-   the flow graph basic blocks (local var 'bb_info'), and contains a list
-   of all insns within that basic block, in the order they are encountered.
-
-   For each entity, any basic block WITHOUT any insns requiring a specific
-   mode are given a single entry, without a mode.  (Each basic block
-   in the flow graph must have at least one entry in the segment table.)
-
-   The LCM algorithm is then run over the flow graph to determine where to
-   place the sets to the highest-priority value in respect of first the first
-   insn in any one block.  Any adjustments required to the transparency
-   vectors are made, then the next iteration starts for the next-lower
-   priority mode, till for each entity all modes are exhausted.
-
-   More details are located in the code for optimize_mode_switching().  */
-
-/* This structure contains the information for each insn which requires
-   either single or double mode to be set.
-   MODE is the mode this insn must be executed in.
-   INSN_PTR is the insn to be executed (may be the note that marks the
-   beginning of a basic block).
-   BBNUM is the flow graph basic block this insn occurs in.
-   NEXT is the next insn in the same basic block.  */
-struct seginfo
-{
-  int mode;
-  rtx insn_ptr;
-  int bbnum;
-  struct seginfo *next;
-  HARD_REG_SET regs_live;
-};
-
-struct bb_info
-{
-  struct seginfo *seginfo;
-  int computing;
-};
-
-/* These bitmaps are used for the LCM algorithm.  */
-
-#ifdef OPTIMIZE_MODE_SWITCHING
-static sbitmap *antic;
-static sbitmap *transp;
-static sbitmap *comp;
-
-static struct seginfo * new_seginfo (int, rtx, int, HARD_REG_SET);
-static void add_seginfo (struct bb_info *, struct seginfo *);
-static void reg_dies (rtx, HARD_REG_SET);
-static void reg_becomes_live (rtx, rtx, void *);
-static void make_preds_opaque (basic_block, int);
-#endif
-
-#ifdef OPTIMIZE_MODE_SWITCHING
-
-/* This function will allocate a new BBINFO structure, initialized
-   with the MODE, INSN, and basic block BB parameters.  */
-
-static struct seginfo *
-new_seginfo (int mode, rtx insn, int bb, HARD_REG_SET regs_live)
-{
-  struct seginfo *ptr;
-  ptr = xmalloc (sizeof (struct seginfo));
-  ptr->mode = mode;
-  ptr->insn_ptr = insn;
-  ptr->bbnum = bb;
-  ptr->next = NULL;
-  COPY_HARD_REG_SET (ptr->regs_live, regs_live);
-  return ptr;
-}
-
-/* Add a seginfo element to the end of a list.
-   HEAD is a pointer to the list beginning.
-   INFO is the structure to be linked in.  */
-
-static void
-add_seginfo (struct bb_info *head, struct seginfo *info)
-{
-  struct seginfo *ptr;
-
-  if (head->seginfo == NULL)
-    head->seginfo = info;
-  else
-    {
-      ptr = head->seginfo;
-      while (ptr->next != NULL)
-	ptr = ptr->next;
-      ptr->next = info;
-    }
-}
-
-/* Make all predecessors of basic block B opaque, recursively, till we hit
-   some that are already non-transparent, or an edge where aux is set; that
-   denotes that a mode set is to be done on that edge.
-   J is the bit number in the bitmaps that corresponds to the entity that
-   we are currently handling mode-switching for.  */
-
-static void
-make_preds_opaque (basic_block b, int j)
-{
-  edge e;
-  edge_iterator ei;
-
-  FOR_EACH_EDGE (e, ei, b->preds)
-    {
-      basic_block pb = e->src;
-
-      if (e->aux || ! TEST_BIT (transp[pb->index], j))
-	continue;
-
-      RESET_BIT (transp[pb->index], j);
-      make_preds_opaque (pb, j);
-    }
-}
-
-/* Record in LIVE that register REG died.  */
-
-static void
-reg_dies (rtx reg, HARD_REG_SET live)
-{
-  int regno, nregs;
-
-  if (!REG_P (reg))
-    return;
-
-  regno = REGNO (reg);
-  if (regno < FIRST_PSEUDO_REGISTER)
-    for (nregs = hard_regno_nregs[regno][GET_MODE (reg)] - 1; nregs >= 0;
-	 nregs--)
-      CLEAR_HARD_REG_BIT (live, regno + nregs);
-}
-
-/* Record in LIVE that register REG became live.
-   This is called via note_stores.  */
-
-static void
-reg_becomes_live (rtx reg, rtx setter ATTRIBUTE_UNUSED, void *live)
-{
-  int regno, nregs;
-
-  if (GET_CODE (reg) == SUBREG)
-    reg = SUBREG_REG (reg);
-
-  if (!REG_P (reg))
-    return;
-
-  regno = REGNO (reg);
-  if (regno < FIRST_PSEUDO_REGISTER)
-    for (nregs = hard_regno_nregs[regno][GET_MODE (reg)] - 1; nregs >= 0;
-	 nregs--)
-      SET_HARD_REG_BIT (* (HARD_REG_SET *) live, regno + nregs);
-}
-
-/* Make sure if MODE_ENTRY is defined the MODE_EXIT is defined
-   and vice versa.  */
-#if defined (MODE_ENTRY) != defined (MODE_EXIT)
- #error "Both MODE_ENTRY and MODE_EXIT must be defined"
-#endif
-
-#if defined (MODE_ENTRY) && defined (MODE_EXIT)
-/* Split the fallthrough edge to the exit block, so that we can note
-   that there NORMAL_MODE is required.  Return the new block if it's
-   inserted before the exit block.  Otherwise return null.  */
-
-static basic_block
-create_pre_exit (int n_entities, int *entity_map, const int *num_modes)
-{
-  edge eg;
-  edge_iterator ei;
-  basic_block pre_exit;
-
-  /* The only non-call predecessor at this stage is a block with a
-     fallthrough edge; there can be at most one, but there could be
-     none at all, e.g. when exit is called.  */
-  pre_exit = 0;
-  FOR_EACH_EDGE (eg, ei, EXIT_BLOCK_PTR->preds)
-    if (eg->flags & EDGE_FALLTHRU)
-      {
-	basic_block src_bb = eg->src;
-	regset live_at_end = src_bb->global_live_at_end;
-	rtx last_insn, ret_reg;
-
-	gcc_assert (!pre_exit);
-	/* If this function returns a value at the end, we have to
-	   insert the final mode switch before the return value copy
-	   to its hard register.  */
-	if (EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 1
-	    && NONJUMP_INSN_P ((last_insn = BB_END (src_bb)))
-	    && GET_CODE (PATTERN (last_insn)) == USE
