This commit was generated by cvs2svn to compensate for changes in r133582,

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1 files changed, 0 insertions, 2334 deletions

diff --git a/contrib/gcc/ssa.c b/contrib/gcc/ssa.c
deleted file mode 100644
index b5c4992..0000000
--- a/contrib/gcc/ssa.c
+++ /dev/null
@@ -1,2334 +0,0 @@
-/* Static Single Assignment conversion routines for the GNU compiler.
-   Copyright (C) 2000, 2001, 2002 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.  */
-
-/* References:
-
-   Building an Optimizing Compiler
-   Robert Morgan
-   Butterworth-Heinemann, 1998
-
-   Static Single Assignment Construction
-   Preston Briggs, Tim Harvey, Taylor Simpson
-   Technical Report, Rice University, 1995
-   ftp://ftp.cs.rice.edu/public/preston/optimizer/SSA.ps.gz.  */
-
-#include "config.h"
-#include "system.h"
-
-#include "rtl.h"
-#include "expr.h"
-#include "varray.h"
-#include "partition.h"
-#include "sbitmap.h"
-#include "hashtab.h"
-#include "regs.h"
-#include "hard-reg-set.h"
-#include "flags.h"
-#include "function.h"
-#include "real.h"
-#include "insn-config.h"
-#include "recog.h"
-#include "basic-block.h"
-#include "output.h"
-#include "ssa.h"
-
-/* TODO:
-
-   Handle subregs better, maybe.  For now, if a reg that's set in a
-   subreg expression is duplicated going into SSA form, an extra copy
-   is inserted first that copies the entire reg into the duplicate, so
-   that the other bits are preserved.  This isn't strictly SSA, since
-   at least part of the reg is assigned in more than one place (though
-   they are adjacent).
-
-   ??? What to do about strict_low_part.  Probably I'll have to split
-   them out of their current instructions first thing.
-
-   Actually the best solution may be to have a kind of "mid-level rtl"
-   in which the RTL encodes exactly what we want, without exposing a
-   lot of niggling processor details.  At some later point we lower
-   the representation, calling back into optabs to finish any necessary
-   expansion.  */
-
-/* All pseudo-registers and select hard registers are converted to SSA
-   form.  When converting out of SSA, these select hard registers are
-   guaranteed to be mapped to their original register number.  Each
-   machine's .h file should define CONVERT_HARD_REGISTER_TO_SSA_P
-   indicating which hard registers should be converted.
-
-   When converting out of SSA, temporaries for all registers are
-   partitioned.  The partition is checked to ensure that all uses of
-   the same hard register in the same machine mode are in the same
-   class.  */
-
-/* If conservative_reg_partition is nonzero, use a conservative
-   register partitioning algorithm (which leaves more regs after
-   emerging from SSA) instead of the coalescing one.  This is being
-   left in for a limited time only, as a debugging tool until the
-   coalescing algorithm is validated.  */
-
-static int conservative_reg_partition;
-
-/* This flag is set when the CFG is in SSA form.  */
-int in_ssa_form = 0;
-
-/* Element I is the single instruction that sets register I.  */
-varray_type ssa_definition;
-
-/* Element I-PSEUDO is the normal register that originated the ssa
-   register in question.  */
-varray_type ssa_rename_from;
-
-/* Element I is the normal register that originated the ssa
-   register in question.
-
-   A hash table stores the (register, rtl) pairs.  These are each
-   xmalloc'ed and deleted when the hash table is destroyed.  */
-htab_t ssa_rename_from_ht;
-
-/* The running target ssa register for a given pseudo register.
-   (Pseudo registers appear in only one mode.)  */
-static rtx *ssa_rename_to_pseudo;
-/* Similar, but for hard registers.  A hard register can appear in
-   many modes, so we store an equivalent pseudo for each of the
-   modes.  */
-static rtx ssa_rename_to_hard[FIRST_PSEUDO_REGISTER][NUM_MACHINE_MODES];
-
-/* ssa_rename_from maps pseudo registers to the original corresponding
-   RTL.  It is implemented as using a hash table.  */
-
-typedef struct {
-  unsigned int reg;
-  rtx original;
-} ssa_rename_from_pair;
-
-struct ssa_rename_from_hash_table_data {
-  sbitmap canonical_elements;
-  partition reg_partition;
-};
-
-static rtx gen_sequence
-  PARAMS ((void));
-static void ssa_rename_from_initialize
-  PARAMS ((void));
-static rtx ssa_rename_from_lookup
-  PARAMS ((int reg));
-static unsigned int original_register
-  PARAMS ((unsigned int regno));
-static void ssa_rename_from_insert
-  PARAMS ((unsigned int reg, rtx r));
-static void ssa_rename_from_free
-  PARAMS ((void));
-typedef int (*srf_trav) PARAMS ((int regno, rtx r, sbitmap canonical_elements, partition reg_partition));
-static void ssa_rename_from_traverse
-  PARAMS ((htab_trav callback_function, sbitmap canonical_elements, partition reg_partition));
-/*static Avoid warnign message.  */ void ssa_rename_from_print
-  PARAMS ((void));
-static int ssa_rename_from_print_1
-  PARAMS ((void **slot, void *data));
-static hashval_t ssa_rename_from_hash_function
-  PARAMS ((const void * srfp));
-static int ssa_rename_from_equal
-  PARAMS ((const void *srfp1, const void *srfp2));
-static void ssa_rename_from_delete
-  PARAMS ((void *srfp));
-
-static rtx ssa_rename_to_lookup
-  PARAMS ((rtx reg));
-static void ssa_rename_to_insert
-  PARAMS ((rtx reg, rtx r));
-
-/* The number of registers that were live on entry to the SSA routines.  */
-static unsigned int ssa_max_reg_num;
-
-/* Local function prototypes.  */
-
-struct rename_context;
-
-static inline rtx * phi_alternative
-  PARAMS ((rtx, int));
-static void compute_dominance_frontiers_1
-  PARAMS ((sbitmap *frontiers, dominance_info idom, int bb, sbitmap done));
-static void find_evaluations_1
-  PARAMS ((rtx dest, rtx set, void *data));
-static void find_evaluations
-  PARAMS ((sbitmap *evals, int nregs));
-static void compute_iterated_dominance_frontiers
-  PARAMS ((sbitmap *idfs, sbitmap *frontiers, sbitmap *evals, int nregs));
-static void insert_phi_node
-  PARAMS ((int regno, int b));
-static void insert_phi_nodes
-  PARAMS ((sbitmap *idfs, sbitmap *evals, int nregs));
-static void create_delayed_rename
-  PARAMS ((struct rename_context *, rtx *));
-static void apply_delayed_renames
-  PARAMS ((struct rename_context *));
-static int rename_insn_1
-  PARAMS ((rtx *ptr, void *data));
-static void rename_block
-  PARAMS ((int b, dominance_info dom));
-static void rename_registers
-  PARAMS ((int nregs, dominance_info idom));
-
-static inline int ephi_add_node
-  PARAMS ((rtx reg, rtx *nodes, int *n_nodes));
-static int * ephi_forward
-  PARAMS ((int t, sbitmap visited, sbitmap *succ, int *tstack));
-static void ephi_backward
-  PARAMS ((int t, sbitmap visited, sbitmap *pred, rtx *nodes));
-static void ephi_create
-  PARAMS ((int t, sbitmap visited, sbitmap *pred, sbitmap *succ, rtx *nodes));
-static void eliminate_phi
-  PARAMS ((edge e, partition reg_partition));
-static int make_regs_equivalent_over_bad_edges
-  PARAMS ((int bb, partition reg_partition));
-
-/* These are used only in the conservative register partitioning
-   algorithms.  */
-static int make_equivalent_phi_alternatives_equivalent
-  PARAMS ((int bb, partition reg_partition));
-static partition compute_conservative_reg_partition
-  PARAMS ((void));
-static int record_canonical_element_1
-  PARAMS ((void **srfp, void *data));
-static int check_hard_regs_in_partition
-  PARAMS ((partition reg_partition));
-static int rename_equivalent_regs_in_insn
-  PARAMS ((rtx *ptr, void *data));
-
-/* These are used in the register coalescing algorithm.  */
-static int coalesce_if_unconflicting
-  PARAMS ((partition p, conflict_graph conflicts, int reg1, int reg2));
-static int coalesce_regs_in_copies
-  PARAMS ((basic_block bb, partition p, conflict_graph conflicts));
-static int coalesce_reg_in_phi
-  PARAMS ((rtx, int dest_regno, int src_regno, void *data));
-static int coalesce_regs_in_successor_phi_nodes
-  PARAMS ((basic_block bb, partition p, conflict_graph conflicts));
-static partition compute_coalesced_reg_partition
-  PARAMS ((void));
-static int mark_reg_in_phi
-  PARAMS ((rtx *ptr, void *data));
-static void mark_phi_and_copy_regs
-  PARAMS ((regset phi_set));
-
-static int rename_equivalent_regs_in_insn
-  PARAMS ((rtx *ptr, void *data));
-static void rename_equivalent_regs
-  PARAMS ((partition reg_partition));
-
-/* Deal with hard registers.  */
-static int conflicting_hard_regs_p
-  PARAMS ((int reg1, int reg2));
-
-/* ssa_rename_to maps registers and machine modes to SSA pseudo registers.  */
-
-/* Find the register associated with REG in the indicated mode.  */
-
-static rtx
-ssa_rename_to_lookup (reg)
-     rtx reg;
-{
-  if (!HARD_REGISTER_P (reg))
-    return ssa_rename_to_pseudo[REGNO (reg) - FIRST_PSEUDO_REGISTER];
-  else
-    return ssa_rename_to_hard[REGNO (reg)][GET_MODE (reg)];
-}
-
-/* Store a new value mapping REG to R in ssa_rename_to.  */
-
-static void
-ssa_rename_to_insert(reg, r)
-     rtx reg;
-     rtx r;
-{
-  if (!HARD_REGISTER_P (reg))
-    ssa_rename_to_pseudo[REGNO (reg) - FIRST_PSEUDO_REGISTER] = r;
-  else
-    ssa_rename_to_hard[REGNO (reg)][GET_MODE (reg)] = r;
-}
-
-/* Prepare ssa_rename_from for use.  */
-
-static void
-ssa_rename_from_initialize ()
-{
-  /* We use an arbitrary initial hash table size of 64.  */
-  ssa_rename_from_ht = htab_create (64,
-				    &ssa_rename_from_hash_function,
-				    &ssa_rename_from_equal,
-				    &ssa_rename_from_delete);
-}
-
-/* Find the REG entry in ssa_rename_from.  Return NULL_RTX if no entry is
-   found.  */
-
-static rtx
-ssa_rename_from_lookup (reg)
-     int reg;
-{
-  ssa_rename_from_pair srfp;
-  ssa_rename_from_pair *answer;
-  srfp.reg = reg;
-  srfp.original = NULL_RTX;
-  answer = (ssa_rename_from_pair *)
-    htab_find_with_hash (ssa_rename_from_ht, (void *) &srfp, reg);
-  return (answer == 0 ? NULL_RTX : answer->original);
-}
-
-/* Find the number of the original register specified by REGNO.  If
-   the register is a pseudo, return the original register's number.
