Change RNode structure from union to struct

All kind of AST nodes use same struct RNode, which has u1, u2, u3 union members
for holding different kind of data.
This has two problems.

1. Low flexibility of data structure

Some nodes, for example NODE_TRUE, don’t use u1, u2, u3. On the other hand,
NODE_OP_ASGN2 needs more than three union members. However they use same
structure definition, need to allocate three union members for NODE_TRUE and
need to separate NODE_OP_ASGN2 into another node.
This change removes the restriction so make it possible to
change data structure by each node type.

2. No compile time check for union member access

It’s developer’s responsibility for using correct member for each node type when it’s union.
This change clarifies which node has which type of fields and enables compile time check.

This commit also changes node_buffer_elem_struct buf management to handle
different size data with alignment.

1 files changed, 462 insertions, 456 deletions

diff --git a/compile.c b/compile.c
index c7bc538c09..c286df0869 100644
--- a/compile.c
+++ b/compile.c
@@ -333,10 +333,10 @@ static void iseq_add_setlocal(rb_iseq_t *iseq, LINK_ANCHOR *const seq, const NOD
   (debug_compile("== " desc "\n", \
                  iseq_compile_each(iseq, (anchor), (node), (popped))))
 
-#define COMPILE_RECV(anchor, desc, node) \
+#define COMPILE_RECV(anchor, desc, node, recv) \
     (private_recv_p(node) ? \
      (ADD_INSN(anchor, node, putself), VM_CALL_FCALL) : \
-     COMPILE(anchor, desc, node->nd_recv) ? 0 : -1)
+     COMPILE(anchor, desc, recv) ? 0 : -1)
 
 #define OPERAND_AT(insn, idx) \
   (((INSN*)(insn))->operands[(idx)])
@@ -753,8 +753,8 @@ rb_iseq_compile_node(rb_iseq_t *iseq, const NODE *node)
     /* assume node is T_NODE */
     else if (nd_type_p(node, NODE_SCOPE)) {
         /* iseq type of top, method, class, block */
-        iseq_set_local_table(iseq, node->nd_tbl);
-        iseq_set_arguments(iseq, ret, node->nd_args);
+        iseq_set_local_table(iseq, RNODE_SCOPE(node)->nd_tbl);
+        iseq_set_arguments(iseq, ret, RNODE_SCOPE(node)->nd_args);
 
         switch (ISEQ_BODY(iseq)->type) {
           case ISEQ_TYPE_BLOCK:
@@ -769,7 +769,7 @@ rb_iseq_compile_node(rb_iseq_t *iseq, const NODE *node)
                 NODE dummy_line_node = generate_dummy_line_node(ISEQ_BODY(iseq)->location.first_lineno, -1);
                 ADD_INSN (ret, &dummy_line_node, nop);
                 ADD_LABEL(ret, start);
-                CHECK(COMPILE(ret, "block body", node->nd_body));
+                CHECK(COMPILE(ret, "block body", RNODE_SCOPE(node)->nd_body));
                 ADD_LABEL(ret, end);
                 ADD_TRACE(ret, RUBY_EVENT_B_RETURN);
                 ISEQ_COMPILE_DATA(iseq)->last_line = ISEQ_BODY(iseq)->location.code_location.end_pos.lineno;
@@ -782,23 +782,23 @@ rb_iseq_compile_node(rb_iseq_t *iseq, const NODE *node)
           case ISEQ_TYPE_CLASS:
             {
                 ADD_TRACE(ret, RUBY_EVENT_CLASS);
-                CHECK(COMPILE(ret, "scoped node", node->nd_body));
+                CHECK(COMPILE(ret, "scoped node", RNODE_SCOPE(node)->nd_body));
                 ADD_TRACE(ret, RUBY_EVENT_END);
                 ISEQ_COMPILE_DATA(iseq)->last_line = nd_line(node);
                 break;
             }
           case ISEQ_TYPE_METHOD:
             {
-                ISEQ_COMPILE_DATA(iseq)->root_node = node->nd_body;
+                ISEQ_COMPILE_DATA(iseq)->root_node = RNODE_SCOPE(node)->nd_body;
                 ADD_TRACE(ret, RUBY_EVENT_CALL);
-                CHECK(COMPILE(ret, "scoped node", node->nd_body));
-                ISEQ_COMPILE_DATA(iseq)->root_node = node->nd_body;
+                CHECK(COMPILE(ret, "scoped node", RNODE_SCOPE(node)->nd_body));
+                ISEQ_COMPILE_DATA(iseq)->root_node = RNODE_SCOPE(node)->nd_body;
                 ADD_TRACE(ret, RUBY_EVENT_RETURN);
                 ISEQ_COMPILE_DATA(iseq)->last_line = nd_line(node);
                 break;
             }
           default: {
-            CHECK(COMPILE(ret, "scoped node", node->nd_body));
+            CHECK(COMPILE(ret, "scoped node", RNODE_SCOPE(node)->nd_body));
             break;
           }
         }
@@ -1817,14 +1817,14 @@ iseq_set_arguments_keywords(rb_iseq_t *iseq, LINK_ANCHOR *const optargs,
 
     while (node) {
         kw++;
-        node = node->nd_next;
+        node = RNODE_KW_ARG(node)->nd_next;
     }
     arg_size += kw;
     keyword->bits_start = arg_size++;
 
     node = args->kw_args;
     while (node) {
-        const NODE *val_node = node->nd_body->nd_value;
+        const NODE *val_node = RNODE_LASGN(RNODE_KW_ARG(node)->nd_body)->nd_value;
         VALUE dv;
 
         if (val_node == NODE_SPECIAL_REQUIRED_KEYWORD) {
@@ -1833,7 +1833,7 @@ iseq_set_arguments_keywords(rb_iseq_t *iseq, LINK_ANCHOR *const optargs,
         else {
             switch (nd_type(val_node)) {
               case NODE_LIT:
-                dv = val_node->nd_lit;
+                dv = RNODE_LIT(val_node)->nd_lit;
                 break;
               case NODE_NIL:
                 dv = Qnil;
@@ -1853,12 +1853,12 @@ iseq_set_arguments_keywords(rb_iseq_t *iseq, LINK_ANCHOR *const optargs,
             rb_ary_push(default_values, dv);
         }
 
-        node = node->nd_next;
+        node = RNODE_KW_ARG(node)->nd_next;
     }
 
     keyword->num = kw;
 
-    if (args->kw_rest_arg->nd_vid != 0) {
+    if (RNODE_DVAR(args->kw_rest_arg)->nd_vid != 0) {
         keyword->rest_start = arg_size++;
         body->param.flags.has_kwrest = TRUE;
     }
@@ -1889,7 +1889,7 @@ iseq_set_arguments(rb_iseq_t *iseq, LINK_ANCHOR *const optargs, const NODE *cons
 
     if (node_args) {
         struct rb_iseq_constant_body *const body = ISEQ_BODY(iseq);
-        struct rb_args_info *args = node_args->nd_ainfo;
+        struct rb_args_info *args = RNODE_ARGS(node_args)->nd_ainfo;
         ID rest_id = 0;
         int last_comma = 0;
         ID block_id = 0;
@@ -1920,8 +1920,8 @@ iseq_set_arguments(rb_iseq_t *iseq, LINK_ANCHOR *const optargs, const NODE *cons
                 label = NEW_LABEL(nd_line(node));
                 rb_ary_push(labels, (VALUE)label | 1);
                 ADD_LABEL(optargs, label);
-                NO_CHECK(COMPILE_POPPED(optargs, "optarg", node->nd_body));
-                node = node->nd_next;
+                NO_CHECK(COMPILE_POPPED(optargs, "optarg", RNODE_OPT_ARG(node)->nd_body));
+                node = RNODE_OPT_ARG(node)->nd_next;
                 i += 1;
             }
 
@@ -4023,16 +4023,16 @@ all_string_result_p(const NODE *node)
       case NODE_STR: case NODE_DSTR:
         return TRUE;
       case NODE_IF: case NODE_UNLESS:
-        if (!node->nd_body || !node->nd_else) return FALSE;
-        if (all_string_result_p(node->nd_body))
-            return all_string_result_p(node->nd_else);
+        if (!RNODE_IF(node)->nd_body || !RNODE_IF(node)->nd_else) return FALSE;
+        if (all_string_result_p(RNODE_IF(node)->nd_body))
+            return all_string_result_p(RNODE_IF(node)->nd_else);
         return FALSE;
       case NODE_AND: case NODE_OR:
-        if (!node->nd_2nd)
-            return all_string_result_p(node->nd_1st);
-        if (!all_string_result_p(node->nd_1st))
+        if (!RNODE_AND(node)->nd_2nd)
+            return all_string_result_p(RNODE_AND(node)->nd_1st);
+        if (!all_string_result_p(RNODE_AND(node)->nd_1st))
             return FALSE;
-        return all_string_result_p(node->nd_2nd);
+        return all_string_result_p(RNODE_AND(node)->nd_2nd);
       default:
         return FALSE;
     }
@@ -4041,8 +4041,8 @@ all_string_result_p(const NODE *node)
 static int
 compile_dstr_fragments(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int *cntp)
 {
-    const NODE *list = node->nd_next;
-    VALUE lit = node->nd_lit;
+    const struct RNode_LIST *list = RNODE_DSTR(node)->nd_next;
+    VALUE lit = RNODE_DSTR(node)->nd_lit;
     LINK_ELEMENT *first_lit = 0;
     int cnt = 0;
 