-	    && GET_CODE ((ret_reg = XEXP (PATTERN (last_insn), 0))) == REG)
-	  {
-	    int ret_start = REGNO (ret_reg);
-	    int nregs = hard_regno_nregs[ret_start][GET_MODE (ret_reg)];
-	    int ret_end = ret_start + nregs;
-	    int short_block = 0;
-	    int maybe_builtin_apply = 0;
-	    int forced_late_switch = 0;
-	    rtx before_return_copy;
-
-	    do
-	      {
-		rtx return_copy = PREV_INSN (last_insn);
-		rtx return_copy_pat, copy_reg;
-		int copy_start, copy_num;
-		int j;
-
-		if (INSN_P (return_copy))
-		  {
-		    if (GET_CODE (PATTERN (return_copy)) == USE
-			&& GET_CODE (XEXP (PATTERN (return_copy), 0)) == REG
-			&& (FUNCTION_VALUE_REGNO_P
-			    (REGNO (XEXP (PATTERN (return_copy), 0)))))
-		      {
-			maybe_builtin_apply = 1;
-			last_insn = return_copy;
-			continue;
-		      }
-		    /* If the return register is not (in its entirety)
-		       likely spilled, the return copy might be
-		       partially or completely optimized away.  */
-		    return_copy_pat = single_set (return_copy);
-		    if (!return_copy_pat)
-		      {
-			return_copy_pat = PATTERN (return_copy);
-			if (GET_CODE (return_copy_pat) != CLOBBER)
-			  break;
-		      }
-		    copy_reg = SET_DEST (return_copy_pat);
-		    if (GET_CODE (copy_reg) == REG)
-		      copy_start = REGNO (copy_reg);
-		    else if (GET_CODE (copy_reg) == SUBREG
-			     && GET_CODE (SUBREG_REG (copy_reg)) == REG)
-		      copy_start = REGNO (SUBREG_REG (copy_reg));
-		    else
-		      break;
-		    if (copy_start >= FIRST_PSEUDO_REGISTER)
-		      break;
-		    copy_num
-		      = hard_regno_nregs[copy_start][GET_MODE (copy_reg)];
-
-		    /* If the return register is not likely spilled, - as is
-		       the case for floating point on SH4 - then it might
-		       be set by an arithmetic operation that needs a
-		       different mode than the exit block.  */
-		    for (j = n_entities - 1; j >= 0; j--)
-		      {
-			int e = entity_map[j];
-			int mode = MODE_NEEDED (e, return_copy);
-
-			if (mode != num_modes[e] && mode != MODE_EXIT (e))
-			  break;
-		      }
-		    if (j >= 0)
-		      {
-			/* For the SH4, floating point loads depend on fpscr,
-			   thus we might need to put the final mode switch
-			   after the return value copy.  That is still OK,
-			   because a floating point return value does not
-			   conflict with address reloads.  */
-			if (copy_start >= ret_start
-			    && copy_start + copy_num <= ret_end
-			    && OBJECT_P (SET_SRC (return_copy_pat)))
-			  forced_late_switch = 1;
-			break;
-		      }
-
-		    if (copy_start >= ret_start
-			&& copy_start + copy_num <= ret_end)
-		      nregs -= copy_num;
-		    else if (!maybe_builtin_apply
-			     || !FUNCTION_VALUE_REGNO_P (copy_start))
-		      break;
-		    last_insn = return_copy;
-		  }
-		/* ??? Exception handling can lead to the return value
-		   copy being already separated from the return value use,
-		   as in  unwind-dw2.c .
-		   Similarly, conditionally returning without a value,
-		   and conditionally using builtin_return can lead to an
-		   isolated use.  */
-		if (return_copy == BB_HEAD (src_bb))
-		  {
-		    short_block = 1;
-		    break;
-		  }
-		last_insn = return_copy;
-	      }
-	    while (nregs);
-	    
-	    /* If we didn't see a full return value copy, verify that there
-	       is a plausible reason for this.  If some, but not all of the
-	       return register is likely spilled, we can expect that there
-	       is a copy for the likely spilled part.  */
-	    gcc_assert (!nregs
-			|| forced_late_switch
-			|| short_block
-			|| !(CLASS_LIKELY_SPILLED_P
-			     (REGNO_REG_CLASS (ret_start)))
-			|| (nregs
-			    != hard_regno_nregs[ret_start][GET_MODE (ret_reg)])
-			/* For multi-hard-register floating point
-		   	   values, sometimes the likely-spilled part
-		   	   is ordinarily copied first, then the other
-		   	   part is set with an arithmetic operation.
-		   	   This doesn't actually cause reload
-		   	   failures, so let it pass.  */
-			|| (GET_MODE_CLASS (GET_MODE (ret_reg)) != MODE_INT
-			    && nregs != 1));
-	    
-	    if (INSN_P (last_insn))
-	      {
-		before_return_copy
-		  = emit_note_before (NOTE_INSN_DELETED, last_insn);
-		/* Instructions preceding LAST_INSN in the same block might
-		   require a different mode than MODE_EXIT, so if we might
-		   have such instructions, keep them in a separate block
-		   from pre_exit.  */
-		if (last_insn != BB_HEAD (src_bb))
-		  src_bb = split_block (src_bb,
-					PREV_INSN (before_return_copy))->dest;
-	      }
-	    else
-	      before_return_copy = last_insn;
-	    pre_exit = split_block (src_bb, before_return_copy)->src;
-	  }
-	else
-	  {
-	    pre_exit = split_edge (eg);
-	    COPY_REG_SET (pre_exit->global_live_at_start, live_at_end);
-	    COPY_REG_SET (pre_exit->global_live_at_end, live_at_end);
-	  }
-      }
-
-  return pre_exit;
-}
-#endif
-
-/* Find all insns that need a particular mode setting, and insert the
-   necessary mode switches.  Return true if we did work.  */
-
-int
-optimize_mode_switching (FILE *file)
-{
-  rtx insn;
-  int e;
-  basic_block bb;
-  int need_commit = 0;
-  sbitmap *kill;
-  struct edge_list *edge_list;
-  static const int num_modes[] = NUM_MODES_FOR_MODE_SWITCHING;
-#define N_ENTITIES ARRAY_SIZE (num_modes)
-  int entity_map[N_ENTITIES];
-  struct bb_info *bb_info[N_ENTITIES];
-  int i, j;
-  int n_entities;
-  int max_num_modes = 0;
-  bool emited = false;
-  basic_block post_entry ATTRIBUTE_UNUSED, pre_exit ATTRIBUTE_UNUSED;
-
-  clear_bb_flags ();
-
-  for (e = N_ENTITIES - 1, n_entities = 0; e >= 0; e--)
-    if (OPTIMIZE_MODE_SWITCHING (e))
-      {
-	int entry_exit_extra = 0;
-
-	/* Create the list of segments within each basic block.