-   Otherwise, return this register number REGNO.  */
-
-static unsigned int
-original_register (regno)
-     unsigned int regno;
-{
-  rtx original_rtx = ssa_rename_from_lookup (regno);
-  return original_rtx != NULL_RTX ? REGNO (original_rtx) : regno;
-}
-
-/* Add mapping from R to REG to ssa_rename_from even if already present.  */
-
-static void
-ssa_rename_from_insert (reg, r)
-     unsigned int reg;
-     rtx r;
-{
-  void **slot;
-  ssa_rename_from_pair *srfp = xmalloc (sizeof (ssa_rename_from_pair));
-  srfp->reg = reg;
-  srfp->original = r;
-  slot = htab_find_slot_with_hash (ssa_rename_from_ht, (const void *) srfp,
-				   reg, INSERT);
-  if (*slot != 0)
-    free ((void *) *slot);
-  *slot = srfp;
-}
-
-/* Apply the CALLBACK_FUNCTION to each element in ssa_rename_from.
-   CANONICAL_ELEMENTS and REG_PARTITION pass data needed by the only
-   current use of this function.  */
-
-static void
-ssa_rename_from_traverse (callback_function,
-			  canonical_elements, reg_partition)
-     htab_trav callback_function;
-     sbitmap canonical_elements;
-     partition reg_partition;
-{
-  struct ssa_rename_from_hash_table_data srfhd;
-  srfhd.canonical_elements = canonical_elements;
-  srfhd.reg_partition = reg_partition;
-  htab_traverse (ssa_rename_from_ht, callback_function, (void *) &srfhd);
-}
-
-/* Destroy ssa_rename_from.  */
-
-static void
-ssa_rename_from_free ()
-{
-  htab_delete (ssa_rename_from_ht);
-}
-
-/* Print the contents of ssa_rename_from.  */
-
-/* static  Avoid erroneous error message.  */
-void
-ssa_rename_from_print ()
-{
-  printf ("ssa_rename_from's hash table contents:\n");
-  htab_traverse (ssa_rename_from_ht, &ssa_rename_from_print_1, NULL);
-}
-
-/* Print the contents of the hash table entry SLOT, passing the unused
-   sttribute DATA.  Used as a callback function with htab_traverse ().  */
-
-static int
-ssa_rename_from_print_1 (slot, data)
-     void **slot;
-     void *data ATTRIBUTE_UNUSED;
-{
-  ssa_rename_from_pair * p = *slot;
-  printf ("ssa_rename_from maps pseudo %i to original %i.\n",
-	  p->reg, REGNO (p->original));
-  return 1;
-}
-
-/* Given a hash entry SRFP, yield a hash value.  */
-
-static hashval_t
-ssa_rename_from_hash_function (srfp)
-     const void *srfp;
-{
-  return ((const ssa_rename_from_pair *) srfp)->reg;
-}
-
-/* Test whether two hash table entries SRFP1 and SRFP2 are equal.  */
-
-static int
-ssa_rename_from_equal (srfp1, srfp2)
-     const void *srfp1;
-     const void *srfp2;
-{
-  return ssa_rename_from_hash_function (srfp1) ==
-    ssa_rename_from_hash_function (srfp2);
-}
-
-/* Delete the hash table entry SRFP.  */
-
-static void
-ssa_rename_from_delete (srfp)
-     void *srfp;
-{
-  free (srfp);
-}
-
-/* Given the SET of a PHI node, return the address of the alternative
-   for predecessor block C.  */
-
-static inline rtx *
-phi_alternative (set, c)
-     rtx set;
-     int c;
-{
-  rtvec phi_vec = XVEC (SET_SRC (set), 0);
-  int v;
-
-  for (v = GET_NUM_ELEM (phi_vec) - 2; v >= 0; v -= 2)
-    if (INTVAL (RTVEC_ELT (phi_vec, v + 1)) == c)
-      return &RTVEC_ELT (phi_vec, v);
-
-  return NULL;
-}
-
-/* Given the SET of a phi node, remove the alternative for predecessor
-   block C.  Return nonzero on success, or zero if no alternative is
-   found for C.  */
-
-int
-remove_phi_alternative (set, block)
-     rtx set;
-     basic_block block;
-{
-  rtvec phi_vec = XVEC (SET_SRC (set), 0);
-  int num_elem = GET_NUM_ELEM (phi_vec);
-  int v, c;
-
-  c = block->index;
-  for (v = num_elem - 2; v >= 0; v -= 2)
-    if (INTVAL (RTVEC_ELT (phi_vec, v + 1)) == c)
-      {
-	if (v < num_elem - 2)
-	  {
-	    RTVEC_ELT (phi_vec, v) = RTVEC_ELT (phi_vec, num_elem - 2);
-	    RTVEC_ELT (phi_vec, v + 1) = RTVEC_ELT (phi_vec, num_elem - 1);
-	  }
-	PUT_NUM_ELEM (phi_vec, num_elem - 2);
-	return 1;
-      }
-
-  return 0;
-}
-
-/* For all registers, find all blocks in which they are set.
-
-   This is the transform of what would be local kill information that
-   we ought to be getting from flow.  */
-
-static sbitmap *fe_evals;
-static int fe_current_bb;
-
-static void
-find_evaluations_1 (dest, set, data)
-     rtx dest;
-     rtx set ATTRIBUTE_UNUSED;
-     void *data ATTRIBUTE_UNUSED;
-{
-  if (GET_CODE (dest) == REG
-      && CONVERT_REGISTER_TO_SSA_P (REGNO (dest)))
-    SET_BIT (fe_evals[REGNO (dest)], fe_current_bb);
-}
-
-static void
-find_evaluations (evals, nregs)
-     sbitmap *evals;
-     int nregs;
-{
-  basic_block bb;
-
-  sbitmap_vector_zero (evals, nregs);
-  fe_evals = evals;
-
-  FOR_EACH_BB_REVERSE (bb)
-    {
-      rtx p, last;
-
-      fe_current_bb = bb->index;
-      p = bb->head;
-      last = bb->end;
-      while (1)
-	{
-	  if (INSN_P (p))
-	    note_stores (PATTERN (p), find_evaluations_1, NULL);
-
-	  if (p == last)
-	    break;
-	  p = NEXT_INSN (p);
-	}
-    }
-}
-
-/* Computing the Dominance Frontier:
-
-   As decribed in Morgan, section 3.5, this may be done simply by
-   walking the dominator tree bottom-up, computing the frontier for
-   the children before the parent.  When considering a block B,
-   there are two cases:
-
-   (1) A flow graph edge leaving B that does not lead to a child
-   of B in the dominator tree must be a block that is either equal
-   to B or not dominated by B.  Such blocks belong in the frontier
-   of B.
-
-   (2) Consider a block X in the frontier of one of the children C
-   of B.  If X is not equal to B and is not dominated by B, it
-   is in the frontier of B.
-*/
-
-static void
-compute_dominance_frontiers_1 (frontiers, idom, bb, done)
-     sbitmap *frontiers;
-     dominance_info idom;
-     int bb;
-     sbitmap done;
-{
-  basic_block b = BASIC_BLOCK (bb);
-  edge e;
-  basic_block c;
-
-  SET_BIT (done, bb);
-  sbitmap_zero (frontiers[bb]);
-
-  /* Do the frontier of the children first.  Not all children in the
-     dominator tree (blocks dominated by this one) are children in the
-     CFG, so check all blocks.  */
-  FOR_EACH_BB (c)
-    if (get_immediate_dominator (idom, c)->index == bb
-	&& ! TEST_BIT (done, c->index))
-      compute_dominance_frontiers_1 (frontiers, idom, c->index, done);
-
-  /* Find blocks conforming to rule (1) above.  */
-  for (e = b->succ; e; e = e->succ_next)
-    {
-      if (e->dest == EXIT_BLOCK_PTR)
-	continue;
-      if (get_immediate_dominator (idom, e->dest)->index != bb)
-	SET_BIT (frontiers[bb], e->dest->index);
-    }
-
-  /* Find blocks conforming to rule (2).  */
-  FOR_EACH_BB (c)
-    if (get_immediate_dominator (idom, c)->index == bb)
-      {
-	int x;
-	EXECUTE_IF_SET_IN_SBITMAP (frontiers[c->index], 0, x,
-	  {
-	    if (get_immediate_dominator (idom, BASIC_BLOCK (x))->index != bb)
-	      SET_BIT (frontiers[bb], x);
-	  });
-      }
-}
-
-void
-compute_dominance_frontiers (frontiers, idom)
-     sbitmap *frontiers;
-     dominance_info idom;
-{
-  sbitmap done = sbitmap_alloc (last_basic_block);
-  sbitmap_zero (done);
-
-  compute_dominance_frontiers_1 (frontiers, idom, 0, done);
-
-  sbitmap_free (done);
-}
-
-/* Computing the Iterated Dominance Frontier:
-
-   This is the set of merge points for a given register.
