diff mbox

[RFC,SSA] Iterator to visit SSA

Message ID CAELXzTMYPu-bUaPnkn0L3=QoiLVNOWUDgdgveYZBjZ56SftXFg@mail.gmail.com
State Superseded
Headers show

Commit Message

Kugan Vivekanandarajah Sept. 7, 2016, 12:21 a.m. UTC
Hi Richard,

On 6 September 2016 at 19:08, Richard Biener <richard.guenther@gmail.com> wrote:
> On Tue, Sep 6, 2016 at 2:24 AM, Kugan Vivekanandarajah

> <kugan.vivekanandarajah@linaro.org> wrote:

>> Hi Richard,

>>

>> On 5 September 2016 at 17:57, Richard Biener <richard.guenther@gmail.com> wrote:

>>> On Mon, Sep 5, 2016 at 7:26 AM, Kugan Vivekanandarajah

>>> <kugan.vivekanandarajah@linaro.org> wrote:

>>>> Hi All,

>>>>

>>>> While looking at gcc source, I noticed that we are iterating over SSA

>>>> variable from 0 to num_ssa_names in some cases and 1 to num_ssa_names

>>>> in others. It seems that variable 0 is always NULL TREE.

>>>

>>> Yeah, that's artificial because we don't assign SSA name version 0 (for some

>>> unknown reason).

>>>

>>>> But it can

>>>> confuse people who are looking for the first time. Therefore It might

>>>> be good to follow some consistent usage here.

>>>>

>>>> It might be also good to gave a FOR_EACH_SSAVAR iterator as we do in

>>>> other case. Here is attempt to do this based on what is done in other

>>>> places. Bootstrapped and regression tested on X86_64-linux-gnu with no

>>>> new regressions. is this OK?

>>>

>>> First of all some bikeshedding - FOR_EACH_SSA_NAME would be better

>>> as SSAVAR might be confused with iterating over SSA_NAME_VAR.

>>>

>>> Then, if you add an iterator why leave the name == NULL handling to consumers?

>>> That looks odd.

>>>

>>> Then, SSA names are just in a vector thus why not re-use the vector iterator?

>>>

>>> That is,

>>>

>>> #define FOR_EACH_SSA_NAME (name) \

>>>   for (unsigned i = 1; SSANAMES (cfun).iterate (i, &name); ++i)

>>>

>>> would be equivalent to your patch?

>>>

>>> Please also don't add new iterators that implicitely use 'cfun' but always use

>>> one that passes it as explicit arg.

>>

>> I think defining FOR_EACH_SSA_NAME with vector iterator is better. But

>> we will not be able to skill NULL ssa_names with that.

>

> Why?  Can't you simply do

>

>   #define FOR_EACH_SSA_NAME (name) \

>     for (unsigned i = 1; SSANAMES (cfun).iterate (i, &name); ++i) \

>        if (name)

>

> ?


Indeed.  I missed the if at the end :(.  Here is an updated patch.
Bootstrapped and regression tested on x86_64-linux-gnu with no new
regressions.

Thanks,
Kugan
>

>> I also added

>> index variable to the macro so that there want be any conflicts if the

>> index variable "i" (or whatever) is also defined in the loop.

>>

>> Bootstrapped and regression tested on x86_64-linux-gnu with no new

>> regressions. Is this OK for trunk?

>>

>> Thanks,

>> Kugan

>>

>>

>> gcc/ChangeLog:

>>

>> 2016-09-06  Kugan Vivekanandarajah  <kuganv@linaro.org>

>>

>>     * tree-ssanames.h (FOR_EACH_SSA_NAME): New.

>>     * cfgexpand.c (update_alias_info_with_stack_vars): Use

>>     FOR_EACH_SSA_NAME to iterate over SSA variables.

>>     (pass_expand::execute): Likewise.

>>     * omp-simd-clone.c (ipa_simd_modify_function_body): Likewise.

>>     * tree-cfg.c (dump_function_to_file): Likewise.

>>     * tree-into-ssa.c (pass_build_ssa::execute): Likewise.

>>     (update_ssa): Likewise.

>>     * tree-ssa-alias.c (dump_alias_info): Likewise.

