From 00f96dc9a9a505ef2d439a808e66226fb8b93baf Mon Sep 17 00:00:00 2001
From: Trevor Saunders <tsaunders@mozilla.com>
Date: Fri, 20 Dec 2013 20:34:33 +0000
Subject: [PATCH] merge auto_vec and stack_vec

From-SVN: r206155
---
 gcc/ChangeLog                  | 14 ++++++++++++
 gcc/ada/ChangeLog              |  5 +++++
 gcc/ada/gcc-interface/decl.c   |  2 +-
 gcc/config/i386/i386.c         |  2 +-
 gcc/cp/ChangeLog               |  5 +++++
 gcc/cp/semantics.c             |  2 +-
 gcc/df-scan.c                  |  8 +++----
 gcc/function.c                 |  2 +-
 gcc/genautomata.c              |  6 ++---
 gcc/gimplify.c                 |  2 +-
 gcc/graphite-clast-to-gimple.c |  2 +-
 gcc/graphite-dependences.c     |  2 +-
 gcc/graphite-scop-detection.c  | 12 +++++-----
 gcc/graphite-sese-to-poly.c    | 16 ++++++-------
 gcc/hw-doloop.c                |  2 +-
 gcc/trans-mem.c                |  2 +-
 gcc/tree-call-cdce.c           |  2 +-
 gcc/tree-data-ref.c            |  4 ++--
 gcc/tree-dfa.c                 |  2 +-
 gcc/tree-if-conv.c             |  2 +-
 gcc/tree-inline.c              |  2 +-
 gcc/tree-loop-distribution.c   |  8 +++----
 gcc/tree-parloops.c            |  6 ++---
 gcc/tree-predcom.c             |  2 +-
 gcc/tree-ssa-alias.c           |  4 ++--
 gcc/tree-ssa-loop-ivcanon.c    |  2 +-
 gcc/tree-ssa-phiopt.c          |  2 +-
 gcc/tree-ssa-threadedge.c      |  2 +-
 gcc/tree-ssa-uncprop.c         |  2 +-
 gcc/tree-vect-loop.c           |  2 +-
 gcc/tree-vect-patterns.c       |  2 +-
 gcc/tree-vect-slp.c            |  2 +-
 gcc/tree-vect-stmts.c          |  6 ++---
 gcc/var-tracking.c             |  6 ++---
 gcc/vec.h                      | 41 ++++++++++++++++++----------------
 35 files changed, 105 insertions(+), 78 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c7a8c254fb85..c6f01720c61a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,17 @@
+2013-12-20  Trevor saunders  <tsaunders@mozilla.com>
+
+	* vec.h (stack_vec): Convert to a templaate specialization of
+	auto_vec.
+	* config/i386/i386.c, df-scan.c, function.c, genautomata.c,
+	gimplify.c, graphite-clast-to-gimple.c, graphite-dependences.c,
+	graphite-scop-detection.c, graphite-sese-to-poly.c, hw-doloop.c,
+	trans-mem.c, tree-call-cdce.c, tree-data-ref.c, tree-dfa.c,
+	tree-if-conv.c, tree-inline.c, tree-loop-distribution.c,
+	tree-parloops.c, tree-predcom.c, tree-ssa-alias.c,
+	tree-ssa-loop-ivcanon.c, tree-ssa-phiopt.c, tree-ssa-threadedge.c,
+	tree-ssa-uncprop.c, tree-vect-loop.c, tree-vect-patterns.c,
+	tree-vect-slp.c, tree-vect-stmts.c, var-tracking.c: Adjust.
+
 2013-12-20  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* config/arm/arm.c (arm_expand_prologue): In a nested APCS frame with
diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index 47279366d82f..8c5ee48dbf7a 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,8 @@
+2013-12-20  Trevor saunders  <tsaunders@mozilla.com>
+
+	* gcc-interface/decl.c (components_to_record): Replace stack_vec with
+	auto_vec.
+
 2013-12-12  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gcc-interface/Makefile.in (ARM linux, GNU eabi): Tweak regexp.
diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c
index a80d1a9c0afa..ad129c6803c1 100644
--- a/gcc/ada/gcc-interface/decl.c
+++ b/gcc/ada/gcc-interface/decl.c
@@ -7010,7 +7010,7 @@ components_to_record (tree gnu_record_type, Node_Id gnat_component_list,
       tree gnu_union_type, gnu_union_name;
       tree this_first_free_pos, gnu_variant_list = NULL_TREE;
       bool union_field_needs_strict_alignment = false;
-      stack_vec <vinfo_t, 16> variant_types;
+      auto_vec <vinfo_t, 16> variant_types;
       vinfo_t *gnu_variant;
       unsigned int variants_align = 0;
       unsigned int i;
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 1710e8c8e38b..0034d3338df2 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -30821,7 +30821,7 @@ ix86_generate_version_dispatcher_body (void *node_p)
 
   push_cfun (DECL_STRUCT_FUNCTION (resolver_decl));
 
