* Makefile.in (tree-vn.o): New.

	(tree-ssa-pre.o): Don't depend on RTL_H.
	* tree-dfa.c (find_referenced_vars): Don't call init_tree_ssa.
	* tree-flow.h (struct var_ann_d): Remove field expr_set.
	(add_to_value, expressions_equal_p, get_value_handle, vn_compute,
	vn_lookup_or_add, vn_add, vn_lookup, vn_init, vn_delete): Declare.
	* tree-optimize.c (execute_init_datastructures): New local function.
	(pass_init_datastructures): New local variable.
	(init_tree_optimization_passes): Sequence pass_init_datastructures.
	* tree-pretty-print.c (MASK_POINTER): Remove.
	(dump_generic_node): Handle VALUE_HANDLE.
	* tree-ssa-pre.c: Move all value numbering routines to tree-vn.c.
	Update callers to use new function names.
	Use VALUE_HANDLE_ID and VALUE_HANDLE_EXPR_SET instead of
	variable annotations.
	* tree-ssa.c (init_tree_ssa): Call vn_init.
	(delete_tree_ssa): Call vn_delete.
	* tree-vn.c: New file.
	* tree.c (tree_size): Handle VALUE_HANDLE.
	(tree_node_structure): Likewise.
	(iterative_hash_expr): Likewise.
	* tree.def (VALUE_HANDLE): New code.
	* tree.h (struct tree_value_handle): New.
	(VALUE_HANDLE_ID): Define.
	(VALUE_HANDLE_EXPR_SET): Define.
	(enum tree_node_structure_enum): Add TS_VALUE_HANDLE.
	(union tree_node): Add struct tree_value_handle.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@83564 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 60 insertions, 262 deletions

diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index c8d8035f5ec..5c32bc28787 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -19,6 +19,7 @@ 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"
@@ -26,11 +27,6 @@ Boston, MA 02111-1307, USA.  */
 #include "errors.h"
 #include "ggc.h"
 #include "tree.h"
-
-/* These RTL headers are needed for basic-block.h.  */
-#include "rtl.h"
-#include "tm_p.h"
-#include "hard-reg-set.h"
 #include "basic-block.h"
 #include "diagnostic.h"
 #include "tree-inline.h"
@@ -48,6 +44,7 @@ Boston, MA 02111-1307, USA.  */
 #include "splay-tree.h"
 #include "bitmap.h"
 #include "langhooks.h"
+
 /* TODO:
    
    1. Implement load value numbering.
@@ -279,10 +276,8 @@ static struct
 static tree find_leader (value_set_t, tree);
 static void value_insert_into_set (value_set_t, tree);
 static void insert_into_set (value_set_t, tree);
-static void add_to_value (tree, tree);
 static value_set_t set_new  (bool);
 static bool is_undefined_value (tree);
-static bool expressions_equal_p (tree, tree);
 static tree create_expression_by_pieces (basic_block, tree, tree);
 
 /* We can add and remove elements and entries to and from sets
@@ -293,117 +288,12 @@ static alloc_pool value_set_node_pool;
 static alloc_pool binary_node_pool;
 static alloc_pool unary_node_pool;
 
-/* The value table that maps expressions to values.  */
-
-static htab_t value_table;
 
 /* The phi_translate_table caches phi translations for a given
    expression and predecessor.  */
 
 static htab_t phi_translate_table;
 