>>     * tree-ssa-ccp.c (ccp_finalize): Likewise.

>>     * tree-ssa-coalesce.c (build_ssa_conflict_graph): Likewise.

>>     (create_outofssa_var_map): Likewise.

>>     (coalesce_ssa_name): Likewise.

>>     * tree-ssa-operands.c (dump_immediate_uses): Likewise.

>>     * tree-ssa-pre.c (compute_avail): Likewise.

>>     * tree-ssa-sccvn.c (init_scc_vn): Likewise.

>>     (scc_vn_restore_ssa_info): Likewise.

>>     (free_scc_vn): Likwise.

>>     (run_scc_vn): Likewise.

>>     * tree-ssa-structalias.c (compute_points_to_sets): Likewise.

>>     * tree-ssa-ter.c (new_temp_expr_table): Likewise.

>>     * tree-ssa-copy.c (fini_copy_prop): Likewise.

>>     * tree-ssa.c (verify_ssa): Likewise.

>>

>>>

>>> Thanks,

>>> Richard.

>>>

>>>

>>>> Thanks,

>>>> Kugan

>>>>

>>>>

>>>> gcc/ChangeLog:

>>>>

>>>> 2016-09-05  Kugan Vivekanandarajah  <kuganv@linaro.org>

>>>>

>>>>     * tree-ssanames.h (ssa_iterator::ssa_iterator): New.

>>>>     (ssa_iterator::get): Likewise.

>>>>     (ssa_iterator::next): Likewise.

>>>>     (FOR_EACH_SSAVAR): Likewise.

>>>>     * cfgexpand.c (update_alias_info_with_stack_vars): Use

>>>>     FOR_EACH_SSAVAR to iterate over SSA variables.

>>>>     (pass_expand::execute): Likewise.

>>>>     * omp-simd-clone.c (ipa_simd_modify_function_body): Likewise.

>>>>     * tree-cfg.c (dump_function_to_file): Likewise.

>>>>     * tree-into-ssa.c (pass_build_ssa::execute): Likewise.

>>>>     (update_ssa): Likewise.

>>>>     * tree-ssa-alias.c (dump_alias_info): Likewise.

>>>>     * tree-ssa-ccp.c (ccp_finalize): Likewise.

>>>>     * tree-ssa-coalesce.c (build_ssa_conflict_graph): Likewise.

>>>>     (create_outofssa_var_map): Likewise.

>>>>     (coalesce_ssa_name): Likewise.

>>>>     * tree-ssa-operands.c (dump_immediate_uses): Likewise.

>>>>     * tree-ssa-pre.c (compute_avail): Likewise.

>>>>     * tree-ssa-sccvn.c (init_scc_vn): Likewise.

>>>>     (scc_vn_restore_ssa_info): Likewise.

>>>>     (free_scc_vn): Likwise.

>>>>     (run_scc_vn): Likewise.

>>>>     * tree-ssa-structalias.c (compute_points_to_sets): Likewise.

>>>>     * tree-ssa-ter.c (new_temp_expr_table): Likewise.
diff mbox

Patch

diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index 130a16b..0611e0f 100644
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -815,16 +815,15 @@  update_alias_info_with_stack_vars (void)
   if (decls_to_partitions)
     {
       unsigned i;
+      tree name;
       hash_set<bitmap> visited;
       bitmap temp = BITMAP_ALLOC (&stack_var_bitmap_obstack);
 
-      for (i = 1; i < num_ssa_names; i++)
+      FOR_EACH_SSA_NAME (i, name)
 	{
-	  tree name = ssa_name (i);
 	  struct ptr_info_def *pi;
 
-	  if (name
-	      && POINTER_TYPE_P (TREE_TYPE (name))
+	  if (POINTER_TYPE_P (TREE_TYPE (name))
 	      && ((pi = SSA_NAME_PTR_INFO (name)) != NULL))
 	    add_partitioned_vars_to_ptset (&pi->pt, decls_to_partitions,
 					   &visited, temp);
@@ -6163,6 +6162,7 @@  pass_expand::execute (function *fun)
   edge e;
   rtx_insn *var_seq, *var_ret_seq;
   unsigned i;
+  tree name;
 
   timevar_push (TV_OUT_OF_SSA);
   rewrite_out_of_ssa (&SA);
@@ -6270,16 +6270,13 @@  pass_expand::execute (function *fun)
 