-	   If NORMAL_MODE is defined, allow for two extra
-	   blocks split from the entry and exit block.  */
-#if defined (MODE_ENTRY) && defined (MODE_EXIT)
-	entry_exit_extra = 3;
-#endif
-	bb_info[n_entities]
-	  = xcalloc (last_basic_block + entry_exit_extra, sizeof **bb_info);
-	entity_map[n_entities++] = e;
-	if (num_modes[e] > max_num_modes)
-	  max_num_modes = num_modes[e];
-      }
-
-  if (! n_entities)
-    return 0;
-
-#if defined (MODE_ENTRY) && defined (MODE_EXIT)
-  /* Split the edge from the entry block, so that we can note that
-     there NORMAL_MODE is supplied.  */
-  post_entry = split_edge (single_succ_edge (ENTRY_BLOCK_PTR));
-  pre_exit = create_pre_exit (n_entities, entity_map, num_modes);
-#endif
-
-  /* Create the bitmap vectors.  */
-
-  antic = sbitmap_vector_alloc (last_basic_block, n_entities);
-  transp = sbitmap_vector_alloc (last_basic_block, n_entities);
-  comp = sbitmap_vector_alloc (last_basic_block, n_entities);
-
-  sbitmap_vector_ones (transp, last_basic_block);
-
-  for (j = n_entities - 1; j >= 0; j--)
-    {
-      int e = entity_map[j];
-      int no_mode = num_modes[e];
-      struct bb_info *info = bb_info[j];
-
-      /* Determine what the first use (if any) need for a mode of entity E is.
-	 This will be the mode that is anticipatable for this block.
-	 Also compute the initial transparency settings.  */
-      FOR_EACH_BB (bb)
-	{
-	  struct seginfo *ptr;
-	  int last_mode = no_mode;
-	  HARD_REG_SET live_now;
-
-	  REG_SET_TO_HARD_REG_SET (live_now,
-				   bb->global_live_at_start);
-	  for (insn = BB_HEAD (bb);
-	       insn != NULL && insn != NEXT_INSN (BB_END (bb));
-	       insn = NEXT_INSN (insn))
-	    {
-	      if (INSN_P (insn))
-		{
-		  int mode = MODE_NEEDED (e, insn);
-		  rtx link;
-
-		  if (mode != no_mode && mode != last_mode)
-		    {
-		      last_mode = mode;
-		      ptr = new_seginfo (mode, insn, bb->index, live_now);
-		      add_seginfo (info + bb->index, ptr);
-		      RESET_BIT (transp[bb->index], j);
-		    }
-#ifdef MODE_AFTER
-		  last_mode = MODE_AFTER (last_mode, insn);
-#endif
-		  /* Update LIVE_NOW.  */
-		  for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
-		    if (REG_NOTE_KIND (link) == REG_DEAD)
-		      reg_dies (XEXP (link, 0), live_now);
-
-		  note_stores (PATTERN (insn), reg_becomes_live, &live_now);
-		  for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
-		    if (REG_NOTE_KIND (link) == REG_UNUSED)
-		      reg_dies (XEXP (link, 0), live_now);
-		}
-	    }
-
-	  info[bb->index].computing = last_mode;
-	  /* Check for blocks without ANY mode requirements.  */
-	  if (last_mode == no_mode)
-	    {
-	      ptr = new_seginfo (no_mode, BB_END (bb), bb->index, live_now);
-	      add_seginfo (info + bb->index, ptr);
-	    }
-	}
-#if defined (MODE_ENTRY) && defined (MODE_EXIT)
-      {
-	int mode = MODE_ENTRY (e);
-
-	if (mode != no_mode)
-	  {
-	    bb = post_entry;
-
-	    /* By always making this nontransparent, we save
-	       an extra check in make_preds_opaque.  We also
-	       need this to avoid confusing pre_edge_lcm when
-	       antic is cleared but transp and comp are set.  */
-	    RESET_BIT (transp[bb->index], j);
-
-	    /* Insert a fake computing definition of MODE into entry
-	       blocks which compute no mode. This represents the mode on
-	       entry.  */
-	    info[bb->index].computing = mode;
-
-	    if (pre_exit)
-	      info[pre_exit->index].seginfo->mode = MODE_EXIT (e);
-	  }
-      }
-#endif /* NORMAL_MODE */
-    }
-
-  kill = sbitmap_vector_alloc (last_basic_block, n_entities);
-  for (i = 0; i < max_num_modes; i++)
-    {
-      int current_mode[N_ENTITIES];
-      sbitmap *delete;
-      sbitmap *insert;
-
-      /* Set the anticipatable and computing arrays.  */
-      sbitmap_vector_zero (antic, last_basic_block);
-      sbitmap_vector_zero (comp, last_basic_block);
-      for (j = n_entities - 1; j >= 0; j--)
-	{
-	  int m = current_mode[j] = MODE_PRIORITY_TO_MODE (entity_map[j], i);
-	  struct bb_info *info = bb_info[j];
-
-	  FOR_EACH_BB (bb)
-	    {
-	      if (info[bb->index].seginfo->mode == m)
-		SET_BIT (antic[bb->index], j);
-
-	      if (info[bb->index].computing == m)
-		SET_BIT (comp[bb->index], j);
-	    }
-	}
-
-      /* Calculate the optimal locations for the
-	 placement mode switches to modes with priority I.  */
-
-      FOR_EACH_BB (bb)
-	sbitmap_not (kill[bb->index], transp[bb->index]);
-      edge_list = pre_edge_lcm (file, 1, transp, comp, antic,
-				kill, &insert, &delete);
-
-      for (j = n_entities - 1; j >= 0; j--)
-	{
-	  /* Insert all mode sets that have been inserted by lcm.  */
-	  int no_mode = num_modes[entity_map[j]];
-
-	  /* Wherever we have moved a mode setting upwards in the flow graph,
-	     the blocks between the new setting site and the now redundant
-	     computation ceases to be transparent for any lower-priority
-	     mode of the same entity.  First set the aux field of each
-	     insertion site edge non-transparent, then propagate the new
-	     non-transparency from the redundant computation upwards till
-	     we hit an insertion site or an already non-transparent block.  */