@@ -4063,7 +4063,7 @@ compile_dstr_fragments(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *cons
     while (list) {
         const NODE *const head = list->nd_head;
         if (nd_type_p(head, NODE_STR)) {
-            lit = rb_fstring(head->nd_lit);
+            lit = rb_fstring(RNODE_STR(head)->nd_lit);
             ADD_INSN1(ret, head, putobject, lit);
             RB_OBJ_WRITTEN(iseq, Qundef, lit);
             lit = Qnil;
@@ -4072,7 +4072,7 @@ compile_dstr_fragments(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *cons
             CHECK(COMPILE(ret, "each string", head));
         }
         cnt++;
-        list = list->nd_next;
+        list = (struct RNode_LIST *)list->nd_next;
     }
     if (NIL_P(lit) && first_lit) {
         ELEM_REMOVE(first_lit);
@@ -4087,12 +4087,12 @@ static int
 compile_block(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int popped)
 {
     while (node && nd_type_p(node, NODE_BLOCK)) {
-        CHECK(COMPILE_(ret, "BLOCK body", node->nd_head,
-                       (node->nd_next ? 1 : popped)));
-        node = node->nd_next;
+        CHECK(COMPILE_(ret, "BLOCK body", RNODE_BLOCK(node)->nd_head,
+                       (RNODE_BLOCK(node)->nd_next ? 1 : popped)));
+        node = RNODE_BLOCK(node)->nd_next;
     }
     if (node) {
-        CHECK(COMPILE_(ret, "BLOCK next", node->nd_next, popped));
+        CHECK(COMPILE_(ret, "BLOCK next", RNODE_BLOCK(node)->nd_next, popped));
     }
     return COMPILE_OK;
 }
@@ -4101,8 +4101,8 @@ static int
 compile_dstr(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node)
 {
     int cnt;
-    if (!node->nd_next) {
-        VALUE lit = rb_fstring(node->nd_lit);
+    if (!RNODE_DSTR(node)->nd_next) {
+        VALUE lit = rb_fstring(RNODE_DSTR(node)->nd_lit);
         ADD_INSN1(ret, node, putstring, lit);
         RB_OBJ_WRITTEN(iseq, Qundef, lit);
     }
@@ -4118,7 +4118,7 @@ compile_dregx(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node)
 {
     int cnt;
     CHECK(compile_dstr_fragments(iseq, ret, node, &cnt));
-    ADD_INSN2(ret, node, toregexp, INT2FIX(node->nd_cflag), INT2FIX(cnt));
+    ADD_INSN2(ret, node, toregexp, INT2FIX(RNODE_DREGX(node)->nd_cflag), INT2FIX(cnt));
     return COMPILE_OK;
 }
 
@@ -4136,7 +4136,7 @@ compile_flip_flop(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const nod
     ADD_INSNL(ret, node, branchif, lend);
 
     /* *flip == 0 */
-    CHECK(COMPILE(ret, "flip2 beg", node->nd_beg));
+    CHECK(COMPILE(ret, "flip2 beg", RNODE_FLIP2(node)->nd_beg));
     ADD_INSNL(ret, node, branchunless, else_label);
     ADD_INSN1(ret, node, putobject, Qtrue);
     ADD_INSN1(ret, node, setspecial, key);
@@ -4146,7 +4146,7 @@ compile_flip_flop(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const nod
 
     /* *flip == 1 */
     ADD_LABEL(ret, lend);
-    CHECK(COMPILE(ret, "flip2 end", node->nd_end));
+    CHECK(COMPILE(ret, "flip2 end", RNODE_FLIP2(node)->nd_end));
     ADD_INSNL(ret, node, branchunless, then_label);
     ADD_INSN1(ret, node, putobject, Qfalse);
     ADD_INSN1(ret, node, setspecial, key);
@@ -4195,8 +4195,8 @@ compile_branch_condition(rb_iseq_t *iseq, LINK_ANCHOR *ret, const NODE *cond,
   again:
     switch (nd_type(cond)) {
       case NODE_AND:
-        CHECK(ok = compile_logical(iseq, ret, cond->nd_1st, NULL, else_label));
-        cond = cond->nd_2nd;
+        CHECK(ok = compile_logical(iseq, ret, RNODE_AND(cond)->nd_1st, NULL, else_label));
+        cond = RNODE_AND(cond)->nd_2nd;
         if (ok == COMPILE_SINGLE) {
             INIT_ANCHOR(ignore);
             ret = ignore;
@@ -4204,8 +4204,8 @@ compile_branch_condition(rb_iseq_t *iseq, LINK_ANCHOR *ret, const NODE *cond,
         }
         goto again;
       case NODE_OR:
-        CHECK(ok = compile_logical(iseq, ret, cond->nd_1st, then_label, NULL));
-        cond = cond->nd_2nd;
+        CHECK(ok = compile_logical(iseq, ret, RNODE_OR(cond)->nd_1st, then_label, NULL));
+        cond = RNODE_OR(cond)->nd_2nd;
         if (ok == COMPILE_SINGLE) {
             INIT_ANCHOR(ignore);
             ret = ignore;
@@ -4277,7 +4277,7 @@ compile_branch_condition(rb_iseq_t *iseq, LINK_ANCHOR *ret, const NODE *cond,
 static int
 keyword_node_p(const NODE *const node)
 {
-    return nd_type_p(node, NODE_HASH) && (node->nd_brace & HASH_BRACE) != HASH_BRACE;
+    return nd_type_p(node, NODE_HASH) && (RNODE_HASH(node)->nd_brace & HASH_BRACE) != HASH_BRACE;
 }
 
 static int
@@ -4290,22 +4290,22 @@ compile_keyword_arg(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
     RUBY_ASSERT(kw_arg_ptr != NULL);
     RUBY_ASSERT(flag != NULL);
 
-    if (root_node->nd_head && nd_type_p(root_node->nd_head, NODE_LIST)) {
-        const NODE *node = root_node->nd_head;
+    if (RNODE_HASH(root_node)->nd_head && nd_type_p(RNODE_HASH(root_node)->nd_head, NODE_LIST)) {
+        const NODE *node = RNODE_HASH(root_node)->nd_head;
         int seen_nodes = 0;
 
         while (node) {
-            const NODE *key_node = node->nd_head;
+            const NODE *key_node = RNODE_LIST(node)->nd_head;
             seen_nodes++;
 
             assert(nd_type_p(node, NODE_LIST));
-            if (key_node && nd_type_p(key_node, NODE_LIT) && SYMBOL_P(key_node->nd_lit)) {
+            if (key_node && nd_type_p(key_node, NODE_LIT) && SYMBOL_P(RNODE_LIT(key_node)->nd_lit)) {
                 /* can be keywords */
             }
             else {
                 if (flag) {
                     *flag |= VM_CALL_KW_SPLAT;
-                    if (seen_nodes > 1 || node->nd_next->nd_next) {
+                    if (seen_nodes > 1 || RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_next) {
                         /* A new hash will be created for the keyword arguments
                          * in this case, so mark the method as passing mutable
                          * keyword splat.
@@ -4315,14 +4315,14 @@ compile_keyword_arg(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
                 }
                 return FALSE;
             }
-            node = node->nd_next; /* skip value node */
-            node = node->nd_next;
+            node = RNODE_LIST(node)->nd_next; /* skip value node */
+            node = RNODE_LIST(node)->nd_next;
         }
 
         /* may be keywords */
-        node = root_node->nd_head;
+        node = RNODE_HASH(root_node)->nd_head;
         {
-            int len = (int)node->nd_alen / 2;
+            int len = (int)RNODE_LIST(node)->as.nd_alen / 2;
             struct rb_callinfo_kwarg *kw_arg =
                 rb_xmalloc_mul_add(len, sizeof(VALUE), sizeof(struct rb_callinfo_kwarg));
             VALUE *keywords = kw_arg->keywords;
@@ -4331,10 +4331,10 @@ compile_keyword_arg(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
 
             *kw_arg_ptr = kw_arg;
 