   /* Now propagate the RTL assignment of each partition to the
      underlying var of each SSA_NAME.  */
-  for (i = 1; i < num_ssa_names; i++)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
-
-      if (!name
-	  /* We might have generated new SSA names in
-	     update_alias_info_with_stack_vars.  They will have a NULL
-	     defining statements, and won't be part of the partitioning,
-	     so ignore those.  */
-	  || !SSA_NAME_DEF_STMT (name))
+      /* We might have generated new SSA names in
+	 update_alias_info_with_stack_vars.  They will have a NULL
+	 defining statements, and won't be part of the partitioning,
+	 so ignore those.  */
+      if (!SSA_NAME_DEF_STMT (name))
 	continue;
 
       adjust_one_expanded_partition_var (name);
@@ -6288,17 +6285,15 @@  pass_expand::execute (function *fun)
   /* Clean up RTL of variables that straddle across multiple
      partitions, and check that the rtl of any PARM_DECLs that are not
      cleaned up is that of their default defs.  */
-  for (i = 1; i < num_ssa_names; i++)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
       int part;
 
-      if (!name
-	  /* We might have generated new SSA names in
-	     update_alias_info_with_stack_vars.  They will have a NULL
-	     defining statements, and won't be part of the partitioning,
-	     so ignore those.  */
-	  || !SSA_NAME_DEF_STMT (name))
+      /* We might have generated new SSA names in
+	 update_alias_info_with_stack_vars.  They will have a NULL
+	 defining statements, and won't be part of the partitioning,
+	 so ignore those.  */
+      if (!SSA_NAME_DEF_STMT (name))
 	continue;
       part = var_to_partition (SA.map, name);
       if (part == NO_PARTITION)
diff --git a/gcc/omp-simd-clone.c b/gcc/omp-simd-clone.c
index c418440c..e6589bb 100644
--- a/gcc/omp-simd-clone.c
+++ b/gcc/omp-simd-clone.c
@@ -908,6 +908,7 @@  ipa_simd_modify_function_body (struct cgraph_node *node,
 {
   basic_block bb;
   unsigned int i, j, l;
+  tree name;
 
   /* Re-use the adjustments array, but this time use it to replace
      every function argument use to an offset into the corresponding
@@ -931,11 +932,9 @@  ipa_simd_modify_function_body (struct cgraph_node *node,
     }
 
   l = adjustments.length ();
-  for (i = 1; i < num_ssa_names; i++)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
-      if (name
-	  && SSA_NAME_VAR (name)
+      if (SSA_NAME_VAR (name)
 	  && TREE_CODE (SSA_NAME_VAR (name)) == PARM_DECL)
 	{
 	  for (j = 0; j < l; j++)
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 57c8410..72e645d 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -7539,6 +7539,7 @@  dump_function_to_file (tree fndecl, FILE *file, int flags)
   if (fun && fun->decl == fndecl && (fun->curr_properties & PROP_gimple_lcf))
     {
       unsigned ix;
+      tree name;
       ignore_topmost_bind = true;
 
       fprintf (file, "{\n");
@@ -7582,10 +7583,9 @@  dump_function_to_file (tree fndecl, FILE *file, int flags)
 	    any_var = true;
 	  }
       if (gimple_in_ssa_p (cfun))
-	for (ix = 1; ix < num_ssa_names; ++ix)
+	FOR_EACH_SSA_NAME (ix, name)
 	  {
-	    tree name = ssa_name (ix);
-	    if (name && !SSA_NAME_VAR (name))
+	    if (!SSA_NAME_VAR (name))
 	      {
 		fprintf (file, "  ");
 		print_generic_expr (file, TREE_TYPE (name), flags);
diff --git a/gcc/tree-into-ssa.c b/gcc/tree-into-ssa.c
index ceafa68..d73dad7 100644
--- a/gcc/tree-into-ssa.c
+++ b/gcc/tree-into-ssa.c
@@ -2342,6 +2342,7 @@  pass_build_ssa::execute (function *fun)
   bitmap_head *dfs;
   basic_block bb;
   unsigned i;
+  tree decl, name;
 
