X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Ftree-dfa.c;h=4e65c5dffc8914698e20e83a9167b9aef4842015;hb=f816ec49370bf5b0c3a5abf6a4e0392db78af2b0;hp=f3fa63aa6d89620bb4164d1a5cb6d55575f56240;hpb=5135beeb0469cb7a97d30f237701d6362e5ceaf8;p=pf3gnuchains%2Fgcc-fork.git

diff --git a/gcc/tree-dfa.c b/gcc/tree-dfa.c
index f3fa63aa6d8..4e65c5dffc8 100644
--- a/gcc/tree-dfa.c
+++ b/gcc/tree-dfa.c
@@ -42,10 +42,10 @@ Boston, MA 02111-1307, USA.  */
 #include "tree-gimple.h"
 #include "tree-flow.h"
 #include "tree-inline.h"
-#include "tree-alias-common.h"
 #include "tree-pass.h"
 #include "convert.h"
 #include "params.h"
+#include "cgraph.h"
 
 /* Build and maintain data flow information for trees.  */
 
@@ -59,8 +59,9 @@ struct dfa_stats_d
   long num_phis;
   long num_phi_args;
   int max_num_phi_args;
-  long num_vdefs;
+  long num_v_may_defs;
   long num_vuses;
+  long num_v_must_defs;
 };
 
 
@@ -80,8 +81,6 @@ static tree find_vars_r (tree *, int *, void *);
 static void add_referenced_var (tree, struct walk_state *);
 static void compute_immediate_uses_for_phi (tree, bool (*)(tree));
 static void compute_immediate_uses_for_stmt (tree, int, bool (*)(tree));
-static void find_hidden_use_vars (tree);
-static tree find_hidden_use_vars_r (tree *, int *, void *);
 
 
 /* Global declarations.  */
@@ -108,26 +107,8 @@ find_referenced_vars (void)
   basic_block bb;
   block_stmt_iterator si;
   struct walk_state walk_state;
-  tree block;
-
-  /* This is the very first pass in preparation for building the SSA
-     form of the function, so initialize internal data structures now.  */
-  init_tree_ssa ();
-
-  /* Walk the lexical blocks in the function looking for variables that may
-     have been used to declare VLAs and for nested functions.  Both
-     constructs create hidden uses of variables. 
-
-     Note that at this point we may have multiple blocks hung off
-     DECL_INITIAL chained through the BLOCK_CHAIN field due to
-     how inlining works.  Egad.  */
-  block = DECL_INITIAL (current_function_decl);
-  while (block)
-    {
-      find_hidden_use_vars (block);
-      block = BLOCK_CHAIN (block);
-    }
 
+  cgraph_reset_static_var_maps ();
   vars_found = htab_create (50, htab_hash_pointer, htab_eq_pointer, NULL);
   memset (&walk_state, 0, sizeof (walk_state));
   walk_state.vars_found = vars_found;
@@ -155,12 +136,13 @@ struct tree_opt_pass pass_referenced_vars =
   PROP_referenced_vars,			/* properties_provided */
   0,					/* properties_destroyed */
   0,					/* todo_flags_start */
-  0,					/* todo_flags_finish */
+  0,                                    /* todo_flags_finish */
+  0				        /* letter */
 };
 
 
-/* Compute immediate uses.  
-   
+/* Compute immediate uses.
+
    CALC_FOR is an optional function pointer which indicates whether
       immediate uses information should be calculated for a given SSA
       variable.  If NULL, then information is computed for all
@@ -180,8 +162,21 @@ compute_immediate_uses (int flags, bool (*calc_for)(tree))
     {
       tree phi;
 
-      for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
-	compute_immediate_uses_for_phi (phi, calc_for);
+      for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+	{
+	  if (is_gimple_reg (PHI_RESULT (phi)))
+	    {
+	      if (!(flags & TDFA_USE_OPS))
+		continue;
+	    }
+	  else
+	    {
+	      if (!(flags & TDFA_USE_VOPS))
+		continue;
+	    }
+
+	  compute_immediate_uses_for_phi (phi, calc_for);
+	}
 
       for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
         {
@@ -193,28 +188,46 @@ compute_immediate_uses (int flags, bool (*calc_for)(tree))
 }
 
 
-/* Invalidates dataflow information for a statement STMT.  */
+/* Invalidates dataflow information for a statement STMT.   */
 