-/* Compare two expressions E1 and E2 and return true if they are
-   equal.  */
-
-static bool
-expressions_equal_p (tree e1, tree e2)
-{
-  tree te1, te2;
-  
-  if (e1 == e2)
-    return true;
-  
-  te1 = TREE_TYPE (e1);
-  te2 = TREE_TYPE (e2);
-
-  if (TREE_CODE (e1) == TREE_CODE (e2) 
-      && (te1 == te2 || lang_hooks.types_compatible_p (te1, te2))
-      && operand_equal_p (e1, e2, 0))
-    return true;
-  return false;
-}
-
-/* Map expressions to values.  These are simple pairs of expressions
-   and the values they represent.  To find the value represented by
-   an expression, we use a hash table where the elements are {e,v}
-   pairs, and the expression is the key.  */
-
-typedef struct val_expr_pair_d
-{
-  tree v, e;
-  hashval_t hashcode;
-} *val_expr_pair_t;
-
-
-/* Hash a {v,e} pair that is pointed to by P.
-   The hashcode is cached in the val_expr_pair, so we just return
-   that.  */
-
-static hashval_t
-val_expr_pair_hash (const void *p)
-{
-  const val_expr_pair_t ve = (val_expr_pair_t) p;
-  return ve->hashcode;
-}
-
-
-/* Given two val_expr_pair_t's, return true if they represent the same
-   expression, false otherwise.
-   P1 and P2 should point to the val_expr_pair_t's to be compared.  */
-
-static int
-val_expr_pair_expr_eq (const void *p1, const void *p2)
-{
-  const val_expr_pair_t ve1 = (val_expr_pair_t) p1;
-  const val_expr_pair_t ve2 = (val_expr_pair_t) p2;
-
-  if (expressions_equal_p (ve1->e, ve2->e))
-    return true;
-  
-  return false;
-}
-
-
-/* Get the value handle of EXPR.  This is the only correct way to get
-   the value handle for a "thing". 
-   Returns NULL if the value handle does not exist.  */
-
-tree
-get_value_handle (tree expr)
-{
-  /* We should never see these.  */
-  if (DECL_P (expr))
-    abort ();
-  else if (TREE_CODE (expr) == SSA_NAME)
-    {
-      return SSA_NAME_VALUE (expr);
-    }
-  else if (TREE_CODE_CLASS (TREE_CODE (expr)) == 'c')
-    return expr;
-  else if (EXPR_P (expr))
-    {
-      tree_ann_t ann = tree_ann (expr);  
-      if (ann)
-	return ann->common.value_handle;
-      return NULL;
-    }
-  abort ();
-}
-
-
-/* Set the value handle for expression E to value V */
-   
-void
-set_value_handle (tree e, tree v)
-{
-  if (DECL_P (e))
-    abort ();
-  else if (TREE_CODE (e) == SSA_NAME)
-    SSA_NAME_VALUE (e) = v;
-  else if (EXPR_P (e))
-    get_tree_ann (e)->common.value_handle = v;
-}
-
 /* A three tuple {e, pred, v} used to cache phi translations in the
    phi_translate_table.  */
 
@@ -468,7 +358,7 @@ phi_trans_lookup (tree e, basic_block pred)
   struct expr_pred_trans_d ept;
   ept.e = e;
   ept.pred = pred;
-  ept.hashcode = iterative_hash_expr (e, (unsigned long) pred);
+  ept.hashcode = vn_compute (e, (unsigned long) pred);
   slot = htab_find_slot_with_hash (phi_translate_table, &ept, ept.hashcode,
 				   NO_INSERT);
   if (!slot)
@@ -489,7 +379,7 @@ phi_trans_add (tree e, tree v, basic_block pred)
   new_pair->e = e;
   new_pair->pred = pred;
   new_pair->v = v;
-  new_pair->hashcode = iterative_hash_expr (e, (unsigned long) pred);
+  new_pair->hashcode = vn_compute (e, (unsigned long) pred);
   slot = htab_find_slot_with_hash (phi_translate_table, new_pair,
 				   new_pair->hashcode, INSERT);
   if (*slot)
@@ -497,31 +387,11 @@ phi_trans_add (tree e, tree v, basic_block pred)
   *slot = (void *) new_pair;
 }
 
-/* Search in TABLE for an existing instance of expression E,
-   and return its value, or NULL if none has been set.  */
-
-static inline tree
-lookup (htab_t table, tree e)
-{
-  void **slot;
-  struct val_expr_pair_d vep = {NULL, NULL, 0};
-  if (TREE_CODE_CLASS (TREE_CODE (e)) == 'c')
-    return e;
-  vep.e = e;
-  vep.hashcode = iterative_hash_expr (e,0); 
-  slot = htab_find_slot_with_hash (table, &vep, vep.hashcode, NO_INSERT);
-  if (!slot)
-    return NULL_TREE;
-  else
-    return ((val_expr_pair_t) *slot)->v;
-}
-
 /* Add expression E to the expression set of value V.  */
 
