[3/3] Introduce gswitch and use it in various places

diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index 05d0f51..6daa929 100644
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -3161,7 +3161,7 @@  expand_gimple_stmt_1 (gimple *stmt)
     case GIMPLE_PREDICT:
       break;
     case GIMPLE_SWITCH:
-      expand_case (stmt);
+      expand_case (as_a <gswitch *> (stmt));
       break;
     case GIMPLE_ASM:
       expand_asm_stmt (stmt);
diff --git a/gcc/coretypes.h b/gcc/coretypes.h
index 9a1f172..5783b04 100644
--- a/gcc/coretypes.h
+++ b/gcc/coretypes.h
@@ -67,6 +67,11 @@  typedef const union tree_node *const_tree;
 class gimple;
 typedef gimple *gimple_seq;
 struct gimple_stmt_iterator;
+
+/* Forward declarations of gimple subclasses.
+   Keep this in the same order as the corresponding codes in gimple.def.  */
+class gswitch;
+
 union section;
 typedef union section section;
 struct gcc_options;
diff --git a/gcc/doc/gimple.texi b/gcc/doc/gimple.texi
index 54bad5d..088a498 100644
--- a/gcc/doc/gimple.texi
+++ b/gcc/doc/gimple.texi
@@ -311,12 +311,14 @@  kinds, along with their relationships to @code{GSS_} values (layouts) and
      |   |    (no GSS layout)
      |   |
      |   + gimple_with_ops
-     |   |        layout: GSS_WITH_OPS
-     |   |        Used for 5 codes: GIMPLE_COND
-     |   |                          GIMPLE_DEBUG
-     |   |                          GIMPLE_GOTO
-     |   |                          GIMPLE_LABEL
-     |   |                          GIMPLE_SWITCH
+     |   |   |    layout: GSS_WITH_OPS
+     |   |   |    Used for 4 codes: GIMPLE_COND
+     |   |   |                      GIMPLE_DEBUG
+     |   |   |                      GIMPLE_GOTO
+     |   |   |                      GIMPLE_LABEL
+     |   |   |
+     |   |   + gswitch
+     |   |            code: GIMPLE_SWITCH
      |   |
      |   + gimple_with_memory_ops_base
      |       |    layout: GSS_WITH_MEM_OPS_BASE
@@ -2252,7 +2254,7 @@  Set @code{RETVAL} to be the return value for @code{GIMPLE_RETURN} @code{G}.
 @subsection @code{GIMPLE_SWITCH}
 @cindex @code{GIMPLE_SWITCH}
 
-@deftypefn {GIMPLE function} gimple *gimple_build_switch (tree index, @
+@deftypefn {GIMPLE function} gswitch *gimple_build_switch (tree index, @
 tree default_label, @code{VEC}(tree,heap) *args)
 Build a @code{GIMPLE_SWITCH} statement.  @code{INDEX} is the index variable
 to switch on, and @code{DEFAULT_LABEL} represents the default label.
@@ -2260,44 +2262,46 @@  to switch on, and @code{DEFAULT_LABEL} represents the default label.
 non-default case labels.  Each label is a tree of code @code{CASE_LABEL_EXPR}.
 @end deftypefn
 
-@deftypefn {GIMPLE function} unsigned gimple_switch_num_labels (gimple *g)
+@deftypefn {GIMPLE function} unsigned gimple_switch_num_labels (@
+const gswitch *g)
 Return the number of labels associated with the switch statement
 @code{G}.
 @end deftypefn
 
 @deftypefn {GIMPLE function} void gimple_switch_set_num_labels (@
-gimple *g, unsigned nlabels)
+gswitch *g, unsigned nlabels)
 Set @code{NLABELS} to be the number of labels for the switch statement
 @code{G}.
 @end deftypefn
 
-@deftypefn {GIMPLE function} tree gimple_switch_index (gimple *g)
+@deftypefn {GIMPLE function} tree gimple_switch_index (const gswitch *g)
 Return the index variable used by the switch statement @code{G}.
 @end deftypefn
 
-@deftypefn {GIMPLE function} void gimple_switch_set_index (gimple *g, @
+@deftypefn {GIMPLE function} void gimple_switch_set_index (gswitch *g, @
 tree index)
 Set @code{INDEX} to be the index variable for switch statement @code{G}.
 @end deftypefn
 
-@deftypefn {GIMPLE function} tree gimple_switch_label (gimple *g, @
+@deftypefn {GIMPLE function} tree gimple_switch_label (const gswitch *g, @
 unsigned index)
 Return the label numbered @code{INDEX}. The default label is 0, followed
 by any labels in a switch statement.
 @end deftypefn
 
-@deftypefn {GIMPLE function} void gimple_switch_set_label (gimple *g, @
+@deftypefn {GIMPLE function} void gimple_switch_set_label (gswitch *g, @
 unsigned index, tree label)
 Set the label number @code{INDEX} to @code{LABEL}. 0 is always the default
 label.
 @end deftypefn
 
-@deftypefn {GIMPLE function} tree gimple_switch_default_label (gimple *g)
+@deftypefn {GIMPLE function} tree gimple_switch_default_label (@
+const gswitch *g)
 Return the default label for a switch statement.
 @end deftypefn
 
 @deftypefn {GIMPLE function} void gimple_switch_set_default_label (@
-gimple *g, tree label)
+gswitch *g, tree label)
 Set the default label for a switch statement.
 @end deftypefn
 
diff --git a/gcc/expr.h b/gcc/expr.h
index 43cd3c9..e3634c3 100644
--- a/gcc/expr.h
+++ b/gcc/expr.h
@@ -777,7 +777,7 @@  rtx get_personality_function (tree);
 /* In stmt.c */
 