-
-   This is not particularly intuitive.  See section 7.1 of Morgan, in
-   particular figures 7.3 and 7.4 and the immediately surrounding text.
-*/
-
-static void
-compute_iterated_dominance_frontiers (idfs, frontiers, evals, nregs)
-     sbitmap *idfs;
-     sbitmap *frontiers;
-     sbitmap *evals;
-     int nregs;
-{
-  sbitmap worklist;
-  int reg, passes = 0;
-
-  worklist = sbitmap_alloc (last_basic_block);
-
-  for (reg = 0; reg < nregs; ++reg)
-    {
-      sbitmap idf = idfs[reg];
-      int b, changed;
-
-      /* Start the iterative process by considering those blocks that
-	 evaluate REG.  We'll add their dominance frontiers to the
-	 IDF, and then consider the blocks we just added.  */
-      sbitmap_copy (worklist, evals[reg]);
-
-      /* Morgan's algorithm is incorrect here.  Blocks that evaluate
-	 REG aren't necessarily in REG's IDF.  Start with an empty IDF.  */
-      sbitmap_zero (idf);
-
-      /* Iterate until the worklist is empty.  */
-      do
-	{
-	  changed = 0;
-	  passes++;
-	  EXECUTE_IF_SET_IN_SBITMAP (worklist, 0, b,
-	    {
-	      RESET_BIT (worklist, b);
-	      /* For each block on the worklist, add to the IDF all
-		 blocks on its dominance frontier that aren't already
-		 on the IDF.  Every block that's added is also added
-		 to the worklist.  */
-	      sbitmap_union_of_diff (worklist, worklist, frontiers[b], idf);
-	      sbitmap_a_or_b (idf, idf, frontiers[b]);
-	      changed = 1;
-	    });
-	}
-      while (changed);
-    }
-
-  sbitmap_free (worklist);
-
-  if (rtl_dump_file)
-    {
-      fprintf (rtl_dump_file,
-	       "Iterated dominance frontier: %d passes on %d regs.\n",
-	       passes, nregs);
-    }
-}
-
-/* Insert the phi nodes.  */
-
-static void
-insert_phi_node (regno, bb)
-     int regno, bb;
-{
-  basic_block b = BASIC_BLOCK (bb);
-  edge e;
-  int npred, i;
-  rtvec vec;
-  rtx phi, reg;
-  rtx insn;
-  int end_p;
-
-  /* Find out how many predecessors there are.  */
-  for (e = b->pred, npred = 0; e; e = e->pred_next)
-    if (e->src != ENTRY_BLOCK_PTR)
-      npred++;
-
-  /* If this block has no "interesting" preds, then there is nothing to
-     do.  Consider a block that only has the entry block as a pred.  */
-  if (npred == 0)
-    return;
-
-  /* This is the register to which the phi function will be assigned.  */
-  reg = regno_reg_rtx[regno];
-
-  /* Construct the arguments to the PHI node.  The use of pc_rtx is just
-     a placeholder; we'll insert the proper value in rename_registers.  */
-  vec = rtvec_alloc (npred * 2);
-  for (e = b->pred, i = 0; e ; e = e->pred_next, i += 2)
-    if (e->src != ENTRY_BLOCK_PTR)
-      {
-	RTVEC_ELT (vec, i + 0) = pc_rtx;
-	RTVEC_ELT (vec, i + 1) = GEN_INT (e->src->index);
-      }
-
-  phi = gen_rtx_PHI (VOIDmode, vec);
-  phi = gen_rtx_SET (VOIDmode, reg, phi);
-
-  insn = first_insn_after_basic_block_note (b);
-  end_p = PREV_INSN (insn) == b->end;
-  emit_insn_before (phi, insn);
-  if (end_p)
-    b->end = PREV_INSN (insn);
-}
-
-static void
-insert_phi_nodes (idfs, evals, nregs)
-     sbitmap *idfs;
-     sbitmap *evals ATTRIBUTE_UNUSED;
-     int nregs;
-{
-  int reg;
-
-  for (reg = 0; reg < nregs; ++reg)
-    if (CONVERT_REGISTER_TO_SSA_P (reg))
-    {
-      int b;
-      EXECUTE_IF_SET_IN_SBITMAP (idfs[reg], 0, b,
-	{
-	  if (REGNO_REG_SET_P (BASIC_BLOCK (b)->global_live_at_start, reg))
-	    insert_phi_node (reg, b);
-	});
-    }
-}
-
-/* Rename the registers to conform to SSA.
-
-   This is essentially the algorithm presented in Figure 7.8 of Morgan,
-   with a few changes to reduce pattern search time in favor of a bit
-   more memory usage.  */
-
-/* One of these is created for each set.  It will live in a list local
-   to its basic block for the duration of that block's processing.  */
-struct rename_set_data
-{
-  struct rename_set_data *next;
-  /* This is the SET_DEST of the (first) SET that sets the REG.  */
-  rtx *reg_loc;
-  /* This is what used to be at *REG_LOC.  */
-  rtx old_reg;
-  /* This is the REG that will replace OLD_REG.  It's set only
-     when the rename data is moved onto the DONE_RENAMES queue.  */
-  rtx new_reg;
-  /* This is what to restore ssa_rename_to_lookup (old_reg) to.  It is
-     usually the previous contents of ssa_rename_to_lookup (old_reg).  */
-  rtx prev_reg;
-  /* This is the insn that contains all the SETs of the REG.  */
-  rtx set_insn;
-};
-
-/* This struct is used to pass information to callback functions while
-   renaming registers.  */
-struct rename_context
-{
-  struct rename_set_data *new_renames;
-  struct rename_set_data *done_renames;
-  rtx current_insn;
-};
-
-/* Queue the rename of *REG_LOC.  */
-static void
-create_delayed_rename (c, reg_loc)
-     struct rename_context *c;
-     rtx *reg_loc;
-{
-  struct rename_set_data *r;
-  r = (struct rename_set_data *) xmalloc (sizeof(*r));
-
-  if (GET_CODE (*reg_loc) != REG
-      || !CONVERT_REGISTER_TO_SSA_P (REGNO (*reg_loc)))
-    abort ();
-
-  r->reg_loc = reg_loc;
-  r->old_reg = *reg_loc;
-  r->prev_reg = ssa_rename_to_lookup(r->old_reg);
-  r->set_insn = c->current_insn;
-  r->next = c->new_renames;
-  c->new_renames = r;
-}
-
-/* This is part of a rather ugly hack to allow the pre-ssa regno to be
-   reused.  If, during processing, a register has not yet been touched,
-   ssa_rename_to[regno][machno] will be NULL.  Now, in the course of pushing
-   and popping values from ssa_rename_to, when we would ordinarily
-   pop NULL back in, we pop RENAME_NO_RTX.  We treat this exactly the
-   same as NULL, except that it signals that the original regno has
-   already been reused.  */
-#define RENAME_NO_RTX  pc_rtx
-
-/* Move all the entries from NEW_RENAMES onto DONE_RENAMES by
-   applying all the renames on NEW_RENAMES.  */
-
-static void
-apply_delayed_renames (c)
-       struct rename_context *c;
-{
-  struct rename_set_data *r;
-  struct rename_set_data *last_r = NULL;
-
-  for (r = c->new_renames; r != NULL; r = r->next)
-    {
-      int new_regno;
-
-      /* Failure here means that someone has a PARALLEL that sets
-	 a register twice (bad!).  */
-      if (ssa_rename_to_lookup (r->old_reg) != r->prev_reg)
-	abort ();
-      /* Failure here means we have changed REG_LOC before applying
-	 the rename.  */
-      /* For the first set we come across, reuse the original regno.  */
-      if (r->prev_reg == NULL_RTX && !HARD_REGISTER_P (r->old_reg))
-	{
-	  r->new_reg = r->old_reg;
-	  /* We want to restore RENAME_NO_RTX rather than NULL_RTX.  */
-	  r->prev_reg = RENAME_NO_RTX;
-	}
-      else
-	r->new_reg = gen_reg_rtx (GET_MODE (r->old_reg));
-      new_regno = REGNO (r->new_reg);
-      ssa_rename_to_insert (r->old_reg, r->new_reg);
-
-      if (new_regno >= (int) ssa_definition->num_elements)
-	{
-	  int new_limit = new_regno * 5 / 4;
-	  VARRAY_GROW (ssa_definition, new_limit);
-	}
-
-      VARRAY_RTX (ssa_definition, new_regno) = r->set_insn;
-      ssa_rename_from_insert (new_regno, r->old_reg);
-      last_r = r;
-    }
-  if (last_r != NULL)
-    {
-      last_r->next = c->done_renames;
-      c->done_renames = c->new_renames;
-      c->new_renames = NULL;
-    }
-}
-
-/* Part one of the first step of rename_block, called through for_each_rtx.
-   Mark pseudos that are set for later update.  Transform uses of pseudos.  */
-
-static int
-rename_insn_1 (ptr, data)
-     rtx *ptr;
-     void *data;
-{
-  rtx x = *ptr;
-  struct rename_context *context = data;
-
-  if (x == NULL_RTX)
-    return 0;
-
-  switch (GET_CODE (x))
-    {
-    case SET:
-      {
-	rtx *destp = &SET_DEST (x);
-	rtx dest = SET_DEST (x);
-
-	/* An assignment to a paradoxical SUBREG does not read from
-	   the destination operand, and thus does not need to be
-	   wrapped into a SEQUENCE when translating into SSA form.