-static void
+void
 free_df_for_stmt (tree stmt)
 {
-  stmt_ann_t ann = stmt_ann (stmt);
+  dataflow_t *df;
 
-  if (ann && ann->df)
+  if (TREE_CODE (stmt) == PHI_NODE)
+    df = &PHI_DF (stmt);
+  else
     {
-      /* If we have a varray of immediate uses, then go ahead and release
-	 it for re-use.  */
-      if (ann->df->immediate_uses)
-	ggc_free (ann->df->immediate_uses);
-
-      /* Similarly for the main dataflow structure.  */
-      ggc_free (ann->df);
-      ann->df = NULL;
+      stmt_ann_t ann = stmt_ann (stmt);
+
+      if (!ann)
+	return;
+
+      df = &ann->df;
     }
+
+  if (!*df)
+    return;
+      
+  /* If we have a varray of immediate uses, then go ahead and release
+     it for re-use.  */
+  if ((*df)->immediate_uses)
+    ggc_free ((*df)->immediate_uses);
+
+  /* Similarly for the main dataflow structure.  */
+  ggc_free (*df);
+  *df = NULL;
 }
 
 
-/* Invalidate dataflow information for the whole function.  */
+/* Invalidate dataflow information for the whole function. 
+
+   Note this only invalidates dataflow information on statements and
+   PHI nodes which are reachable.
+
+   A deleted statement may still have attached dataflow information
+   on it.  */
 
 void
 free_df (void)
@@ -226,7 +239,7 @@ free_df (void)
     {
       tree phi;
 
-      for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
+      for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
 	free_df_for_stmt (phi);
 
       for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
@@ -250,17 +263,14 @@ compute_immediate_uses_for_phi (tree phi, bool (*calc_for)(tree))
 {
   int i;
 
-#ifdef ENABLE_CHECKING
-  if (TREE_CODE (phi) != PHI_NODE)
-    abort ();
-#endif
+  gcc_assert (TREE_CODE (phi) == PHI_NODE);
 
   for (i = 0; i < PHI_NUM_ARGS (phi); i++)
     {
       tree arg = PHI_ARG_DEF (phi, i);
 
       if (TREE_CODE (arg) == SSA_NAME && (!calc_for || calc_for (arg)))
-	{ 
+	{
 	  tree imm_rdef_stmt = SSA_NAME_DEF_STMT (PHI_ARG_DEF (phi, i));
 	  if (!IS_EMPTY_STMT (imm_rdef_stmt))
 	    add_immediate_use (imm_rdef_stmt, phi);
@@ -277,26 +287,17 @@ compute_immediate_uses_for_phi (tree phi, bool (*calc_for)(tree))
 static void
 compute_immediate_uses_for_stmt (tree stmt, int flags, bool (*calc_for)(tree))
 {
-  size_t i;
-  use_optype uses;
-  vuse_optype vuses;
-  vdef_optype vdefs;
-  stmt_ann_t ann;
+  tree use;
+  ssa_op_iter iter;
 
-#ifdef ENABLE_CHECKING
   /* PHI nodes are handled elsewhere.  */
-  if (TREE_CODE (stmt) == PHI_NODE)
-    abort ();
-#endif
+  gcc_assert (TREE_CODE (stmt) != PHI_NODE);
 
   /* Look at USE_OPS or VUSE_OPS according to FLAGS.  */
-  ann = stmt_ann (stmt);
   if (flags & TDFA_USE_OPS)
     {
-      uses = USE_OPS (ann);
-      for (i = 0; i < NUM_USES (uses); i++)
+      FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE)
 	{
-	  tree use = USE_OP (uses, i);
 	  tree imm_stmt = SSA_NAME_DEF_STMT (use);
 	  if (!IS_EMPTY_STMT (imm_stmt) && (!calc_for || calc_for (use)))
 	    add_immediate_use (imm_stmt, stmt);
@@ -305,21 +306,10 @@ compute_immediate_uses_for_stmt (tree stmt, int flags, bool (*calc_for)(tree))
 