 /* Expand a GIMPLE_SWITCH statement.  */
-extern void expand_case (gimple *);
+extern void expand_case (gswitch *);
 
 /* Like expand_case but special-case for SJLJ exception dispatching.  */
 extern void expand_sjlj_dispatch_table (rtx, vec<tree> );
diff --git a/gcc/gdbhooks.py b/gcc/gdbhooks.py
index a0d94bb..7838668 100644
--- a/gcc/gdbhooks.py
+++ b/gcc/gdbhooks.py
@@ -454,7 +454,9 @@  def build_pretty_printer():
                              'tree', TreePrinter)
     pp.add_printer_for_types(['cgraph_node *'],
                              'cgraph_node', CGraphNodePrinter)
-    pp.add_printer_for_types(['gimple *'],
+    pp.add_printer_for_types(['gimple *',
+                              # Keep this in the same order as gimple.def:
+                              'gswitch *'],
                              'gimple',
                              GimplePrinter)
     pp.add_printer_for_types(['basic_block', 'basic_block_def *'],
diff --git a/gcc/gimple-pretty-print.c b/gcc/gimple-pretty-print.c
index 205cccb..307b7d3 100644
--- a/gcc/gimple-pretty-print.c
+++ b/gcc/gimple-pretty-print.c
@@ -775,7 +775,7 @@  dump_gimple_call (pretty_printer *buffer, gimple *gs, int spc, int flags)
    pp_gimple_stmt_1.  */
 
 static void
-dump_gimple_switch (pretty_printer *buffer, gimple *gs, int spc, int flags)
+dump_gimple_switch (pretty_printer *buffer, gswitch *gs, int spc, int flags)
 {
   unsigned int i;
 
@@ -2120,7 +2120,7 @@  pp_gimple_stmt_1 (pretty_printer *buffer, gimple *gs, int spc, int flags)
       break;
 
     case GIMPLE_SWITCH:
-      dump_gimple_switch (buffer, gs, spc, flags);
+      dump_gimple_switch (buffer, as_a <gswitch *> (gs), spc, flags);
       break;
 
     case GIMPLE_TRY:
diff --git a/gcc/gimple.c b/gcc/gimple.c
index 281815c..25e0fb9 100644
--- a/gcc/gimple.c
+++ b/gcc/gimple.c
@@ -714,13 +714,14 @@  gimple_build_resx (int region)
    NLABELS is the number of labels in the switch excluding the default.
    DEFAULT_LABEL is the default label for the switch statement.  */
 
-gimple *
+gswitch *
 gimple_build_switch_nlabels (unsigned nlabels, tree index, tree default_label)
 {
   /* nlabels + 1 default label + 1 index.  */
   gcc_checking_assert (default_label);
-  gimple *p = gimple_build_with_ops (GIMPLE_SWITCH, ERROR_MARK,
-				    1 + 1 + nlabels);
+  gswitch *p =
+    as_a <gswitch *> (gimple_build_with_ops (GIMPLE_SWITCH, ERROR_MARK,
+					     1 + 1 + nlabels));
   gimple_switch_set_index (p, index);
   gimple_switch_set_default_label (p, default_label);
   return p;
@@ -732,12 +733,12 @@  gimple_build_switch_nlabels (unsigned nlabels, tree index, tree default_label)
    DEFAULT_LABEL is the default label
    ARGS is a vector of labels excluding the default.  */
 
-gimple *
+gswitch *
 gimple_build_switch (tree index, tree default_label, vec<tree> args)
 {
   unsigned i, nlabels = args.length ();
 
-  gimple *p = gimple_build_switch_nlabels (nlabels, index, default_label);
+  gswitch *p = gimple_build_switch_nlabels (nlabels, index, default_label);
 
   /* Copy the labels from the vector to the switch statement.  */
   for (i = 0; i < nlabels; i++)
diff --git a/gcc/gimple.h b/gcc/gimple.h
index 173f1b4..e1df705 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -764,6 +764,16 @@  enum gimple_statement_structure_enum {
 };
 #undef DEFGSSTRUCT
 
+/* A statement with the invariant that
+      stmt->code == GIMPLE_SWITCH
+   i.e. a switch statement.  */
+
+struct GTY((tag("GSS_WITH_OPS")))
+  gswitch : public gimple_with_ops
+{
+  /* no additional fields; this uses the layout for GSS_WITH_OPS. */
+};
+
 template <>
 template <>
 inline bool
@@ -951,6 +961,14 @@  is_a_helper <gphi *>::test (gimple *gs)
 template <>
 template <>
 inline bool
+is_a_helper <gswitch *>::test (gimple *gs)
+{
+  return gs->code == GIMPLE_SWITCH;
+}
+
+template <>
+template <>
+inline bool
 is_a_helper <gtransaction *>::test (gimple *gs)
 {
   return gs->code == GIMPLE_TRANSACTION;
@@ -1143,6 +1161,14 @@  is_a_helper <const gphi *>::test (const gimple *gs)
 template <>
 template <>
 inline bool
+is_a_helper <const gswitch *>::test (const gimple *gs)
+{
+  return gs->code == GIMPLE_SWITCH;
+}
+
+template <>
+template <>
+inline bool
 is_a_helper <const gtransaction *>::test (const gimple *gs)
 {
   return gs->code == GIMPLE_TRANSACTION;
@@ -1193,8 +1219,8 @@  gtry *gimple_build_try (gimple_seq, gimple_seq,
 			enum gimple_try_flags);
 gimple *gimple_build_wce (gimple_seq);
 gimple *gimple_build_resx (int);
-gimple *gimple_build_switch_nlabels (unsigned, tree, tree);
-gimple *gimple_build_switch (tree, tree, vec<tree> );
+gswitch *gimple_build_switch_nlabels (unsigned, tree, tree);
+gswitch *gimple_build_switch (tree, tree, vec<tree> );
 gimple *gimple_build_eh_dispatch (int);
 gimple *gimple_build_debug_bind_stat (tree, tree, gimple *MEM_STAT_DECL);
 #define gimple_build_debug_bind(var,val,stmt)			\
@@ -3908,7 +3934,7 @@  gimple_eh_dispatch_set_region (gimple *gs, int region)
 /* Return the number of labels associated with the switch statement GS.  */
 