-	   We merely strip off the SUBREG and proceed normally for
-	   this case.  */
-	if (GET_CODE (dest) == SUBREG
-	    && (GET_MODE_SIZE (GET_MODE (dest))
-		> GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))))
-	    && GET_CODE (SUBREG_REG (dest)) == REG
-	    && CONVERT_REGISTER_TO_SSA_P (REGNO (SUBREG_REG (dest))))
-	  {
-	    destp = &XEXP (dest, 0);
-	    dest = XEXP (dest, 0);
-	  }
-
-	/* Some SETs also use the REG specified in their LHS.
-	   These can be detected by the presence of
-	   STRICT_LOW_PART, SUBREG, SIGN_EXTRACT, and ZERO_EXTRACT
-	   in the LHS.  Handle these by changing
-	   (set (subreg (reg foo)) ...)
-	   into
-	   (sequence [(set (reg foo_1) (reg foo))
-	              (set (subreg (reg foo_1)) ...)])
-
-	   FIXME: Much of the time this is too much.  For some constructs
-	   we know that the output register is strictly an output
-	   (paradoxical SUBREGs and some libcalls for example).
-
-	   For those cases we are better off not making the false
-	   dependency.  */
-	if (GET_CODE (dest) == STRICT_LOW_PART
-	    || GET_CODE (dest) == SUBREG
-	    || GET_CODE (dest) == SIGN_EXTRACT
-	    || GET_CODE (dest) == ZERO_EXTRACT)
-	  {
-	    rtx i, reg;
-	    reg = dest;
-
-	    while (GET_CODE (reg) == STRICT_LOW_PART
-		   || GET_CODE (reg) == SUBREG
-		   || GET_CODE (reg) == SIGN_EXTRACT
-		   || GET_CODE (reg) == ZERO_EXTRACT)
-		reg = XEXP (reg, 0);
-
-	    if (GET_CODE (reg) == REG
-		&& CONVERT_REGISTER_TO_SSA_P (REGNO (reg)))
-	      {
-		/* Generate (set reg reg), and do renaming on it so
-		   that it becomes (set reg_1 reg_0), and we will
-		   replace reg with reg_1 in the SUBREG.  */
-
-		struct rename_set_data *saved_new_renames;
-		saved_new_renames = context->new_renames;
-		context->new_renames = NULL;
-		i = emit_insn (gen_rtx_SET (VOIDmode, reg, reg));
-		for_each_rtx (&i, rename_insn_1, data);
-		apply_delayed_renames (context);
-		context->new_renames = saved_new_renames;
-	      }
-	  }
-	else if (GET_CODE (dest) == REG
-		 && CONVERT_REGISTER_TO_SSA_P (REGNO (dest)))
-	  {
-	    /* We found a genuine set of an interesting register.  Tag
-	       it so that we can create a new name for it after we finish
-	       processing this insn.  */
-
-	    create_delayed_rename (context, destp);
-
-	    /* Since we do not wish to (directly) traverse the
-	       SET_DEST, recurse through for_each_rtx for the SET_SRC
-	       and return.  */
-	    if (GET_CODE (x) == SET)
-	      for_each_rtx (&SET_SRC (x), rename_insn_1, data);
-	    return -1;
-	  }
-
-	/* Otherwise, this was not an interesting destination.  Continue
-	   on, marking uses as normal.  */
-	return 0;
-      }
-
-    case REG:
-      if (CONVERT_REGISTER_TO_SSA_P (REGNO (x))
-	  && REGNO (x) < ssa_max_reg_num)
-	{
-	  rtx new_reg = ssa_rename_to_lookup (x);
-
-	  if (new_reg != RENAME_NO_RTX && new_reg != NULL_RTX)
-	    {
-	      if (GET_MODE (x) != GET_MODE (new_reg))
-		abort ();
-	      *ptr = new_reg;
-	    }
-	  else
-	    {
-	      /* Undefined value used, rename it to a new pseudo register so
-		 that it cannot conflict with an existing register.  */
-	      *ptr = gen_reg_rtx (GET_MODE (x));
-	    }
-	}
-      return -1;
-
-    case CLOBBER:
-      /* There is considerable debate on how CLOBBERs ought to be
-	 handled in SSA.  For now, we're keeping the CLOBBERs, which
-	 means that we don't really have SSA form.  There are a couple
-	 of proposals for how to fix this problem, but neither is
-	 implemented yet.  */
-      {
-	rtx dest = XCEXP (x, 0, CLOBBER);
-	if (REG_P (dest))
-	  {
-	    if (CONVERT_REGISTER_TO_SSA_P (REGNO (dest))
-		&& REGNO (dest) < ssa_max_reg_num)
-	      {
-		rtx new_reg = ssa_rename_to_lookup (dest);
-		if (new_reg != NULL_RTX && new_reg != RENAME_NO_RTX)
-		    XCEXP (x, 0, CLOBBER) = new_reg;
-	      }
-	    /* Stop traversing.  */
-	    return -1;
-	  }
-	else
-	  /* Continue traversing.  */
-	  return 0;
-      }
-
-    case PHI:
-      /* Never muck with the phi.  We do that elsewhere, special-like.  */
-      return -1;
-
-    default:
-      /* Anything else, continue traversing.  */
-      return 0;
-    }
-}
-
-static rtx
-gen_sequence ()
-{
-  rtx first_insn = get_insns ();
-  rtx result;
-  rtx tem;
-  int i;
-  int len;
-
-  /* Count the insns in the chain.  */
-  len = 0;
-  for (tem = first_insn; tem; tem = NEXT_INSN (tem))
-    len++;
-
-  result = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (len));
-
-  for (i = 0, tem = first_insn; tem; tem = NEXT_INSN (tem), i++)
-    XVECEXP (result, 0, i) = tem;
-
-  return result;
-}
-
-static void
-rename_block (bb, idom)
-     int bb;
-     dominance_info idom;
-{
-  basic_block b = BASIC_BLOCK (bb);
-  edge e;
-  rtx insn, next, last;
-  struct rename_set_data *set_data = NULL;
-  basic_block c;
-
-  /* Step One: Walk the basic block, adding new names for sets and
-     replacing uses.  */
-
-  next = b->head;
-  last = b->end;
-  do
-    {
-      insn = next;
-      if (INSN_P (insn))
-	{
-	  struct rename_context context;
-	  context.done_renames = set_data;
-	  context.new_renames = NULL;
-	  context.current_insn = insn;
-
-	  start_sequence ();
-	  for_each_rtx (&PATTERN (insn), rename_insn_1, &context);
-	  for_each_rtx (&REG_NOTES (insn), rename_insn_1, &context);
-
-	  /* Sometimes, we end up with a sequence of insns that
-	     SSA needs to treat as a single insn.  Wrap these in a
-	     SEQUENCE.  (Any notes now get attached to the SEQUENCE,
-	     not to the old version inner insn.)  */
-	  if (get_insns () != NULL_RTX)
-	    {
-	      rtx seq;
-	      int i;
-
-	      emit (PATTERN (insn));
-	      seq = gen_sequence ();
-	      /* We really want a SEQUENCE of SETs, not a SEQUENCE
-		 of INSNs.  */
-	      for (i = 0; i < XVECLEN (seq, 0); i++)
-		XVECEXP (seq, 0, i) = PATTERN (XVECEXP (seq, 0, i));
-	      PATTERN (insn) = seq;
-	    }
-	  end_sequence ();
-
-	  apply_delayed_renames (&context);
-	  set_data = context.done_renames;
-	}
-
-      next = NEXT_INSN (insn);
-    }
-  while (insn != last);
-
-  /* Step Two: Update the phi nodes of this block's successors.  */
-
-  for (e = b->succ; e; e = e->succ_next)
-    {
-      if (e->dest == EXIT_BLOCK_PTR)
-	continue;
-
-      insn = first_insn_after_basic_block_note (e->dest);
-
-      while (PHI_NODE_P (insn))
-	{
-	  rtx phi = PATTERN (insn);
-	  rtx reg;
-
-	  /* Find out which of our outgoing registers this node is
-	     intended to replace.  Note that if this is not the first PHI
-	     node to have been created for this register, we have to
-	     jump through rename links to figure out which register
-	     we're talking about.  This can easily be recognized by
-	     noting that the regno is new to this pass.  */
-	  reg = SET_DEST (phi);
-	  if (REGNO (reg) >= ssa_max_reg_num)
-	    reg = ssa_rename_from_lookup (REGNO (reg));
-	  if (reg == NULL_RTX)
-	    abort ();
-	  reg = ssa_rename_to_lookup (reg);
-
-	  /* It is possible for the variable to be uninitialized on
-	     edges in.  Reduce the arity of the PHI so that we don't
-	     consider those edges.  */
-	  if (reg == NULL || reg == RENAME_NO_RTX)
-	    {
-	      if (! remove_phi_alternative (phi, b))
-		abort ();
-	    }
-	  else
-	    {
-	      /* When we created the PHI nodes, we did not know what mode
-		 the register should be.  Now that we've found an original,
-		 we can fill that in.  */
-	      if (GET_MODE (SET_DEST (phi)) == VOIDmode)
-		PUT_MODE (SET_DEST (phi), GET_MODE (reg));
-	      else if (GET_MODE (SET_DEST (phi)) != GET_MODE (reg))
-		abort ();
-
-	      *phi_alternative (phi, bb) = reg;
-	    }
-
-	  insn = NEXT_INSN (insn);
-	}
-    }
-
-  /* Step Three: Do the same to the children of this block in
-     dominator order.  */
-
-  FOR_EACH_BB (c)
-    if (get_immediate_dominator (idom, c)->index == bb)