-	  for (e = NUM_EDGES (edge_list) - 1; e >= 0; e--)
-	    {
-	      edge eg = INDEX_EDGE (edge_list, e);
-	      int mode;
-	      basic_block src_bb;
-	      HARD_REG_SET live_at_edge;
-	      rtx mode_set;
-
-	      eg->aux = 0;
-
-	      if (! TEST_BIT (insert[e], j))
-		continue;
-
-	      eg->aux = (void *)1;
-
-	      mode = current_mode[j];
-	      src_bb = eg->src;
-
-	      REG_SET_TO_HARD_REG_SET (live_at_edge,
-				       src_bb->global_live_at_end);
-
-	      start_sequence ();
-	      EMIT_MODE_SET (entity_map[j], mode, live_at_edge);
-	      mode_set = get_insns ();
-	      end_sequence ();
-
-	      /* Do not bother to insert empty sequence.  */
-	      if (mode_set == NULL_RTX)
-		continue;
-
-	      /* If this is an abnormal edge, we'll insert at the end
-		 of the previous block.  */
-	      if (eg->flags & EDGE_ABNORMAL)
-		{
-		  emited = true;
-		  if (JUMP_P (BB_END (src_bb)))
-		    emit_insn_before (mode_set, BB_END (src_bb));
-		  else
-		    {
-		      /* It doesn't make sense to switch to normal
-		         mode after a CALL_INSN.  The cases in which a
-		         CALL_INSN may have an abnormal edge are
-		         sibcalls and EH edges.  In the case of
-		         sibcalls, the dest basic-block is the
-		         EXIT_BLOCK, that runs in normal mode; it is
-		         assumed that a sibcall insn requires normal
-		         mode itself, so no mode switch would be
-		         required after the call (it wouldn't make
-		         sense, anyway).  In the case of EH edges, EH
-		         entry points also start in normal mode, so a
-		         similar reasoning applies.  */
-		      gcc_assert (NONJUMP_INSN_P (BB_END (src_bb)));
-		      emit_insn_after (mode_set, BB_END (src_bb));
-		    }
-		  bb_info[j][src_bb->index].computing = mode;
-		  RESET_BIT (transp[src_bb->index], j);
-		}
-	      else
-		{
-		  need_commit = 1;
-		  insert_insn_on_edge (mode_set, eg);
-		}
-	    }
-
-	  FOR_EACH_BB_REVERSE (bb)
-	    if (TEST_BIT (delete[bb->index], j))
-	      {
-		make_preds_opaque (bb, j);
-		/* Cancel the 'deleted' mode set.  */
-		bb_info[j][bb->index].seginfo->mode = no_mode;
-	      }
-	}
-
-      sbitmap_vector_free (delete);
-      sbitmap_vector_free (insert);
-      clear_aux_for_edges ();
-      free_edge_list (edge_list);
-    }
-
-  /* Now output the remaining mode sets in all the segments.  */
-  for (j = n_entities - 1; j >= 0; j--)
-    {
-      int no_mode = num_modes[entity_map[j]];
-
-      FOR_EACH_BB_REVERSE (bb)
-	{
-	  struct seginfo *ptr, *next;
-	  for (ptr = bb_info[j][bb->index].seginfo; ptr; ptr = next)
-	    {
-	      next = ptr->next;
-	      if (ptr->mode != no_mode)
-		{
-		  rtx mode_set;
-
-		  start_sequence ();
-		  EMIT_MODE_SET (entity_map[j], ptr->mode, ptr->regs_live);
-		  mode_set = get_insns ();
-		  end_sequence ();
-
-		  /* Insert MODE_SET only if it is nonempty.  */
-		  if (mode_set != NULL_RTX)
-		    {
-		      emited = true;
-		      if (NOTE_P (ptr->insn_ptr)
-			  && (NOTE_LINE_NUMBER (ptr->insn_ptr)
-			      == NOTE_INSN_BASIC_BLOCK))
-			emit_insn_after (mode_set, ptr->insn_ptr);
-		      else
-			emit_insn_before (mode_set, ptr->insn_ptr);
-		    }
-		}
-
-	      free (ptr);
-	    }
-	}
-
-      free (bb_info[j]);
-    }
-
-  /* Finished. Free up all the things we've allocated.  */
-
-  sbitmap_vector_free (kill);
-  sbitmap_vector_free (antic);
-  sbitmap_vector_free (transp);
-  sbitmap_vector_free (comp);
-
-  if (need_commit)
-    commit_edge_insertions ();
-
-#if defined (MODE_ENTRY) && defined (MODE_EXIT)
-  cleanup_cfg (CLEANUP_NO_INSN_DEL);
-#else
-  if (!need_commit && !emited)
-    return 0;
-#endif
-
-  max_regno = max_reg_num ();
-  allocate_reg_info (max_regno, FALSE, FALSE);
-  update_life_info_in_dirty_blocks (UPDATE_LIFE_GLOBAL_RM_NOTES,
-				    (PROP_DEATH_NOTES | PROP_KILL_DEAD_CODE
-				     | PROP_SCAN_DEAD_CODE));
-
-  return 1;
-}
-#endif /* OPTIMIZE_MODE_SWITCHING */
diff --git a/gcc/mode-switching.c b/gcc/mode-switching.c
new file mode 100644
index 00000000000..57eb1d21dc1
--- /dev/null
+++ b/gcc/mode-switching.c
@@ -0,0 +1,711 @@
+/* CPU mode switching
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
+   Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "rtl.h"
+#include "regs.h"
+#include "hard-reg-set.h"
+#include "flags.h"
+#include "real.h"
+#include "insn-config.h"
+#include "recog.h"
+#include "basic-block.h"
+#include "output.h"
+#include "tm_p.h"
+#include "function.h"
+
+/* We want target macros for the mode switching code to be able to refer
+   to instruction attribute values.  */
+#include "insn-attr.h"
+
+#ifdef OPTIMIZE_MODE_SWITCHING
+
+/* The algorithm for setting the modes consists of scanning the insn list
+   and finding all the insns which require a specific mode.  Each insn gets
+   a unique struct seginfo element.  These structures are inserted into a list
+   for each basic block.  For each entity, there is an array of bb_info over
+   the flow graph basic blocks (local var 'bb_info'), and contains a list
+   of all insns within that basic block, in the order they are encountered.