-  stack_vec<tree, 2> fn_ver_vec;
+  auto_vec<tree, 2> fn_ver_vec;
 
   for (versn_info = node_version_info->next; versn_info;
        versn_info = versn_info->next)
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 96bc0d9e8855..98022633e0f3 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2013-12-20  Trevor saunders  <tsaunders@mozilla.com>
+
+	* semantics.c (build_anon_member_initialization): Replace
+	stack_vec<T, N> with auto_vec<T, N>.
+
 2013-12-18  Balaji V. Iyer  <balaji.v.iyer@intel.com>
 
 	* parser.c (cp_parser_cilk_simd_clause_name): Changed cilk_clause_name
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 63f50fb47052..c08d53f48985 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -7439,7 +7439,7 @@ build_anon_member_initialization (tree member, tree init,
      to build up the initializer from the outside in so that we can reuse
      previously built CONSTRUCTORs if this is, say, the second field in an
      anonymous struct.  So we use a vec as a stack.  */
-  stack_vec<tree, 2> fields;
+  auto_vec<tree, 2> fields;
   do
     {
       fields.safe_push (TREE_OPERAND (member, 1));
diff --git a/gcc/df-scan.c b/gcc/df-scan.c
index a35b12fbebba..a7272ce88c58 100644
--- a/gcc/df-scan.c
+++ b/gcc/df-scan.c
@@ -86,10 +86,10 @@ static HARD_REG_SET elim_reg_set;
 
 struct df_collection_rec
 {
-  stack_vec<df_ref, 128> def_vec;
-  stack_vec<df_ref, 32> use_vec;
-  stack_vec<df_ref, 32> eq_use_vec;
-  stack_vec<df_mw_hardreg_ptr, 32> mw_vec;
+  auto_vec<df_ref, 128> def_vec;
+  auto_vec<df_ref, 32> use_vec;
+  auto_vec<df_ref, 32> eq_use_vec;
+  auto_vec<df_mw_hardreg_ptr, 32> mw_vec;
 };
 
 static df_ref df_null_ref_rec[1];
diff --git a/gcc/function.c b/gcc/function.c
index e2d0e233e809..13e98773eb63 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -4114,7 +4114,7 @@ reorder_blocks (void)
   if (block == NULL_TREE)
     return;
 
-  stack_vec<tree, 10> block_stack;
+  auto_vec<tree, 10> block_stack;
 
   /* Reset the TREE_ASM_WRITTEN bit for all blocks.  */
   clear_block_marks (block);
diff --git a/gcc/genautomata.c b/gcc/genautomata.c
index 372ba90efc8d..a66a21920a36 100644
--- a/gcc/genautomata.c
+++ b/gcc/genautomata.c
@@ -3349,7 +3349,7 @@ uniq_sort_alt_states (alt_state_t alt_states_list)
   if (alt_states_list->next_alt_state == 0)
     return alt_states_list;
 
-  stack_vec<alt_state_t, 150> alt_states;
+  auto_vec<alt_state_t, 150> alt_states;
   for (curr_alt_state = alt_states_list;
        curr_alt_state != NULL;
        curr_alt_state = curr_alt_state->next_alt_state)
@@ -5484,7 +5484,7 @@ form_ainsn_with_same_reservs (automaton_t automaton)
 {
   ainsn_t curr_ainsn;
   size_t i;
-  stack_vec<ainsn_t, 150> last_insns;
+  auto_vec<ainsn_t, 150> last_insns;
 
   for (curr_ainsn = automaton->ainsn_list;
        curr_ainsn != NULL;
@@ -5555,7 +5555,7 @@ make_automaton (automaton_t automaton)
   state_t state;
   state_t start_state;
   state_t state2;
-  stack_vec<state_t, 150> state_stack;
+  auto_vec<state_t, 150> state_stack;
   int states_n;
   reserv_sets_t reservs_matter = form_reservs_matter (automaton);
 