-      rename_block (c->index, idom);
-
-  /* Step Four: Update the sets to refer to their new register,
-     and restore ssa_rename_to to its previous state.  */
-
-  while (set_data)
-    {
-      struct rename_set_data *next;
-      rtx old_reg = *set_data->reg_loc;
-
-      if (*set_data->reg_loc != set_data->old_reg)
-	abort ();
-      *set_data->reg_loc = set_data->new_reg;
-
-      ssa_rename_to_insert (old_reg, set_data->prev_reg);
-
-      next = set_data->next;
-      free (set_data);
-      set_data = next;
-    }
-}
-
-static void
-rename_registers (nregs, idom)
-     int nregs;
-     dominance_info idom;
-{
-  VARRAY_RTX_INIT (ssa_definition, nregs * 3, "ssa_definition");
-  ssa_rename_from_initialize ();
-
-  ssa_rename_to_pseudo = (rtx *) alloca (nregs * sizeof(rtx));
-  memset ((char *) ssa_rename_to_pseudo, 0, nregs * sizeof(rtx));
-  memset ((char *) ssa_rename_to_hard, 0,
-	 FIRST_PSEUDO_REGISTER * NUM_MACHINE_MODES * sizeof (rtx));
-
-  rename_block (0, idom);
-
-  /* ??? Update basic_block_live_at_start, and other flow info
-     as needed.  */
-
-  ssa_rename_to_pseudo = NULL;
-}
-
-/* The main entry point for moving to SSA.  */
-
-void
-convert_to_ssa ()
-{
-  /* Element I is the set of blocks that set register I.  */
-  sbitmap *evals;
-
-  /* Dominator bitmaps.  */
-  sbitmap *dfs;
-  sbitmap *idfs;
-
-  /* Element I is the immediate dominator of block I.  */
-  dominance_info idom;
-
-  int nregs;
-
-  basic_block bb;
-
-  /* Don't do it twice.  */
-  if (in_ssa_form)
-    abort ();
-
-  /* Need global_live_at_{start,end} up to date.  Do not remove any
-     dead code.  We'll let the SSA optimizers do that.  */
-  life_analysis (get_insns (), NULL, 0);
-
-  idom = calculate_dominance_info (CDI_DOMINATORS);
-
-  if (rtl_dump_file)
-    {
-      fputs (";; Immediate Dominators:\n", rtl_dump_file);
-      FOR_EACH_BB (bb)
-	fprintf (rtl_dump_file, ";\t%3d = %3d\n", bb->index,
-		 get_immediate_dominator (idom, bb)->index);
-      fflush (rtl_dump_file);
-    }
-
-  /* Compute dominance frontiers.  */
-
-  dfs = sbitmap_vector_alloc (last_basic_block, last_basic_block);
-  compute_dominance_frontiers (dfs, idom);
-
-  if (rtl_dump_file)
-    {
-      dump_sbitmap_vector (rtl_dump_file, ";; Dominance Frontiers:",
-			   "; Basic Block", dfs, last_basic_block);
-      fflush (rtl_dump_file);
-    }
-
-  /* Compute register evaluations.  */
-
-  ssa_max_reg_num = max_reg_num ();
-  nregs = ssa_max_reg_num;
-  evals = sbitmap_vector_alloc (nregs, last_basic_block);
-  find_evaluations (evals, nregs);
-
-  /* Compute the iterated dominance frontier for each register.  */
-
-  idfs = sbitmap_vector_alloc (nregs, last_basic_block);
-  compute_iterated_dominance_frontiers (idfs, dfs, evals, nregs);
-
-  if (rtl_dump_file)
-    {
-      dump_sbitmap_vector (rtl_dump_file, ";; Iterated Dominance Frontiers:",
-			   "; Register", idfs, nregs);
-      fflush (rtl_dump_file);
-    }
-
-  /* Insert the phi nodes.  */
-
-  insert_phi_nodes (idfs, evals, nregs);
-
-  /* Rename the registers to satisfy SSA.  */
-
-  rename_registers (nregs, idom);
-
-  /* All done!  Clean up and go home.  */
-
-  sbitmap_vector_free (dfs);
-  sbitmap_vector_free (evals);
-  sbitmap_vector_free (idfs);
-  in_ssa_form = 1;
-
-  reg_scan (get_insns (), max_reg_num (), 1);
-  free_dominance_info (idom);
-}
-
-/* REG is the representative temporary of its partition.  Add it to the
-   set of nodes to be processed, if it hasn't been already.  Return the
-   index of this register in the node set.  */
-
-static inline int
-ephi_add_node (reg, nodes, n_nodes)
-     rtx reg, *nodes;
-     int *n_nodes;
-{
-  int i;
-  for (i = *n_nodes - 1; i >= 0; --i)
-    if (REGNO (reg) == REGNO (nodes[i]))
-      return i;
-
-  nodes[i = (*n_nodes)++] = reg;
-  return i;
-}
-
-/* Part one of the topological sort.  This is a forward (downward) search
-   through the graph collecting a stack of nodes to process.  Assuming no
-   cycles, the nodes at top of the stack when we are finished will have
-   no other dependencies.  */
-
-static int *
-ephi_forward (t, visited, succ, tstack)
-     int t;
-     sbitmap visited;
-     sbitmap *succ;
-     int *tstack;
-{
-  int s;
-
-  SET_BIT (visited, t);
-
-  EXECUTE_IF_SET_IN_SBITMAP (succ[t], 0, s,
-    {
-      if (! TEST_BIT (visited, s))
-	tstack = ephi_forward (s, visited, succ, tstack);
-    });
-
-  *tstack++ = t;
-  return tstack;
-}
-
-/* Part two of the topological sort.  The is a backward search through
-   a cycle in the graph, copying the data forward as we go.  */
-
-static void
-ephi_backward (t, visited, pred, nodes)
-     int t;
-     sbitmap visited, *pred;
-     rtx *nodes;
-{
-  int p;
-
-  SET_BIT (visited, t);
-
-  EXECUTE_IF_SET_IN_SBITMAP (pred[t], 0, p,
-    {
-      if (! TEST_BIT (visited, p))
-	{
-	  ephi_backward (p, visited, pred, nodes);
-	  emit_move_insn (nodes[p], nodes[t]);
-	}
-    });
-}
-
-/* Part two of the topological sort.  Create the copy for a register
-   and any cycle of which it is a member.  */
-
-static void
-ephi_create (t, visited, pred, succ, nodes)
-     int t;
-     sbitmap visited, *pred, *succ;
-     rtx *nodes;
-{
-  rtx reg_u = NULL_RTX;
-  int unvisited_predecessors = 0;
-  int p;
-
-  /* Iterate through the predecessor list looking for unvisited nodes.
-     If there are any, we have a cycle, and must deal with that.  At
-     the same time, look for a visited predecessor.  If there is one,
-     we won't need to create a temporary.  */
-
-  EXECUTE_IF_SET_IN_SBITMAP (pred[t], 0, p,
-    {
-      if (! TEST_BIT (visited, p))
-	unvisited_predecessors = 1;
-      else if (!reg_u)
-	reg_u = nodes[p];
-    });
-
-  if (unvisited_predecessors)
-    {
-      /* We found a cycle.  Copy out one element of the ring (if necessary),
-	 then traverse the ring copying as we go.  */
-
-      if (!reg_u)
-	{
-	  reg_u = gen_reg_rtx (GET_MODE (nodes[t]));
-	  emit_move_insn (reg_u, nodes[t]);
-	}
-
-      EXECUTE_IF_SET_IN_SBITMAP (pred[t], 0, p,
-	{
-	  if (! TEST_BIT (visited, p))
-	    {
-	      ephi_backward (p, visited, pred, nodes);
-	      emit_move_insn (nodes[p], reg_u);
-	    }
-	});
-    }
-  else
-    {
-      /* No cycle.  Just copy the value from a successor.  */
-
-      int s;
-      EXECUTE_IF_SET_IN_SBITMAP (succ[t], 0, s,
-	{
-	  SET_BIT (visited, t);
-	  emit_move_insn (nodes[t], nodes[s]);
-	  return;
-	});
-    }
-}
-
-/* Convert the edge to normal form.  */
-
-static void
-eliminate_phi (e, reg_partition)
-     edge e;
-     partition reg_partition;
-{
-  int n_nodes;
-  sbitmap *pred, *succ;
-  sbitmap visited;
-  rtx *nodes;
-  int *stack, *tstack;
-  rtx insn;
-  int i;
-
-  /* Collect an upper bound on the number of registers needing processing.  */
-
-  insn = first_insn_after_basic_block_note (e->dest);
-
-  n_nodes = 0;
-  while (PHI_NODE_P (insn))
-    {
-      insn = next_nonnote_insn (insn);
-      n_nodes += 2;
-    }
-
-  if (n_nodes == 0)
-    return;
-
-  /* Build the auxiliary graph R(B).
-
-     The nodes of the graph are the members of the register partition
-     present in Phi(B).  There is an edge from FIND(T0)->FIND(T1) for
-     each T0 = PHI(...,T1,...), where T1 is for the edge from block C.  */
-
-  nodes = (rtx *) alloca (n_nodes * sizeof(rtx));
-  pred = sbitmap_vector_alloc (n_nodes, n_nodes);
-  succ = sbitmap_vector_alloc (n_nodes, n_nodes);
-  sbitmap_vector_zero (pred, n_nodes);
-  sbitmap_vector_zero (succ, n_nodes);
-
-  insn = first_insn_after_basic_block_note (e->dest);
-
-  n_nodes = 0;
-  for (; PHI_NODE_P (insn); insn = next_nonnote_insn (insn))
-    {
-      rtx* preg = phi_alternative (PATTERN (insn), e->src->index);
-      rtx tgt = SET_DEST (PATTERN (insn));
-      rtx reg;
-
-      /* There may be no phi alternative corresponding to this edge.