+
+   For each entity, any basic block WITHOUT any insns requiring a specific
+   mode are given a single entry, without a mode.  (Each basic block
+   in the flow graph must have at least one entry in the segment table.)
+
+   The LCM algorithm is then run over the flow graph to determine where to
+   place the sets to the highest-priority value in respect of first the first
+   insn in any one block.  Any adjustments required to the transparency
+   vectors are made, then the next iteration starts for the next-lower
+   priority mode, till for each entity all modes are exhausted.
+
+   More details are located in the code for optimize_mode_switching().  */
+
+/* This structure contains the information for each insn which requires
+   either single or double mode to be set.
+   MODE is the mode this insn must be executed in.
+   INSN_PTR is the insn to be executed (may be the note that marks the
+   beginning of a basic block).
+   BBNUM is the flow graph basic block this insn occurs in.
+   NEXT is the next insn in the same basic block.  */
+struct seginfo
+{
+  int mode;
+  rtx insn_ptr;
+  int bbnum;
+  struct seginfo *next;
+  HARD_REG_SET regs_live;
+};
+
+struct bb_info
+{
+  struct seginfo *seginfo;
+  int computing;
+};
+
+/* These bitmaps are used for the LCM algorithm.  */
+
+static sbitmap *antic;
+static sbitmap *transp;
+static sbitmap *comp;
+
+static struct seginfo * new_seginfo (int, rtx, int, HARD_REG_SET);
+static void add_seginfo (struct bb_info *, struct seginfo *);
+static void reg_dies (rtx, HARD_REG_SET);
+static void reg_becomes_live (rtx, rtx, void *);
+static void make_preds_opaque (basic_block, int);
+
+
+/* This function will allocate a new BBINFO structure, initialized
+   with the MODE, INSN, and basic block BB parameters.  */
+
+static struct seginfo *
+new_seginfo (int mode, rtx insn, int bb, HARD_REG_SET regs_live)
+{
+  struct seginfo *ptr;
+  ptr = xmalloc (sizeof (struct seginfo));
+  ptr->mode = mode;
+  ptr->insn_ptr = insn;
+  ptr->bbnum = bb;
+  ptr->next = NULL;
+  COPY_HARD_REG_SET (ptr->regs_live, regs_live);
+  return ptr;
+}
+
+/* Add a seginfo element to the end of a list.
+   HEAD is a pointer to the list beginning.
+   INFO is the structure to be linked in.  */
+
+static void
+add_seginfo (struct bb_info *head, struct seginfo *info)
+{
+  struct seginfo *ptr;
+
+  if (head->seginfo == NULL)
+    head->seginfo = info;
+  else
+    {
+      ptr = head->seginfo;
+      while (ptr->next != NULL)
+	ptr = ptr->next;
+      ptr->next = info;
+    }
+}
+
+/* Make all predecessors of basic block B opaque, recursively, till we hit
+   some that are already non-transparent, or an edge where aux is set; that
+   denotes that a mode set is to be done on that edge.
+   J is the bit number in the bitmaps that corresponds to the entity that
+   we are currently handling mode-switching for.  */
+
+static void
+make_preds_opaque (basic_block b, int j)
+{
+  edge e;
+  edge_iterator ei;
+
+  FOR_EACH_EDGE (e, ei, b->preds)
+    {
+      basic_block pb = e->src;
+
+      if (e->aux || ! TEST_BIT (transp[pb->index], j))
+	continue;
+
+      RESET_BIT (transp[pb->index], j);
+      make_preds_opaque (pb, j);
+    }
+}
+
+/* Record in LIVE that register REG died.  */
+
+static void
+reg_dies (rtx reg, HARD_REG_SET live)
+{
+  int regno, nregs;
+
+  if (!REG_P (reg))
+    return;
+
+  regno = REGNO (reg);
+  if (regno < FIRST_PSEUDO_REGISTER)
+    for (nregs = hard_regno_nregs[regno][GET_MODE (reg)] - 1; nregs >= 0;
+	 nregs--)
+      CLEAR_HARD_REG_BIT (live, regno + nregs);
+}
+
+/* Record in LIVE that register REG became live.