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 1ca847ac7597..1ca4ad1bb33c 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -1846,7 +1846,7 @@ gimplify_compound_lval (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
 
   /* Create a stack of the subexpressions so later we can walk them in
      order from inner to outer.  */
-  stack_vec<tree, 10> expr_stack;
+  auto_vec<tree, 10> expr_stack;
 
   /* We can handle anything that get_inner_reference can deal with.  */
   for (p = expr_p; ; p = &TREE_OPERAND (*p, 0))
diff --git a/gcc/graphite-clast-to-gimple.c b/gcc/graphite-clast-to-gimple.c
index 038c4f2abb2f..2b9e743e7300 100644
--- a/gcc/graphite-clast-to-gimple.c
+++ b/gcc/graphite-clast-to-gimple.c
@@ -1659,7 +1659,7 @@ debug_generated_program (scop_p scop)
 bool
 gloog (scop_p scop, bb_pbb_htab_type bb_pbb_mapping)
 {
-  stack_vec<tree, 10> newivs;
+  auto_vec<tree, 10> newivs;
   loop_p context_loop;
   sese region = SCOP_REGION (scop);
   ifsese if_region = NULL;
diff --git a/gcc/graphite-dependences.c b/gcc/graphite-dependences.c
index c0d769c7dd64..f16cb938b3dd 100644
--- a/gcc/graphite-dependences.c
+++ b/gcc/graphite-dependences.c
@@ -593,7 +593,7 @@ loop_is_parallel_p (loop_p loop, bb_pbb_htab_type bb_pbb_mapping, int depth)
   scop_p scop;
 
   timevar_push (TV_GRAPHITE_DATA_DEPS);
-  stack_vec<poly_bb_p, 3> body;
+  auto_vec<poly_bb_p, 3> body;
   scop = get_loop_body_pbbs (loop, bb_pbb_mapping, &body);
   dependences = loop_level_carries_dependences (scop, body, depth);
   timevar_pop (TV_GRAPHITE_DATA_DEPS);
diff --git a/gcc/graphite-scop-detection.c b/gcc/graphite-scop-detection.c
index fea15e55abe9..0722ab8bbbff 100644
--- a/gcc/graphite-scop-detection.c
+++ b/gcc/graphite-scop-detection.c
@@ -481,7 +481,7 @@ scopdet_basic_block_info (basic_block bb, loop_p outermost_loop,
 
     case GBB_LOOP_SING_EXIT_HEADER:
       {
-	stack_vec<sd_region, 3> regions;
+	auto_vec<sd_region, 3> regions;
 	struct scopdet_info sinfo;
 	edge exit_e = single_exit (loop);
 
@@ -546,7 +546,7 @@ scopdet_basic_block_info (basic_block bb, loop_p outermost_loop,
       {
         /* XXX: For now we just do not join loops with multiple exits.  If the
            exits lead to the same bb it may be possible to join the loop.  */
-        stack_vec<sd_region, 3> regions;
+        auto_vec<sd_region, 3> regions;
         vec<edge> exits = get_loop_exit_edges (loop);
         edge e;
         int i;
@@ -589,7 +589,7 @@ scopdet_basic_block_info (basic_block bb, loop_p outermost_loop,
       }
     case GBB_COND_HEADER:
       {
-	stack_vec<sd_region, 3> regions;
+	auto_vec<sd_region, 3> regions;
 	struct scopdet_info sinfo;
 	vec<basic_block> dominated;
 	int i;
@@ -1192,7 +1192,7 @@ print_graphite_statistics (FILE* file, vec<scop_p> scops)
 static void
 limit_scops (vec<scop_p> *scops)
 {
-  stack_vec<sd_region, 3> regions;
+  auto_vec<sd_region, 3> regions;
 
   int i;
   scop_p scop;
@@ -1404,7 +1404,7 @@ void
 build_scops (vec<scop_p> *scops)
 {
   struct loop *loop = current_loops->tree_root;
-  stack_vec<sd_region, 3> regions;
+  auto_vec<sd_region, 3> regions;
 
   canonicalize_loop_closed_ssa_form ();
   build_scops_1 (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
@@ -1595,7 +1595,7 @@ dot_all_scops (vec<scop_p> scops)
 DEBUG_FUNCTION void
 dot_scop (scop_p scop)
 {
-  stack_vec<scop_p, 1> scops;
+  auto_vec<scop_p, 1> scops;
 