-            for (i=0; node != NULL; i++, node = node->nd_next->nd_next) {
-                const NODE *key_node = node->nd_head;
-                const NODE *val_node = node->nd_next->nd_head;
-                keywords[i] = key_node->nd_lit;
+            for (i=0; node != NULL; i++, node = RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_next) {
+                const NODE *key_node = RNODE_LIST(node)->nd_head;
+                const NODE *val_node = RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_head;
+                keywords[i] = RNODE_LIT(key_node)->nd_lit;
                 NO_CHECK(COMPILE(ret, "keyword values", val_node));
             }
             assert(i == len);
@@ -4349,17 +4349,17 @@ compile_args(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, NODE **k
 {
     int len = 0;
 
-    for (; node; len++, node = node->nd_next) {
+    for (; node; len++, node = RNODE_LIST(node)->nd_next) {
         if (CPDEBUG > 0) {
             EXPECT_NODE("compile_args", node, NODE_LIST, -1);
         }
 
-        if (node->nd_next == NULL && keyword_node_p(node->nd_head)) { /* last node is kwnode */
-            *kwnode_ptr = node->nd_head;
+        if (RNODE_LIST(node)->nd_next == NULL && keyword_node_p(RNODE_LIST(node)->nd_head)) { /* last node is kwnode */
+            *kwnode_ptr = RNODE_LIST(node)->nd_head;
         }
         else {
-            RUBY_ASSERT(!keyword_node_p(node->nd_head));
-            NO_CHECK(COMPILE_(ret, "array element", node->nd_head, FALSE));
+            RUBY_ASSERT(!keyword_node_p(RNODE_LIST(node)->nd_head));
+            NO_CHECK(COMPILE_(ret, "array element", RNODE_LIST(node)->nd_head, FALSE));
         }
     }
 
@@ -4396,15 +4396,15 @@ static_literal_value(const NODE *node, rb_iseq_t *iseq)
         if (ISEQ_COMPILE_DATA(iseq)->option->debug_frozen_string_literal || RTEST(ruby_debug)) {
             VALUE lit;
             VALUE debug_info = rb_ary_new_from_args(2, rb_iseq_path(iseq), INT2FIX((int)nd_line(node)));
-            lit = rb_str_dup(node->nd_lit);
+            lit = rb_str_dup(RNODE_STR(node)->nd_lit);
             rb_ivar_set(lit, id_debug_created_info, rb_obj_freeze(debug_info));
             return rb_str_freeze(lit);
         }
         else {
-            return rb_fstring(node->nd_lit);
+            return rb_fstring(RNODE_STR(node)->nd_lit);
         }
       default:
-        return node->nd_lit;
+        return RNODE_LIT(node)->nd_lit;
     }
 }
 
@@ -4423,8 +4423,8 @@ compile_array(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int pop
     EXPECT_NODE("compile_array", node, NODE_LIST, -1);
 
     if (popped) {
-        for (; node; node = node->nd_next) {
-            NO_CHECK(COMPILE_(ret, "array element", node->nd_head, popped));
+        for (; node; node = RNODE_LIST(node)->nd_next) {
+            NO_CHECK(COMPILE_(ret, "array element", RNODE_LIST(node)->nd_head, popped));
         }
         return 1;
     }
@@ -4483,10 +4483,10 @@ compile_array(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int pop
         int count = 1;
 
         /* pre-allocation check (this branch can be omittable) */
-        if (static_literal_node_p(node->nd_head, iseq)) {
+        if (static_literal_node_p(RNODE_LIST(node)->nd_head, iseq)) {
             /* count the elements that are optimizable */
-            const NODE *node_tmp = node->nd_next;
-            for (; node_tmp && static_literal_node_p(node_tmp->nd_head, iseq); node_tmp = node_tmp->nd_next)
+            const NODE *node_tmp = RNODE_LIST(node)->nd_next;
+            for (; node_tmp && static_literal_node_p(RNODE_LIST(node_tmp)->nd_head, iseq); node_tmp = RNODE_LIST(node_tmp)->nd_next)
                 count++;
 
             if ((first_chunk && stack_len == 0 && !node_tmp) || count >= min_tmp_ary_len) {
@@ -4494,8 +4494,8 @@ compile_array(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int pop
                 VALUE ary = rb_ary_hidden_new(count);
 
                 /* Create a hidden array */
-                for (; count; count--, node = node->nd_next)
-                    rb_ary_push(ary, static_literal_value(node->nd_head, iseq));
+                for (; count; count--, node = RNODE_LIST(node)->nd_next)
+                    rb_ary_push(ary, static_literal_value(RNODE_LIST(node)->nd_head, iseq));
                 OBJ_FREEZE(ary);
 
                 /* Emit optimized code */
@@ -4513,15 +4513,15 @@ compile_array(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int pop
         }
 
         /* Base case: Compile "count" elements */
-        for (; count; count--, node = node->nd_next) {
+        for (; count; count--, node = RNODE_LIST(node)->nd_next) {
             if (CPDEBUG > 0) {
                 EXPECT_NODE("compile_array", node, NODE_LIST, -1);
             }
 
-            NO_CHECK(COMPILE_(ret, "array element", node->nd_head, 0));
+            NO_CHECK(COMPILE_(ret, "array element", RNODE_LIST(node)->nd_head, 0));
             stack_len++;
 
-            if (!node->nd_next && keyword_node_p(node->nd_head)) {
+            if (!RNODE_LIST(node)->nd_next && keyword_node_p(RNODE_LIST(node)->nd_head)) {
                 /* Reached the end, and the last element is a keyword */
                 FLUSH_CHUNK(newarraykwsplat);
                 return 1;
@@ -4559,7 +4559,7 @@ compile_array_1(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node)
 static inline int
 static_literal_node_pair_p(const NODE *node, const rb_iseq_t *iseq)
 {
-    return node->nd_head && static_literal_node_p(node->nd_head, iseq) && static_literal_node_p(node->nd_next->nd_head, iseq);
+    return RNODE_LIST(node)->nd_head && static_literal_node_p(RNODE_LIST(node)->nd_head, iseq) && static_literal_node_p(RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_head, iseq);
 }
 
 static int
@@ -4567,7 +4567,7 @@ compile_hash(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int meth
 {
     const NODE *line_node = node;
 
-    node = node->nd_head;
+    node = RNODE_HASH(node)->nd_head;
 
     if (!node || nd_type_p(node, NODE_ZLIST)) {
         if (!popped) {
@@ -4579,8 +4579,8 @@ compile_hash(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int meth
     EXPECT_NODE("compile_hash", node, NODE_LIST, -1);
 
     if (popped) {
-        for (; node; node = node->nd_next) {
-            NO_CHECK(COMPILE_(ret, "hash element", node->nd_head, popped));
+        for (; node; node = RNODE_LIST(node)->nd_next) {
+            NO_CHECK(COMPILE_(ret, "hash element", RNODE_LIST(node)->nd_head, popped));
         }
         return 1;
     }
@@ -4633,8 +4633,8 @@ compile_hash(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int meth
         /* pre-allocation check (this branch can be omittable) */
         if (static_literal_node_pair_p(node, iseq)) {
             /* count the elements that are optimizable */
-            const NODE *node_tmp = node->nd_next->nd_next;
-            for (; node_tmp && static_literal_node_pair_p(node_tmp, iseq); node_tmp = node_tmp->nd_next->nd_next)
+            const NODE *node_tmp = RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_next;
+            for (; node_tmp && static_literal_node_pair_p(node_tmp, iseq); node_tmp = RNODE_LIST(RNODE_LIST(node_tmp)->nd_next)->nd_next)
                 count++;
 
             if ((first_chunk && stack_len == 0 && !node_tmp) || count >= min_tmp_hash_len) {
@@ -4642,10 +4642,10 @@ compile_hash(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int meth
                 VALUE ary = rb_ary_hidden_new(count);
 
                 /* Create a hidden hash */
-                for (; count; count--, node = node->nd_next->nd_next) {
+                for (; count; count--, node = RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_next) {
                     VALUE elem[2];
-                    elem[0] = static_literal_value(node->nd_head, iseq);
-                    elem[1] = static_literal_value(node->nd_next->nd_head, iseq);
+                    elem[0] = static_literal_value(RNODE_LIST(node)->nd_head, iseq);
+                    elem[1] = static_literal_value(RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_head, iseq);
                     rb_ary_cat(ary, elem, 2);
                 }
                 VALUE hash = rb_hash_new_with_size(RARRAY_LEN(ary) / 2);
@@ -4672,16 +4672,16 @@ compile_hash(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int meth
         }
 
         /* Base case: Compile "count" elements */
-        for (; count; count--, node = node->nd_next->nd_next) {
+        for (; count; count--, node = RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_next) {
 
             if (CPDEBUG > 0) {
                 EXPECT_NODE("compile_hash", node, NODE_LIST, -1);
             }
 