+   This is called via note_stores.  */
+
+static void
+reg_becomes_live (rtx reg, rtx setter ATTRIBUTE_UNUSED, void *live)
+{
+  int regno, nregs;
+
+  if (GET_CODE (reg) == SUBREG)
+    reg = SUBREG_REG (reg);
+
+  if (!REG_P (reg))
+    return;
+
+  regno = REGNO (reg);
+  if (regno < FIRST_PSEUDO_REGISTER)
+    for (nregs = hard_regno_nregs[regno][GET_MODE (reg)] - 1; nregs >= 0;
+	 nregs--)
+      SET_HARD_REG_BIT (* (HARD_REG_SET *) live, regno + nregs);
+}
+
+/* Make sure if MODE_ENTRY is defined the MODE_EXIT is defined
+   and vice versa.  */
+#if defined (MODE_ENTRY) != defined (MODE_EXIT)
+ #error "Both MODE_ENTRY and MODE_EXIT must be defined"
+#endif
+
+#if defined (MODE_ENTRY) && defined (MODE_EXIT)
+/* Split the fallthrough edge to the exit block, so that we can note
+   that there NORMAL_MODE is required.  Return the new block if it's
+   inserted before the exit block.  Otherwise return null.  */
+
+static basic_block
+create_pre_exit (int n_entities, int *entity_map, const int *num_modes)
+{
+  edge eg;
+  edge_iterator ei;
+  basic_block pre_exit;
+
+  /* The only non-call predecessor at this stage is a block with a
+     fallthrough edge; there can be at most one, but there could be
+     none at all, e.g. when exit is called.  */
+  pre_exit = 0;
+  FOR_EACH_EDGE (eg, ei, EXIT_BLOCK_PTR->preds)
+    if (eg->flags & EDGE_FALLTHRU)
+      {
+	basic_block src_bb = eg->src;
+	regset live_at_end = src_bb->global_live_at_end;
+	rtx last_insn, ret_reg;
+
+	gcc_assert (!pre_exit);
+	/* If this function returns a value at the end, we have to
+	   insert the final mode switch before the return value copy
+	   to its hard register.  */
+	if (EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 1
+	    && NONJUMP_INSN_P ((last_insn = BB_END (src_bb)))
+	    && GET_CODE (PATTERN (last_insn)) == USE
+	    && GET_CODE ((ret_reg = XEXP (PATTERN (last_insn), 0))) == REG)
+	  {
+	    int ret_start = REGNO (ret_reg);
+	    int nregs = hard_regno_nregs[ret_start][GET_MODE (ret_reg)];
+	    int ret_end = ret_start + nregs;
+	    int short_block = 0;
+	    int maybe_builtin_apply = 0;
+	    int forced_late_switch = 0;
+	    rtx before_return_copy;
+
+	    do
+	      {
+		rtx return_copy = PREV_INSN (last_insn);
+		rtx return_copy_pat, copy_reg;
+		int copy_start, copy_num;
+		int j;
+
+		if (INSN_P (return_copy))
+		  {
+		    if (GET_CODE (PATTERN (return_copy)) == USE
+			&& GET_CODE (XEXP (PATTERN (return_copy), 0)) == REG
+			&& (FUNCTION_VALUE_REGNO_P
+			    (REGNO (XEXP (PATTERN (return_copy), 0)))))
+		      {
+			maybe_builtin_apply = 1;
+			last_insn = return_copy;
+			continue;
+		      }
+		    /* If the return register is not (in its entirety)
+		       likely spilled, the return copy might be
+		       partially or completely optimized away.  */
+		    return_copy_pat = single_set (return_copy);
+		    if (!return_copy_pat)
+		      {
+			return_copy_pat = PATTERN (return_copy);
+			if (GET_CODE (return_copy_pat) != CLOBBER)
+			  break;
+		      }
+		    copy_reg = SET_DEST (return_copy_pat);
+		    if (GET_CODE (copy_reg) == REG)
+		      copy_start = REGNO (copy_reg);
+		    else if (GET_CODE (copy_reg) == SUBREG
+			     && GET_CODE (SUBREG_REG (copy_reg)) == REG)
+		      copy_start = REGNO (SUBREG_REG (copy_reg));
+		    else
+		      break;
+		    if (copy_start >= FIRST_PSEUDO_REGISTER)
+		      break;
+		    copy_num
+		      = hard_regno_nregs[copy_start][GET_MODE (copy_reg)];
+
+		    /* If the return register is not likely spilled, - as is
+		       the case for floating point on SH4 - then it might
+		       be set by an arithmetic operation that needs a
+		       different mode than the exit block.  */
+		    for (j = n_entities - 1; j >= 0; j--)
+		      {
+			int e = entity_map[j];
+			int mode = MODE_NEEDED (e, return_copy);
+
+			if (mode != num_modes[e] && mode != MODE_EXIT (e))
+			  break;
+		      }
+		    if (j >= 0)
+		      {
+			/* For the SH4, floating point loads depend on fpscr,
+			   thus we might need to put the final mode switch
+			   after the return value copy.  That is still OK,
+			   because a floating point return value does not
+			   conflict with address reloads.  */
+			if (copy_start >= ret_start
+			    && copy_start + copy_num <= ret_end
+			    && OBJECT_P (SET_SRC (return_copy_pat)))
+			  forced_late_switch = 1;
+			break;
+		      }
+
+		    if (copy_start >= ret_start
+			&& copy_start + copy_num <= ret_end)
+		      nregs -= copy_num;
+		    else if (!maybe_builtin_apply
+			     || !FUNCTION_VALUE_REGNO_P (copy_start))
+		      break;
+		    last_insn = return_copy;
+		  }
+		/* ??? Exception handling can lead to the return value
+		   copy being already separated from the return value use,
+		   as in  unwind-dw2.c .
+		   Similarly, conditionally returning without a value,
+		   and conditionally using builtin_return can lead to an
+		   isolated use.  */
+		if (return_copy == BB_HEAD (src_bb))
+		  {
+		    short_block = 1;
+		    break;
+		  }
+		last_insn = return_copy;
+	      }
+	    while (nregs);
+	    
+	    /* If we didn't see a full return value copy, verify that there
+	       is a plausible reason for this.  If some, but not all of the
+	       return register is likely spilled, we can expect that there
+	       is a copy for the likely spilled part.  */
+	    gcc_assert (!nregs
+			|| forced_late_switch
+			|| short_block
+			|| !(CLASS_LIKELY_SPILLED_P
+			     (REGNO_REG_CLASS (ret_start)))
+			|| (nregs
+			    != hard_regno_nregs[ret_start][GET_MODE (ret_reg)])
+			/* For multi-hard-register floating point
+		   	   values, sometimes the likely-spilled part
+		   	   is ordinarily copied first, then the other
+		   	   part is set with an arithmetic operation.