   if (scop)
     scops.safe_push (scop);
diff --git a/gcc/graphite-sese-to-poly.c b/gcc/graphite-sese-to-poly.c
index 66c1b6ef95e3..1f54eb9816f8 100644
--- a/gcc/graphite-sese-to-poly.c
+++ b/gcc/graphite-sese-to-poly.c
@@ -1245,7 +1245,7 @@ public:
   virtual void after_dom_children (basic_block);
 
 private:
-  stack_vec<gimple, 3> m_conditions, m_cases;
+  auto_vec<gimple, 3> m_conditions, m_cases;
   sese m_region;
 };
 
@@ -1890,7 +1890,7 @@ build_scop_drs (scop_p scop)
   int i, j;
   poly_bb_p pbb;
   data_reference_p dr;
-  stack_vec<data_reference_p, 3> drs;
+  auto_vec<data_reference_p, 3> drs;
 
   /* Remove all the PBBs that do not have data references: these basic
      blocks are not handled in the polyhedral representation.  */
@@ -1988,7 +1988,7 @@ insert_stmts (scop_p scop, gimple stmt, gimple_seq stmts,
 	      gimple_stmt_iterator insert_gsi)
 {
   gimple_stmt_iterator gsi;
-  stack_vec<gimple, 3> x;
+  auto_vec<gimple, 3> x;
 
   gimple_seq_add_stmt (&stmts, stmt);
   for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi))
@@ -2007,7 +2007,7 @@ insert_out_of_ssa_copy (scop_p scop, tree res, tree expr, gimple after_stmt)
   gimple_stmt_iterator gsi;
   tree var = force_gimple_operand (expr, &stmts, true, NULL_TREE);
   gimple stmt = gimple_build_assign (unshare_expr (res), var);
-  stack_vec<gimple, 3> x;
+  auto_vec<gimple, 3> x;
 
   gimple_seq_add_stmt (&stmts, stmt);
   for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi))
@@ -2062,7 +2062,7 @@ insert_out_of_ssa_copy_on_edge (scop_p scop, edge e, tree res, tree expr)
   tree var = force_gimple_operand (expr, &stmts, true, NULL_TREE);
   gimple stmt = gimple_build_assign (unshare_expr (res), var);
   basic_block bb;
-  stack_vec<gimple, 3> x;
+  auto_vec<gimple, 3> x;
 
   gimple_seq_add_stmt (&stmts, stmt);
   for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi))
@@ -2870,7 +2870,7 @@ remove_phi (gimple phi)
   tree def;
   use_operand_p use_p;
   gimple_stmt_iterator gsi;
-  stack_vec<gimple, 3> update;
+  auto_vec<gimple, 3> update;
   unsigned int i;
   gimple stmt;
 
@@ -3028,8 +3028,8 @@ rewrite_commutative_reductions_out_of_ssa_close_phi (scop_p scop,
 						     gimple close_phi)
 {
   bool res;
-  stack_vec<gimple, 10> in;
-  stack_vec<gimple, 10> out;
+  auto_vec<gimple, 10> in;
+  auto_vec<gimple, 10> out;
 
   detect_commutative_reduction (scop, close_phi, &in, &out);
   res = in.length () > 1;
diff --git a/gcc/hw-doloop.c b/gcc/hw-doloop.c
index b6184a26d87f..4e67760cb8b5 100644
--- a/gcc/hw-doloop.c
+++ b/gcc/hw-doloop.c
@@ -252,7 +252,7 @@ discover_loop (hwloop_info loop, basic_block tail_bb, rtx tail_insn, rtx reg)
   loop->head = BRANCH_EDGE (tail_bb)->dest;
   loop->successor = FALLTHRU_EDGE (tail_bb)->dest;
 
-  stack_vec<basic_block, 20> works;
+  auto_vec<basic_block, 20> works;
   works.safe_push (loop->head);
 
   found_tail = false;
diff --git a/gcc/trans-mem.c b/gcc/trans-mem.c
index ba344887d91e..941035bc0ba1 100644
--- a/gcc/trans-mem.c
+++ b/gcc/trans-mem.c
@@ -4532,7 +4532,7 @@ ipa_tm_scan_irr_function (struct cgraph_node *node, bool for_clone)
   calculate_dominance_info (CDI_DOMINATORS);
 
   d = get_cg_data (&node, true);
-  stack_vec<basic_block, 10> queue;
+  auto_vec<basic_block, 10> queue;
   new_irr = BITMAP_ALLOC (&tm_obstack);
 