-            if (node->nd_head) {
+            if (RNODE_LIST(node)->nd_head) {
                 /* Normal key-value pair */
-                NO_CHECK(COMPILE_(anchor, "hash key element", node->nd_head, 0));
-                NO_CHECK(COMPILE_(anchor, "hash value element", node->nd_next->nd_head, 0));
+                NO_CHECK(COMPILE_(anchor, "hash key element", RNODE_LIST(node)->nd_head, 0));
+                NO_CHECK(COMPILE_(anchor, "hash value element", RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_head, 0));
                 stack_len += 2;
 
                 /* If there are many pushed elements, flush them to avoid stack overflow */
@@ -4691,10 +4691,10 @@ compile_hash(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int meth
                 /* kwsplat case: foo(..., **kw, ...) */
                 FLUSH_CHUNK();
 
-                const NODE *kw = node->nd_next->nd_head;
-                int empty_kw = nd_type_p(kw, NODE_LIT) && RB_TYPE_P(kw->nd_lit, T_HASH); /* foo(  ..., **{}, ...) */
+                const NODE *kw = RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_head;
+                int empty_kw = nd_type_p(kw, NODE_LIT) && RB_TYPE_P(RNODE_LIT(kw)->nd_lit, T_HASH); /* foo(  ..., **{}, ...) */
                 int first_kw = first_chunk && stack_len == 0; /* foo(1,2,3, **kw, ...) */
-                int last_kw = !node->nd_next->nd_next;        /* foo(  ..., **kw) */
+                int last_kw = !RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_next; /* foo(  ..., **kw) */
                 int only_kw = last_kw && first_kw;            /* foo(1,2,3, **kw) */
 
                 if (empty_kw) {
@@ -4757,7 +4757,7 @@ rb_node_case_when_optimizable_literal(const NODE *const node)
 {
     switch (nd_type(node)) {
       case NODE_LIT: {
-        VALUE v = node->nd_lit;
+        VALUE v = RNODE_LIT(node)->nd_lit;
         double ival;
         if (RB_FLOAT_TYPE_P(v) &&
             modf(RFLOAT_VALUE(v), &ival) == 0.0) {
@@ -4778,7 +4778,7 @@ rb_node_case_when_optimizable_literal(const NODE *const node)
       case NODE_FALSE:
         return Qfalse;
       case NODE_STR:
-        return rb_fstring(node->nd_lit);
+        return rb_fstring(RNODE_LIT(node)->nd_lit);
     }
     return Qundef;
 }
@@ -4788,7 +4788,7 @@ when_vals(rb_iseq_t *iseq, LINK_ANCHOR *const cond_seq, const NODE *vals,
           LABEL *l1, int only_special_literals, VALUE literals)
 {
     while (vals) {
-        const NODE *val = vals->nd_head;
+        const NODE *val = RNODE_LIST(vals)->nd_head;
         VALUE lit = rb_node_case_when_optimizable_literal(val);
 
         if (UNDEF_P(lit)) {
@@ -4799,8 +4799,8 @@ when_vals(rb_iseq_t *iseq, LINK_ANCHOR *const cond_seq, const NODE *vals,
         }
 
         if (nd_type_p(val, NODE_STR)) {
-            debugp_param("nd_lit", val->nd_lit);
-            lit = rb_fstring(val->nd_lit);
+            debugp_param("nd_lit", RNODE_STR(val)->nd_lit);
+            lit = rb_fstring(RNODE_STR(val)->nd_lit);
             ADD_INSN1(cond_seq, val, putobject, lit);
             RB_OBJ_WRITTEN(iseq, Qundef, lit);
         }
@@ -4812,7 +4812,7 @@ when_vals(rb_iseq_t *iseq, LINK_ANCHOR *const cond_seq, const NODE *vals,
         ADD_INSN1(cond_seq, vals, topn, INT2FIX(1));
         ADD_CALL(cond_seq, vals, idEqq, INT2FIX(1));
         ADD_INSNL(cond_seq, val, branchif, l1);
-        vals = vals->nd_next;
+        vals = RNODE_LIST(vals)->nd_next;
     }
     return only_special_literals;
 }
@@ -4830,19 +4830,19 @@ when_splat_vals(rb_iseq_t *iseq, LINK_ANCHOR *const cond_seq, const NODE *vals,
         break;
       case NODE_SPLAT:
         ADD_INSN (cond_seq, line_node, dup);
-        CHECK(COMPILE(cond_seq, "when splat", vals->nd_head));
+        CHECK(COMPILE(cond_seq, "when splat", RNODE_SPLAT(vals)->nd_head));
         ADD_INSN1(cond_seq, line_node, splatarray, Qfalse);
         ADD_INSN1(cond_seq, line_node, checkmatch, INT2FIX(VM_CHECKMATCH_TYPE_CASE | VM_CHECKMATCH_ARRAY));
         ADD_INSNL(cond_seq, line_node, branchif, l1);
         break;
       case NODE_ARGSCAT:
-        CHECK(when_splat_vals(iseq, cond_seq, vals->nd_head, l1, only_special_literals, literals));
-        CHECK(when_splat_vals(iseq, cond_seq, vals->nd_body, l1, only_special_literals, literals));
+        CHECK(when_splat_vals(iseq, cond_seq, RNODE_ARGSCAT(vals)->nd_head, l1, only_special_literals, literals));
+        CHECK(when_splat_vals(iseq, cond_seq, RNODE_ARGSCAT(vals)->nd_body, l1, only_special_literals, literals));
         break;
       case NODE_ARGSPUSH:
-        CHECK(when_splat_vals(iseq, cond_seq, vals->nd_head, l1, only_special_literals, literals));
+        CHECK(when_splat_vals(iseq, cond_seq, RNODE_ARGSPUSH(vals)->nd_head, l1, only_special_literals, literals));
         ADD_INSN (cond_seq, line_node, dup);
-        CHECK(COMPILE(cond_seq, "when argspush body", vals->nd_body));
+        CHECK(COMPILE(cond_seq, "when argspush body", RNODE_ARGSPUSH(vals)->nd_body));
         ADD_INSN1(cond_seq, line_node, checkmatch, INT2FIX(VM_CHECKMATCH_TYPE_CASE));
         ADD_INSNL(cond_seq, line_node, branchif, l1);
         break;
@@ -5062,7 +5062,7 @@ compile_massign_lhs(rb_iseq_t *iseq, LINK_ANCHOR *const pre, LINK_ANCHOR *const
         break;
       }
       case NODE_CDECL:
-        if (!node->nd_vid) {
+        if (!RNODE_CDECL(node)->nd_vid) {
             /* Special handling only needed for expr::C, not for C */
             INSN *iobj;
 
@@ -5100,8 +5100,8 @@ static int
 compile_massign_opt_lhs(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *lhsn)
 {
     if (lhsn) {
-        CHECK(compile_massign_opt_lhs(iseq, ret, lhsn->nd_next));
-        CHECK(compile_massign_lhs(iseq, ret, ret, ret, ret, lhsn->nd_head, NULL, 0));
+        CHECK(compile_massign_opt_lhs(iseq, ret, RNODE_LIST(lhsn)->nd_next));
+        CHECK(compile_massign_lhs(iseq, ret, ret, ret, ret, RNODE_LIST(lhsn)->nd_head, NULL, 0));
     }
     return COMPILE_OK;
 }
@@ -5131,29 +5131,29 @@ compile_massign_opt(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
     }
 
     while (lhsn) {
-        const NODE *ln = lhsn->nd_head;
+        const NODE *ln = RNODE_LIST(lhsn)->nd_head;
         switch (nd_type(ln)) {
           case NODE_LASGN:
           case NODE_DASGN:
           case NODE_IASGN:
           case NODE_CVASGN:
-            MEMORY(ln->nd_vid);
+            MEMORY(RNODE_LASGN(ln)->nd_vid);
             break;
           default:
             return 0;
         }
-        lhsn = lhsn->nd_next;
+        lhsn = RNODE_LIST(lhsn)->nd_next;
         llen++;
     }
 
     while (rhsn) {
         if (llen <= rlen) {
-            NO_CHECK(COMPILE_POPPED(ret, "masgn val (popped)", rhsn->nd_head));
+            NO_CHECK(COMPILE_POPPED(ret, "masgn val (popped)", RNODE_LIST(rhsn)->nd_head));
         }
         else {
-            NO_CHECK(COMPILE(ret, "masgn val", rhsn->nd_head));
+            NO_CHECK(COMPILE(ret, "masgn val", RNODE_LIST(rhsn)->nd_head));
         }
-        rhsn = rhsn->nd_next;
+        rhsn = RNODE_LIST(rhsn)->nd_next;
         rlen++;
     }
 