-	 This indicates that the phi variable is undefined along this
-	 edge.  */
-      if (preg == NULL)
-	continue;
-      reg = *preg;
-
-      if (GET_CODE (reg) != REG || GET_CODE (tgt) != REG)
-	abort ();
-
-      reg = regno_reg_rtx[partition_find (reg_partition, REGNO (reg))];
-      tgt = regno_reg_rtx[partition_find (reg_partition, REGNO (tgt))];
-      /* If the two registers are already in the same partition,
-	 nothing will need to be done.  */
-      if (reg != tgt)
-	{
-	  int ireg, itgt;
-
-	  ireg = ephi_add_node (reg, nodes, &n_nodes);
-	  itgt = ephi_add_node (tgt, nodes, &n_nodes);
-
-	  SET_BIT (pred[ireg], itgt);
-	  SET_BIT (succ[itgt], ireg);
-	}
-    }
-
-  if (n_nodes == 0)
-    goto out;
-
-  /* Begin a topological sort of the graph.  */
-
-  visited = sbitmap_alloc (n_nodes);
-  sbitmap_zero (visited);
-
-  tstack = stack = (int *) alloca (n_nodes * sizeof (int));
-
-  for (i = 0; i < n_nodes; ++i)
-    if (! TEST_BIT (visited, i))
-      tstack = ephi_forward (i, visited, succ, tstack);
-
-  sbitmap_zero (visited);
-
-  /* As we find a solution to the tsort, collect the implementation
-     insns in a sequence.  */
-  start_sequence ();
-
-  while (tstack != stack)
-    {
-      i = *--tstack;
-      if (! TEST_BIT (visited, i))
-	ephi_create (i, visited, pred, succ, nodes);
-    }
-
-  insn = get_insns ();
-  end_sequence ();
-  insert_insn_on_edge (insn, e);
-  if (rtl_dump_file)
-    fprintf (rtl_dump_file, "Emitting copy on edge (%d,%d)\n",
-	     e->src->index, e->dest->index);
-
-  sbitmap_free (visited);
-out:
-  sbitmap_vector_free (pred);
-  sbitmap_vector_free (succ);
-}
-
-/* For basic block B, consider all phi insns which provide an
-   alternative corresponding to an incoming abnormal critical edge.
-   Place the phi alternative corresponding to that abnormal critical
-   edge in the same register class as the destination of the set.
-
-   From Morgan, p. 178:
-
-     For each abnormal critical edge (C, B),
-     if T0 = phi (T1, ..., Ti, ..., Tm) is a phi node in B,
-     and C is the ith predecessor of B,
-     then T0 and Ti must be equivalent.
-
-   Return nonzero iff any such cases were found for which the two
-   regs were not already in the same class.  */
-
-static int
-make_regs_equivalent_over_bad_edges (bb, reg_partition)
-     int bb;
-     partition reg_partition;
-{
-  int changed = 0;
-  basic_block b = BASIC_BLOCK (bb);
-  rtx phi;
-
-  /* Advance to the first phi node.  */
-  phi = first_insn_after_basic_block_note (b);
-
-  /* Scan all the phi nodes.  */
-  for (;
-       PHI_NODE_P (phi);
-       phi = next_nonnote_insn (phi))
-    {
-      edge e;
-      int tgt_regno;
-      rtx set = PATTERN (phi);
-      rtx tgt = SET_DEST (set);
-
-      /* The set target is expected to be an SSA register.  */
-      if (GET_CODE (tgt) != REG
-	  || !CONVERT_REGISTER_TO_SSA_P (REGNO (tgt)))
-	abort ();
-      tgt_regno = REGNO (tgt);
-
-      /* Scan incoming abnormal critical edges.  */
-      for (e = b->pred; e; e = e->pred_next)
-	if ((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))
-	  {
-	    rtx *alt = phi_alternative (set, e->src->index);
-	    int alt_regno;
-
-	    /* If there is no alternative corresponding to this edge,
-	       the value is undefined along the edge, so just go on.  */
-	    if (alt == 0)
-	      continue;
-
-	    /* The phi alternative is expected to be an SSA register.  */
-	    if (GET_CODE (*alt) != REG
-		|| !CONVERT_REGISTER_TO_SSA_P (REGNO (*alt)))
-	      abort ();
-	    alt_regno = REGNO (*alt);
-
-	    /* If the set destination and the phi alternative aren't
-	       already in the same class...  */
-	    if (partition_find (reg_partition, tgt_regno)
-		!= partition_find (reg_partition, alt_regno))
-	      {
-		/* ... make them such.  */
-		if (conflicting_hard_regs_p (tgt_regno, alt_regno))
-		  /* It is illegal to unify a hard register with a
-		     different register.  */
-		  abort ();
-
-		partition_union (reg_partition,
-				 tgt_regno, alt_regno);
-		++changed;
-	      }
-	  }
-    }
-
-  return changed;
-}
-
-/* Consider phi insns in basic block BB pairwise.  If the set target
-   of both isns are equivalent pseudos, make the corresponding phi
-   alternatives in each phi corresponding equivalent.
-
-   Return nonzero if any new register classes were unioned.  */
-
-static int
-make_equivalent_phi_alternatives_equivalent (bb, reg_partition)
-     int bb;
-     partition reg_partition;
-{
-  int changed = 0;
-  basic_block b = BASIC_BLOCK (bb);
-  rtx phi;
-
-  /* Advance to the first phi node.  */
-  phi = first_insn_after_basic_block_note (b);
-
-  /* Scan all the phi nodes.  */
-  for (;
-       PHI_NODE_P (phi);
-       phi = next_nonnote_insn (phi))
-    {
-      rtx set = PATTERN (phi);
-      /* The regno of the destination of the set.  */
-      int tgt_regno = REGNO (SET_DEST (PATTERN (phi)));
-
-      rtx phi2 = next_nonnote_insn (phi);
-
-      /* Scan all phi nodes following this one.  */
-      for (;
-	   PHI_NODE_P (phi2);
-	   phi2 = next_nonnote_insn (phi2))
-	{
-	  rtx set2 = PATTERN (phi2);
-	  /* The regno of the destination of the set.  */
-	  int tgt2_regno = REGNO (SET_DEST (set2));
-
-	  /* Are the set destinations equivalent regs?  */
-	  if (partition_find (reg_partition, tgt_regno) ==
-	      partition_find (reg_partition, tgt2_regno))
-	    {
-	      edge e;
-	      /* Scan over edges.  */
-	      for (e = b->pred; e; e = e->pred_next)
-		{
-		  int pred_block = e->src->index;
-		  /* Identify the phi alternatives from both phi
-		     nodes corresponding to this edge.  */
-		  rtx *alt = phi_alternative (set, pred_block);
-		  rtx *alt2 = phi_alternative (set2, pred_block);
-
-		  /* If one of the phi nodes doesn't have a
-		     corresponding alternative, just skip it.  */
-		  if (alt == 0 || alt2 == 0)
-		    continue;
-
-		  /* Both alternatives should be SSA registers.  */
-		  if (GET_CODE (*alt) != REG
-		      || !CONVERT_REGISTER_TO_SSA_P (REGNO (*alt)))
-		    abort ();
-		  if (GET_CODE (*alt2) != REG
-		      || !CONVERT_REGISTER_TO_SSA_P (REGNO (*alt2)))
-		    abort ();
-
-		  /* If the alternatives aren't already in the same
-		     class ...  */
-		  if (partition_find (reg_partition, REGNO (*alt))
-		      != partition_find (reg_partition, REGNO (*alt2)))
-		    {
-		      /* ... make them so.  */
-		      if (conflicting_hard_regs_p (REGNO (*alt), REGNO (*alt2)))
-			/* It is illegal to unify a hard register with
-			   a different register.  */
-			abort ();
-
-		      partition_union (reg_partition,
-				       REGNO (*alt), REGNO (*alt2));
-		      ++changed;
-		    }
-		}
-	    }
-	}
-    }
-
-  return changed;
-}
-
-/* Compute a conservative partition of outstanding pseudo registers.
-   See Morgan 7.3.1.  */
-
-static partition
-compute_conservative_reg_partition ()
-{
-  basic_block bb;
-  int changed = 0;
-
-  /* We don't actually work with hard registers, but it's easier to
-     carry them around anyway rather than constantly doing register
-     number arithmetic.  */
-  partition p =
-    partition_new (ssa_definition->num_elements);
-
-  /* The first priority is to make sure registers that might have to
-     be copied on abnormal critical edges are placed in the same
-     partition.  This saves us from having to split abnormal critical
-     edges.  */
-  FOR_EACH_BB_REVERSE (bb)
-    changed += make_regs_equivalent_over_bad_edges (bb->index, p);
-
-  /* Now we have to insure that corresponding arguments of phi nodes
-     assigning to corresponding regs are equivalent.  Iterate until
-     nothing changes.  */
-  while (changed > 0)
-    {
-      changed = 0;
-      FOR_EACH_BB_REVERSE (bb)
-	changed += make_equivalent_phi_alternatives_equivalent (bb->index, p);
-    }
-
-  return p;
-}
-
-/* The following functions compute a register partition that attempts
-   to eliminate as many reg copies and phi node copies as possible by
-   coalescing registers.   This is the strategy:
-
-    1. As in the conservative case, the top priority is to coalesce
-       registers that otherwise would cause copies to be placed on
-       abnormal critical edges (which isn't possible).
-
-    2. Figure out which regs are involved (in the LHS or RHS) of
-       copies and phi nodes.  Compute conflicts among these regs.
-
-    3. Walk around the instruction stream, placing two regs in the
-       same class of the partition if one appears on the LHS and the
-       other on the RHS of a copy or phi node and the two regs don't
-       conflict.  The conflict information of course needs to be
-       updated.
-
-    4. If anything has changed, there may be new opportunities to
-       coalesce regs, so go back to 2.
-*/
-
-/* If REG1 and REG2 don't conflict in CONFLICTS, place them in the
-   same class of partition P, if they aren't already.  Update
-   CONFLICTS appropriately.
-
-   Returns one if REG1 and REG2 were placed in the same class but were
-   not previously; zero otherwise.