-static inline void
+void
 add_to_value (tree v, tree e)
 {
-  var_ann_t va;
   /* For values representing non-CST nodes, but still function
      invariant things we mark TREE_CONSTANT as true and set the tree
      chain to the actual constant.  This is because unlike values
@@ -536,106 +406,40 @@ add_to_value (tree v, tree e)
       TREE_CHAIN (v) = e;
       return;
     }
-  va = var_ann (v);
-  if (va->expr_set == NULL)
-    va->expr_set = set_new (false);
-  insert_into_set (va->expr_set, e);
-}
-
-/* Insert E into TABLE with value V, and add expression E to the value
-   set for value V.  */
-
-static inline void
-add (htab_t table, tree e, tree v)
-{
-
-  void **slot;
-  val_expr_pair_t new_pair = xmalloc (sizeof (struct val_expr_pair_d));
-  new_pair->e = e;
-  new_pair->v = v;
-  new_pair->hashcode = iterative_hash_expr (e, 0);
-  slot = htab_find_slot_with_hash (table, new_pair, new_pair->hashcode,
-				   INSERT);
-  if (*slot)
-    free (*slot);
-  *slot = (void *) new_pair;
-  set_value_handle (e, v);
-
-  add_to_value (v, e);
- 
-}
-
-/* A unique counter that is incremented every time we create a new
-   value.  */
-static int pre_uid;
 
-/* Create a new value handle for expression EXPR.  */
-
-static tree
-create_new_value (tree expr)
-{
-  tree a = create_tmp_var_raw (TREE_TYPE (expr), "value");
-  create_var_ann (a);
-  var_ann (a)->uid = pre_uid++;
+  if (VALUE_HANDLE_EXPR_SET (v) == NULL)
+    VALUE_HANDLE_EXPR_SET (v) = set_new (false);
 
-  if (dump_file && (dump_flags & TDF_DETAILS))
-    {     
-      fprintf (dump_file, "Created value ");
-      print_generic_expr (dump_file, a, dump_flags);
-      fprintf (dump_file, " for ");
-      print_generic_expr (dump_file, expr, dump_flags);
-      fprintf (dump_file, "\n");
-    }
-  return a;
+  insert_into_set (VALUE_HANDLE_EXPR_SET (v), e);
 }
 
-/* Like lookup, but creates a new value for expression E if E doesn't
-   already have a value.
-   Return the existing/created value for E.  */
-
-static inline tree
-lookup_or_add (htab_t table, tree e)
-{
-  tree x = lookup (table, e);
-  if (x == NULL_TREE)
-    {
-      tree v;
-      v = create_new_value (e);
-      add (table, e, v);
-      x = v;
-    }
-  set_value_handle (e, x);
-  return x;
-}
 
-  
 /* Return true if value V exists in the bitmap for SET.  */
 
 static inline bool
 value_exists_in_set_bitmap (value_set_t set, tree v)
 {
-  if (TREE_CODE (v) != VAR_DECL)
-    abort ();
-
   if (!set->values)
     return false;
-  return bitmap_bit_p (set->values, get_var_ann (v)->uid);
+
+  return bitmap_bit_p (set->values, VALUE_HANDLE_ID (v));
 }
 
+
 /* Remove value V from the bitmap for SET.  */
 
 static void
 value_remove_from_set_bitmap (value_set_t set, tree v)
 {
-  if (TREE_CODE (v) != VAR_DECL)
-    abort ();
 #ifdef ENABLE_CHECKING
   if (!set->indexed)
     abort ();
 #endif
+
   if (!set->values)
     return;
-  bitmap_clear_bit (set->values, get_var_ann (v)->uid);
+
+  bitmap_clear_bit (set->values, VALUE_HANDLE_ID (v));
 }
 