+		   	   This doesn't actually cause reload
+		   	   failures, so let it pass.  */
+			|| (GET_MODE_CLASS (GET_MODE (ret_reg)) != MODE_INT
+			    && nregs != 1));
+	    
+	    if (INSN_P (last_insn))
+	      {
+		before_return_copy
+		  = emit_note_before (NOTE_INSN_DELETED, last_insn);
+		/* Instructions preceding LAST_INSN in the same block might
+		   require a different mode than MODE_EXIT, so if we might
+		   have such instructions, keep them in a separate block
+		   from pre_exit.  */
+		if (last_insn != BB_HEAD (src_bb))
+		  src_bb = split_block (src_bb,
+					PREV_INSN (before_return_copy))->dest;
+	      }
+	    else
+	      before_return_copy = last_insn;
+	    pre_exit = split_block (src_bb, before_return_copy)->src;
+	  }
+	else
+	  {
+	    pre_exit = split_edge (eg);
+	    COPY_REG_SET (pre_exit->global_live_at_start, live_at_end);
+	    COPY_REG_SET (pre_exit->global_live_at_end, live_at_end);
+	  }
+      }
+
+  return pre_exit;
+}
+#endif
+
+/* Find all insns that need a particular mode setting, and insert the
+   necessary mode switches.  Return true if we did work.  */
+
+int
+optimize_mode_switching (FILE *file)
+{
+  rtx insn;
+  int e;
+  basic_block bb;
+  int need_commit = 0;
+  sbitmap *kill;
+  struct edge_list *edge_list;
+  static const int num_modes[] = NUM_MODES_FOR_MODE_SWITCHING;
+#define N_ENTITIES ARRAY_SIZE (num_modes)
+  int entity_map[N_ENTITIES];
+  struct bb_info *bb_info[N_ENTITIES];
+  int i, j;
+  int n_entities;
+  int max_num_modes = 0;
+  bool emited = false;
+  basic_block post_entry ATTRIBUTE_UNUSED, pre_exit ATTRIBUTE_UNUSED;
+
+  clear_bb_flags ();
+
+  for (e = N_ENTITIES - 1, n_entities = 0; e >= 0; e--)
+    if (OPTIMIZE_MODE_SWITCHING (e))
+      {
+	int entry_exit_extra = 0;
+
+	/* Create the list of segments within each basic block.
+	   If NORMAL_MODE is defined, allow for two extra
+	   blocks split from the entry and exit block.  */
+#if defined (MODE_ENTRY) && defined (MODE_EXIT)
+	entry_exit_extra = 3;
+#endif
+	bb_info[n_entities]
+	  = xcalloc (last_basic_block + entry_exit_extra, sizeof **bb_info);
+	entity_map[n_entities++] = e;
+	if (num_modes[e] > max_num_modes)
+	  max_num_modes = num_modes[e];
+      }
+
+  if (! n_entities)
+    return 0;
+
+#if defined (MODE_ENTRY) && defined (MODE_EXIT)
+  /* Split the edge from the entry block, so that we can note that
+     there NORMAL_MODE is supplied.  */
+  post_entry = split_edge (single_succ_edge (ENTRY_BLOCK_PTR));
+  pre_exit = create_pre_exit (n_entities, entity_map, num_modes);
+#endif
+
+  /* Create the bitmap vectors.  */
+
+  antic = sbitmap_vector_alloc (last_basic_block, n_entities);
+  transp = sbitmap_vector_alloc (last_basic_block, n_entities);
+  comp = sbitmap_vector_alloc (last_basic_block, n_entities);
+
+  sbitmap_vector_ones (transp, last_basic_block);
+
+  for (j = n_entities - 1; j >= 0; j--)
+    {
+      int e = entity_map[j];
+      int no_mode = num_modes[e];
+      struct bb_info *info = bb_info[j];
+
+      /* Determine what the first use (if any) need for a mode of entity E is.
+	 This will be the mode that is anticipatable for this block.
+	 Also compute the initial transparency settings.  */
+      FOR_EACH_BB (bb)
+	{
+	  struct seginfo *ptr;
+	  int last_mode = no_mode;
+	  HARD_REG_SET live_now;
+
+	  REG_SET_TO_HARD_REG_SET (live_now,
+				   bb->global_live_at_start);
+	  for (insn = BB_HEAD (bb);
+	       insn != NULL && insn != NEXT_INSN (BB_END (bb));
+	       insn = NEXT_INSN (insn))
+	    {
+	      if (INSN_P (insn))
+		{
+		  int mode = MODE_NEEDED (e, insn);
+		  rtx link;
+
+		  if (mode != no_mode && mode != last_mode)
+		    {
+		      last_mode = mode;
+		      ptr = new_seginfo (mode, insn, bb->index, live_now);
+		      add_seginfo (info + bb->index, ptr);
+		      RESET_BIT (transp[bb->index], j);
+		    }
+#ifdef MODE_AFTER
+		  last_mode = MODE_AFTER (last_mode, insn);
+#endif
+		  /* Update LIVE_NOW.  */
+		  for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+		    if (REG_NOTE_KIND (link) == REG_DEAD)
+		      reg_dies (XEXP (link, 0), live_now);
+
+		  note_stores (PATTERN (insn), reg_becomes_live, &live_now);
+		  for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+		    if (REG_NOTE_KIND (link) == REG_UNUSED)
+		      reg_dies (XEXP (link, 0), live_now);
+		}
+	    }
+
+	  info[bb->index].computing = last_mode;
+	  /* Check for blocks without ANY mode requirements.  */
+	  if (last_mode == no_mode)
+	    {
+	      ptr = new_seginfo (no_mode, BB_END (bb), bb->index, live_now);
+	      add_seginfo (info + bb->index, ptr);
+	    }
+	}
+#if defined (MODE_ENTRY) && defined (MODE_EXIT)
+      {
+	int mode = MODE_ENTRY (e);
+
+	if (mode != no_mode)
+	  {
+	    bb = post_entry;
+
+	    /* By always making this nontransparent, we save
+	       an extra check in make_preds_opaque.  We also
+	       need this to avoid confusing pre_edge_lcm when
+	       antic is cleared but transp and comp are set.  */
+	    RESET_BIT (transp[bb->index], j);
+
+	    /* Insert a fake computing definition of MODE into entry
+	       blocks which compute no mode. This represents the mode on
+	       entry.  */
+	    info[bb->index].computing = mode;
+
+	    if (pre_exit)
+	      info[pre_exit->index].seginfo->mode = MODE_EXIT (e);
+	  }
+      }
+#endif /* NORMAL_MODE */
+    }
+
+  kill = sbitmap_vector_alloc (last_basic_block, n_entities);
+  for (i = 0; i < max_num_modes; i++)
+    {
+      int current_mode[N_ENTITIES];