@@ -5170,9 +5170,9 @@ compile_massign_opt(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
 static int
 compile_massign0(rb_iseq_t *iseq, LINK_ANCHOR *const pre, LINK_ANCHOR *const rhs, LINK_ANCHOR *const lhs, LINK_ANCHOR *const post, const NODE *const node, struct masgn_state *state, int popped)
 {
-    const NODE *rhsn = node->nd_value;
-    const NODE *splatn = node->nd_args;
-    const NODE *lhsn = node->nd_head;
+    const NODE *rhsn = RNODE_MASGN(node)->nd_value;
+    const NODE *splatn = RNODE_MASGN(node)->nd_args;
+    const NODE *lhsn = RNODE_MASGN(node)->nd_head;
     const NODE *lhsn_count = lhsn;
     int lhs_splat = (splatn && NODE_NAMED_REST_P(splatn)) ? 1 : 0;
 
@@ -5182,20 +5182,20 @@ compile_massign0(rb_iseq_t *iseq, LINK_ANCHOR *const pre, LINK_ANCHOR *const rhs
 
     while (lhsn_count) {
         llen++;
-        lhsn_count = lhsn_count->nd_next;
+        lhsn_count = RNODE_LIST(lhsn_count)->nd_next;
     }
     while (lhsn) {
-        CHECK(compile_massign_lhs(iseq, pre, rhs, lhs, post, lhsn->nd_head, state, (llen - lpos) + lhs_splat + state->lhs_level));
+        CHECK(compile_massign_lhs(iseq, pre, rhs, lhs, post, RNODE_LIST(lhsn)->nd_head, state, (llen - lpos) + lhs_splat + state->lhs_level));
         lpos++;
-        lhsn = lhsn->nd_next;
+        lhsn = RNODE_LIST(lhsn)->nd_next;
     }
 
     if (lhs_splat) {
         if (nd_type_p(splatn, NODE_POSTARG)) {
             /*a, b, *r, p1, p2 */
-            const NODE *postn = splatn->nd_2nd;
-            const NODE *restn = splatn->nd_1st;
-            int plen = (int)postn->nd_alen;
+            const NODE *postn = RNODE_POSTARG(splatn)->nd_2nd;
+            const NODE *restn = RNODE_POSTARG(splatn)->nd_1st;
+            int plen = (int)RNODE_LIST(postn)->as.nd_alen;
             int ppos = 0;
             int flag = 0x02 | (NODE_NAMED_REST_P(restn) ? 0x01 : 0x00);
 
@@ -5205,9 +5205,9 @@ compile_massign0(rb_iseq_t *iseq, LINK_ANCHOR *const pre, LINK_ANCHOR *const rhs
                 CHECK(compile_massign_lhs(iseq, pre, rhs, lhs, post, restn, state, 1 + plen + state->lhs_level));
             }
             while (postn) {
-                CHECK(compile_massign_lhs(iseq, pre, rhs, lhs, post, postn->nd_head, state, (plen - ppos) + state->lhs_level));
+                CHECK(compile_massign_lhs(iseq, pre, rhs, lhs, post, RNODE_LIST(postn)->nd_head, state, (plen - ppos) + state->lhs_level));
                 ppos++;
-                postn = postn->nd_next;
+                postn = RNODE_LIST(postn)->nd_next;
             }
         }
         else {
@@ -5233,7 +5233,7 @@ compile_massign0(rb_iseq_t *iseq, LINK_ANCHOR *const pre, LINK_ANCHOR *const rhs
 static int
 compile_massign(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int popped)
 {
-    if (!popped || node->nd_args || !compile_massign_opt(iseq, ret, node->nd_value, node->nd_head)) {
+    if (!popped || RNODE_MASGN(node)->nd_args || !compile_massign_opt(iseq, ret, RNODE_MASGN(node)->nd_value, RNODE_MASGN(node)->nd_head)) {
         struct masgn_state state;
         state.lhs_level = popped ? 0 : 1;
         state.nested = 0;
@@ -5282,15 +5282,15 @@ collect_const_segments(rb_iseq_t *iseq, const NODE *node)
     for (;;) {
         switch (nd_type(node)) {
           case NODE_CONST:
-            rb_ary_unshift(arr, ID2SYM(node->nd_vid));
+            rb_ary_unshift(arr, ID2SYM(RNODE_CONST(node)->nd_vid));
             return arr;
           case NODE_COLON3:
-            rb_ary_unshift(arr, ID2SYM(node->nd_mid));
+            rb_ary_unshift(arr, ID2SYM(RNODE_COLON3(node)->nd_mid));
             rb_ary_unshift(arr, ID2SYM(idNULL));
             return arr;
           case NODE_COLON2:
-            rb_ary_unshift(arr, ID2SYM(node->nd_mid));
-            node = node->nd_head;
+            rb_ary_unshift(arr, ID2SYM(RNODE_COLON2(node)->nd_mid));
+            node = RNODE_COLON2(node)->nd_head;
             break;
           default:
             return Qfalse;
@@ -5304,22 +5304,22 @@ compile_const_prefix(rb_iseq_t *iseq, const NODE *const node,
 {
     switch (nd_type(node)) {
       case NODE_CONST:
-        debugi("compile_const_prefix - colon", node->nd_vid);
+        debugi("compile_const_prefix - colon", RNODE_CONST(node)->nd_vid);
         ADD_INSN1(body, node, putobject, Qtrue);
-        ADD_INSN1(body, node, getconstant, ID2SYM(node->nd_vid));
+        ADD_INSN1(body, node, getconstant, ID2SYM(RNODE_CONST(node)->nd_vid));
         break;
       case NODE_COLON3:
-        debugi("compile_const_prefix - colon3", node->nd_mid);
+        debugi("compile_const_prefix - colon3", RNODE_COLON3(node)->nd_mid);
         ADD_INSN(body, node, pop);
         ADD_INSN1(body, node, putobject, rb_cObject);
         ADD_INSN1(body, node, putobject, Qtrue);
-        ADD_INSN1(body, node, getconstant, ID2SYM(node->nd_mid));
+        ADD_INSN1(body, node, getconstant, ID2SYM(RNODE_COLON3(node)->nd_mid));
         break;
       case NODE_COLON2:
-        CHECK(compile_const_prefix(iseq, node->nd_head, pref, body));
-        debugi("compile_const_prefix - colon2", node->nd_mid);
+        CHECK(compile_const_prefix(iseq, RNODE_COLON2(node)->nd_head, pref, body));
+        debugi("compile_const_prefix - colon2", RNODE_COLON2(node)->nd_mid);
         ADD_INSN1(body, node, putobject, Qfalse);
-        ADD_INSN1(body, node, getconstant, ID2SYM(node->nd_mid));
+        ADD_INSN1(body, node, getconstant, ID2SYM(RNODE_COLON2(node)->nd_mid));
         break;
       default:
         CHECK(COMPILE(pref, "const colon2 prefix", node));
@@ -5336,9 +5336,9 @@ compile_cpath(LINK_ANCHOR *const ret, rb_iseq_t *iseq, const NODE *cpath)
         ADD_INSN1(ret, cpath, putobject, rb_cObject);
         return VM_DEFINECLASS_FLAG_SCOPED;
     }
-    else if (cpath->nd_head) {
+    else if (RNODE_COLON2(cpath)->nd_head) {
         /* Bar::Foo */
-        NO_CHECK(COMPILE(ret, "nd_else->nd_head", cpath->nd_head));
+        NO_CHECK(COMPILE(ret, "nd_else->nd_head", RNODE_COLON2(cpath)->nd_head));
         return VM_DEFINECLASS_FLAG_SCOPED;
     }
     else {
@@ -5352,9 +5352,9 @@ compile_cpath(LINK_ANCHOR *const ret, rb_iseq_t *iseq, const NODE *cpath)
 static inline int
 private_recv_p(const NODE *node)
 {
-    if (nd_type_p(node->nd_recv, NODE_SELF)) {
-        NODE *self = node->nd_recv;
-        return self->nd_state != 0;
+    if (nd_type_p(RNODE_CALL(node)->nd_recv, NODE_SELF)) {
+        NODE *self = RNODE_CALL(node)->nd_recv;
+        return RNODE_SELF(self)->nd_state != 0;
     }
     return 0;
 }
@@ -5396,13 +5396,13 @@ defined_expr0(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
         const NODE *vals = node;
 
         do {
-            defined_expr0(iseq, ret, vals->nd_head, lfinish, Qfalse, false);
+            defined_expr0(iseq, ret, RNODE_LIST(vals)->nd_head, lfinish, Qfalse, false);
 