 
@@ -645,20 +449,21 @@ value_remove_from_set_bitmap (value_set_t set, tree v)
 static inline void
 value_insert_into_set_bitmap (value_set_t set, tree v)
 {
-  if (TREE_CODE (v) != VAR_DECL)
-    abort ();  
 #ifdef ENABLE_CHECKING
   if (!set->indexed)
     abort ();
 #endif
+
   if (set->values == NULL)
     {
       set->values = BITMAP_GGC_ALLOC ();
       bitmap_clear (set->values);
     }
-  bitmap_set_bit (set->values, get_var_ann (v)->uid);
+
+  bitmap_set_bit (set->values, VALUE_HANDLE_ID (v));
 }
 
+
 /* Create a new set.  */
 
 static value_set_t
@@ -681,8 +486,6 @@ insert_into_set (value_set_t set, tree expr)
 {
   value_set_node_t newnode = pool_alloc (value_set_node_pool);
   tree val = get_value_handle (expr);
-  if (DECL_P (expr))
-    abort ();
   
   if (val == NULL)
     abort ();
@@ -873,7 +676,6 @@ value_insert_into_set (value_set_t set, tree expr)
 {
   tree val = get_value_handle (expr);
 
-
   /* Constant and invariant values exist everywhere, and thus,
      actually keeping them in the sets is pointless.  */
   if (TREE_CONSTANT (val))
@@ -913,13 +715,16 @@ print_value_set (FILE *outfile, value_set_t set,
 }
 
 /* Print out the expressions that have VAL to OUTFILE.  */
+
 void
 print_value_expressions (FILE *outfile, tree val)
 {
-  var_ann_t va = var_ann (val);
-  if (va && va->expr_set)
-    print_value_set (outfile, va->expr_set, 
-		     IDENTIFIER_POINTER (DECL_NAME (val)), 0);
+  if (VALUE_HANDLE_EXPR_SET (val))
+    {
+      char s[10];
+      sprintf (s, "VH.%04d", VALUE_HANDLE_ID (val));
+      print_value_set (outfile, VALUE_HANDLE_EXPR_SET (val), s, 0);
+    }
 }
 
 
@@ -983,7 +788,7 @@ phi_translate (tree expr, value_set_t set,  basic_block pred,
 	    create_tree_ann (newexpr);
 	    TREE_OPERAND (newexpr, 0) = newop1 == oldop1 ? oldop1 : get_value_handle (newop1);
 	    TREE_OPERAND (newexpr, 1) = newop2 == oldop2 ? oldop2 : get_value_handle (newop2);
-	    lookup_or_add (value_table, newexpr);
+	    vn_lookup_or_add (newexpr);
 	    expr = newexpr;
 	    phi_trans_add (oldexpr, newexpr, pred);	    
 	  }
@@ -1010,7 +815,7 @@ phi_translate (tree expr, value_set_t set,  basic_block pred,
 	    memcpy (newexpr, expr, tree_size (expr));
 	    create_tree_ann (newexpr);	 
 	    TREE_OPERAND (newexpr, 0) = get_value_handle (newop1);
-	    lookup_or_add (value_table, newexpr);
+	    vn_lookup_or_add (newexpr);
 	    expr = newexpr;
 	    phi_trans_add (oldexpr, newexpr, pred);
 	  }
@@ -1035,7 +840,7 @@ phi_translate (tree expr, value_set_t set,  basic_block pred,
 	      tree val;
 	      if (is_undefined_value (PHI_ARG_DEF (phi, i)))
 		return NULL;
-	      val = lookup_or_add (value_table, PHI_ARG_DEF (phi, i));
+	      val = vn_lookup_or_add (PHI_ARG_DEF (phi, i));
 	      return PHI_ARG_DEF (phi, i);
 	    }
       }
@@ -1328,15 +1133,6 @@ compute_antic (void)
     fprintf (dump_file, "compute_antic required %d iterations\n", num_iterations);
 }
 
-/* Get the expressions represented by value VAL.  */
-
-static value_set_t
-get_expr_set (tree val)
-{
-  var_ann_t va = var_ann (val);
-  return va->expr_set;
-}
-
 
