2005-05-15 Daniel Berlin <dberlin@dberlin.org>

	Fix PR tree-optimization/21576

	* tree-ssa-pre.c (expression_node_pool): New pool.
	(comparison_node_pool): Ditto.
	(list_node_pool): Ditto.
	(pool_copy_list): New function.
	(phi_translate): Handle CALL_EXPR.
	(valid_in_set): Ditto.
	(create_expression_by_pieces): Ditto.
	(insert_into_preds_of_block): Ditto.
	(insert_aux): Ditto.
	(compute_avail): Ditto.
	(create_value_expr_from): Handle TREE_LIST and CALL_EXPR.
	(can_value_number_call): New function.
	(find_leader): Update comment.
	(init_pre): Create new pools.
	(fini_pre): Free new pools.
	(pass_pre): Add TODO_update_ssa for the future when we are going
	to need vops.
	* tree-vn.c (expressions_equal_p): Handle TREE_LIST.
	(set_value_handle): Ditto.
	(get_value_handle): Ditto.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@99759 138bc75d-0d04-0410-961f-82ee72b054a4

9 files changed, 419 insertions, 20 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ef16d8ba29e..24444470364 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,28 @@
+2005-05-15  Daniel Berlin  <dberlin@dberlin.org>
+	    
+	Fix PR tree-optimization/21576
+	
+	* tree-ssa-pre.c (expression_node_pool): New pool.
+	(comparison_node_pool): Ditto.
+	(list_node_pool): Ditto.
+	(pool_copy_list): New function.
+	(phi_translate): Handle CALL_EXPR.
+	(valid_in_set): Ditto.
+	(create_expression_by_pieces): Ditto.
+	(insert_into_preds_of_block): Ditto.
+	(insert_aux): Ditto.
+	(compute_avail): Ditto.
+	(create_value_expr_from): Handle TREE_LIST and CALL_EXPR.
+	(can_value_number_call): New function.
+	(find_leader): Update comment.
+	(init_pre): Create new pools.
+	(fini_pre): Free new pools.
+	(pass_pre): Add TODO_update_ssa for the future when we are going
+	to need vops.
+	* tree-vn.c (expressions_equal_p): Handle TREE_LIST.
+	(set_value_handle): Ditto.
+	(get_value_handle): Ditto.
+
 2005-05-15  Richard Earnshaw  <richard.earnshaw@arm.com>
 