   /* Initialize operand data structures.  */
   init_ssa_operands (fun);
@@ -2385,11 +2386,9 @@  pass_build_ssa::execute (function *fun)
   /* Try to get rid of all gimplifier generated temporaries by making
      its SSA names anonymous.  This way we can garbage collect them
      all after removing unused locals which we do in our TODO.  */
-  for (i = 1; i < num_ssa_names; ++i)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree decl, name = ssa_name (i);
-      if (!name
-	  || SSA_NAME_IS_DEFAULT_DEF (name))
+      if (SSA_NAME_IS_DEFAULT_DEF (name))
 	continue;
       decl = SSA_NAME_VAR (name);
       if (decl
@@ -3165,7 +3164,7 @@  update_ssa (unsigned update_flags)
   unsigned i = 0;
   bool insert_phi_p;
   sbitmap_iterator sbi;
-  tree sym;
+  tree sym, name;
 
   /* Only one update flag should be set.  */
   gcc_assert (update_flags == TODO_update_ssa
@@ -3284,11 +3283,9 @@  update_ssa (unsigned update_flags)
       prepare_block_for_update (start_bb, insert_phi_p);
 
       if (flag_checking)
-	for (i = 1; i < num_ssa_names; ++i)
+	FOR_EACH_SSA_NAME (i, name)
 	  {
-	    tree name = ssa_name (i);
-	    if (!name
-		|| virtual_operand_p (name))
+	    if (virtual_operand_p (name))
 	      continue;
 
 	    /* For all but virtual operands, which do not have SSA names
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 8051a66..de0b1f9 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -450,6 +450,7 @@  void
 dump_alias_info (FILE *file)
 {
   unsigned i;
+  tree ptr;
   const char *funcname
     = lang_hooks.decl_printable_name (current_function_decl, 2);
   tree var;
@@ -471,13 +472,11 @@  dump_alias_info (FILE *file)
 
   fprintf (file, "\n\nFlow-insensitive points-to information\n\n");
 
-  for (i = 1; i < num_ssa_names; i++)
+  FOR_EACH_SSA_NAME (i, ptr)
     {
-      tree ptr = ssa_name (i);
       struct ptr_info_def *pi;
 
-      if (ptr == NULL_TREE
-	  || !POINTER_TYPE_P (TREE_TYPE (ptr))
+      if (!POINTER_TYPE_P (TREE_TYPE (ptr))
 	  || SSA_NAME_IN_FREE_LIST (ptr))
 	continue;
 
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 9871304..cbded7b 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -898,24 +898,23 @@  ccp_finalize (bool nonzero_p)
 {
   bool something_changed;
   unsigned i;
+  tree name;
 
   do_dbg_cnt ();
 
   /* Derive alignment and misalignment information from partially
      constant pointers in the lattice or nonzero bits from partially
      constant integers.  */
-  for (i = 1; i < num_ssa_names; ++i)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
       ccp_prop_value_t *val;
       unsigned int tem, align;
 
-      if (!name
-	  || (!POINTER_TYPE_P (TREE_TYPE (name))
-	      && (!INTEGRAL_TYPE_P (TREE_TYPE (name))
-		  /* Don't record nonzero bits before IPA to avoid
-		     using too much memory.  */
-		  || !nonzero_p)))
+      if (!POINTER_TYPE_P (TREE_TYPE (name))
+	  && (!INTEGRAL_TYPE_P (TREE_TYPE (name))
+	      /* Don't record nonzero bits before IPA to avoid
+		 using too much memory.  */
+	      || !nonzero_p))
 	continue;
 
       val = get_value (name);
diff --git a/gcc/tree-ssa-coalesce.c b/gcc/tree-ssa-coalesce.c
index 34c3fa1..d9a27ee 100644
--- a/gcc/tree-ssa-coalesce.c
+++ b/gcc/tree-ssa-coalesce.c
@@ -955,12 +955,11 @@  build_ssa_conflict_graph (tree_live_info_p liveinfo)
       if (bb == entry)
 	{
 	  unsigned i;
-	  for (i = 1; i < num_ssa_names; i++)
-	    {
-	      tree var = ssa_name (i);
+	  tree var;
 