   if (flags & TDFA_USE_VOPS)
     {
-      vuses = VUSE_OPS (ann);
-      for (i = 0; i < NUM_VUSES (vuses); i++)
-	{
-	  tree vuse = VUSE_OP (vuses, i);
-	  tree imm_rdef_stmt = SSA_NAME_DEF_STMT (vuse);
-	  if (!IS_EMPTY_STMT (imm_rdef_stmt) && (!calc_for || calc_for (vuse)))
-	    add_immediate_use (imm_rdef_stmt, stmt);
-	}
-
-      vdefs = VDEF_OPS (ann);
-      for (i = 0; i < NUM_VDEFS (vdefs); i++)
+      FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_VIRTUAL_USES)
 	{
-	  tree vuse = VDEF_OP (vdefs, i);
-	  tree imm_rdef_stmt = SSA_NAME_DEF_STMT (vuse);
-	  if (!IS_EMPTY_STMT (imm_rdef_stmt) && (!calc_for || calc_for (vuse)))
+	  tree imm_rdef_stmt = SSA_NAME_DEF_STMT (use);
+	  if (!IS_EMPTY_STMT (imm_rdef_stmt) && (!calc_for || calc_for (use)))
 	    add_immediate_use (imm_rdef_stmt, stmt);
 	}
     }
@@ -332,38 +322,44 @@ compute_immediate_uses_for_stmt (tree stmt, int flags, bool (*calc_for)(tree))
 static void
 add_immediate_use (tree stmt, tree use_stmt)
 {
-  stmt_ann_t ann = get_stmt_ann (stmt);
-  struct dataflow_d *df;
+  struct dataflow_d **df;
 
-  df = ann->df;
-  if (df == NULL)
+  if (TREE_CODE (stmt) == PHI_NODE)
+    df = &PHI_DF (stmt);
+  else
     {
-      df = ann->df = ggc_alloc (sizeof (struct dataflow_d));
-      memset ((void *) df, 0, sizeof (struct dataflow_d));
-      df->uses[0] = use_stmt;
+      stmt_ann_t ann = get_stmt_ann (stmt);
+      df = &ann->df;
+    }
+
+  if (*df == NULL)
+    {
+      *df = ggc_alloc (sizeof (struct dataflow_d));
+      memset ((void *) *df, 0, sizeof (struct dataflow_d));
+      (*df)->uses[0] = use_stmt;
       return;
     }
 
-  if (!df->uses[1])
+  if (!(*df)->uses[1])
     {
-      df->uses[1] = use_stmt;
+      (*df)->uses[1] = use_stmt;
       return;
     }
 
-  if (ann->df->immediate_uses == NULL)
-    VARRAY_TREE_INIT (ann->df->immediate_uses, 4, "immediate_uses");
+  if ((*df)->immediate_uses == NULL)
+    VARRAY_TREE_INIT ((*df)->immediate_uses, 4, "immediate_uses");
 
-  VARRAY_PUSH_TREE (ann->df->immediate_uses, use_stmt);
+  VARRAY_PUSH_TREE ((*df)->immediate_uses, use_stmt);
 }
 
 
 /* If the immediate use of USE points to OLD, then redirect it to NEW.  */
- 
+
 static void
 redirect_immediate_use (tree use, tree old, tree new)
 {
   tree imm_stmt = SSA_NAME_DEF_STMT (use);
-  struct dataflow_d *df = get_stmt_ann (imm_stmt)->df;
+  struct dataflow_d *df = get_immediate_uses (imm_stmt);
   unsigned int num_uses = num_immediate_uses (df);
   unsigned int i;
 
@@ -387,21 +383,11 @@ redirect_immediate_use (tree use, tree old, tree new)
 void
 redirect_immediate_uses (tree old, tree new)
 {
-  stmt_ann_t ann = get_stmt_ann (old);
-  use_optype uses = USE_OPS (ann);
-  vuse_optype vuses = VUSE_OPS (ann);
-  vdef_optype vdefs = VDEF_OPS (ann);
-  unsigned int i;
+  ssa_op_iter iter;
+  tree val;
 
-  /* Look at USE_OPS or VUSE_OPS according to FLAGS.  */
-  for (i = 0; i < NUM_USES (uses); i++)
-    redirect_immediate_use (USE_OP (uses, i), old, new); 
-
-  for (i = 0; i < NUM_VUSES (vuses); i++)
-    redirect_immediate_use (VUSE_OP (vuses, i), old, new);
-
-  for (i = 0; i < NUM_VDEFS (vdefs); i++)
-    redirect_immediate_use (VDEF_OP (vdefs, i), old, new);
+  FOR_EACH_SSA_TREE_OPERAND (val, old, iter, SSA_OP_ALL_USES)
+    redirect_immediate_use (val, old, new);
 }
 