-
-   See Morgan figure 11.15.  */
-
-static int
-coalesce_if_unconflicting (p, conflicts, reg1, reg2)
-     partition p;
-     conflict_graph conflicts;
-     int reg1;
-     int reg2;
-{
-  int reg;
-
-  /* Work only on SSA registers.  */
-  if (!CONVERT_REGISTER_TO_SSA_P (reg1) || !CONVERT_REGISTER_TO_SSA_P (reg2))
-    return 0;
-
-  /* Find the canonical regs for the classes containing REG1 and
-     REG2.  */
-  reg1 = partition_find (p, reg1);
-  reg2 = partition_find (p, reg2);
-
-  /* If they're already in the same class, there's nothing to do.  */
-  if (reg1 == reg2)
-    return 0;
-
-  /* If the regs conflict, our hands are tied.  */
-  if (conflicting_hard_regs_p (reg1, reg2) ||
-      conflict_graph_conflict_p (conflicts, reg1, reg2))
-    return 0;
-
-  /* We're good to go.  Put the regs in the same partition.  */
-  partition_union (p, reg1, reg2);
-
-  /* Find the new canonical reg for the merged class.  */
-  reg = partition_find (p, reg1);
-
-  /* Merge conflicts from the two previous classes.  */
-  conflict_graph_merge_regs (conflicts, reg, reg1);
-  conflict_graph_merge_regs (conflicts, reg, reg2);
-
-  return 1;
-}
-
-/* For each register copy insn in basic block BB, place the LHS and
-   RHS regs in the same class in partition P if they do not conflict
-   according to CONFLICTS.
-
-   Returns the number of changes that were made to P.
-
-   See Morgan figure 11.14.  */
-
-static int
-coalesce_regs_in_copies (bb, p, conflicts)
-     basic_block bb;
-     partition p;
-     conflict_graph conflicts;
-{
-  int changed = 0;
-  rtx insn;
-  rtx end = bb->end;
-
-  /* Scan the instruction stream of the block.  */
-  for (insn = bb->head; insn != end; insn = NEXT_INSN (insn))
-    {
-      rtx pattern;
-      rtx src;
-      rtx dest;
-
-      /* If this isn't a set insn, go to the next insn.  */
-      if (GET_CODE (insn) != INSN)
-	continue;
-      pattern = PATTERN (insn);
-      if (GET_CODE (pattern) != SET)
-	continue;
-
-      src = SET_SRC (pattern);
-      dest = SET_DEST (pattern);
-
-      /* We're only looking for copies.  */
-      if (GET_CODE (src) != REG || GET_CODE (dest) != REG)
-	continue;
-
-      /* Coalesce only if the reg modes are the same.  As long as
-	 each reg's rtx is unique, it can have only one mode, so two
-	 pseudos of different modes can't be coalesced into one.
-
-         FIXME: We can probably get around this by inserting SUBREGs
-         where appropriate, but for now we don't bother.  */
-      if (GET_MODE (src) != GET_MODE (dest))
-	continue;
-
-      /* Found a copy; see if we can use the same reg for both the
-	 source and destination (and thus eliminate the copy,
-	 ultimately).  */
-      changed += coalesce_if_unconflicting (p, conflicts,
-					    REGNO (src), REGNO (dest));
-    }
-
-  return changed;
-}
-
-struct phi_coalesce_context
-{
-  partition p;
-  conflict_graph conflicts;
-  int changed;
-};
-
-/* Callback function for for_each_successor_phi.  If the set
-   destination and the phi alternative regs do not conflict, place
-   them in the same paritition class.  DATA is a pointer to a
-   phi_coalesce_context struct.  */
-
-static int
-coalesce_reg_in_phi (insn, dest_regno, src_regno, data)
-     rtx insn ATTRIBUTE_UNUSED;
-     int dest_regno;
-     int src_regno;
-     void *data;
-{
-  struct phi_coalesce_context *context =
-    (struct phi_coalesce_context *) data;
-
-  /* Attempt to use the same reg, if they don't conflict.  */
-  context->changed
-    += coalesce_if_unconflicting (context->p, context->conflicts,
-				  dest_regno, src_regno);
-  return 0;
-}
-
-/* For each alternative in a phi function corresponding to basic block
-   BB (in phi nodes in successor block to BB), place the reg in the
-   phi alternative and the reg to which the phi value is set into the
-   same class in partition P, if allowed by CONFLICTS.
-
-   Return the number of changes that were made to P.
-
-   See Morgan figure 11.14.  */
-
-static int
-coalesce_regs_in_successor_phi_nodes (bb, p, conflicts)
-     basic_block bb;
-     partition p;
-     conflict_graph conflicts;
-{
-  struct phi_coalesce_context context;
-  context.p = p;
-  context.conflicts = conflicts;
-  context.changed = 0;
-
-  for_each_successor_phi (bb, &coalesce_reg_in_phi, &context);
-
-  return context.changed;
-}
-
-/* Compute and return a partition of pseudos.  Where possible,
-   non-conflicting pseudos are placed in the same class.
-
-   The caller is responsible for deallocating the returned partition.  */
-
-static partition
-compute_coalesced_reg_partition ()
-{
-  basic_block bb;
-  int changed = 0;
-  regset_head phi_set_head;
-  regset phi_set = &phi_set_head;
-
-  partition p =
-    partition_new (ssa_definition->num_elements);
-
-  /* The first priority is to make sure registers that might have to
-     be copied on abnormal critical edges are placed in the same
-     partition.  This saves us from having to split abnormal critical
-     edges (which can't be done).  */
-  FOR_EACH_BB_REVERSE (bb)
-    make_regs_equivalent_over_bad_edges (bb->index, p);
-
-  INIT_REG_SET (phi_set);
-
-  do
-    {
-      conflict_graph conflicts;
-
-      changed = 0;
-
-      /* Build the set of registers involved in phi nodes, either as
-	 arguments to the phi function or as the target of a set.  */
-      CLEAR_REG_SET (phi_set);
-      mark_phi_and_copy_regs (phi_set);
-
-      /* Compute conflicts.  */
-      conflicts = conflict_graph_compute (phi_set, p);
-
-      /* FIXME: Better would be to process most frequently executed
-	 blocks first, so that most frequently executed copies would
-	 be more likely to be removed by register coalescing.  But any
-	 order will generate correct, if non-optimal, results.  */
-      FOR_EACH_BB_REVERSE (bb)
-	{
-	  changed += coalesce_regs_in_copies (bb, p, conflicts);
-	  changed +=
-	    coalesce_regs_in_successor_phi_nodes (bb, p, conflicts);
-	}
-
-      conflict_graph_delete (conflicts);
-    }
-  while (changed > 0);
-
-  FREE_REG_SET (phi_set);
-
-  return p;
-}
-
-/* Mark the regs in a phi node.  PTR is a phi expression or one of its
-   components (a REG or a CONST_INT).  DATA is a reg set in which to
-   set all regs.  Called from for_each_rtx.  */
-
-static int
-mark_reg_in_phi (ptr, data)
-     rtx *ptr;
-     void *data;
-{
-  rtx expr = *ptr;
-  regset set = (regset) data;
-
-  switch (GET_CODE (expr))
-    {
-    case REG:
-      SET_REGNO_REG_SET (set, REGNO (expr));
-      /* Fall through.  */
-    case CONST_INT:
-    case PHI:
-      return 0;
-    default:
-      abort ();
-    }
-}
-
-/* Mark in PHI_SET all pseudos that are used in a phi node -- either
-   set from a phi expression, or used as an argument in one.  Also
-   mark regs that are the source or target of a reg copy.  Uses
-   ssa_definition.  */
-
-static void
-mark_phi_and_copy_regs (phi_set)
-     regset phi_set;
-{
-  unsigned int reg;
-
-  /* Scan the definitions of all regs.  */
-  for (reg = 0; reg < VARRAY_SIZE (ssa_definition); ++reg)
-    if (CONVERT_REGISTER_TO_SSA_P (reg))
-      {
-	rtx insn = VARRAY_RTX (ssa_definition, reg);
-	rtx pattern;
-	rtx src;
-
-	if (insn == NULL
-	    || (GET_CODE (insn) == NOTE
-		&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED))
-	  continue;
-	pattern = PATTERN (insn);
-	/* Sometimes we get PARALLEL insns.  These aren't phi nodes or
-	   copies.  */
-	if (GET_CODE (pattern) != SET)
-	  continue;
-	src = SET_SRC (pattern);
-
-	if (GET_CODE (src) == REG)
-	  {
-	    /* It's a reg copy.  */
-	    SET_REGNO_REG_SET (phi_set, reg);
-	    SET_REGNO_REG_SET (phi_set, REGNO (src));
-	  }
-	else if (GET_CODE (src) == PHI)
-	  {
-	    /* It's a phi node.  Mark the reg being set.  */
-	    SET_REGNO_REG_SET (phi_set, reg);
-	    /* Mark the regs used in the phi function.  */
-	    for_each_rtx (&src, mark_reg_in_phi, phi_set);
-	  }
-	/* ... else nothing to do.  */
-      }
-}
-
-/* Rename regs in insn PTR that are equivalent.  DATA is the register
-   partition which specifies equivalences.  */
-
-static int
-rename_equivalent_regs_in_insn (ptr, data)
-     rtx *ptr;
-     void* data;
-{
-  rtx x = *ptr;
-  partition reg_partition = (partition) data;
-
-  if (x == NULL_RTX)
-    return 0;
-
-  switch (GET_CODE (x))
-    {
-    case REG:
-      if (CONVERT_REGISTER_TO_SSA_P (REGNO (x)))
-	{
-	  unsigned int regno = REGNO (x);
-	  unsigned int new_regno = partition_find (reg_partition, regno);
-	  rtx canonical_element_rtx = ssa_rename_from_lookup (new_regno);
-