-	      if (!var
-		  || !SSA_NAME_IS_DEFAULT_DEF (var)
+	  FOR_EACH_SSA_NAME (i, var)
+	    {
+	      if (!SSA_NAME_IS_DEFAULT_DEF (var)
 		  || !SSA_NAME_VAR (var)
 		  || VAR_P (SSA_NAME_VAR (var)))
 		continue;
@@ -1261,10 +1260,9 @@  create_outofssa_var_map (coalesce_list *cl, bitmap used_in_copy)
   /* Now process result decls and live on entry variables for entry into
      the coalesce list.  */
   first = NULL_TREE;
-  for (i = 1; i < num_ssa_names; i++)
+  FOR_EACH_SSA_NAME (i, var)
     {
-      var = ssa_name (i);
-      if (var != NULL_TREE && !virtual_operand_p (var))
+      if (!virtual_operand_p (var))
         {
 	  coalesce_with_default (var, cl, used_in_copy);
 
@@ -1806,6 +1804,7 @@  coalesce_ssa_name (void)
   bitmap used_in_copies = BITMAP_ALLOC (NULL);
   var_map map;
   unsigned int i;
+  tree a;
 
   cl = create_coalesce_list ();
   map = create_outofssa_var_map (cl, used_in_copies);
@@ -1817,12 +1816,9 @@  coalesce_ssa_name (void)
     {
       hash_table<ssa_name_var_hash> ssa_name_hash (10);
 
-      for (i = 1; i < num_ssa_names; i++)
+      FOR_EACH_SSA_NAME (i, a)
 	{
-	  tree a = ssa_name (i);
-
-	  if (a
-	      && SSA_NAME_VAR (a)
+	  if (SSA_NAME_VAR (a)
 	      && !DECL_IGNORED_P (SSA_NAME_VAR (a))
 	      && (!has_zero_uses (a) || !SSA_NAME_IS_DEFAULT_DEF (a)
 		  || !VAR_P (SSA_NAME_VAR (a))))
diff --git a/gcc/tree-ssa-copy.c b/gcc/tree-ssa-copy.c
index 3d17926..1a3c69f 100644
--- a/gcc/tree-ssa-copy.c
+++ b/gcc/tree-ssa-copy.c
@@ -503,14 +503,13 @@  static bool
 fini_copy_prop (void)
 {
   unsigned i;
+  tree var;
 
   /* Set the final copy-of value for each variable by traversing the
      copy-of chains.  */
-  for (i = 1; i < num_ssa_names; i++)
+  FOR_EACH_SSA_NAME (i, var)
     {
-      tree var = ssa_name (i);
-      if (!var
-	  || !copy_of[i].value
+      if (!copy_of[i].value
 	  || copy_of[i].value == var)
 	continue;
 
diff --git a/gcc/tree-ssa-operands.c b/gcc/tree-ssa-operands.c
index eccea2f..140e1c5 100644
--- a/gcc/tree-ssa-operands.c
+++ b/gcc/tree-ssa-operands.c
@@ -1247,11 +1247,8 @@  dump_immediate_uses (FILE *file)
   unsigned int x;
 
   fprintf (file, "Immediate_uses: \n\n");
-  for (x = 1; x < num_ssa_names; x++)
+  FOR_EACH_SSA_NAME (x, var)
     {
-      var = ssa_name (x);
-      if (!var)
-        continue;
       dump_immediate_uses_for (file, var);
     }
 }
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index fdb1c2c..b608a8d 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -3670,15 +3670,14 @@  compute_avail (void)
   basic_block *worklist;
   size_t sp = 0;
   unsigned i;
+  tree name;
 