 	* arm.c (thumb_unexpanded_epilogue): Delete unused variable 'mode'.
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-cse-1.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-cse-1.c
index 82687d71913..5bbfd3d17fb 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-cse-1.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-cse-1.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */ 
-/* { dg-options "-O2 -fdump-tree-dom1-details" } */
+/* { dg-options "-O2 -fdump-tree-fre-details" } */
 int t(int a) __attribute__ ((const));
 void q (void);
 void
@@ -12,5 +12,5 @@ threading(int a,int b)
 	}
 }
 /* We should thread the jump twice and eliminate it.  */
-/* { dg-final { scan-tree-dump-times "Replaced.* t " 1 "dom1"} } */
-/* { dg-final { cleanup-tree-dump "dom1" } } */
+/* { dg-final { scan-tree-dump-times "Replaced.* t " 1 "fre"} } */
+/* { dg-final { cleanup-tree-dump "fre" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-10.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-10.c
new file mode 100644
index 00000000000..127caa6cd6b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-10.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */ 
+/* { dg-options "-O2 -fno-tree-dominator-opts -fdump-tree-fre-stats" } */
+double cos (double);
+void link_error();
+void f(double a)
+{
+  double b = cos (a);
+  double c = cos (a);
+  if (b != c)
+    link_error();
+}
+
+/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "fre"} } */
+/* { dg-final { cleanup-tree-dump "fre" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-11.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-11.c
new file mode 100644
index 00000000000..26c47b1830b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-11.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */ 
+/* { dg-options "-O2 -fdump-tree-pre-stats" } */
+double cos (double);
+double f(double a)
+{
+  double b;
+  double c,d;
+ if (a < 2.0)
+   {
+     c = cos (a);
+   }
+ else
+   {
+     c = 1.0; 
+   }
+ d = cos (a);
+ return d + c;
+}
+
+/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre"} } */
+/* { dg-final { cleanup-tree-dump "pre" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-12.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-12.c
new file mode 100644
index 00000000000..fd80e3d8d50
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-12.c
@@ -0,0 +1,27 @@
+/* { dg-do compile } */ 
+/* { dg-options "-O2 -fdump-tree-pre-stats" } */
+double cos (double) __attribute__ ((const));
+double sin (double) __attribute__ ((const));
+double f(double a)
+{
+  double b;
+  double c,d;
+  double (*fp) (double) __attribute__ ((const));
+  /* Fully redundant call, but we need a phi node to merge the results.  */
+  if (a < 2.0)
+    {
+      fp = sin;
+      c = fp (a);
+    }
+  else
+    {
+      c = 1.0; 
+      fp = cos;
+      c = fp (a);
+    }
+  d = fp (a);
+  return d + c;
+}
+
+/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre"} } */
+/* { dg-final { cleanup-tree-dump "pre" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-13.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-13.c
new file mode 100644
index 00000000000..dfce46b9907
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-13.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */ 
+/* { dg-options "-O2 -fdump-tree-pre-stats" } */
+double cos (double) __attribute__ ((const));
+double sin (double) __attribute__ ((const));
+double f(double a)
+{
+  double b;
+  double c,d;
+  double (*fp) (double) __attribute__ ((const));
+  /* Partially redundant call */
+  if (a < 2.0)
+    {
+      fp = sin;
+      c = fp (a);
+    }
+  else
+    {
+      c = 1.0; 
+      fp = cos;
+    }
+  d = fp (a);
+  return d + c;
+}
+
+/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre"} } */
+/* { dg-final { cleanup-tree-dump "pre" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-9.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-9.c
new file mode 100644
index 00000000000..32e37b99703
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-9.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */ 
+/* { dg-options "-O2 -fno-tree-dominator-opts -fdump-tree-fre-stats" } */
+int
+foo (unsigned long a)
+{
+  int b = __builtin_clzl (a);
+  int c = __builtin_clzl (a);
+  if (b == c)
+    return 1;
+  return 0;
+}
+/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "fre"} } */
+/* { dg-final { cleanup-tree-dump "fre" } } */
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 0494774b608..859bf096210 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -305,6 +305,9 @@ static alloc_pool value_set_node_pool;
 static alloc_pool binary_node_pool;
 static alloc_pool unary_node_pool;
 static alloc_pool reference_node_pool;
+static alloc_pool comparison_node_pool;
+static alloc_pool expression_node_pool;
+static alloc_pool list_node_pool;
 static bitmap_obstack grand_bitmap_obstack;
 
 /* Set of blocks with statements that have had its EH information
@@ -855,6 +858,35 @@ fully_constant_expression (tree t)
   return t;
 }
 
+/* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
+   For example, this can copy a list made of TREE_LIST nodes.  
+   Allocates the nodes in list_node_pool*/
+
+static tree
+pool_copy_list (tree list)
+{
+  tree head;
+  tree prev, next;
+
+  if (list == 0)
+    return 0;
+  head = pool_alloc (list_node_pool);
+  
+  memcpy (head, list, tree_size (list));
+  prev = head;
+  
+  next = TREE_CHAIN (list);
+  while (next)
+    {
+      TREE_CHAIN (prev) = pool_alloc (list_node_pool);
+      memcpy (TREE_CHAIN (prev), next, tree_size (next));
+      prev = TREE_CHAIN (prev);
+      next = TREE_CHAIN (next);
+    }
+  return head;
+}
+
+
 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
    the phis in PRED.  Return NULL if we can't find a leader for each
    part of the translated expression.  */
@@ -879,6 +911,89 @@ phi_translate (tree expr, value_set_t set, basic_block pred,
   