-	  if (canonical_element_rtx != NULL_RTX &&
-	      HARD_REGISTER_P (canonical_element_rtx))
-	    {
-	      if (REGNO (canonical_element_rtx) != regno)
-		*ptr = canonical_element_rtx;
-	    }
-	  else if (regno != new_regno)
-	    {
-	      rtx new_reg = regno_reg_rtx[new_regno];
-	      if (GET_MODE (x) != GET_MODE (new_reg))
-		abort ();
-	      *ptr = new_reg;
-	    }
-	}
-      return -1;
-
-    case PHI:
-      /* No need to rename the phi nodes.  We'll check equivalence
-	 when inserting copies.  */
-      return -1;
-
-    default:
-      /* Anything else, continue traversing.  */
-      return 0;
-    }
-}
-
-/* Record the register's canonical element stored in SRFP in the
-   canonical_elements sbitmap packaged in DATA.  This function is used
-   as a callback function for traversing ssa_rename_from.  */
-
-static int
-record_canonical_element_1 (srfp, data)
-     void **srfp;
-     void *data;
-{
-  unsigned int reg = ((ssa_rename_from_pair *) *srfp)->reg;
-  sbitmap canonical_elements =
-    ((struct ssa_rename_from_hash_table_data *) data)->canonical_elements;
-  partition reg_partition =
-    ((struct ssa_rename_from_hash_table_data *) data)->reg_partition;
-
-  SET_BIT (canonical_elements, partition_find (reg_partition, reg));
-  return 1;
-}
-
-/* For each class in the REG_PARTITION corresponding to a particular
-   hard register and machine mode, check that there are no other
-   classes with the same hard register and machine mode.  Returns
-   nonzero if this is the case, i.e., the partition is acceptable.  */
-
-static int
-check_hard_regs_in_partition (reg_partition)
-     partition reg_partition;
-{
-  /* CANONICAL_ELEMENTS has a nonzero bit if a class with the given register
-     number and machine mode has already been seen.  This is a
-     problem with the partition.  */
-  sbitmap canonical_elements;
-  int element_index;
-  int already_seen[FIRST_PSEUDO_REGISTER][NUM_MACHINE_MODES];
-  int reg;
-  int mach_mode;
-
-  /* Collect a list of canonical elements.  */
-  canonical_elements = sbitmap_alloc (max_reg_num ());
-  sbitmap_zero (canonical_elements);
-  ssa_rename_from_traverse (&record_canonical_element_1,
-			    canonical_elements, reg_partition);
-
-  /* We have not seen any hard register uses.  */
-  for (reg = 0; reg < FIRST_PSEUDO_REGISTER; ++reg)
-    for (mach_mode = 0; mach_mode < NUM_MACHINE_MODES; ++mach_mode)
-      already_seen[reg][mach_mode] = 0;
-
-  /* Check for classes with the same hard register and machine mode.  */
-  EXECUTE_IF_SET_IN_SBITMAP (canonical_elements, 0, element_index,
-  {
-    rtx hard_reg_rtx = ssa_rename_from_lookup (element_index);
-    if (hard_reg_rtx != NULL_RTX &&
-	HARD_REGISTER_P (hard_reg_rtx) &&
-	already_seen[REGNO (hard_reg_rtx)][GET_MODE (hard_reg_rtx)] != 0)
-	  /* Two distinct partition classes should be mapped to the same
-	     hard register.  */
-	  return 0;
-  });
-
-  sbitmap_free (canonical_elements);
-
-  return 1;
-}
-
-/* Rename regs that are equivalent in REG_PARTITION.  Also collapse
-   any SEQUENCE insns.  */
-
-static void
-rename_equivalent_regs (reg_partition)
-     partition reg_partition;
-{
-  basic_block b;
-
-  FOR_EACH_BB_REVERSE (b)
-    {
-      rtx next = b->head;
-      rtx last = b->end;
-      rtx insn;
-
-      do
-	{
-	  insn = next;
-	  if (INSN_P (insn))
-	    {
-	      for_each_rtx (&PATTERN (insn),
-			    rename_equivalent_regs_in_insn,
-			    reg_partition);
-	      for_each_rtx (&REG_NOTES (insn),
-			    rename_equivalent_regs_in_insn,
-			    reg_partition);
-
-	      if (GET_CODE (PATTERN (insn)) == SEQUENCE)
-		{
-		  rtx s = PATTERN (insn);
-		  int slen = XVECLEN (s, 0);
-		  int i;
-
-		  if (slen <= 1)
-		    abort ();
-
-		  PATTERN (insn) = XVECEXP (s, 0, slen-1);
-		  for (i = 0; i < slen - 1; i++)
-		    emit_insn_before (XVECEXP (s, 0, i), insn);
-		}
-	    }
-
-	  next = NEXT_INSN (insn);
-	}
-      while (insn != last);
-    }
-}
-
-/* The main entry point for moving from SSA.  */
-
-void
-convert_from_ssa ()
-{
-  basic_block b, bb;
-  partition reg_partition;
-  rtx insns = get_insns ();
-
-  /* Need global_live_at_{start,end} up to date.  There should not be
-     any significant dead code at this point, except perhaps dead
-     stores.  So do not take the time to perform dead code elimination.
-
-     Register coalescing needs death notes, so generate them.  */
-  life_analysis (insns, NULL, PROP_DEATH_NOTES);
-
-  /* Figure out which regs in copies and phi nodes don't conflict and
-     therefore can be coalesced.  */
-  if (conservative_reg_partition)
-    reg_partition = compute_conservative_reg_partition ();
-  else
-    reg_partition = compute_coalesced_reg_partition ();
-
-  if (!check_hard_regs_in_partition (reg_partition))
-    /* Two separate partitions should correspond to the same hard
-       register but do not.  */
-    abort ();
-
-  rename_equivalent_regs (reg_partition);
-
-  /* Eliminate the PHI nodes.  */
-  FOR_EACH_BB_REVERSE (b)
-    {
-      edge e;
-
-      for (e = b->pred; e; e = e->pred_next)
-	if (e->src != ENTRY_BLOCK_PTR)
-	  eliminate_phi (e, reg_partition);
-    }
-
-  partition_delete (reg_partition);
-
-  /* Actually delete the PHI nodes.  */
-  FOR_EACH_BB_REVERSE (bb)
-    {
-      rtx insn = bb->head;
-
-      while (1)
-	{
-	  /* If this is a PHI node delete it.  */
-	  if (PHI_NODE_P (insn))
-	    {
-	      if (insn == bb->end)
-		bb->end = PREV_INSN (insn);
-	      insn = delete_insn (insn);
-	    }
-	  /* Since all the phi nodes come at the beginning of the
-	     block, if we find an ordinary insn, we can stop looking
-	     for more phi nodes.  */
-	  else if (INSN_P (insn))
-	    break;
-	  /* If we've reached the end of the block, stop.  */
-	  else if (insn == bb->end)
-	    break;
-	  else
-	    insn = NEXT_INSN (insn);
-	}
-    }
-
-  /* Commit all the copy nodes needed to convert out of SSA form.  */
-  commit_edge_insertions ();
-
-  in_ssa_form = 0;
-
-  count_or_remove_death_notes (NULL, 1);
-
-  /* Deallocate the data structures.  */
-  ssa_definition = 0;
-  ssa_rename_from_free ();
-}
-
-/* Scan phi nodes in successors to BB.  For each such phi node that
-   has a phi alternative value corresponding to BB, invoke FN.  FN
-   is passed the entire phi node insn, the regno of the set
-   destination, the regno of the phi argument corresponding to BB,
-   and DATA.
-
-   If FN ever returns nonzero, stops immediately and returns this
-   value.  Otherwise, returns zero.  */
-
-int
-for_each_successor_phi (bb, fn, data)
-     basic_block bb;
-     successor_phi_fn fn;
-     void *data;
-{
-  edge e;
-
-  if (bb == EXIT_BLOCK_PTR)
-    return 0;
-
-  /* Scan outgoing edges.  */
-  for (e = bb->succ; e != NULL; e = e->succ_next)
-    {
-      rtx insn;
-
-      basic_block successor = e->dest;
-      if (successor == ENTRY_BLOCK_PTR
-	  || successor == EXIT_BLOCK_PTR)
-	continue;
-
-      /* Advance to the first non-label insn of the successor block.  */
-      insn = first_insn_after_basic_block_note (successor);
-
-      if (insn == NULL)
-	continue;
-
-      /* Scan phi nodes in the successor.  */
-      for ( ; PHI_NODE_P (insn); insn = NEXT_INSN (insn))
-	{
-	  int result;
-	  rtx phi_set = PATTERN (insn);
-	  rtx *alternative = phi_alternative (phi_set, bb->index);
-	  rtx phi_src;
-
-	  /* This phi function may not have an alternative
-	     corresponding to the incoming edge, indicating the
-	     assigned variable is not defined along the edge.  */
-	  if (alternative == NULL)
-	    continue;
-	  phi_src = *alternative;
-
-	  /* Invoke the callback.  */
-	  result = (*fn) (insn, REGNO (SET_DEST (phi_set)),
-			  REGNO (phi_src), data);
-
-	  /* Terminate if requested.  */
-	  if (result != 0)
-	    return result;
-	}
-    }
-
-  return 0;
-}
-
-/* Assuming the ssa_rename_from mapping has been established, yields
-   nonzero if 1) only one SSA register of REG1 and REG2 comes from a
-   hard register or 2) both SSA registers REG1 and REG2 come from
-   different hard registers.  */
-
-static int
-conflicting_hard_regs_p (reg1, reg2)
-     int reg1;
-     int reg2;
-{
-  int orig_reg1 = original_register (reg1);
-  int orig_reg2 = original_register (reg2);
-  if (HARD_REGISTER_NUM_P (orig_reg1) && HARD_REGISTER_NUM_P (orig_reg2)
-      && orig_reg1 != orig_reg2)
-    return 1;
-  if (HARD_REGISTER_NUM_P (orig_reg1) && !HARD_REGISTER_NUM_P (orig_reg2))
-    return 1;
-  if (!HARD_REGISTER_NUM_P (orig_reg1) && HARD_REGISTER_NUM_P (orig_reg2))
-    return 1;
-
-  return 0;
-}