 
@@ -415,20 +401,16 @@ create_var_ann (tree t)
 {
   var_ann_t ann;
 
-#if defined ENABLE_CHECKING
-  if (t == NULL_TREE
-      || !DECL_P (t)
-      || (t->common.ann
-	  && t->common.ann->common.type != VAR_ANN))
-    abort ();
-#endif
+  gcc_assert (t);
+  gcc_assert (DECL_P (t));
+  gcc_assert (!t->common.ann || t->common.ann->common.type == VAR_ANN);
 
   ann = ggc_alloc (sizeof (*ann));
   memset ((void *) ann, 0, sizeof (*ann));
 
   ann->common.type = VAR_ANN;
 
-  t->common.ann = (tree_ann) ann;
+  t->common.ann = (tree_ann_t) ann;
 
   return ann;
 }
@@ -441,12 +423,8 @@ create_stmt_ann (tree t)
 {
   stmt_ann_t ann;
 
-#if defined ENABLE_CHECKING
-  if ((!is_gimple_stmt (t) && !is_essa_node (t))
-      || (t->common.ann
-	  && t->common.ann->common.type != STMT_ANN))
-    abort ();
-#endif
+  gcc_assert (is_gimple_stmt (t));
+  gcc_assert (!t->common.ann || t->common.ann->common.type == STMT_ANN);
 
   ann = ggc_alloc (sizeof (*ann));
   memset ((void *) ann, 0, sizeof (*ann));
@@ -456,44 +434,42 @@ create_stmt_ann (tree t)
   /* Since we just created the annotation, mark the statement modified.  */
   ann->modified = true;
 
-  t->common.ann = (tree_ann) ann;
+  t->common.ann = (tree_ann_t) ann;
 
   return ann;
 }
 
 
-/* Create a new annotation for an SSA name T.  */
+/* Create a new annotation for a tree T.  */
 
-ssa_name_ann_t
-create_ssa_name_ann (tree t)
+tree_ann_t
+create_tree_ann (tree t)
 {
-  ssa_name_ann_t ann;
+  tree_ann_t ann;
 
-#if defined ENABLE_CHECKING
-  if (t == NULL_TREE
-      || (t->common.ann
-	  && t->common.ann->common.type != SSA_NAME_ANN))
-    abort ();
-#endif
+  gcc_assert (t);
+  gcc_assert (!t->common.ann || t->common.ann->common.type == TREE_ANN_COMMON);
 
   ann = ggc_alloc (sizeof (*ann));
   memset ((void *) ann, 0, sizeof (*ann));
 
-  ann->common.type = SSA_NAME_ANN;
-  t->common.ann = (tree_ann) ann;
+  ann->common.type = TREE_ANN_COMMON;
+  t->common.ann = ann;
 
   return ann;
 }
 
-
 /* Build a temporary.  Make sure and register it to be renamed.  */
 
 tree
 make_rename_temp (tree type, const char *prefix)
 {
   tree t = create_tmp_var (type, prefix);
-  add_referenced_tmp_var (t);
-  bitmap_set_bit (vars_to_rename, var_ann (t)->uid);
+  if (referenced_vars)
+    {
+      add_referenced_tmp_var (t);
+      bitmap_set_bit (vars_to_rename, var_ann (t)->uid);
+    }
   return t;
 }
 
@@ -510,7 +486,7 @@ dump_referenced_vars (FILE *file)
 {
   size_t i;
 
-  fprintf (file, "\nReferenced variables in %s: %u\n\n", 
+  fprintf (file, "\nReferenced variables in %s: %u\n\n",
 	   get_name (current_function_decl), (unsigned) num_referenced_vars);
 
   for (i = 0; i < num_referenced_vars; i++)
@@ -539,6 +515,13 @@ dump_variable (FILE *file, tree var)
 {
   var_ann_t ann;
 