   switch (TREE_CODE_CLASS (TREE_CODE (expr)))
     {
+    case tcc_expression:
+      {
+	if (TREE_CODE (expr) != CALL_EXPR)
+	  return NULL;
+	else
+	  {
+	    tree oldop0 = TREE_OPERAND (expr, 0);
+	    tree oldarglist = TREE_OPERAND (expr, 1);
+	    tree oldop2 = TREE_OPERAND (expr, 2);
+	    tree newop0;
+	    tree newarglist;
+	    tree newop2 = NULL;
+	    tree oldwalker;
+	    tree newwalker;
+	    tree newexpr;
+	    bool listchanged = false;
+
+	    /* Call expressions are kind of weird because they have an
+	       argument list.  We don't want to value number the list
+	       as one value number, because that doesn't make much
+	       sense, and just breaks the support functions we call,
+	       which expect TREE_OPERAND (call_expr, 2) to be a
+	       TREE_LIST. */	      
+	    
+	    newop0 = phi_translate (find_leader (set, oldop0),
+				    set, pred, phiblock);
+	    if (newop0 == NULL)
+	      return NULL;
+	    if (oldop2)
+	      {
+		newop2 = phi_translate (find_leader (set, oldop2),
+					set, pred, phiblock);
+		if (newop2 == NULL)
+		  return NULL;
+	      }
+
+	    /* phi translate the argument list piece by piece.
+	       
+	      We could actually build the list piece by piece here,
+	      but it's likely to not be worth the memory we will save,
+	      unless you have millions of call arguments.  */
+
+	    newarglist = pool_copy_list (oldarglist);
+	    for (oldwalker = oldarglist, newwalker = newarglist;
+		 oldwalker && newwalker;
+		 oldwalker = TREE_CHAIN (oldwalker), 
+		   newwalker = TREE_CHAIN (newwalker))
+	      {
+		
+		tree oldval = TREE_VALUE (oldwalker);
+		tree newval;
+		if (oldval)
+		  {
+		    newval = phi_translate (find_leader (set, oldval),
+					    set, pred, phiblock);
+		    if (newval == NULL)
+		      return NULL;
+		    if (newval != oldval)
+		      {
+			listchanged = true;
+			TREE_VALUE (newwalker) = get_value_handle (newval);
+		      }
+		  }
+	      }
+	    if (listchanged)
+	      vn_lookup_or_add (newarglist, NULL);
+	    
+	    if (listchanged || (newop0 != oldop0) || (oldop2 != newop2))
+	      {
+		newexpr = pool_alloc (expression_node_pool);
+		memcpy (newexpr, expr, tree_size (expr));
+		TREE_OPERAND (newexpr, 0) = newop0 == oldop0 ? oldop0 : get_value_handle (newop0);
+		TREE_OPERAND (newexpr, 1) = listchanged ? newarglist : oldarglist;
+		TREE_OPERAND (newexpr, 2) = newop2 == oldop2 ? oldop2 : get_value_handle (newop2);
+		create_tree_ann (newexpr);	 
+		vn_lookup_or_add (newexpr, NULL);
+		expr = newexpr;
+		phi_trans_add (oldexpr, newexpr, pred);
+	      }
+	  }
+      }
+      return expr;
+
     case tcc_reference:
       /* XXX: Until we have PRE of loads working, none will be ANTIC.  */
       return NULL;
@@ -1084,10 +1199,10 @@ find_leader (value_set_t set, tree val)
    we have a leader for each part of the expression (if it consists of
    values), or the expression is an SSA_NAME.  
 
-   NB:  We never should run into a case where we have SSA_NAME +
+   NB: We never should run into a case where we have SSA_NAME +
    SSA_NAME or SSA_NAME + value.  The sets valid_in_set is called on,
-   the ANTIC sets, will only ever have SSA_NAME's or binary value
-   expression (IE VALUE1 + VALUE2)  */
+   the ANTIC sets, will only ever have SSA_NAME's or value expressions
+   (IE VALUE1 + VALUE2, *VALUE1, VALUE1 < VALUE2)  */
 
 static bool
 valid_in_set (value_set_t set, tree expr)
@@ -1107,7 +1222,31 @@ valid_in_set (value_set_t set, tree expr)
 	tree op1 = TREE_OPERAND (expr, 0);
 	return set_contains_value (set, op1);
       }
+      
+    case tcc_expression:
+      {
+	if (TREE_CODE (expr) == CALL_EXPR)
+	  {
+	    tree op0 = TREE_OPERAND (expr, 0);
+	    tree arglist = TREE_OPERAND (expr, 1);
+	    tree op2 = TREE_OPERAND (expr, 2);
 