             if (!lfinish[1]) {
                 lfinish[1] = NEW_LABEL(line);
             }
             ADD_INSNL(ret, line_node, branchunless, lfinish[1]);
-        } while ((vals = vals->nd_next) != NULL);
+        } while ((vals = RNODE_LIST(vals)->nd_next) != NULL);
       }
         /* fall through */
       case NODE_STR:
@@ -5423,47 +5423,47 @@ defined_expr0(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
 #define PUSH_VAL(type) (needstr == Qfalse ? Qtrue : rb_iseq_defined_string(type))
       case NODE_IVAR:
         ADD_INSN3(ret, line_node, definedivar,
-                  ID2SYM(node->nd_vid), get_ivar_ic_value(iseq,node->nd_vid), PUSH_VAL(DEFINED_IVAR));
+                  ID2SYM(RNODE_IVAR(node)->nd_vid), get_ivar_ic_value(iseq,RNODE_IVAR(node)->nd_vid), PUSH_VAL(DEFINED_IVAR));
         return;
 
       case NODE_GVAR:
         ADD_INSN(ret, line_node, putnil);
         ADD_INSN3(ret, line_node, defined, INT2FIX(DEFINED_GVAR),
-                  ID2SYM(node->nd_vid), PUSH_VAL(DEFINED_GVAR));
+                  ID2SYM(RNODE_GVAR(node)->nd_vid), PUSH_VAL(DEFINED_GVAR));
         return;
 
       case NODE_CVAR:
         ADD_INSN(ret, line_node, putnil);
         ADD_INSN3(ret, line_node, defined, INT2FIX(DEFINED_CVAR),
-                  ID2SYM(node->nd_vid), PUSH_VAL(DEFINED_CVAR));
+                  ID2SYM(RNODE_CVAR(node)->nd_vid), PUSH_VAL(DEFINED_CVAR));
         return;
 
       case NODE_CONST:
         ADD_INSN(ret, line_node, putnil);
         ADD_INSN3(ret, line_node, defined, INT2FIX(DEFINED_CONST),
-                  ID2SYM(node->nd_vid), PUSH_VAL(DEFINED_CONST));
+                  ID2SYM(RNODE_CONST(node)->nd_vid), PUSH_VAL(DEFINED_CONST));
         return;
       case NODE_COLON2:
         if (!lfinish[1]) {
             lfinish[1] = NEW_LABEL(line);
         }
-        defined_expr0(iseq, ret, node->nd_head, lfinish, Qfalse, false);
+        defined_expr0(iseq, ret, RNODE_COLON2(node)->nd_head, lfinish, Qfalse, false);
         ADD_INSNL(ret, line_node, branchunless, lfinish[1]);
-        NO_CHECK(COMPILE(ret, "defined/colon2#nd_head", node->nd_head));
+        NO_CHECK(COMPILE(ret, "defined/colon2#nd_head", RNODE_COLON2(node)->nd_head));
 
-        if (rb_is_const_id(node->nd_mid)) {
+        if (rb_is_const_id(RNODE_COLON2(node)->nd_mid)) {
             ADD_INSN3(ret, line_node, defined, INT2FIX(DEFINED_CONST_FROM),
-                    ID2SYM(node->nd_mid), PUSH_VAL(DEFINED_CONST));
+                    ID2SYM(RNODE_COLON2(node)->nd_mid), PUSH_VAL(DEFINED_CONST));
         }
         else {
             ADD_INSN3(ret, line_node, defined, INT2FIX(DEFINED_METHOD),
-                    ID2SYM(node->nd_mid), PUSH_VAL(DEFINED_METHOD));
+                    ID2SYM(RNODE_COLON2(node)->nd_mid), PUSH_VAL(DEFINED_METHOD));
         }
         return;
       case NODE_COLON3:
         ADD_INSN1(ret, line_node, putobject, rb_cObject);
         ADD_INSN3(ret, line_node, defined,
-                  INT2FIX(DEFINED_CONST_FROM), ID2SYM(node->nd_mid), PUSH_VAL(DEFINED_CONST));
+                  INT2FIX(DEFINED_CONST_FROM), ID2SYM(RNODE_COLON3(node)->nd_mid), PUSH_VAL(DEFINED_CONST));
         return;
 
         /* method dispatch */
@@ -5476,7 +5476,7 @@ defined_expr0(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
             (type == NODE_CALL || type == NODE_OPCALL ||
              (type == NODE_ATTRASGN && !private_recv_p(node)));
 
-        if (node->nd_args || explicit_receiver) {
+        if (RNODE_CALL(node)->nd_args || explicit_receiver) {
             if (!lfinish[1]) {
                 lfinish[1] = NEW_LABEL(line);
             }
@@ -5484,31 +5484,31 @@ defined_expr0(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
                 lfinish[2] = NEW_LABEL(line);
             }
         }
-        if (node->nd_args) {
-            defined_expr0(iseq, ret, node->nd_args, lfinish, Qfalse, false);
+        if (RNODE_CALL(node)->nd_args) {
+            defined_expr0(iseq, ret, RNODE_CALL(node)->nd_args, lfinish, Qfalse, false);
             ADD_INSNL(ret, line_node, branchunless, lfinish[1]);
         }
         if (explicit_receiver) {
-            defined_expr0(iseq, ret, node->nd_recv, lfinish, Qfalse, true);
-            switch (nd_type(node->nd_recv)) {
+            defined_expr0(iseq, ret, RNODE_CALL(node)->nd_recv, lfinish, Qfalse, true);
+            switch (nd_type(RNODE_CALL(node)->nd_recv)) {
               case NODE_CALL:
               case NODE_OPCALL:
               case NODE_VCALL:
               case NODE_FCALL:
               case NODE_ATTRASGN:
                 ADD_INSNL(ret, line_node, branchunless, lfinish[2]);
-                compile_call(iseq, ret, node->nd_recv, nd_type(node->nd_recv), line_node, 0, true);
+                compile_call(iseq, ret, RNODE_CALL(node)->nd_recv, nd_type(RNODE_CALL(node)->nd_recv), line_node, 0, true);
                 break;
               default:
                 ADD_INSNL(ret, line_node, branchunless, lfinish[1]);
-                NO_CHECK(COMPILE(ret, "defined/recv", node->nd_recv));
+                NO_CHECK(COMPILE(ret, "defined/recv", RNODE_CALL(node)->nd_recv));
                 break;
             }
             if (keep_result) {
                 ADD_INSN(ret, line_node, dup);
             }
             ADD_INSN3(ret, line_node, defined, INT2FIX(DEFINED_METHOD),
-                      ID2SYM(node->nd_mid), PUSH_VAL(DEFINED_METHOD));
+                      ID2SYM(RNODE_CALL(node)->nd_mid), PUSH_VAL(DEFINED_METHOD));
         }
         else {
             ADD_INSN(ret, line_node, putself);
@@ -5516,7 +5516,7 @@ defined_expr0(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
                 ADD_INSN(ret, line_node, dup);
             }
             ADD_INSN3(ret, line_node, defined, INT2FIX(DEFINED_FUNC),
-                      ID2SYM(node->nd_mid), PUSH_VAL(DEFINED_METHOD));
+                      ID2SYM(RNODE_CALL(node)->nd_mid), PUSH_VAL(DEFINED_METHOD));
         }
         return;
       }
@@ -5531,7 +5531,7 @@ defined_expr0(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
       case NODE_NTH_REF:
         ADD_INSN(ret, line_node, putnil);
         ADD_INSN3(ret, line_node, defined, INT2FIX(DEFINED_REF),
-                  INT2FIX((node->nd_nth << 1) | (type == NODE_BACK_REF)),
+                  INT2FIX((RNODE_BACK_REF(node)->nd_nth << 1) | (type == NODE_BACK_REF)),
                   PUSH_VAL(DEFINED_GVAR));
         return;
 
@@ -5607,7 +5607,7 @@ compile_defined_expr(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const
 {
     const int line = nd_line(node);
     const NODE *line_node = node;
-    if (!node->nd_head) {
+    if (!RNODE_DEFINED(node)->nd_head) {
         VALUE str = rb_iseq_defined_string(DEFINED_NIL);
         ADD_INSN1(ret, line_node, putobject, str);
     }
@@ -5617,7 +5617,7 @@ compile_defined_expr(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const
         lfinish[0] = NEW_LABEL(line);
         lfinish[1] = 0;
         lfinish[2] = 0;
-        defined_expr(iseq, ret, node->nd_head, lfinish, needstr);
+        defined_expr(iseq, ret, RNODE_DEFINED(node)->nd_head, lfinish, needstr);
         if (lfinish[1]) {
             ELEM_INSERT_NEXT(last, &new_insn_body(iseq, line_node, BIN(putnil), 0)->link);
             ADD_INSN(ret, line_node, swap);
@@ -5741,10 +5741,10 @@ check_keyword(const NODE *node)
     /* This check is essentially a code clone of compile_keyword_arg. */
 
     if (nd_type_p(node, NODE_LIST)) {
-        while (node->nd_next) {
-            node = node->nd_next;
+        while (RNODE_LIST(node)->nd_next) {
+            node = RNODE_LIST(node)->nd_next;
         }
-        node = node->nd_head;
+        node = RNODE_LIST(node)->nd_head;
     }
 
     return keyword_node_p(node);
@@ -5756,9 +5756,9 @@ keyword_node_single_splat_p(NODE *kwnode)
 {
     RUBY_ASSERT(keyword_node_p(kwnode));
 