+  if (TREE_CODE (var) == SSA_NAME)
+    {
+      if (POINTER_TYPE_P (TREE_TYPE (var)))
+	dump_points_to_info_for (file, var);
+      var = SSA_NAME_VAR (var);
+    }
+
   if (var == NULL_TREE)
     {
       fprintf (file, "<nil>");
@@ -546,16 +529,13 @@ dump_variable (FILE *file, tree var)
     }
 
   print_generic_expr (file, var, dump_flags);
-  
-  if (TREE_CODE (var) == SSA_NAME)
-    var = SSA_NAME_VAR (var);
 
   ann = var_ann (var);
 
   fprintf (file, ", UID %u", (unsigned) ann->uid);
 
-  if (ann->has_hidden_use)
-    fprintf (file, ", has hidden uses");
+  fprintf (file, ", ");
+  print_generic_expr (file, TREE_TYPE (var), dump_flags);
 
   if (ann->type_mem_tag)
     {
@@ -566,8 +546,11 @@ dump_variable (FILE *file, tree var)
   if (ann->is_alias_tag)
     fprintf (file, ", is an alias tag");
 
-  if (needs_to_live_in_memory (var))
-    fprintf (file, ", is %s", TREE_STATIC (var) ? "static" : "global");
+  if (TREE_ADDRESSABLE (var))
+    fprintf (file, ", is addressable");
+  
+  if (is_global_var (var))
+    fprintf (file, ", is global");
 
   if (is_call_clobbered (var))
     fprintf (file, ", call clobbered");
@@ -613,7 +596,7 @@ dump_immediate_uses (FILE *file)
     {
       tree phi;
 
-      for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
+      for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
 	dump_immediate_uses_for (file, phi);
 
       for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
@@ -695,7 +678,7 @@ dump_dfa_stats (FILE *file)
 
   size = num_referenced_vars * sizeof (tree);
   total += size;
-  fprintf (file, fmt_str_1, "Referenced variables", num_referenced_vars, 
+  fprintf (file, fmt_str_1, "Referenced variables", num_referenced_vars,
 	   SCALE (size), LABEL (size));
 
   size = dfa_stats.num_stmt_anns * sizeof (struct stmt_ann_d);
@@ -723,9 +706,14 @@ dump_dfa_stats (FILE *file)
   fprintf (file, fmt_str_1, "VUSE operands", dfa_stats.num_vuses,
 	   SCALE (size), LABEL (size));
 
-  size = dfa_stats.num_vdefs * sizeof (tree *);
+  size = dfa_stats.num_v_may_defs * sizeof (tree *);
   total += size;
-  fprintf (file, fmt_str_1, "VDEF operands", dfa_stats.num_vdefs,
+  fprintf (file, fmt_str_1, "V_MAY_DEF operands", dfa_stats.num_v_may_defs,
+	   SCALE (size), LABEL (size));
+
+  size = dfa_stats.num_v_must_defs * sizeof (tree *);
+  total += size;
+  fprintf (file, fmt_str_1, "V_MUST_DEF operands", dfa_stats.num_v_must_defs,
 	   SCALE (size), LABEL (size));
 
   size = dfa_stats.num_phis * sizeof (struct tree_phi_node);
@@ -772,8 +760,7 @@ collect_dfa_stats (struct dfa_stats_d *dfa_stats_p)
   basic_block bb;
   block_stmt_iterator i;
 
-  if (dfa_stats_p == NULL)
-    abort ();
+  gcc_assert (dfa_stats_p);
 
   memset ((void *)dfa_stats_p, 0, sizeof (struct dfa_stats_d));
 
@@ -790,7 +777,7 @@ collect_dfa_stats (struct dfa_stats_d *dfa_stats_p)
   FOR_EACH_BB (bb)
     {
       tree phi;
-      for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
+      for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
 	{
 	  dfa_stats_p->num_phis++;
 	  dfa_stats_p->num_phi_args += PHI_NUM_ARGS (phi);
@@ -821,8 +808,11 @@ collect_dfa_stats_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
 	    dfa_stats_p->num_stmt_anns++;
 	    dfa_stats_p->num_defs += NUM_DEFS (DEF_OPS (ann));
 	    dfa_stats_p->num_uses += NUM_USES (USE_OPS (ann));
-	    dfa_stats_p->num_vdefs += NUM_VDEFS (VDEF_OPS (ann));
+	    dfa_stats_p->num_v_may_defs +=
+	                 NUM_V_MAY_DEFS (V_MAY_DEF_OPS (ann));
 	    dfa_stats_p->num_vuses += NUM_VUSES (VUSE_OPS (ann));
+	    dfa_stats_p->num_v_must_defs +=
+	                 NUM_V_MUST_DEFS (V_MUST_DEF_OPS (ann));
 	    break;
 	  }
 