+      sbitmap *delete;
+      sbitmap *insert;
+
+      /* Set the anticipatable and computing arrays.  */
+      sbitmap_vector_zero (antic, last_basic_block);
+      sbitmap_vector_zero (comp, last_basic_block);
+      for (j = n_entities - 1; j >= 0; j--)
+	{
+	  int m = current_mode[j] = MODE_PRIORITY_TO_MODE (entity_map[j], i);
+	  struct bb_info *info = bb_info[j];
+
+	  FOR_EACH_BB (bb)
+	    {
+	      if (info[bb->index].seginfo->mode == m)
+		SET_BIT (antic[bb->index], j);
+
+	      if (info[bb->index].computing == m)
+		SET_BIT (comp[bb->index], j);
+	    }
+	}
+
+      /* Calculate the optimal locations for the
+	 placement mode switches to modes with priority I.  */
+
+      FOR_EACH_BB (bb)
+	sbitmap_not (kill[bb->index], transp[bb->index]);
+      edge_list = pre_edge_lcm (file, 1, transp, comp, antic,
+				kill, &insert, &delete);
+
+      for (j = n_entities - 1; j >= 0; j--)
+	{
+	  /* Insert all mode sets that have been inserted by lcm.  */
+	  int no_mode = num_modes[entity_map[j]];
+
+	  /* Wherever we have moved a mode setting upwards in the flow graph,
+	     the blocks between the new setting site and the now redundant
+	     computation ceases to be transparent for any lower-priority
+	     mode of the same entity.  First set the aux field of each
+	     insertion site edge non-transparent, then propagate the new
+	     non-transparency from the redundant computation upwards till
+	     we hit an insertion site or an already non-transparent block.  */
+	  for (e = NUM_EDGES (edge_list) - 1; e >= 0; e--)
+	    {
+	      edge eg = INDEX_EDGE (edge_list, e);
+	      int mode;
+	      basic_block src_bb;
+	      HARD_REG_SET live_at_edge;
+	      rtx mode_set;
+
+	      eg->aux = 0;
+
+	      if (! TEST_BIT (insert[e], j))
+		continue;
+
+	      eg->aux = (void *)1;
+
+	      mode = current_mode[j];
+	      src_bb = eg->src;
+
+	      REG_SET_TO_HARD_REG_SET (live_at_edge,
+				       src_bb->global_live_at_end);
+
+	      start_sequence ();
+	      EMIT_MODE_SET (entity_map[j], mode, live_at_edge);
+	      mode_set = get_insns ();
+	      end_sequence ();
+
+	      /* Do not bother to insert empty sequence.  */
+	      if (mode_set == NULL_RTX)
+		continue;
+
+	      /* If this is an abnormal edge, we'll insert at the end
+		 of the previous block.  */
+	      if (eg->flags & EDGE_ABNORMAL)
+		{
+		  emited = true;
+		  if (JUMP_P (BB_END (src_bb)))
+		    emit_insn_before (mode_set, BB_END (src_bb));
+		  else
+		    {
+		      /* It doesn't make sense to switch to normal
+		         mode after a CALL_INSN.  The cases in which a
+		         CALL_INSN may have an abnormal edge are
+		         sibcalls and EH edges.  In the case of
+		         sibcalls, the dest basic-block is the
+		         EXIT_BLOCK, that runs in normal mode; it is
+		         assumed that a sibcall insn requires normal
+		         mode itself, so no mode switch would be
+		         required after the call (it wouldn't make
+		         sense, anyway).  In the case of EH edges, EH
+		         entry points also start in normal mode, so a
+		         similar reasoning applies.  */
+		      gcc_assert (NONJUMP_INSN_P (BB_END (src_bb)));
+		      emit_insn_after (mode_set, BB_END (src_bb));
+		    }
+		  bb_info[j][src_bb->index].computing = mode;
+		  RESET_BIT (transp[src_bb->index], j);
+		}
+	      else
+		{
+		  need_commit = 1;
+		  insert_insn_on_edge (mode_set, eg);
+		}
+	    }
+
+	  FOR_EACH_BB_REVERSE (bb)
+	    if (TEST_BIT (delete[bb->index], j))
+	      {
+		make_preds_opaque (bb, j);
+		/* Cancel the 'deleted' mode set.  */
+		bb_info[j][bb->index].seginfo->mode = no_mode;
+	      }
+	}
+
+      sbitmap_vector_free (delete);
+      sbitmap_vector_free (insert);
+      clear_aux_for_edges ();
+      free_edge_list (edge_list);
+    }
+
+  /* Now output the remaining mode sets in all the segments.  */
+  for (j = n_entities - 1; j >= 0; j--)
+    {
+      int no_mode = num_modes[entity_map[j]];
+
+      FOR_EACH_BB_REVERSE (bb)
+	{
+	  struct seginfo *ptr, *next;
+	  for (ptr = bb_info[j][bb->index].seginfo; ptr; ptr = next)
+	    {
+	      next = ptr->next;
+	      if (ptr->mode != no_mode)
+		{
+		  rtx mode_set;
+
+		  start_sequence ();
+		  EMIT_MODE_SET (entity_map[j], ptr->mode, ptr->regs_live);
+		  mode_set = get_insns ();
+		  end_sequence ();
+
+		  /* Insert MODE_SET only if it is nonempty.  */
+		  if (mode_set != NULL_RTX)
+		    {
+		      emited = true;
+		      if (NOTE_P (ptr->insn_ptr)
+			  && (NOTE_LINE_NUMBER (ptr->insn_ptr)
+			      == NOTE_INSN_BASIC_BLOCK))
+			emit_insn_after (mode_set, ptr->insn_ptr);
+		      else
+			emit_insn_before (mode_set, ptr->insn_ptr);
+		    }
+		}
+
+	      free (ptr);
+	    }
+	}
+
+      free (bb_info[j]);
+    }
+
+  /* Finished. Free up all the things we've allocated.  */
+
+  sbitmap_vector_free (kill);
+  sbitmap_vector_free (antic);
+  sbitmap_vector_free (transp);
+  sbitmap_vector_free (comp);
+
+  if (need_commit)
+    commit_edge_insertions ();
+
+#if defined (MODE_ENTRY) && defined (MODE_EXIT)
+  cleanup_cfg (CLEANUP_NO_INSN_DEL);
+#else
+  if (!need_commit && !emited)
+    return 0;
+#endif
+
+  max_regno = max_reg_num ();
+  allocate_reg_info (max_regno, FALSE, FALSE);
+  update_life_info_in_dirty_blocks (UPDATE_LIFE_GLOBAL_RM_NOTES,
+				    (PROP_DEATH_NOTES | PROP_KILL_DEAD_CODE
+				     | PROP_SCAN_DEAD_CODE));
+
+  return 1;
+}
+#endif /* OPTIMIZE_MODE_SWITCHING */