   /* We pretend that default definitions are defined in the entry block.
      This includes function arguments and the static chain decl.  */
-  for (i = 1; i < num_ssa_names; ++i)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
       pre_expr e;
-      if (!name
-	  || !SSA_NAME_IS_DEFAULT_DEF (name)
+      if (!SSA_NAME_IS_DEFAULT_DEF (name)
 	  || has_zero_uses (name)
 	  || virtual_operand_p (name))
 	continue;
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 21b3d56..898a7c6 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -4291,6 +4291,7 @@  static void
 init_scc_vn (void)
 {
   size_t i;
+  tree name;
   int j;
   int *rpo_numbers_temp;
 
@@ -4339,12 +4340,8 @@  init_scc_vn (void)
 
   /* Create the VN_INFO structures, and initialize value numbers to
      TOP or VARYING for parameters.  */
-  for (i = 1; i < num_ssa_names; i++)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
-      if (!name)
-	continue;
-
       VN_INFO_GET (name)->valnum = VN_TOP;
       VN_INFO (name)->needs_insertion = false;
       VN_INFO (name)->expr = NULL;
@@ -4402,11 +4399,12 @@  init_scc_vn (void)
 void
 scc_vn_restore_ssa_info (void)
 {
-  for (unsigned i = 0; i < num_ssa_names; i++)
+  unsigned i;
+  tree name;
+
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
-      if (name
-	  && has_VN_INFO (name))
+      if (has_VN_INFO (name))
 	{
 	  if (VN_INFO (name)->needs_insertion)
 	    ;
@@ -4428,6 +4426,7 @@  void
 free_scc_vn (void)
 {
   size_t i;
+  tree name;
 
   delete constant_to_value_id;
   constant_to_value_id = NULL;
@@ -4436,11 +4435,9 @@  free_scc_vn (void)
   shared_lookup_references.release ();
   XDELETEVEC (rpo_numbers);
 
-  for (i = 0; i < num_ssa_names; i++)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
-      if (name
-	  && has_VN_INFO (name)
+      if (has_VN_INFO (name)
 	  && VN_INFO (name)->needs_insertion)
 	release_ssa_name (name);
     }
@@ -4757,6 +4754,7 @@  bool
 run_scc_vn (vn_lookup_kind default_vn_walk_kind_)
 {
   size_t i;
+  tree name;
 
   default_vn_walk_kind = default_vn_walk_kind_;
 
@@ -4797,9 +4795,8 @@  run_scc_vn (vn_lookup_kind default_vn_walk_kind_)
 
   /* Initialize the value ids and prune out remaining VN_TOPs
      from dead code.  */
-  for (i = 1; i < num_ssa_names; ++i)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
       vn_ssa_aux_t info;
       if (!name)
 	continue;
@@ -4814,12 +4811,9 @@  run_scc_vn (vn_lookup_kind default_vn_walk_kind_)
     }
 
   /* Propagate.  */
-  for (i = 1; i < num_ssa_names; ++i)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
       vn_ssa_aux_t info;
-      if (!name)
-	continue;
       info = VN_INFO (name);
       if (TREE_CODE (info->valnum) == SSA_NAME
 	  && info->valnum != name
@@ -4832,11 +4826,9 @@  run_scc_vn (vn_lookup_kind default_vn_walk_kind_)
   if (dump_file && (dump_flags & TDF_DETAILS))
     {
       fprintf (dump_file, "Value numbers:\n");
-      for (i = 0; i < num_ssa_names; i++)
+      FOR_EACH_SSA_NAME (i, name)
 	{
-	  tree name = ssa_name (i);
-	  if (name
-	      && VN_INFO (name)->visited
+	  if (VN_INFO (name)->visited
 	      && SSA_VAL (name) != name)
 	    {
 	      print_generic_expr (dump_file, name, 0);
diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index fd96c3a..0149bec 100644
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -7029,6 +7029,7 @@  compute_points_to_sets (void)
 {
   basic_block bb;
   unsigned i;
+  tree ptr;
   varinfo_t vi;
 
   timevar_push (TV_TREE_PTA);
@@ -7077,11 +7078,9 @@  compute_points_to_sets (void)
   cfun->gimple_df->escaped.escaped = 0;
 