@@ -848,24 +838,17 @@ collect_dfa_stats_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
 static tree
 find_vars_r (tree *tp, int *walk_subtrees, void *data)
 {
-  tree t = *tp;
-  struct walk_state *walk_state = (struct walk_state *)data;
+  struct walk_state *walk_state = (struct walk_state *) data;
 
-  if (SSA_VAR_P (t))
-    {
-      /* If T is a regular variable that the optimizers are interested
-	 in, add it to the list of variables.  */
-      add_referenced_var (t, walk_state);
-    }
-  else if (DECL_P (t)
-	   || TYPE_P (t)
-	   || TREE_CODE_CLASS (TREE_CODE (t)) == 'c')
-    {
-      /* Type, _DECL and constant nodes have no interesting children.
-	 Ignore them.  */
-      *walk_subtrees = 0;
-    }
+  /* If T is a regular variable that the optimizers are interested
+     in, add it to the list of variables.  */
+  if (SSA_VAR_P (*tp))
+    add_referenced_var (*tp, walk_state);
 
+  /* Type, _DECL and constant nodes have no interesting children.
+     Ignore them.  */
+  else if (IS_TYPE_OR_DECL_P (*tp) || CONSTANT_CLASS_P (*tp))
+    *walk_subtrees = 0;
 
   return NULL_TREE;
 }
@@ -901,14 +884,17 @@ add_referenced_var (tree var, struct walk_state *walk_state)
       v_ann->uid = num_referenced_vars;
       VARRAY_PUSH_TREE (referenced_vars, var);
 
-      /* Global and static variables are call-clobbered, always.  */
-      if (needs_to_live_in_memory (var))
+      /* Global variables are always call-clobbered.  */
+      if (is_global_var (var))
 	mark_call_clobbered (var);
 
-      /* DECL_NONLOCAL variables should not be removed, as they are needed
-	 to emit nested functions.  */
-      if (DECL_NONLOCAL (var))
-	v_ann->used = 1;
+      /* If an initialized global variable then register the initializer
+	 as well.  */
+      if (POINTER_TYPE_P (TREE_TYPE (var))
+	  && TREE_READONLY (var)
+	  && DECL_INITIAL (var)
+	  && TREE_CODE (DECL_INITIAL (var)) == ADDR_EXPR)
+      	walk_tree (&DECL_INITIAL (var), find_vars_r, walk_state, 0);
     }
 }
 
@@ -918,112 +904,24 @@ add_referenced_var (tree var, struct walk_state *walk_state)
 tree
 get_virtual_var (tree var)
 {
-  enum tree_code code;
-
   STRIP_NOPS (var);
 
   if (TREE_CODE (var) == SSA_NAME)
     var = SSA_NAME_VAR (var);
 
-  code = TREE_CODE (var);
+  while (TREE_CODE (var) == REALPART_EXPR || TREE_CODE (var) == IMAGPART_EXPR
+	 || handled_component_p (var))
+    var = TREE_OPERAND (var, 0);
 
-  while (code == ARRAY_REF
-         || code == COMPONENT_REF
-	 || code == REALPART_EXPR
-	 || code == IMAGPART_EXPR)
-    {
-      var = TREE_OPERAND (var, 0);
-      code = TREE_CODE (var);
-    }
-
-#ifdef ENABLE_CHECKING
   /* Treating GIMPLE registers as virtual variables makes no sense.
      Also complain if we couldn't extract a _DECL out of the original
      expression.  */
-  if (!SSA_VAR_P (var)
-      || is_gimple_reg (var))
-    abort ();
-#endif
+  gcc_assert (SSA_VAR_P (var));
+  gcc_assert (!is_gimple_reg (var));
 