-    NODE *node = kwnode->nd_head;
-    return node->nd_head == NULL &&
-           node->nd_next->nd_next == NULL;
+    NODE *node = RNODE_HASH(kwnode)->nd_head;
+    return RNODE_LIST(node)->nd_head == NULL &&
+           RNODE_LIST(RNODE_LIST(node)->nd_next)->nd_next == NULL;
 }
 
 static int
@@ -5788,7 +5788,7 @@ setup_args_core(rb_iseq_t *iseq, LINK_ANCHOR *const args, const NODE *argn,
       }
       case NODE_SPLAT: {
           // f(*a)
-          NO_CHECK(COMPILE(args, "args (splat)", argn->nd_head));
+          NO_CHECK(COMPILE(args, "args (splat)", RNODE_SPLAT(argn)->nd_head));
           ADD_INSN1(args, argn, splatarray, RBOOL(dup_rest));
           if (flag_ptr) *flag_ptr |= VM_CALL_ARGS_SPLAT;
           RUBY_ASSERT(flag_ptr == NULL || (*flag_ptr & VM_CALL_KW_SPLAT) == 0);
@@ -5796,19 +5796,19 @@ setup_args_core(rb_iseq_t *iseq, LINK_ANCHOR *const args, const NODE *argn,
       }
       case NODE_ARGSCAT: {
           if (flag_ptr) *flag_ptr |= VM_CALL_ARGS_SPLAT;
-          int argc = setup_args_core(iseq, args, argn->nd_head, 1, NULL, NULL);
+          int argc = setup_args_core(iseq, args, RNODE_ARGSCAT(argn)->nd_head, 1, NULL, NULL);
 
-          if (nd_type_p(argn->nd_body, NODE_LIST)) {
-              int rest_len = compile_args(iseq, args, argn->nd_body, &kwnode);
+          if (nd_type_p(RNODE_ARGSCAT(argn)->nd_body, NODE_LIST)) {
+              int rest_len = compile_args(iseq, args, RNODE_ARGSCAT(argn)->nd_body, &kwnode);
               if (kwnode) rest_len--;
               ADD_INSN1(args, argn, newarray, INT2FIX(rest_len));
           }
           else {
-              RUBY_ASSERT(!check_keyword(argn->nd_body));
-              NO_CHECK(COMPILE(args, "args (cat: splat)", argn->nd_body));
+              RUBY_ASSERT(!check_keyword(RNODE_ARGSCAT(argn)->nd_body));
+              NO_CHECK(COMPILE(args, "args (cat: splat)", RNODE_ARGSCAT(argn)->nd_body));
           }
 
-          if (nd_type_p(argn->nd_head, NODE_LIST)) {
+          if (nd_type_p(RNODE_ARGSCAT(argn)->nd_head, NODE_LIST)) {
               ADD_INSN1(args, argn, splatarray, Qtrue);
               argc += 1;
           }
@@ -5830,21 +5830,21 @@ setup_args_core(rb_iseq_t *iseq, LINK_ANCHOR *const args, const NODE *argn,
       }
       case NODE_ARGSPUSH: {
           if (flag_ptr) *flag_ptr |= VM_CALL_ARGS_SPLAT;
-          int argc = setup_args_core(iseq, args, argn->nd_head, 1, NULL, NULL);
+          int argc = setup_args_core(iseq, args, RNODE_ARGSPUSH(argn)->nd_head, 1, NULL, NULL);
 
-          if (nd_type_p(argn->nd_body, NODE_LIST)) {
-              int rest_len = compile_args(iseq, args, argn->nd_body, &kwnode);
+          if (nd_type_p(RNODE_ARGSPUSH(argn)->nd_body, NODE_LIST)) {
+              int rest_len = compile_args(iseq, args, RNODE_ARGSPUSH(argn)->nd_body, &kwnode);
               if (kwnode) rest_len--;
               ADD_INSN1(args, argn, newarray, INT2FIX(rest_len));
               ADD_INSN1(args, argn, newarray, INT2FIX(1));
               ADD_INSN(args, argn, concatarray);
           }
           else {
-              if (keyword_node_p(argn->nd_body)) {
-                  kwnode = argn->nd_body;
+              if (keyword_node_p(RNODE_ARGSPUSH(argn)->nd_body)) {
+                  kwnode = RNODE_ARGSPUSH(argn)->nd_body;
               }
               else {
-                  NO_CHECK(COMPILE(args, "args (cat: splat)", argn->nd_body));
+                  NO_CHECK(COMPILE(args, "args (cat: splat)", RNODE_ARGSPUSH(argn)->nd_body));
                   ADD_INSN1(args, argn, newarray, INT2FIX(1));
                   ADD_INSN(args, argn, concatarray);
               }
@@ -5877,7 +5877,7 @@ setup_args(rb_iseq_t *iseq, LINK_ANCHOR *const args, const NODE *argn,
         unsigned int dup_rest = 1;
         DECL_ANCHOR(arg_block);
         INIT_ANCHOR(arg_block);
-        NO_CHECK(COMPILE(arg_block, "block", argn->nd_body));
+        NO_CHECK(COMPILE(arg_block, "block", RNODE_BLOCK_PASS(argn)->nd_body));
 
         *flag |= VM_CALL_ARGS_BLOCKARG;
 
@@ -5891,7 +5891,7 @@ setup_args(rb_iseq_t *iseq, LINK_ANCHOR *const args, const NODE *argn,
                 dup_rest = 0;
             }
         }
-        ret = INT2FIX(setup_args_core(iseq, args, argn->nd_head, dup_rest, flag, keywords));
+        ret = INT2FIX(setup_args_core(iseq, args, RNODE_BLOCK_PASS(argn)->nd_head, dup_rest, flag, keywords));
         ADD_SEQ(args, arg_block);
     }
     else {
@@ -5931,19 +5931,19 @@ compile_named_capture_assign(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE
     ADD_INSN(ret, line_node, dup);
     ADD_INSNL(ret, line_node, branchunless, fail_label);
 
-    for (vars = node; vars; vars = vars->nd_next) {
+    for (vars = node; vars; vars = RNODE_BLOCK(vars)->nd_next) {
         INSN *cap;
-        if (vars->nd_next) {
+        if (RNODE_BLOCK(vars)->nd_next) {
             ADD_INSN(ret, line_node, dup);
         }
         last = ret->last;
-        NO_CHECK(COMPILE_POPPED(ret, "capture", vars->nd_head));
+        NO_CHECK(COMPILE_POPPED(ret, "capture", RNODE_BLOCK(vars)->nd_head));
         last = last->next; /* putobject :var */
         cap = new_insn_send(iseq, line_node, idAREF, INT2FIX(1),
                             NULL, INT2FIX(0), NULL);
         ELEM_INSERT_PREV(last->next, (LINK_ELEMENT *)cap);
 #if !defined(NAMED_CAPTURE_SINGLE_OPT) || NAMED_CAPTURE_SINGLE_OPT-0
-        if (!vars->nd_next && vars == node) {
+        if (!RNODE_BLOCK(vars)->nd_next && vars == node) {
             /* only one name */
             DECL_ANCHOR(nom);
 
@@ -5964,9 +5964,9 @@ compile_named_capture_assign(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE
     ADD_INSNL(ret, line_node, jump, end_label);
     ADD_LABEL(ret, fail_label);
     ADD_INSN(ret, line_node, pop);
-    for (vars = node; vars; vars = vars->nd_next) {
+    for (vars = node; vars; vars = RNODE_BLOCK(vars)->nd_next) {
         last = ret->last;
-        NO_CHECK(COMPILE_POPPED(ret, "capture", vars->nd_head));
+        NO_CHECK(COMPILE_POPPED(ret, "capture", RNODE_BLOCK(vars)->nd_head));
         last = last->next; /* putobject :var */
         ((INSN*)last)->insn_id = BIN(putnil);
         ((INSN*)last)->operand_size = 0;
@@ -5980,7 +5980,7 @@ optimizable_range_item_p(const NODE *n)
     if (!n) return FALSE;
     switch (nd_type(n)) {
       case NODE_LIT:
-        return RB_INTEGER_TYPE_P(n->nd_lit);
+        return RB_INTEGER_TYPE_P(RNODE_LIT(n)->nd_lit);
       case NODE_NIL:
         return TRUE;
       default:
@@ -5991,8 +5991,8 @@ optimizable_range_item_p(const NODE *n)
 static int
 compile_if(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int popped, const enum node_type type)
 {
-    const NODE *const node_body = type == NODE_IF ? node->nd_body : node->nd_else;
-    const NODE *const node_else = type == NODE_IF ? node->nd_else : node->nd_body;
+    const NODE *const node_body = type == NODE_IF ? RNODE_IF(node)->nd_body : RNODE_UNLESS(node)->nd_else;
+    const NODE *const node_else = type == NODE_IF ? RNODE_IF(node)->nd_else : RNODE_UNLESS(node)->nd_body;
 
     const int line = nd_line(node);
     const NODE *line_node = node;
@@ -6005,7 +6005,7 @@ compile_if(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int
     else_label = NEW_LABEL(line);
     end_label = 0;
 