   /* Scan each tm region, propagating irrevocable status through the tree.  */
diff --git a/gcc/tree-call-cdce.c b/gcc/tree-call-cdce.c
index 32d0d5a93a1b..5e59cad9958f 100644
--- a/gcc/tree-call-cdce.c
+++ b/gcc/tree-call-cdce.c
@@ -727,7 +727,7 @@ shrink_wrap_one_built_in_call (gimple bi_call)
   tree bi_call_label_decl;
   gimple bi_call_label;
 
-  stack_vec<gimple, 12> conds;
+  auto_vec<gimple, 12> conds;
   gen_shrink_wrap_conditions (bi_call, conds, &nconds);
 
   /* This can happen if the condition generator decides
diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
index 94c7917344a5..03060201649d 100644
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -4453,7 +4453,7 @@ find_data_references_in_stmt (struct loop *nest, gimple stmt,
 			      vec<data_reference_p> *datarefs)
 {
   unsigned i;
-  stack_vec<data_ref_loc, 2> references;
+  auto_vec<data_ref_loc, 2> references;
   data_ref_loc *ref;
   bool ret = true;
   data_reference_p dr;
@@ -4483,7 +4483,7 @@ graphite_find_data_references_in_stmt (loop_p nest, loop_p loop, gimple stmt,
 				       vec<data_reference_p> *datarefs)
 {
   unsigned i;
-  stack_vec<data_ref_loc, 2> references;
+  auto_vec<data_ref_loc, 2> references;
   data_ref_loc *ref;
   bool ret = true;
   data_reference_p dr;
diff --git a/gcc/tree-dfa.c b/gcc/tree-dfa.c
index 302822c1f207..e014a719e5ab 100644
--- a/gcc/tree-dfa.c
+++ b/gcc/tree-dfa.c
@@ -737,7 +737,7 @@ dump_enumerated_decls (FILE *file, int flags)
 {
   basic_block bb;
   struct walk_stmt_info wi;
-  stack_vec<numbered_tree, 40> decl_list;
+  auto_vec<numbered_tree, 40> decl_list;
 
   memset (&wi, '\0', sizeof (wi));
   wi.info = (void *) &decl_list;
diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c
index 59404ec14e2f..283f476be220 100644
--- a/gcc/tree-if-conv.c
+++ b/gcc/tree-if-conv.c
@@ -1314,7 +1314,7 @@ if_convertible_loop_p (struct loop *loop, bool *any_mask_load_store)
 
   refs.create (5);
   ddrs.create (25);
-  stack_vec<loop_p, 3> loop_nest;
+  auto_vec<loop_p, 3> loop_nest;
   res = if_convertible_loop_p_1 (loop, &loop_nest, &refs, &ddrs,
 				 any_mask_load_store);
 
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 96a480593d46..4f14e5e10b09 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -5240,7 +5240,7 @@ tree_function_versioning (tree old_decl, tree new_decl,
   unsigned i;
   struct ipa_replace_map *replace_info;
   basic_block old_entry_block, bb;
-  stack_vec<gimple, 10> init_stmts;
+  auto_vec<gimple, 10> init_stmts;
   tree vars = NULL_TREE;
 
   gcc_assert (TREE_CODE (old_decl) == FUNCTION_DECL
diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c
index c16e51fb7c7f..c536162b5f9a 100644
--- a/gcc/tree-loop-distribution.c
+++ b/gcc/tree-loop-distribution.c
@@ -448,7 +448,7 @@ build_rdg (vec<loop_p> loop_nest, control_dependences *cd)
   vec<data_reference_p> datarefs;
 
   /* Create the RDG vertices from the stmts of the loop nest.  */
-  stack_vec<gimple, 10> stmts;
+  auto_vec<gimple, 10> stmts;
   stmts_from_loop (loop_nest[0], &stmts);
   rdg = new_graph (stmts.length ());
   datarefs.create (10);
@@ -964,7 +964,7 @@ static partition_t
 build_rdg_partition_for_vertex (struct graph *rdg, int v)
 {
   partition_t partition = partition_alloc (NULL, NULL);
-  stack_vec<int, 3> nodes;
+  auto_vec<int, 3> nodes;
   unsigned i;
   int x;
 