 /* Find a leader for an expression, or generate one using
    create_expression_by_pieces if it's ANTIC but
@@ -1364,7 +1160,7 @@ find_or_generate_expression (basic_block block, tree expr, tree stmts)
      not really .  */
   if (genop == NULL)
     {
-      genop = get_expr_set (expr)->head->expr;
+      genop = VALUE_HANDLE_EXPR_SET (expr)->head->expr;
       if (TREE_CODE_CLASS (TREE_CODE (genop)) != '1'
 	  && TREE_CODE_CLASS (TREE_CODE (genop)) != '2')
 	abort ();
@@ -1445,7 +1241,7 @@ create_expression_by_pieces (basic_block block, tree expr, tree stmts)
       
     }
   v = get_value_handle (expr);
-  add (value_table, name, v);
+  vn_add (name, v);
   insert_into_set (NEW_SETS (block), name);
   value_insert_into_set (AVAIL_OUT (block), name);
   if (dump_file && (dump_flags & TDF_DETAILS))
@@ -1610,7 +1406,7 @@ insert_aux (basic_block block)
 			  temp = create_tmp_var (type, "prephitmp");
 			  add_referenced_tmp_var (temp);
 			  temp = create_phi_node (temp, block);
-			  add (value_table, PHI_RESULT (temp), val);
+			  vn_add (PHI_RESULT (temp), val);
 
 #if 0
 			  if (!set_contains_value (AVAIL_OUT (block), val))
@@ -1679,17 +1475,19 @@ insert (void)
     fprintf (dump_file, "insert required %d iterations\n", num_iterations);
 }
 
+
 /* Return true if EXPR has no defining statement in this procedure,
    *AND* isn't a live-on-entry parameter.  */
+
 static bool
 is_undefined_value (tree expr)
 {  
-  
 #ifdef ENABLE_CHECKING
   /* We should never be handed DECL's  */
   if (DECL_P (expr))
     abort ();
 #endif
+
   if (TREE_CODE (expr) == SSA_NAME)
     {
       /* XXX: Is this the correct test?  */
@@ -1698,6 +1496,7 @@ is_undefined_value (tree expr)
       if (IS_EMPTY_STMT (SSA_NAME_DEF_STMT (expr)))
 	return true;
     }
+
   return false;
 }
 
@@ -1731,7 +1530,7 @@ compute_avail (basic_block block)
 	    {
 	      tree val;
 	      tree def = default_def (param);
-	      val = lookup_or_add (value_table, def);
+	      val = vn_lookup_or_add (def);
 	      insert_into_set (TMP_GEN (block), def);
 	      value_insert_into_set (AVAIL_OUT (block), def);
 	    }
@@ -1746,6 +1545,7 @@ compute_avail (basic_block block)
       dom = get_immediate_dominator (CDI_DOMINATORS, block);
       if (dom)
 	set_copy (AVAIL_OUT (block), AVAIL_OUT (dom));
+
       for (phi = phi_nodes (block); phi; phi = PHI_CHAIN (phi))
 	{
 	  /* Ignore virtual PHIs until we can do PRE on expressions
@@ -1753,7 +1553,7 @@ compute_avail (basic_block block)
 	  if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi))))
 	    continue;
 