+	    /* Check the non-list operands first.  */
+	    if (!set_contains_value (set, op0)
+		|| (op2 && !set_contains_value (set, op2)))
+	      return false;
+
+	    /* Now check the operands.  */
+	    for (; arglist; arglist = TREE_CHAIN (arglist))
+	      {
+		if (!set_contains_value (set, TREE_VALUE (arglist)))
+		  return false;
+	      }
+	    return true;
+	  }
+	return false;
+      }
+      
     case tcc_reference:
       /* XXX: Until PRE of loads works, no reference nodes are ANTIC.  */
       return false;
@@ -1189,7 +1328,7 @@ compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
      translate through.  */
   else if (single_succ_p (block))
     {
-      phi_translate_set (ANTIC_OUT, ANTIC_IN(single_succ (block)),
+      phi_translate_set (ANTIC_OUT, ANTIC_IN (single_succ (block)),
 			 block, single_succ (block));
     }
   /* If we have multiple successors, we take the intersection of all of
@@ -1359,6 +1498,42 @@ create_expression_by_pieces (basic_block block, tree expr, tree stmts)
 
   switch (TREE_CODE_CLASS (TREE_CODE (expr)))
     {
+    case tcc_expression:
+      {
+	tree op0, op2;
+	tree arglist;
+	tree genop0, genop2;
+	tree genarglist;
+	tree walker, genwalker;
+	
+	gcc_assert (TREE_CODE (expr) == CALL_EXPR);
+	genop2 = NULL;
+	
+	op0 = TREE_OPERAND (expr, 0);
+	arglist = TREE_OPERAND (expr, 1);
+	op2 = TREE_OPERAND (expr, 2);
+	
+	genop0 = find_or_generate_expression (block, op0, stmts);
+	genarglist = copy_list (arglist);
+	for (walker = arglist, genwalker = genarglist;
+	     genwalker && walker;
+	     genwalker = TREE_CHAIN (genwalker), walker = TREE_CHAIN (walker))
+	  {
+	    TREE_VALUE (genwalker) = find_or_generate_expression (block, 
+								  TREE_VALUE (walker), 
+								  stmts);
+	  }
+
+	if (op2)	  
+	  genop2 = find_or_generate_expression (block, op2, stmts);
+	folded = fold (build (TREE_CODE (expr), TREE_TYPE (expr),
+			      genop0, genarglist, genop2));
+	break;
+	
+	
+      }
+      break;
+      
     case tcc_binary:
     case tcc_comparison:
       {
@@ -1499,7 +1674,8 @@ insert_into_preds_of_block (basic_block block, value_set_node_t node,
       eprime = avail[bprime->index];
       if (BINARY_CLASS_P (eprime)
 	  || COMPARISON_CLASS_P (eprime)
-	  || UNARY_CLASS_P (eprime))
+	  || UNARY_CLASS_P (eprime)
+	  || TREE_CODE (eprime) == CALL_EXPR)
 	{
 	  builtexpr = create_expression_by_pieces (bprime,
 						   eprime,
@@ -1613,7 +1789,8 @@ insert_aux (basic_block block)
 		{
 		  if (BINARY_CLASS_P (node->expr)
 		      || COMPARISON_CLASS_P (node->expr)
-		      || UNARY_CLASS_P (node->expr))
+		      || UNARY_CLASS_P (node->expr)
+		      || TREE_CODE (node->expr) == CALL_EXPR)
 		    {
 		      tree *avail;
 		      tree val;
@@ -1817,17 +1994,55 @@ create_value_expr_from (tree expr, basic_block block, tree stmt)
   gcc_assert (TREE_CODE_CLASS (code) == tcc_unary
 	      || TREE_CODE_CLASS (code) == tcc_binary
 	      || TREE_CODE_CLASS (code) == tcc_comparison
-	      || TREE_CODE_CLASS (code) == tcc_reference);
+	      || TREE_CODE_CLASS (code) == tcc_reference
+	      || TREE_CODE_CLASS (code) == tcc_expression
+	      || TREE_CODE_CLASS (code) == tcc_exceptional);
 