 static inline unsigned
-gimple_switch_num_labels (const gimple *gs)
+gimple_switch_num_labels (const gswitch *gs)
 {
   unsigned num_ops;
   GIMPLE_CHECK (gs, GIMPLE_SWITCH);
@@ -3921,7 +3947,7 @@  gimple_switch_num_labels (const gimple *gs)
 /* Set NLABELS to be the number of labels for the switch statement GS.  */
 
 static inline void
-gimple_switch_set_num_labels (gimple *g, unsigned nlabels)
+gimple_switch_set_num_labels (gswitch *g, unsigned nlabels)
 {
   GIMPLE_CHECK (g, GIMPLE_SWITCH);
   gimple_set_num_ops (g, nlabels + 1);
@@ -3951,7 +3977,7 @@  gimple_switch_index_ptr (const gimple *gs)
 /* Set INDEX to be the index variable for switch statement GS.  */
 
 static inline void
-gimple_switch_set_index (gimple *gs, tree index)
+gimple_switch_set_index (gswitch *gs, tree index)
 {
   GIMPLE_CHECK (gs, GIMPLE_SWITCH);
   gcc_gimple_checking_assert (SSA_VAR_P (index) || CONSTANT_CLASS_P (index));
@@ -3963,7 +3989,7 @@  gimple_switch_set_index (gimple *gs, tree index)
    labels in a switch statement.  */
 
 static inline tree
-gimple_switch_label (const gimple *gs, unsigned index)
+gimple_switch_label (const gswitch *gs, unsigned index)
 {
   GIMPLE_CHECK (gs, GIMPLE_SWITCH);
   gcc_gimple_checking_assert (gimple_num_ops (gs) > index + 1);
@@ -3973,7 +3999,7 @@  gimple_switch_label (const gimple *gs, unsigned index)
 /* Set the label number INDEX to LABEL.  0 is always the default label.  */
 
 static inline void
-gimple_switch_set_label (gimple *gs, unsigned index, tree label)
+gimple_switch_set_label (gswitch *gs, unsigned index, tree label)
 {
   GIMPLE_CHECK (gs, GIMPLE_SWITCH);
   gcc_gimple_checking_assert (gimple_num_ops (gs) > index + 1
@@ -3985,7 +4011,7 @@  gimple_switch_set_label (gimple *gs, unsigned index, tree label)
 /* Return the default label for a switch statement.  */
 
 static inline tree
-gimple_switch_default_label (const gimple *gs)
+gimple_switch_default_label (const gswitch *gs)
 {
   tree label = gimple_switch_label (gs, 0);
   gcc_checking_assert (!CASE_LOW (label) && !CASE_HIGH (label));
@@ -3995,7 +4021,7 @@  gimple_switch_default_label (const gimple *gs)
 /* Set the default label for a switch statement.  */
 
 static inline void
-gimple_switch_set_default_label (gimple *gs, tree label)
+gimple_switch_set_default_label (gswitch *gs, tree label)
 {
   gcc_checking_assert (!CASE_LOW (label) && !CASE_HIGH (label));
   gimple_switch_set_label (gs, 0, label);
diff --git a/gcc/ipa-inline-analysis.c b/gcc/ipa-inline-analysis.c
index db9fbf7..f54514a 100644
--- a/gcc/ipa-inline-analysis.c
+++ b/gcc/ipa-inline-analysis.c
@@ -1801,7 +1801,7 @@  set_switch_stmt_execution_predicate (struct ipa_node_params *info,
 				     struct inline_summary *summary,
 				     basic_block bb)
 {
-  gimple *last;
+  gimple *lastg;
   tree op;
   int index;
   struct agg_position_info aggpos;
@@ -1810,9 +1810,10 @@  set_switch_stmt_execution_predicate (struct ipa_node_params *info,
   size_t n;
   size_t case_idx;
 