@@ -1418,7 +1418,7 @@ distribute_loop (struct loop *loop, vec<gimple> stmts,
   int num_sccs = 1;
 
   *nb_calls = 0;
-  stack_vec<loop_p, 3> loop_nest;
+  auto_vec<loop_p, 3> loop_nest;
   if (!find_loop_nest (loop, &loop_nest))
     return 0;
 
@@ -1436,7 +1436,7 @@ distribute_loop (struct loop *loop, vec<gimple> stmts,
   if (dump_file && (dump_flags & TDF_DETAILS))
     dump_rdg (dump_file, rdg);
 
-  stack_vec<partition_t, 3> partitions;
+  auto_vec<partition_t, 3> partitions;
   rdg_build_partitions (rdg, stmts, &partitions);
 
   any_builtin = false;
diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c
index a56145dbebe4..368a05e44411 100644
--- a/gcc/tree-parloops.c
+++ b/gcc/tree-parloops.c
@@ -424,7 +424,7 @@ loop_parallel_p (struct loop *loop, struct obstack * parloop_obstack)
 
   /* Check for problems with dependences.  If the loop can be reversed,
      the iterations are independent.  */
-  stack_vec<loop_p, 3> loop_nest;
+  auto_vec<loop_p, 3> loop_nest;
   datarefs.create (10);
   dependence_relations.create (100);
   if (! compute_data_dependences_for_loop (loop, true, &loop_nest, &datarefs,
@@ -752,7 +752,7 @@ static void
 eliminate_local_variables (edge entry, edge exit)
 {
   basic_block bb;
-  stack_vec<basic_block, 3> body;
+  auto_vec<basic_block, 3> body;
   unsigned i;
   gimple_stmt_iterator gsi;
   bool has_debug_stmt = false;
@@ -1303,7 +1303,7 @@ separate_decls_in_region (edge entry, edge exit,
   tree type, type_name, nvar;
   gimple_stmt_iterator gsi;
   struct clsn_data clsn_data;
-  stack_vec<basic_block, 3> body;
+  auto_vec<basic_block, 3> body;
   basic_block bb;
   basic_block entry_bb = bb1;
   basic_block exit_bb = exit->dest;
diff --git a/gcc/tree-predcom.c b/gcc/tree-predcom.c
index ea31302101fb..4814281fd334 100644
--- a/gcc/tree-predcom.c
+++ b/gcc/tree-predcom.c
@@ -2398,7 +2398,7 @@ tree_predictive_commoning_loop (struct loop *loop)
 
   /* Find the data references and split them into components according to their
      dependence relations.  */
-  stack_vec<loop_p, 3> loop_nest;
+  auto_vec<loop_p, 3> loop_nest;
   dependences.create (10);
   datarefs.create (10);
   if (! compute_data_dependences_for_loop (loop, true, &loop_nest, &datarefs,
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index e412d72a2c2a..0fb4c447ab01 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -768,8 +768,8 @@ aliasing_component_refs_p (tree ref1,
 static bool
 nonoverlapping_component_refs_of_decl_p (tree ref1, tree ref2)
 {
-  stack_vec<tree, 16> component_refs1;
-  stack_vec<tree, 16> component_refs2;
+  auto_vec<tree, 16> component_refs1;
+  auto_vec<tree, 16> component_refs2;
 
   /* Create the stack of handled components for REF1.  */
   while (handled_component_p (ref1))
diff --git a/gcc/tree-ssa-loop-ivcanon.c b/gcc/tree-ssa-loop-ivcanon.c
index fd4ac70821cc..2533971864af 100644
--- a/gcc/tree-ssa-loop-ivcanon.c
+++ b/gcc/tree-ssa-loop-ivcanon.c
@@ -1171,7 +1171,7 @@ tree_unroll_loops_completely_1 (bool may_increase_size, bool unroll_outer,
 unsigned int
 tree_unroll_loops_completely (bool may_increase_size, bool unroll_outer)
 {
-  stack_vec<loop_p, 16> father_stack;
+  auto_vec<loop_p, 16> father_stack;
   bool changed;
   int iteration = 0;
   bool irred_invalidated = false;
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
index b6bb7e9d9067..390258f666be 100644
--- a/gcc/tree-ssa-phiopt.c
+++ b/gcc/tree-ssa-phiopt.c
@@ -1874,7 +1874,7 @@ cond_if_else_store_replacement (basic_block then_bb, basic_block else_bb,
     }
 