-	  lookup_or_add (value_table, PHI_RESULT (phi));
+	  vn_lookup_or_add (PHI_RESULT (phi));
 	  value_insert_into_set (AVAIL_OUT (block), PHI_RESULT (phi));
 	  insert_into_set (PHI_GEN (block), PHI_RESULT (phi));
 	}
@@ -1773,7 +1573,7 @@ compute_avail (basic_block block)
 	      for (j = 0; j < NUM_DEFS (STMT_DEF_OPS (stmt)); j++)
 		{
 		  tree def = DEF_OP (STMT_DEF_OPS (stmt), j);
-		  lookup_or_add (value_table, def);
+		  vn_lookup_or_add (def);
 		  insert_into_set (TMP_GEN (block), def);
 		  value_insert_into_set (AVAIL_OUT (block), def);
 		}
@@ -1782,7 +1582,7 @@ compute_avail (basic_block block)
 		  tree use = USE_OP (STMT_USE_OPS (stmt), j);
 		  if (TREE_CODE (use) == SSA_NAME)
 		    {
-		      lookup_or_add (value_table, use);
+		      vn_lookup_or_add (use);
 		      insert_into_set (TMP_GEN (block), use);
 		      value_insert_into_set (AVAIL_OUT (block), use);
 		    }
@@ -1801,7 +1601,7 @@ compute_avail (basic_block block)
 	      STRIP_USELESS_TYPE_CONVERSION (op1);
 	      if (is_gimple_min_invariant (op1))
 		{
-		  add (value_table, op0, lookup_or_add (value_table, op1));
+		  vn_add (op0, vn_lookup_or_add (op1));
 		  insert_into_set (TMP_GEN (block), op0);
 		  value_insert_into_set (AVAIL_OUT (block), op0);
 		}
@@ -1812,15 +1612,15 @@ compute_avail (basic_block block)
 		  tree newt;
 		  bop1 = TREE_OPERAND (op1, 0);
 		  bop2 = TREE_OPERAND (op1, 1);
-		  val1 = lookup_or_add (value_table, bop1);
-		  val2 = lookup_or_add (value_table, bop2);
+		  val1 = vn_lookup_or_add (bop1);
+		  val2 = vn_lookup_or_add (bop2);
  
 		  newt = pool_alloc (binary_node_pool);
 		  memcpy (newt, op1, tree_size (op1));
 		  TREE_OPERAND (newt, 0) = val1;
 		  TREE_OPERAND (newt, 1) = val2;
-		  val = lookup_or_add (value_table, newt);
-		  add (value_table, op0, val);
+		  val = vn_lookup_or_add (newt);
+		  vn_add (op0, val);
 		  if (!is_undefined_value (bop1))
 		    value_insert_into_set (EXP_GEN (block), bop1);
 		  if (!is_undefined_value (bop2))
@@ -1836,12 +1636,12 @@ compute_avail (basic_block block)
 		  tree val, val1;
 		  tree newt;
 		  uop = TREE_OPERAND (op1, 0);
-		  val1 = lookup_or_add (value_table, uop);
+		  val1 = vn_lookup_or_add (uop);
 		  newt = pool_alloc (unary_node_pool);
 		  memcpy (newt, op1, tree_size (op1));
 		  TREE_OPERAND (newt, 0) = val1;
-		  val = lookup_or_add (value_table, newt);
-		  add (value_table, op0, val);
+		  val = vn_lookup_or_add (newt);
+		  vn_add (op0, val);
 		  if (!is_undefined_value (uop))
 		    value_insert_into_set (EXP_GEN (block), uop);
 		  value_insert_into_set (EXP_GEN (block), newt);
@@ -1850,8 +1650,8 @@ compute_avail (basic_block block)
 		}
 	      else if (TREE_CODE (op1) == SSA_NAME)
 		{
-		  tree val = lookup_or_add (value_table, op1);
-		  add (value_table, op0, val);
+		  tree val = vn_lookup_or_add (op1);
+		  vn_add (op0, val);
 		  if (!is_undefined_value (op1))
 		    value_insert_into_set (EXP_GEN (block), op1);
 		  insert_into_set (TMP_GEN (block), op0);
@@ -1863,7 +1663,7 @@ compute_avail (basic_block block)
 		  for (j = 0; j < NUM_DEFS (STMT_DEF_OPS (stmt)); j++)
 		    {
 		      tree def = DEF_OP (STMT_DEF_OPS (stmt), j);
-		      lookup_or_add (value_table, def);
+		      vn_lookup_or_add (def);
 		      insert_into_set (TMP_GEN (block), def);
 		      value_insert_into_set (AVAIL_OUT (block), def);
 		      if (def != op0)
@@ -1874,7 +1674,7 @@ compute_avail (basic_block block)
 		      tree use = USE_OP (STMT_USE_OPS (stmt), j);
 		      if (TREE_CODE (use) == SSA_NAME)
 			{
-			  lookup_or_add (value_table, use);
+			  vn_lookup_or_add (use);
 			  insert_into_set (TMP_GEN (block), use);
 			  value_insert_into_set (AVAIL_OUT (block), use);
 			}
@@ -1887,7 +1687,7 @@ compute_avail (basic_block block)
 	      for (j = 0; j < NUM_DEFS (STMT_DEF_OPS (stmt)); j++)
 		{
 		  tree def = DEF_OP (STMT_DEF_OPS (stmt), j);
-		  lookup_or_add (value_table, def);
+		  vn_lookup_or_add (def);
 		  insert_into_set (TMP_GEN (block), def);
 		  value_insert_into_set (AVAIL_OUT (block), def);
 		}
@@ -1896,7 +1696,7 @@ compute_avail (basic_block block)
 		  tree use = USE_OP (STMT_USE_OPS (stmt), j);
 		  if (TREE_CODE (use) == SSA_NAME)
 		    {
-		      lookup_or_add (value_table, use);
+		      vn_lookup_or_add (use);
 		      insert_into_set (TMP_GEN (block), use);
 		      value_insert_into_set (AVAIL_OUT (block), use);
 		    }
@@ -1904,13 +1704,14 @@ compute_avail (basic_block block)
 	    }
 	}
     }
+
   for (son = first_dom_son (CDI_DOMINATORS, block);
        son;
        son = next_dom_son (CDI_DOMINATORS, son))
     compute_avail (son);
-
 }
 