-  last = last_stmt (bb);
-  if (!last || gimple_code (last) != GIMPLE_SWITCH)
+  lastg = last_stmt (bb);
+  if (!lastg || gimple_code (lastg) != GIMPLE_SWITCH)
     return;
+  gswitch *last = as_a <gswitch *> (lastg);
   op = gimple_switch_index (last);
   if (!unmodified_parm_or_parm_agg_item (info, last, op, &index, &aggpos))
     return;
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 004aa6d..4ae911a 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -10478,10 +10478,11 @@  diagnose_sb_2 (gimple_stmt_iterator *gsi_p, bool *handled_ops_p,
 
     case GIMPLE_SWITCH:
       {
+	gswitch *switch_stmt = as_a <gswitch *> (stmt);
 	unsigned int i;
-	for (i = 0; i < gimple_switch_num_labels (stmt); ++i)
+	for (i = 0; i < gimple_switch_num_labels (switch_stmt); ++i)
 	  {
-	    tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
+	    tree lab = CASE_LABEL (gimple_switch_label (switch_stmt, i));
 	    n = splay_tree_lookup (all_labels, (splay_tree_key) lab);
 	    if (n && diagnose_sb_0 (gsi_p, context, (gimple *) n->value))
 	      break;
diff --git a/gcc/stmt.c b/gcc/stmt.c
index 23da44a..fd1db8a 100644
--- a/gcc/stmt.c
+++ b/gcc/stmt.c
@@ -1130,7 +1130,7 @@  reset_out_edges_aux (basic_block bb)
    STMT. Record this information in the aux field of the edge.  */
 
 static inline void
-compute_cases_per_edge (gimple *stmt)
+compute_cases_per_edge (gswitch *stmt)
 {
   basic_block bb = gimple_bb (stmt);
   reset_out_edges_aux (bb);
@@ -1152,7 +1152,7 @@  compute_cases_per_edge (gimple *stmt)
    Generate the code to test it and jump to the right place.  */
 
 void
-expand_case (gimple *stmt)
+expand_case (gswitch *stmt)
 {
   tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
   rtx default_label = NULL_RTX;
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 1e219d6..95c96ef 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -152,7 +152,7 @@  static void make_blocks (gimple_seq);
 static void make_edges (void);
 static void assign_discriminators (void);
 static void make_cond_expr_edges (basic_block);
-static void make_gimple_switch_edges (basic_block);
+static void make_gimple_switch_edges (gswitch *, basic_block);
 static bool make_goto_expr_edges (basic_block);
 static void make_gimple_asm_edges (basic_block);
 static edge gimple_redirect_edge_and_branch (edge, basic_block);
@@ -171,8 +171,8 @@  static bool gimple_can_merge_blocks_p (basic_block, basic_block);
 static void remove_bb (basic_block);
 static edge find_taken_edge_computed_goto (basic_block, tree);
 static edge find_taken_edge_cond_expr (basic_block, tree);
-static edge find_taken_edge_switch_expr (basic_block, tree);
-static tree find_case_label_for_value (gimple *, tree);
+static edge find_taken_edge_switch_expr (gswitch *, basic_block, tree);
+static tree find_case_label_for_value (gswitch *, tree);
 
 void
 init_empty_tree_cfg_for_function (struct function *fn)
@@ -771,7 +771,7 @@  make_edges (void)
 	      fallthru = false;
 	      break;
 	    case GIMPLE_SWITCH:
-	      make_gimple_switch_edges (bb);
+	      make_gimple_switch_edges (as_a <gswitch *> (last), bb);
 	      fallthru = false;
 	      break;
 	    case GIMPLE_RESX:
@@ -1096,7 +1096,7 @@  end_recording_case_labels (void)
 	{
 	  gimple *stmt = last_stmt (bb);
 	  if (stmt && gimple_code (stmt) == GIMPLE_SWITCH)
-	    group_case_labels_stmt (stmt);
+	    group_case_labels_stmt (as_a <gswitch *> (stmt));
 	}
     }
   BITMAP_FREE (touched_switch_bbs);
@@ -1108,7 +1108,7 @@  end_recording_case_labels (void)
    Otherwise return NULL.  */
 
 static tree
-get_cases_for_edge (edge e, gimple *t)
+get_cases_for_edge (edge e, gswitch *t)
 {
   void **slot;
   size_t i, n;
@@ -1147,9 +1147,8 @@  get_cases_for_edge (edge e, gimple *t)
 /* Create the edges for a GIMPLE_SWITCH starting at block BB.  */
 
 static void
-make_gimple_switch_edges (basic_block bb)
+make_gimple_switch_edges (gswitch *entry, basic_block bb)
 {
-  gimple *entry = last_stmt (bb);
   size_t i, n;
 
   n = gimple_switch_num_labels (entry);
@@ -1400,12 +1399,13 @@  cleanup_dead_labels (void)
 
 	case GIMPLE_SWITCH:
 	  {
-	    size_t i, n = gimple_switch_num_labels (stmt);
+	    gswitch *switch_stmt = as_a <gswitch *> (stmt);
+	    size_t i, n = gimple_switch_num_labels (switch_stmt);
 
 	    /* Replace all destination labels.  */
 	    for (i = 0; i < n; ++i)
 	      {
-		tree case_label = gimple_switch_label (stmt, i);
+		tree case_label = gimple_switch_label (switch_stmt, i);
 		label = CASE_LABEL (case_label);
 		new_label = main_block_label (label);
 		if (new_label != label)
@@ -1502,7 +1502,7 @@  cleanup_dead_labels (void)
    Eg. three separate entries 1: 2: 3: become one entry 1..3:  */
 
 void
-group_case_labels_stmt (gimple *stmt)
+group_case_labels_stmt (gswitch *stmt)
 {
   int old_size = gimple_switch_num_labels (stmt);
   int i, j, new_size = old_size;
@@ -1590,7 +1590,7 @@  group_case_labels (void)
     {
       gimple *stmt = last_stmt (bb);
       if (stmt && gimple_code (stmt) == GIMPLE_SWITCH)
-	group_case_labels_stmt (stmt);
+	group_case_labels_stmt (as_a <gswitch *> (stmt));
     }
 }
 