   return var;
 }
 
-
-/* Mark variables in BLOCK that have hidden uses.  A hidden use can
-   occur due to VLA declarations or nested functions.   */
-
-static void
-find_hidden_use_vars (tree block)
-{
-  tree sub, decl, tem;
-
-  /* Check all the arrays declared in the block for VLAs.
-     While scanning the block's variables, also see if there is
-     a nested function at this scope.  */
-  for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
-    {
-      int inside_vla = 0;
-      walk_tree (&decl, find_hidden_use_vars_r, &inside_vla, NULL);
-    }
-
-  /* Now repeat the search in any sub-blocks.  */
-  for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
-    find_hidden_use_vars (sub);
-
-  /* A VLA parameter may use a variable which as set from another
-     parameter to declare the size of the VLA.  We need to mark the
-     variable as having a hidden use since it is used to declare the
-     VLA parameter and that declaration is not seen by the SSA code. 
-
-     Note get_pending_sizes clears the PENDING_SIZES chain, so we
-     must restore it. */
-  tem = get_pending_sizes ();
-  put_pending_sizes (tem);
-  for (; tem; tem = TREE_CHAIN (tem))
-    {
-      int inside_vla = 1;
-      walk_tree (&TREE_VALUE (tem), find_hidden_use_vars_r, &inside_vla, NULL);
-    }
-}
-
-
-/* Callback for walk_tree used by find_hidden_use_vars to analyze each 
-   variable in a lexical block.  If the variable's size has a variable
-   size, then mark all objects needed to compute the variable's size
-   as having hidden uses.  */
-
-static tree
-find_hidden_use_vars_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
-			void *data ATTRIBUTE_UNUSED)
-{
-  int *inside_vla = (int *) data;
-
-  /* We need to look for hidden uses due to VLAs in variable
-     definitions.  We originally used to look for these hidden
-     uses in the variable's type, but that's unreliable if the
-     type's size contains a SAVE_EXPR for a different function
-     context than the variable is used within.  */
-  if (SSA_VAR_P (*tp)
-      && ((DECL_SIZE (*tp)
-	   && ! really_constant_p (DECL_SIZE (*tp)))
-	  || (DECL_SIZE_UNIT (*tp)
-	      && ! really_constant_p (DECL_SIZE_UNIT (*tp)))))
-    {
-      int save = *inside_vla;
-
-      *inside_vla = 1;
-      walk_tree (&DECL_SIZE (*tp), find_hidden_use_vars_r, inside_vla, NULL);
-      walk_tree (&DECL_SIZE_UNIT (*tp), find_hidden_use_vars_r,
-		 inside_vla, NULL);
-      *inside_vla = save;
-    }
-  else if (*inside_vla && SSA_VAR_P (*tp))
-    set_has_hidden_use (*tp);
-
-  return NULL_TREE;
-}
-
-
 /* Add a temporary variable to REFERENCED_VARS.  This is similar to
    add_referenced_var, but is used by passes that need to add new temps to
    the REFERENCED_VARS array after the program has been scanned for
@@ -1037,41 +935,18 @@ add_referenced_tmp_var (tree var)
 }
 
 
-/* Return true if VDEFS_AFTER contains fewer entries than VDEFS_BEFORE.
-   Note that this assumes that both varrays are VDEF operands for the same
-   statement.  */
-
-static inline bool
-vdefs_disappeared_p (vdef_optype vdefs_before, vdef_optype vdefs_after)
-{
-  /* If there was nothing before, nothing could've disappeared.  */
-  if (vdefs_before == NULL)
-    return false;
-     
-  /* All/some of them gone.  */
-  if (vdefs_after == NULL
-      || NUM_VDEFS (vdefs_before) > NUM_VDEFS (vdefs_after))
-    return true;
-
-  return false;
-}
-
-
 /* Add all the non-SSA variables found in STMT's operands to the bitmap
    VARS_TO_RENAME.  */
 
 void
 mark_new_vars_to_rename (tree stmt, bitmap vars_to_rename)
 {
-  def_optype defs;
-  use_optype uses;
-  vdef_optype vdefs;
-  vuse_optype vuses;
-  size_t i;
+  ssa_op_iter iter;
+  tree val;
   bitmap vars_in_vops_to_rename;
   bool found_exposed_symbol = false;
-  vdef_optype vdefs_before, vdefs_after;
-  stmt_ann_t ann;
+  int v_may_defs_before, v_may_defs_after;
+  int v_must_defs_before, v_must_defs_after;
 
   vars_in_vops_to_rename = BITMAP_XMALLOC ();
 