   /* Find pairs of stores with equal LHS.  */
-  stack_vec<gimple, 1> then_stores, else_stores;
+  auto_vec<gimple, 1> then_stores, else_stores;
   FOR_EACH_VEC_ELT (then_datarefs, i, then_dr)
     {
       if (DR_IS_READ (then_dr))
diff --git a/gcc/tree-ssa-threadedge.c b/gcc/tree-ssa-threadedge.c
index cb6accf08f4e..e2eb471cb489 100644
--- a/gcc/tree-ssa-threadedge.c
+++ b/gcc/tree-ssa-threadedge.c
@@ -690,7 +690,7 @@ propagate_threaded_block_debug_into (basic_block dest, basic_block src)
       i++;
     }
 
-  stack_vec<tree, alloc_count> fewvars;
+  auto_vec<tree, alloc_count> fewvars;
   pointer_set_t *vars = NULL;
 
   /* If we're already starting with 3/4 of alloc_count, go for a
diff --git a/gcc/tree-ssa-uncprop.c b/gcc/tree-ssa-uncprop.c
index 63a2e10472cb..6318ec1911db 100644
--- a/gcc/tree-ssa-uncprop.c
+++ b/gcc/tree-ssa-uncprop.c
@@ -380,7 +380,7 @@ private:
      leading to this block.  If no such edge equivalency exists, then we
      record NULL.  These equivalences are live until we leave the dominator
      subtree rooted at the block where we record the equivalency.  */
-  stack_vec<tree, 2> m_equiv_stack;
+  auto_vec<tree, 2> m_equiv_stack;
 };
 
 /* Main driver for un-cprop.  */
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index fc3774776480..d13b1df85f91 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -621,7 +621,7 @@ vect_analyze_scalar_cycles_1 (loop_vec_info loop_vinfo, struct loop *loop)
 {
   basic_block bb = loop->header;
   tree init, step;
-  stack_vec<gimple, 64> worklist;
+  auto_vec<gimple, 64> worklist;
   gimple_stmt_iterator gsi;
   bool double_reduc;
 
diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c
index 7823cc3932d4..d1f8123c7a53 100644
--- a/gcc/tree-vect-patterns.c
+++ b/gcc/tree-vect-patterns.c
@@ -3213,7 +3213,7 @@ vect_pattern_recog (loop_vec_info loop_vinfo, bb_vec_info bb_vinfo)
   gimple_stmt_iterator si;
   unsigned int i, j;
   vect_recog_func_ptr vect_recog_func;
-  stack_vec<gimple, 1> stmts_to_replace;
+  auto_vec<gimple, 1> stmts_to_replace;
   gimple stmt;
 
   if (dump_enabled_p ())
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index 2387c0d9dfc3..d1e179651657 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -2029,7 +2029,7 @@ vect_bb_vectorization_profitable_p (bb_vec_info bb_vinfo)
   /* Calculate scalar cost.  */
   FOR_EACH_VEC_ELT (slp_instances, i, instance)
     {
-      stack_vec<bool, 20> life;
+      auto_vec<bool, 20> life;
       life.safe_grow_cleared (SLP_INSTANCE_GROUP_SIZE (instance));
       scalar_cost += vect_bb_slp_scalar_cost (BB_VINFO_BB (bb_vinfo),
 					      SLP_INSTANCE_TREE (instance),
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 3056c2ede008..18cf5630ca2a 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -629,7 +629,7 @@ vect_mark_stmts_to_be_vectorized (loop_vec_info loop_vinfo)
     dump_printf_loc (MSG_NOTE, vect_location,
                      "=== vect_mark_stmts_to_be_vectorized ===\n");
 
-  stack_vec<gimple, 64> worklist;
+  auto_vec<gimple, 64> worklist;
 
   /* 1. Init worklist.  */
   for (i = 0; i < nbbs; i++)
@@ -6605,8 +6605,8 @@ vectorizable_condition (gimple stmt, gimple_stmt_iterator *gsi,
 	{
           if (slp_node)
             {
-              stack_vec<tree, 4> ops;
-	      stack_vec<vec<tree>, 4> vec_defs;
+              auto_vec<tree, 4> ops;
+	      auto_vec<vec<tree>, 4> vec_defs;
 
               ops.safe_push (TREE_OPERAND (cond_expr, 0));
               ops.safe_push (TREE_OPERAND (cond_expr, 1));
diff --git a/gcc/var-tracking.c b/gcc/var-tracking.c
index 8eb86bf4feb2..b0d7922ce823 100644
--- a/gcc/var-tracking.c
+++ b/gcc/var-tracking.c
@@ -7931,7 +7931,7 @@ struct expand_loc_callback_data
 