@@ -2055,8 +2055,8 @@  find_taken_edge (basic_block bb, tree val)
   if (gimple_code (stmt) == GIMPLE_COND)
     return find_taken_edge_cond_expr (bb, val);
 
-  if (gimple_code (stmt) == GIMPLE_SWITCH)
-    return find_taken_edge_switch_expr (bb, val);
+  if (gswitch *switch_stmt = dyn_cast <gswitch *> (stmt))
+    return find_taken_edge_switch_expr (switch_stmt, bb, val);
 
   if (computed_goto_p (stmt))
     {
@@ -2115,14 +2115,13 @@  find_taken_edge_cond_expr (basic_block bb, tree val)
    NULL if any edge may be taken.  */
 
 static edge
-find_taken_edge_switch_expr (basic_block bb, tree val)
+find_taken_edge_switch_expr (gswitch *switch_stmt, basic_block bb,
+			     tree val)
 {
   basic_block dest_bb;
   edge e;
-  gimple *switch_stmt;
   tree taken_case;
 
-  switch_stmt = last_stmt (bb);
   taken_case = find_case_label_for_value (switch_stmt, val);
   dest_bb = label_to_block (CASE_LABEL (taken_case));
 
@@ -2137,7 +2136,7 @@  find_taken_edge_switch_expr (basic_block bb, tree val)
    sorted: We can do a binary search for a case matching VAL.  */
 
 static tree
-find_case_label_for_value (gimple *switch_stmt, tree val)
+find_case_label_for_value (gswitch *switch_stmt, tree val)
 {
   size_t low, high, n = gimple_switch_num_labels (switch_stmt);
   tree default_case = gimple_switch_default_label (switch_stmt);
@@ -4264,7 +4263,7 @@  verify_gimple_goto (gimple *stmt)
    is a problem, otherwise false.  */
 
 static bool
-verify_gimple_switch (gimple *stmt)
+verify_gimple_switch (gswitch *stmt)
 {
   unsigned int i, n;
   tree elt, prev_upper_bound = NULL_TREE;
@@ -4446,7 +4445,7 @@  verify_gimple_stmt (gimple *stmt)
       return verify_gimple_goto (stmt);
 
     case GIMPLE_SWITCH:
-      return verify_gimple_switch (stmt);
+      return verify_gimple_switch (as_a <gswitch *> (stmt));
 
     case GIMPLE_RETURN:
       return verify_gimple_return (stmt);
@@ -5179,26 +5178,27 @@  gimple_verify_flow_info (void)
 
 	case GIMPLE_SWITCH:
 	  {
+	    gswitch *switch_stmt = as_a <gswitch *> (stmt);
 	    tree prev;
 	    edge e;
 	    size_t i, n;
 
-	    n = gimple_switch_num_labels (stmt);
+	    n = gimple_switch_num_labels (switch_stmt);
 
 	    /* Mark all the destination basic blocks.  */
 	    for (i = 0; i < n; ++i)
 	      {
-		tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
+		tree lab = CASE_LABEL (gimple_switch_label (switch_stmt, i));
 		basic_block label_bb = label_to_block (lab);
 		gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
 		label_bb->aux = (void *)1;
 	      }
 
 	    /* Verify that the case labels are sorted.  */
-	    prev = gimple_switch_label (stmt, 0);
+	    prev = gimple_switch_label (switch_stmt, 0);
 	    for (i = 1; i < n; ++i)
 	      {
-		tree c = gimple_switch_label (stmt, i);
+		tree c = gimple_switch_label (switch_stmt, i);
 		if (!CASE_LOW (c))
 		  {
 		    error ("found default case not at the start of "
@@ -5244,7 +5244,7 @@  gimple_verify_flow_info (void)
 	    /* Check that we have all of them.  */
 	    for (i = 0; i < n; ++i)
 	      {
-		tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
+		tree lab = CASE_LABEL (gimple_switch_label (switch_stmt, i));
 		basic_block label_bb = label_to_block (lab);
 
 		if (label_bb->aux != (void *)2)
@@ -5432,8 +5432,9 @@  gimple_redirect_edge_and_branch (edge e, basic_block dest)
 
     case GIMPLE_SWITCH:
       {
+	gswitch *switch_stmt = as_a <gswitch *> (stmt);
 	tree label = gimple_block_label (dest);
-        tree cases = get_cases_for_edge (e, stmt);
+        tree cases = get_cases_for_edge (e, switch_stmt);
 
 	/* If we have a list of cases associated with E, then use it
 	   as it's a lot faster than walking the entire case vector.  */
@@ -5454,7 +5455,7 @@  gimple_redirect_edge_and_branch (edge e, basic_block dest)
 	       to move all the cases associated with E to E2.  */
 	    if (e2)
 	      {
-		tree cases2 = get_cases_for_edge (e2, stmt);
+		tree cases2 = get_cases_for_edge (e2, switch_stmt);
 