@@ -1084,23 +959,15 @@ mark_new_vars_to_rename (tree stmt, bitmap vars_to_rename)
      We flag them in a separate bitmap because we don't really want to
      rename them if there are not any newly exposed symbols in the
      statement operands.  */
-  ann = stmt_ann (stmt);
-  vdefs_before = vdefs = VDEF_OPS (ann);
-  for (i = 0; i < NUM_VDEFS (vdefs); i++)
-    {
-      tree var = VDEF_RESULT (vdefs, i);
-      if (!DECL_P (var))
-	var = SSA_NAME_VAR (var);
-      bitmap_set_bit (vars_in_vops_to_rename, var_ann (var)->uid);
-    }
+  v_may_defs_before = NUM_V_MAY_DEFS (STMT_V_MAY_DEF_OPS (stmt));
+  v_must_defs_before = NUM_V_MUST_DEFS (STMT_V_MUST_DEF_OPS (stmt));
 
-  vuses = VUSE_OPS (ann);
-  for (i = 0; i < NUM_VUSES (vuses); i++)
+  FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, 
+			     SSA_OP_VMAYDEF | SSA_OP_VUSE | SSA_OP_VMUSTDEF)
     {
-      tree var = VUSE_OP (vuses, i);
-      if (!DECL_P (var))
-	var = SSA_NAME_VAR (var);
-      bitmap_set_bit (vars_in_vops_to_rename, var_ann (var)->uid);
+      if (!DECL_P (val))
+	val = SSA_NAME_VAR (val);
+      bitmap_set_bit (vars_in_vops_to_rename, var_ann (val)->uid);
     }
 
   /* Now force an operand re-scan on the statement and mark any newly
@@ -1108,47 +975,17 @@ mark_new_vars_to_rename (tree stmt, bitmap vars_to_rename)
   modify_stmt (stmt);
   get_stmt_operands (stmt);
 
-  defs = DEF_OPS (ann);
-  for (i = 0; i < NUM_DEFS (defs); i++)
-    {
-      tree var = DEF_OP (defs, i);
-      if (DECL_P (var))
-	{
-	  found_exposed_symbol = true;
-	  bitmap_set_bit (vars_to_rename, var_ann (var)->uid);
-	}
-    }
-
-  uses = USE_OPS (ann);
-  for (i = 0; i < NUM_USES (uses); i++)
-    {
-      tree var = USE_OP (uses, i);
-      if (DECL_P (var))
-	{
-	  found_exposed_symbol = true;
-	  bitmap_set_bit (vars_to_rename, var_ann (var)->uid);
-	}
-    }
+  v_may_defs_after = NUM_V_MAY_DEFS (STMT_V_MAY_DEF_OPS (stmt));
+  v_must_defs_after = NUM_V_MUST_DEFS (STMT_V_MUST_DEF_OPS (stmt));
 
-  vdefs_after = vdefs = VDEF_OPS (ann);
-  for (i = 0; i < NUM_VDEFS (vdefs); i++)
-    {
-      tree var = VDEF_RESULT (vdefs, i);
-      if (DECL_P (var))
-	{
-	  found_exposed_symbol = true;
-	  bitmap_set_bit (vars_to_rename, var_ann (var)->uid);
-	}
-    }
+  FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, 
+			     SSA_OP_VMAYDEF | SSA_OP_VUSE | SSA_OP_VMUSTDEF)
 
-  vuses = VUSE_OPS (ann);
-  for (i = 0; i < NUM_VUSES (vuses); i++)
     {
-      tree var = VUSE_OP (vuses, i);
-      if (DECL_P (var))
+      if (DECL_P (val))
 	{
 	  found_exposed_symbol = true;
-	  bitmap_set_bit (vars_to_rename, var_ann (var)->uid);
+	  bitmap_set_bit (vars_to_rename, var_ann (val)->uid);
 	}
     }
 
@@ -1158,7 +995,8 @@ mark_new_vars_to_rename (tree stmt, bitmap vars_to_rename)
      vanishing VDEFs because in those cases, the names that were formerly
      generated by this statement are not going to be available anymore.  */
   if (found_exposed_symbol
-      || vdefs_disappeared_p (vdefs_before, vdefs_after))
+      || v_may_defs_before > v_may_defs_after
+      || v_must_defs_before > v_must_defs_after)
     bitmap_a_or_b (vars_to_rename, vars_to_rename, vars_in_vops_to_rename);
 
   BITMAP_XFREE (vars_in_vops_to_rename);