   /* Compute the points-to sets for pointer SSA_NAMEs.  */
-  for (i = 0; i < num_ssa_names; ++i)
+  FOR_EACH_SSA_NAME (i, ptr)
     {
-      tree ptr = ssa_name (i);
-      if (ptr
-	  && POINTER_TYPE_P (TREE_TYPE (ptr)))
+      if (POINTER_TYPE_P (TREE_TYPE (ptr)))
 	find_what_p_points_to (cfun->decl, ptr);
     }
 
diff --git a/gcc/tree-ssa-ter.c b/gcc/tree-ssa-ter.c
index 2a772b2..16ccd9d 100644
--- a/gcc/tree-ssa-ter.c
+++ b/gcc/tree-ssa-ter.c
@@ -186,6 +186,7 @@  static temp_expr_table *
 new_temp_expr_table (var_map map)
 {
   unsigned x;
+  tree name;
 
   temp_expr_table *t = XNEW (struct temp_expr_table);
   t->map = map;
@@ -201,12 +202,9 @@  new_temp_expr_table (var_map map)
 
   t->replaceable_expressions = NULL;
   t->num_in_part = XCNEWVEC (int, num_var_partitions (map));
-  for (x = 1; x < num_ssa_names; x++)
+  FOR_EACH_SSA_NAME (x, name)
     {
       int p;
-      tree name = ssa_name (x);
-      if (!name)
-        continue;
       p = var_to_partition (map, name);
       if (p != NO_PARTITION)
         t->num_in_part[p]++;
diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c
index aae383d..b243f5c 100644
--- a/gcc/tree-ssa.c
+++ b/gcc/tree-ssa.c
@@ -1010,6 +1010,7 @@  verify_ssa (bool check_modified_stmt, bool check_ssa_operands)
   basic_block *definition_block = XCNEWVEC (basic_block, num_ssa_names);
   ssa_op_iter iter;
   tree op;
+  tree name;
   enum dom_state orig_dom_state = dom_info_state (CDI_DOMINATORS);
   bitmap names_defined_in_bb = BITMAP_ALLOC (NULL);
 
@@ -1018,24 +1019,20 @@  verify_ssa (bool check_modified_stmt, bool check_ssa_operands)
   timevar_push (TV_TREE_SSA_VERIFY);
 
   /* Keep track of SSA names present in the IL.  */
-  for (i = 1; i < num_ssa_names; i++)
+  FOR_EACH_SSA_NAME (i, name)
     {
-      tree name = ssa_name (i);
-      if (name)
-	{
-	  gimple *stmt;
-	  TREE_VISITED (name) = 0;
+      gimple *stmt;
+      TREE_VISITED (name) = 0;
 
-	  verify_ssa_name (name, virtual_operand_p (name));
+      verify_ssa_name (name, virtual_operand_p (name));
 
-	  stmt = SSA_NAME_DEF_STMT (name);
-	  if (!gimple_nop_p (stmt))
-	    {
-	      basic_block bb = gimple_bb (stmt);
-	      if (verify_def (bb, definition_block,
-			      name, stmt, virtual_operand_p (name)))
-		goto err;
-	    }
+      stmt = SSA_NAME_DEF_STMT (name);
+      if (!gimple_nop_p (stmt))
+	{
+	  basic_block bb = gimple_bb (stmt);
+	  if (verify_def (bb, definition_block,
+			  name, stmt, virtual_operand_p (name)))
+	    goto err;
 	}
     }
 
diff --git a/gcc/tree-ssanames.h b/gcc/tree-ssanames.h
index 8e66ce6..1d53774 100644
--- a/gcc/tree-ssanames.h
+++ b/gcc/tree-ssanames.h
@@ -62,6 +62,10 @@  struct GTY ((variable_size)) range_info_def {
 #define num_ssa_names (vec_safe_length (cfun->gimple_df->ssa_names))
 #define ssa_name(i) ((*cfun->gimple_df->ssa_names)[(i)])
 
+#define FOR_EACH_SSA_NAME(I, VAR) \
+  for (I = 1; SSANAMES (cfun)->iterate (I, &VAR); ++I)	\
+    if (VAR)
+
 /* Sets the value range to SSA.  */
 extern void set_range_info (tree, enum value_range_type, const wide_int_ref &,
 			    const wide_int_ref &);