 		CASE_CHAIN (last) = CASE_CHAIN (cases2);
 		CASE_CHAIN (cases2) = first;
@@ -5463,11 +5464,11 @@  gimple_redirect_edge_and_branch (edge e, basic_block dest)
 	  }
 	else
 	  {
-	    size_t i, n = gimple_switch_num_labels (stmt);
+	    size_t i, n = gimple_switch_num_labels (switch_stmt);
 
 	    for (i = 0; i < n; i++)
 	      {
-		tree elt = gimple_switch_label (stmt, i);
+		tree elt = gimple_switch_label (switch_stmt, i);
 		if (label_to_block (CASE_LABEL (elt)) == e->dest)
 		  CASE_LABEL (elt) = label;
 	      }
diff --git a/gcc/tree-cfg.h b/gcc/tree-cfg.h
index 2bcfedf..30f6fbf 100644
--- a/gcc/tree-cfg.h
+++ b/gcc/tree-cfg.h
@@ -32,7 +32,7 @@  extern void end_recording_case_labels (void);
 extern basic_block label_to_block_fn (struct function *, tree);
 #define label_to_block(t) (label_to_block_fn (cfun, t))
 extern void cleanup_dead_labels (void);
-extern void group_case_labels_stmt (gimple *);
+extern void group_case_labels_stmt (gswitch *);
 extern void group_case_labels (void);
 extern void replace_uses_by (tree, tree);
 extern basic_block single_noncomplex_succ (basic_block bb);
diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c
index fd3057d..e6c9030 100644
--- a/gcc/tree-eh.c
+++ b/gcc/tree-eh.c
@@ -713,7 +713,7 @@  maybe_record_in_goto_queue (struct leh_state *state, gimple *stmt)
    of the labels will leave outer GIMPLE_TRY_FINALLY nodes. Verify this.  */
 
 static void
-verify_norecord_switch_expr (struct leh_state *state, gimple *switch_expr)
+verify_norecord_switch_expr (struct leh_state *state, gswitch *switch_expr)
 {
   struct leh_tf_state *tf = state->tf;
   size_t i, n;
@@ -2057,7 +2057,7 @@  lower_eh_constructs_2 (struct leh_state *state, gimple_stmt_iterator *gsi)
       break;
 
     case GIMPLE_SWITCH:
-      verify_norecord_switch_expr (state, stmt);
+      verify_norecord_switch_expr (state, as_a <gswitch *> (stmt));
       break;
 
     case GIMPLE_TRY:
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 6f72d21..c6cf093 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -3811,15 +3811,18 @@  estimate_num_insns (gimple *stmt, eni_weights *weights)
       break;
 
     case GIMPLE_SWITCH:
-      /* Take into account cost of the switch + guess 2 conditional jumps for
-         each case label.
-
-	 TODO: once the switch expansion logic is sufficiently separated, we can
-	 do better job on estimating cost of the switch.  */
-      if (weights->time_based)
-        cost = floor_log2 (gimple_switch_num_labels (stmt)) * 2;
-      else
-        cost = gimple_switch_num_labels (stmt) * 2;
+      {
+	gswitch *switch_stmt = as_a <gswitch *> (stmt);
+	/* Take into account cost of the switch + guess 2 conditional jumps for
+	   each case label.
+
+	   TODO: once the switch expansion logic is sufficiently separated, we can
+	   do better job on estimating cost of the switch.  */
+	if (weights->time_based)
+	  cost = floor_log2 (gimple_switch_num_labels (switch_stmt)) * 2;
+	else
+	  cost = gimple_switch_num_labels (switch_stmt) * 2;
+      }
       break;
 
     case GIMPLE_CALL:
diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c
index 282d5db..8f08a34 100644
--- a/gcc/tree-loop-distribution.c
+++ b/gcc/tree-loop-distribution.c
@@ -685,10 +685,10 @@  generate_loops_for_partition (struct loop *loop, partition_t partition,
 		  gimple_cond_make_false (stmt);
 		  update_stmt (stmt);
 		}
-	      else if (gimple_code (stmt) == GIMPLE_SWITCH)
+	      else if (gswitch *switch_stmt = dyn_cast <gswitch *> (stmt))
 		{
 		  gimple_switch_set_index
-		      (stmt, CASE_LOW (gimple_switch_label (stmt, 1)));
+		      (switch_stmt, CASE_LOW (gimple_switch_label (switch_stmt, 1)));
 		  update_stmt (stmt);
 		}
 	      else
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c
index 7683fb6..8abee2f 100644
--- a/gcc/tree-ssa-dom.c
+++ b/gcc/tree-ssa-dom.c
@@ -1782,21 +1782,21 @@  record_edge_info (basic_block bb)
       gimple *stmt = gsi_stmt (gsi);
       location_t loc = gimple_location (stmt);
 
-      if (gimple_code (stmt) == GIMPLE_SWITCH)
+      if (gswitch *switch_stmt = dyn_cast <gswitch *> (stmt))
 	{
-	  tree index = gimple_switch_index (stmt);
+	  tree index = gimple_switch_index (switch_stmt);
 
 	  if (TREE_CODE (index) == SSA_NAME)
 	    {
 	      int i;
-              int n_labels = gimple_switch_num_labels (stmt);
+              int n_labels = gimple_switch_num_labels (switch_stmt);
 	      tree *info = XCNEWVEC (tree, last_basic_block_for_fn (cfun));
 	      edge e;
 	      edge_iterator ei;
 
 	      for (i = 0; i < n_labels; i++)
 		{
-		  tree label = gimple_switch_label (stmt, i);
+		  tree label = gimple_switch_label (switch_stmt, i);
 		  basic_block target_bb = label_to_block (CASE_LABEL (label));
 		  if (CASE_HIGH (label)
 		      || !CASE_LOW (label)
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index d990100..0b68e07 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -1284,7 +1284,7 @@  simplify_not_neg_expr (gimple_stmt_iterator *gsi_p)
    have values outside the range of the new type.  */
 