   /* Stack of values and debug_exprs under expansion, and their
      children.  */
-  stack_vec<rtx, 4> expanding;
+  auto_vec<rtx, 4> expanding;
 
   /* Stack of values and debug_exprs whose expansion hit recursion
      cycles.  They will have VALUE_RECURSED_INTO marked when added to
@@ -7939,7 +7939,7 @@ struct expand_loc_callback_data
      resolves to a valid location.  So, if the flag remains set at the
      end of the search, we know no valid location for this one can
      possibly exist.  */
-  stack_vec<rtx, 4> pending;
+  auto_vec<rtx, 4> pending;
 
   /* The maximum depth among the sub-expressions under expansion.
      Zero indicates no expansion so far.  */
@@ -8886,7 +8886,7 @@ process_changed_values (variable_table_type htab)
 {
   int i, n;
   rtx val;
-  stack_vec<rtx, 20> changed_values_stack;
+  auto_vec<rtx, 20> changed_values_stack;
 
   /* Move values from changed_variables to changed_values_stack.  */
   changed_variables
diff --git a/gcc/vec.h b/gcc/vec.h
index 03455851b0fd..afde351a7965 100644
--- a/gcc/vec.h
+++ b/gcc/vec.h
@@ -1184,25 +1184,17 @@ public:
 };
 
 
-/* auto_vec is a sub class of vec whose storage is released when it is
-  destroyed. */
-template<typename T>
+/* auto_vec is a subclass of vec that automatically manages creating and
+   releasing the internal vector. If N is non zero then it has N elements of
+   internal storage.  The default is no internal storage, and you probably only
+   want to ask for internal storage for vectors on the stack because if the
+   size of the vector is larger than the internal storage that space is wasted.
+   */
+template<typename T, size_t N = 0>
 class auto_vec : public vec<T, va_heap>
 {
 public:
-  auto_vec () { this->m_vec = NULL; }
-  auto_vec (size_t n) { this->create (n); }
-  ~auto_vec () { this->release (); }
-};
-
-/* stack_vec is a subclass of vec containing N elements of internal storage.
-  You probably only want to allocate this on the stack because if the array
-  ends up being larger or much smaller than N it will be wasting space. */
-template<typename T, size_t N>
-class stack_vec : public vec<T, va_heap>
-{
-public:
-  stack_vec ()
+  auto_vec ()
   {
     m_header.m_alloc = N;
     m_header.m_has_auto_buf = 1;
@@ -1210,7 +1202,7 @@ public:
     this->m_vec = reinterpret_cast<vec<T, va_heap, vl_embed> *> (&m_header);
   }
 
-  ~stack_vec ()
+  ~auto_vec ()
   {
     this->release ();
   }
@@ -1222,6 +1214,17 @@ private:
   T m_data[N];
 };
 
+/* auto_vec is a sub class of vec whose storage is released when it is
+  destroyed. */
+template<typename T>
+class auto_vec<T, 0> : public vec<T, va_heap>
+{
+public:
+  auto_vec () { this->m_vec = NULL; }
+  auto_vec (size_t n) { this->create (n); }
+  ~auto_vec () { this->release (); }
+};
+
 
 /* Allocate heap memory for pointer V and create the internal vector
    with space for NELEMS elements.  If NELEMS is 0, the internal
@@ -1421,7 +1424,7 @@ vec<T, va_heap, vl_ptr>::release (void)
 
   if (using_auto_storage ())
     {
-      static_cast<stack_vec<T, 1> *> (this)->m_header.m_num = 0;
+      static_cast<auto_vec<T, 1> *> (this)->m_header.m_num = 0;
       return;
     }
 
@@ -1654,7 +1657,7 @@ vec<T, va_heap, vl_ptr>::using_auto_storage () const
     return false;
 
   const vec_prefix *auto_header
-    = &static_cast<const stack_vec<T, 1> *> (this)->m_header;
+    = &static_cast<const auto_vec<T, 1> *> (this)->m_header;
   return reinterpret_cast<vec_prefix *> (m_vec) == auto_header;
 }
 
-- 
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