   if (TREE_CODE_CLASS (code) == tcc_unary)
     pool = unary_node_pool;
   else if (TREE_CODE_CLASS (code) == tcc_reference)
     pool = reference_node_pool;
-  else
+  else if (TREE_CODE_CLASS (code) == tcc_binary)
     pool = binary_node_pool;
+  else if (TREE_CODE_CLASS (code) == tcc_comparison)
+    pool = comparison_node_pool;
+  else if (TREE_CODE_CLASS (code) == tcc_exceptional)
+    {
+      gcc_assert (code == TREE_LIST);
+      pool = list_node_pool;
+    }
+  else 
+    {
+      gcc_assert (code == CALL_EXPR);
+      pool = expression_node_pool;
+    }
 
   vexpr = pool_alloc (pool);
   memcpy (vexpr, expr, tree_size (expr));
+  
+  /* This case is only for TREE_LIST's that appear as part of
+     CALL_EXPR's.  Anything else is a bug, but we can't easily verify
+     this, hence tihs comment.  TREE_LIST is not handled by the
+     general case below is because they don't have a fixed length, or
+     operands, so you can't access purpose/value/chain through
+     TREE_OPERAND macros.  */
+
+  if (code == TREE_LIST)
+    {
+      tree temp = NULL_TREE;
+      if (TREE_CHAIN (vexpr))
+	temp = create_value_expr_from (TREE_CHAIN (vexpr), block, stmt);      
+      TREE_CHAIN (vexpr) = temp ? temp : TREE_CHAIN (vexpr);
+      
+      /* This is the equivalent of inserting op into EXP_GEN like we
+	 do below */
+      if (!is_undefined_value (TREE_VALUE (vexpr)))
+	value_insert_into_set (EXP_GEN (block), TREE_VALUE (vexpr));      
+	  
+      TREE_VALUE (vexpr) = vn_lookup_or_add (TREE_VALUE (vexpr), NULL);
+
+      return vexpr;
+    }
 
   for (i = 0; i < TREE_CODE_LENGTH (code); i++)
     {
@@ -1846,18 +2061,32 @@ create_value_expr_from (tree expr, basic_block block, tree stmt)
 	  return NULL;
 	}
 
-      /* Recursively value-numberize reference ops */
+      /* Recursively value-numberize reference ops and tree lists.  */
       if (REFERENCE_CLASS_P (op))
 	{
 	  tree tempop = create_value_expr_from (op, block, stmt);
 	  op = tempop ? tempop : op;
 	  val = vn_lookup_or_add (op, stmt);
 	}
+      else if (TREE_CODE (op) == TREE_LIST)
+	{
+	  tree tempop;
+	  
+	  gcc_assert (TREE_CODE (expr) == CALL_EXPR);
+	  tempop = create_value_expr_from (op, block, stmt);
+	  
+	  op = tempop ? tempop : op;
+	  vn_lookup_or_add (op, NULL);
+	  /* Unlike everywhere else, we do *not* want to replace the
+	     TREE_LIST itself with a value number, because support
+	     functions we call will blow up.  */
+	  val = op;
+	}
       else       
 	/* Create a value handle for OP and add it to VEXPR.  */
 	val = vn_lookup_or_add (op, NULL);
 
-      if (!is_undefined_value (op))
+      if (!is_undefined_value (op) && TREE_CODE (op) != TREE_LIST)
 	value_insert_into_set (EXP_GEN (block), op);
 
       if (TREE_CODE (val) == VALUE_HANDLE)
@@ -1870,6 +2099,22 @@ create_value_expr_from (tree expr, basic_block block, tree stmt)
 }
 
 
+/* Return true if we can value number a call.  This is true if we have
+   a pure or constant call.  */
+static bool
+can_value_number_call (tree stmt)
+{
+  tree call = get_call_expr_in (stmt);
+
+  /* This is a temporary restriction until we translate vuses through
+     phi nodes.  */
+  if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
+    return false;  
+  if (call_expr_flags (call)  & (ECF_PURE | ECF_CONST))
+    return true;
+  return false;
+}
+
 /* Compute the AVAIL set for all basic blocks.
 