 static void
-simplify_gimple_switch_label_vec (gimple *stmt, tree index_type)
+simplify_gimple_switch_label_vec (gswitch *stmt, tree index_type)
 {
   unsigned int branch_num = gimple_switch_num_labels (stmt);
   auto_vec<tree> labels (branch_num);
@@ -1354,7 +1354,7 @@  simplify_gimple_switch_label_vec (gimple *stmt, tree index_type)
    the condition which we may be able to optimize better.  */
 
 static bool
-simplify_gimple_switch (gimple *stmt)
+simplify_gimple_switch (gswitch *stmt)
 {
   /* The optimization that we really care about is removing unnecessary
      casts.  That will let us do much better in propagating the inferred
@@ -3811,7 +3811,7 @@  pass_forwprop::execute (function *fun)
 	      }
 
 	    case GIMPLE_SWITCH:
-	      changed = simplify_gimple_switch (stmt);
+	      changed = simplify_gimple_switch (as_a <gswitch *> (stmt));
 	      break;
 
 	    case GIMPLE_COND:
diff --git a/gcc/tree-ssa-uncprop.c b/gcc/tree-ssa-uncprop.c
index 4c196e1..9b0f9d3 100644
--- a/gcc/tree-ssa-uncprop.c
+++ b/gcc/tree-ssa-uncprop.c
@@ -171,14 +171,14 @@  associate_equivalences_with_edges (void)
       /* For a SWITCH_EXPR, a case label which represents a single
 	 value and which is the only case label which reaches the
 	 target block creates an equivalence.  */
-      else if (gimple_code (stmt) == GIMPLE_SWITCH)
+      else if (gswitch *switch_stmt = dyn_cast <gswitch *> (stmt))
 	{
-	  tree cond = gimple_switch_index (stmt);
+	  tree cond = gimple_switch_index (switch_stmt);
 
 	  if (TREE_CODE (cond) == SSA_NAME
 	      && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (cond))
 	    {
-	      int i, n_labels = gimple_switch_num_labels (stmt);
+	      int i, n_labels = gimple_switch_num_labels (switch_stmt);
 	      tree *info = XCNEWVEC (tree, last_basic_block_for_fn (cfun));
 
 	      /* Walk over the case label vector.  Record blocks
@@ -186,7 +186,7 @@  associate_equivalences_with_edges (void)
 		 a single value.  */
 	      for (i = 0; i < n_labels; i++)
 		{
-		  tree label = gimple_switch_label (stmt, i);
+		  tree label = gimple_switch_label (switch_stmt, i);
 		  basic_block bb = label_to_block (CASE_LABEL (label));
 
 		  if (CASE_HIGH (label)
diff --git a/gcc/tree-switch-conversion.c b/gcc/tree-switch-conversion.c
index f5de6d9..ece86e5 100644
--- a/gcc/tree-switch-conversion.c
+++ b/gcc/tree-switch-conversion.c
@@ -299,7 +299,7 @@  case_bit_test_cmp (const void *p1, const void *p2)
     node targets.  */
 
 static void
-emit_case_bit_tests (gimple *swtch, tree index_expr,
+emit_case_bit_tests (gswitch *swtch, tree index_expr,
 		     tree minval, tree range)
 {
   struct case_bit_test test[MAX_CASE_BIT_TESTS];
@@ -615,7 +615,7 @@  struct switch_conv_info
 /* Collect information about GIMPLE_SWITCH statement SWTCH into INFO.  */
 
 static void
-collect_switch_conv_info (gimple *swtch, struct switch_conv_info *info)
+collect_switch_conv_info (gswitch *swtch, struct switch_conv_info *info)
 {
   unsigned int branch_num = gimple_switch_num_labels (swtch);
   tree min_case, max_case;
@@ -859,7 +859,7 @@  gather_default_values (tree default_case, struct switch_conv_info *info)
    order of phi nodes.  SWTCH is the switch statement being converted.  */
 
 static void
-build_constructors (gimple *swtch, struct switch_conv_info *info)
+build_constructors (gswitch *swtch, struct switch_conv_info *info)
 {
   unsigned i, branch_num = gimple_switch_num_labels (swtch);
   tree pos = info->range_min;
@@ -953,7 +953,7 @@  constructor_contains_same_values_p (vec<constructor_elt, va_gc> *vec)
    all the constants.  */
 
 static tree
-array_value_type (gimple *swtch, tree type, int num,
+array_value_type (gswitch *swtch, tree type, int num,
 		  struct switch_conv_info *info)
 {
   unsigned int i, len = vec_safe_length (info->constructors[num]);
@@ -1030,7 +1030,7 @@  array_value_type (gimple *swtch, tree type, int num,
    new array.  */
 
 static void
-build_one_array (gimple *swtch, int num, tree arr_index_type, gimple *phi,
+build_one_array (gswitch *swtch, int num, tree arr_index_type, gimple *phi,
 		 tree tidx, struct switch_conv_info *info)
 {
   tree name, cst;
@@ -1096,7 +1096,7 @@  build_one_array (gimple *swtch, int num, tree arr_index_type, gimple *phi,
    them.  */
 
 static void
-build_arrays (gimple *swtch, struct switch_conv_info *info)
+build_arrays (gswitch *swtch, struct switch_conv_info *info)
 {
   tree arr_index_type;
   tree tidx, sub, utype;
@@ -1217,7 +1217,7 @@  fix_phi_nodes (edge e1f, edge e2f, basic_block bbf,
 */
 
 static void
-gen_inbound_check (gimple *swtch, struct switch_conv_info *info)
+gen_inbound_check (gswitch *swtch, struct switch_conv_info *info)
 {
   tree label_decl1 = create_artificial_label (UNKNOWN_LOCATION);
   tree label_decl2 = create_artificial_label (UNKNOWN_LOCATION);
@@ -1337,7 +1337,7 @@  gen_inbound_check (gimple *swtch, struct switch_conv_info *info)
    conversion failed.  */
 
 static const char *
-process_switch (gimple *swtch)
+process_switch (gswitch *swtch)
 {
   struct switch_conv_info info;
 