+
 /* Eliminate fully redundant computations.  */
 
 static void
@@ -1931,6 +1732,7 @@ eliminate (void)
 	      || NUM_V_MAY_DEFS (STMT_V_MAY_DEF_OPS (stmt))
 	      || stmt_ann (stmt)->has_volatile_ops)
             continue;
+
           /* Lookup the RHS of the expression, see if we have an
 	     available computation for it. If so, replace the RHS with
 	     the available computation.  */
@@ -1945,8 +1747,8 @@ eliminate (void)
 		  || (TREE_CODE_CLASS (TREE_CODE (expr)) != '2' 
 		   && TREE_CODE_CLASS (TREE_CODE (expr)) != '1'))
 		continue;
-	      sprime = find_leader (AVAIL_OUT (b),
-				    lookup (value_table, t));
+
+	      sprime = find_leader (AVAIL_OUT (b), vn_lookup (t));
               if (sprime 
 		  && sprime != t 
 		  && may_propagate_copy (sprime, TREE_OPERAND (stmt, 1)))
@@ -1965,11 +1767,11 @@ eliminate (void)
                   modify_stmt (stmt);
                 }
             }
-
         }
     }
 }
 
+
 /* Main entry point to the SSA-PRE pass.
 
    PHASE indicates which dump file from the DUMP_FILES array to use when
@@ -1980,7 +1782,6 @@ execute_pre (void)
 {
   size_t tsize;
   basic_block bb;
-  pre_uid = num_referenced_vars;
   memset (&pre_stats, 0, sizeof (pre_stats));
   FOR_ALL_BB (bb)
     {
@@ -1989,8 +1790,6 @@ execute_pre (void)
   phi_translate_table = htab_create (511, expr_pred_trans_hash,
 				     expr_pred_trans_eq,
 				     free);
-  value_table = htab_create (511, val_expr_pair_hash,
-			     val_expr_pair_expr_eq, free);
   value_set_pool = create_alloc_pool ("Value sets",
 				      sizeof (struct value_set), 30);
   value_set_node_pool = create_alloc_pool ("Value set nodes",
@@ -2048,7 +1847,6 @@ execute_pre (void)
   free_alloc_pool (value_set_node_pool);
   free_alloc_pool (binary_node_pool);
   free_alloc_pool (unary_node_pool);
-  htab_delete (value_table);
   htab_delete (phi_translate_table);
   
   FOR_ALL_BB (bb)