    This function performs value numbering of the statements in each basic
@@ -1964,7 +2209,9 @@ compute_avail (void)
 	      if (UNARY_CLASS_P (rhs)
 		  || BINARY_CLASS_P (rhs)
 		  || COMPARISON_CLASS_P (rhs)
-		  || REFERENCE_CLASS_P (rhs))
+		  || REFERENCE_CLASS_P (rhs)
+		  || (TREE_CODE (rhs) == CALL_EXPR
+		      && can_value_number_call (stmt)))
 		{
 		  /* For binary, unary, and reference expressions,
 		     create a duplicate expression with the operands
@@ -2245,6 +2492,12 @@ init_pre (bool do_fre)
 				       tree_code_size (NEGATE_EXPR), 30);
   reference_node_pool = create_alloc_pool ("Reference tree nodes",
 					   tree_code_size (ARRAY_REF), 30);
+  expression_node_pool = create_alloc_pool ("Expression tree nodes",
+					    tree_code_size (CALL_EXPR), 30);
+  list_node_pool = create_alloc_pool ("List tree nodes",
+				      tree_code_size (TREE_LIST), 30);  
+  comparison_node_pool = create_alloc_pool ("Comparison tree nodes",
+      					    tree_code_size (EQ_EXPR), 30);
   FOR_ALL_BB (bb)
     {
       EXP_GEN (bb) = set_new (true);
@@ -2273,6 +2526,9 @@ fini_pre (bool do_fre)
   free_alloc_pool (binary_node_pool);
   free_alloc_pool (reference_node_pool);
   free_alloc_pool (unary_node_pool);
+  free_alloc_pool (list_node_pool);
+  free_alloc_pool (expression_node_pool);
+  free_alloc_pool (comparison_node_pool);
   htab_delete (phi_translate_table);
   remove_fake_exit_edges ();
 
@@ -2398,7 +2654,8 @@ struct tree_opt_pass pass_pre =
   0,					/* properties_provided */
   0,					/* properties_destroyed */
   0,					/* todo_flags_start */
-  TODO_dump_func | TODO_ggc_collect | TODO_verify_ssa, /* todo_flags_finish */
+  TODO_update_ssa | TODO_dump_func | TODO_ggc_collect 
+  | TODO_verify_ssa, /* todo_flags_finish */
   0					/* letter */
 };
 
diff --git a/gcc/tree-vn.c b/gcc/tree-vn.c
index 5f003720e4d..e46fafaf308 100644
--- a/gcc/tree-vn.c
+++ b/gcc/tree-vn.c
@@ -119,9 +119,25 @@ expressions_equal_p (tree e1, tree e2)
   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, OEP_PURE_SAME))
+  if (TREE_CODE (e1) == TREE_LIST && TREE_CODE (e2) == TREE_LIST)
+    {
+      tree lop1 = e1;
+      tree lop2 = e2;
+      for (lop1 = e1, lop2 = e2;
+	   lop1 || lop2;
+	   lop1 = TREE_CHAIN (lop1), lop2 = TREE_CHAIN (lop2))
+	{
+	  if (!lop1 || !lop2)
+	    return false;
+	  if (!expressions_equal_p (TREE_VALUE (lop1), TREE_VALUE (lop2)))
+	    return false;
+	}
+      return true;
+
+    }
+  else if (TREE_CODE (e1) == TREE_CODE (e2) 
+	   && (te1 == te2 || lang_hooks.types_compatible_p (te1, te2))
+	   && operand_equal_p (e1, e2, OEP_PURE_SAME))
     return true;
 
   return false;
@@ -166,7 +182,7 @@ set_value_handle (tree e, tree v)
 {
   if (TREE_CODE (e) == SSA_NAME)
     SSA_NAME_VALUE (e) = v;
-  else if (EXPR_P (e) || DECL_P (e))
+  else if (EXPR_P (e) || DECL_P (e) || TREE_CODE (e) == TREE_LIST)
     get_tree_ann (e)->common.value_handle = v;
   else
     /* Do nothing.  Constants are their own value handles.  */
@@ -271,7 +287,7 @@ get_value_handle (tree expr)
 
   if (TREE_CODE (expr) == SSA_NAME)
     return SSA_NAME_VALUE (expr);
-  else if (EXPR_P (expr) || DECL_P (expr))
+  else if (EXPR_P (expr) || DECL_P (expr) || TREE_CODE (expr) == TREE_LIST)
     {
       tree_ann_t ann = tree_ann (expr);
       return ((ann) ? ann->common.value_handle : NULL_TREE);