@@ -1473,7 +1473,7 @@  pass_convert_switch::execute (function *fun)
 	    putc ('\n', dump_file);
 	  }
 
-	failure_reason = process_switch (stmt);
+	failure_reason = process_switch (as_a <gswitch *> (stmt));
 	if (! failure_reason)
 	  {
 	    if (dump_file)
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 55576f9..0978d3d 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -169,7 +169,7 @@  static bool values_propagated;
 static int *vr_phi_edge_counts;
 
 typedef struct {
-  gimple *stmt;
+  gswitch *stmt;
   tree vec;
 } switch_update;
 
@@ -5535,7 +5535,7 @@  compare_case_labels (const void *p1, const void *p2)
    list of assertions for the corresponding operands.  */
 
 static bool
-find_switch_asserts (basic_block bb, gimple *last)
+find_switch_asserts (basic_block bb, gswitch *last)
 {
   bool need_assert;
   gimple_stmt_iterator bsi;
@@ -5706,7 +5706,7 @@  find_assert_locations_1 (basic_block bb, sbitmap live)
   if (last
       && gimple_code (last) == GIMPLE_SWITCH
       && !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
-    need_assert |= find_switch_asserts (bb, last);
+    need_assert |= find_switch_asserts (bb, as_a <gswitch *> (last));
 
   /* Traverse all the statements in BB marking used names and looking
      for statements that may infer assertions for their used operands.  */
@@ -7187,7 +7187,7 @@  vrp_visit_cond_stmt (gimple *stmt, edge *taken_edge_p)
    returned. */
 
 static bool
-find_case_label_index (gimple *stmt, size_t start_idx, tree val, size_t *idx)
+find_case_label_index (gswitch *stmt, size_t start_idx, tree val, size_t *idx)
 {
   size_t n = gimple_switch_num_labels (stmt);
   size_t low, high;
@@ -7237,7 +7237,7 @@  find_case_label_index (gimple *stmt, size_t start_idx, tree val, size_t *idx)
    Returns true if the default label is not needed. */
 
 static bool
-find_case_label_range (gimple *stmt, tree min, tree max, size_t *min_idx,
+find_case_label_range (gswitch *stmt, tree min, tree max, size_t *min_idx,
 		       size_t *max_idx)
 {
   size_t i, j;
@@ -7293,7 +7293,7 @@  find_case_label_range (gimple *stmt, tree min, tree max, size_t *min_idx,
    Returns true if the default label is not needed.  */
 
 static bool
-find_case_label_ranges (gimple *stmt, value_range_t *vr, size_t *min_idx1,
+find_case_label_ranges (gswitch *stmt, value_range_t *vr, size_t *min_idx1,
 			size_t *max_idx1, size_t *min_idx2,
 			size_t *max_idx2)
 {
@@ -7371,7 +7371,7 @@  find_case_label_ranges (gimple *stmt, value_range_t *vr, size_t *min_idx1,
    SSA_PROP_VARYING.  */
 
 static enum ssa_prop_result
-vrp_visit_switch_stmt (gimple *stmt, edge *taken_edge_p)
+vrp_visit_switch_stmt (gswitch *stmt, edge *taken_edge_p)
 {
   tree op, val;
   value_range_t *vr;
@@ -7486,8 +7486,8 @@  vrp_visit_stmt (gimple *stmt, edge *taken_edge_p, tree *output_p)
     return vrp_visit_assignment_or_call (stmt, output_p);
   else if (gimple_code (stmt) == GIMPLE_COND)
     return vrp_visit_cond_stmt (stmt, taken_edge_p);
-  else if (gimple_code (stmt) == GIMPLE_SWITCH)
-    return vrp_visit_switch_stmt (stmt, taken_edge_p);
+  else if (gswitch *switch_stmt = dyn_cast <gswitch *> (stmt))
+    return vrp_visit_switch_stmt (switch_stmt, taken_edge_p);
 
   /* All other statements produce nothing of interest for VRP, so mark
      their outputs varying and prevent further simulation.  */
@@ -8955,7 +8955,7 @@  simplify_cond_using_ranges (gimple *stmt)
    argument.  */
 
 static bool
-simplify_switch_using_ranges (gimple *stmt)
+simplify_switch_using_ranges (gswitch *stmt)
 {
   tree op = gimple_switch_index (stmt);
   value_range_t *vr;
@@ -9349,8 +9349,8 @@  simplify_stmt_using_ranges (gimple_stmt_iterator *gsi)
     }
   else if (gimple_code (stmt) == GIMPLE_COND)
     return simplify_cond_using_ranges (stmt);
-  else if (gimple_code (stmt) == GIMPLE_SWITCH)
-    return simplify_switch_using_ranges (stmt);
+  else if (gswitch *switch_stmt = dyn_cast <gswitch *> (stmt))
+    return simplify_switch_using_ranges (switch_stmt);
   else if (is_gimple_call (stmt)
 	   && gimple_call_internal_p (stmt))
     return simplify_internal_call_using_ranges (gsi, stmt);