-    compile_branch_condition(iseq, cond_seq, node->nd_cond, then_label, else_label);
+    compile_branch_condition(iseq, cond_seq, RNODE_IF(node)->nd_cond, then_label, else_label);
     ADD_SEQ(ret, cond_seq);
 
     if (then_label->refcnt && else_label->refcnt) {
@@ -6085,11 +6085,11 @@ compile_case(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_nod
 
     RHASH_TBL_RAW(literals)->type = &cdhash_type;
 
-    CHECK(COMPILE(head, "case base", node->nd_head));
+    CHECK(COMPILE(head, "case base", RNODE_CASE(node)->nd_head));
 
     branches = decl_branch_base(iseq, node, "case");
 
-    node = node->nd_body;
+    node = RNODE_CASE(node)->nd_body;
     EXPECT_NODE("NODE_CASE", node, NODE_WHEN, COMPILE_NG);
     type = nd_type(node);
     line = nd_line(node);
@@ -6109,14 +6109,14 @@ compile_case(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_nod
         add_trace_branch_coverage(
                 iseq,
                 body_seq,
-                node->nd_body ? node->nd_body : node,
+                RNODE_WHEN(node)->nd_body ? RNODE_WHEN(node)->nd_body : node,
                 branch_id++,
                 "when",
                 branches);
-        CHECK(COMPILE_(body_seq, "when body", node->nd_body, popped));
+        CHECK(COMPILE_(body_seq, "when body", RNODE_WHEN(node)->nd_body, popped));
         ADD_INSNL(body_seq, line_node, jump, endlabel);
 
-        vals = node->nd_head;
+        vals = RNODE_WHEN(node)->nd_head;
         if (vals) {
             switch (nd_type(vals)) {
               case NODE_LIST:
@@ -6137,7 +6137,7 @@ compile_case(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_nod
             EXPECT_NODE_NONULL("NODE_CASE", node, NODE_LIST, COMPILE_NG);
         }
 
-        node = node->nd_next;
+        node = RNODE_WHEN(node)->nd_next;
         if (!node) {
             break;
         }
@@ -6182,7 +6182,7 @@ compile_case2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_no
 {
     const NODE *vals;
     const NODE *val;
-    const NODE *node = orig_node->nd_body;
+    const NODE *node = RNODE_CASE2(orig_node)->nd_body;
     LABEL *endlabel;
     DECL_ANCHOR(body_seq);
     VALUE branches = Qfalse;
@@ -6200,14 +6200,14 @@ compile_case2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_no
         add_trace_branch_coverage(
                 iseq,
                 body_seq,
-                node->nd_body ? node->nd_body : node,
+                RNODE_WHEN(node)->nd_body ? RNODE_WHEN(node)->nd_body : node,
                 branch_id++,
                 "when",
                 branches);
-        CHECK(COMPILE_(body_seq, "when", node->nd_body, popped));
+        CHECK(COMPILE_(body_seq, "when", RNODE_WHEN(node)->nd_body, popped));
         ADD_INSNL(body_seq, node, jump, endlabel);
 
-        vals = node->nd_head;
+        vals = RNODE_WHEN(node)->nd_head;
         if (!vals) {
             EXPECT_NODE_NONULL("NODE_WHEN", node, NODE_LIST, COMPILE_NG);
         }
@@ -6215,12 +6215,12 @@ compile_case2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_no
           case NODE_LIST:
             while (vals) {
                 LABEL *lnext;
-                val = vals->nd_head;
+                val = RNODE_LIST(vals)->nd_head;
                 lnext = NEW_LABEL(nd_line(val));
                 debug_compile("== when2\n", (void)0);
                 CHECK(compile_branch_condition(iseq, ret, val, l1, lnext));
                 ADD_LABEL(ret, lnext);
-                vals = vals->nd_next;
+                vals = RNODE_LIST(vals)->nd_next;
             }
             break;
           case NODE_SPLAT:
@@ -6234,7 +6234,7 @@ compile_case2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_no
           default:
             UNKNOWN_NODE("NODE_WHEN", vals, COMPILE_NG);
         }
-        node = node->nd_next;
+        node = RNODE_WHEN(node)->nd_next;
     }
     /* else */
     add_trace_branch_coverage(
@@ -6326,10 +6326,10 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
          * match_failed:
          *   goto unmatched
          */
-        struct rb_ary_pattern_info *apinfo = node->nd_apinfo;
+        struct rb_ary_pattern_info *apinfo = RNODE_ARYPTN(node)->nd_apinfo;
         const NODE *args = apinfo->pre_args;
-        const int pre_args_num = apinfo->pre_args ? rb_long2int(apinfo->pre_args->nd_alen) : 0;
-        const int post_args_num = apinfo->post_args ? rb_long2int(apinfo->post_args->nd_alen) : 0;
+        const int pre_args_num = apinfo->pre_args ? rb_long2int(RNODE_LIST(apinfo->pre_args)->as.nd_alen) : 0;
+        const int post_args_num = apinfo->post_args ? rb_long2int(RNODE_LIST(apinfo->post_args)->as.nd_alen) : 0;
 
         const int min_argc = pre_args_num + post_args_num;
         const int use_rest_num = apinfo->rest_arg && (NODE_NAMED_REST_P(apinfo->rest_arg) ||
@@ -6370,8 +6370,8 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
             ADD_INSN(ret, line_node, dup);
             ADD_INSN1(ret, line_node, putobject, INT2FIX(i));
             ADD_SEND(ret, line_node, idAREF, INT2FIX(1)); // (2)
-            CHECK(iseq_compile_pattern_match(iseq, ret, args->nd_head, match_failed, in_single_pattern, in_alt_pattern, base_index + 1 /* (2) */, false));
-            args = args->nd_next;
+            CHECK(iseq_compile_pattern_match(iseq, ret, RNODE_LIST(args)->nd_head, match_failed, in_single_pattern, in_alt_pattern, base_index + 1 /* (2) */, false));
+            args = RNODE_LIST(args)->nd_next;
         }
 
         if (apinfo->rest_arg) {
@@ -6408,8 +6408,8 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
             ADD_SEND(ret, line_node, idPLUS, INT2FIX(1));
 
             ADD_SEND(ret, line_node, idAREF, INT2FIX(1)); // (4)
-            CHECK(iseq_compile_pattern_match(iseq, ret, args->nd_head, match_failed, in_single_pattern, in_alt_pattern, base_index + 1 /* (4) */, false));
-            args = args->nd_next;
+            CHECK(iseq_compile_pattern_match(iseq, ret, RNODE_LIST(args)->nd_head, match_failed, in_single_pattern, in_alt_pattern, base_index + 1 /* (4) */, false));
+            args = RNODE_LIST(args)->nd_next;
         }
 
         ADD_INSN(ret, line_node, pop);
@@ -6487,9 +6487,9 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
          * match_failed:
          *   goto unmatched
          */
-        struct rb_fnd_pattern_info *fpinfo = node->nd_fpinfo;
+        struct rb_fnd_pattern_info *fpinfo = RNODE_FNDPTN(node)->nd_fpinfo;
         const NODE *args = fpinfo->args;
-        const int args_num = fpinfo->args ? rb_long2int(fpinfo->args->nd_alen) : 0;
+        const int args_num = fpinfo->args ? rb_long2int(RNODE_LIST(fpinfo->args)->as.nd_alen) : 0;
 
         LABEL *match_failed, *type_error, *deconstruct, *deconstructed;
         match_failed = NEW_LABEL(line);
@@ -6542,8 +6542,8 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
                 }
                 ADD_SEND(ret, line_node, idAREF, INT2FIX(1)); // (5)
 
-                CHECK(iseq_compile_pattern_match(iseq, ret, args->nd_head, next_loop, in_single_pattern, in_alt_pattern, base_index + 4 /* (2), (3), (4), (5) */, false));
-                args = args->nd_next;
+                CHECK(iseq_compile_pattern_match(iseq, ret, RNODE_LIST(args)->nd_head, next_loop, in_single_pattern, in_alt_pattern, base_index + 4 /* (2), (3), (4), (5) */, false));
+                args = RNODE_LIST(args)->nd_next;
             }
 
             if (NODE_NAMED_REST_P(fpinfo->pre_rest_arg)) {
@@ -6674,12 +6674,12 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
         match_failed = NEW_LABEL(line);
         type_error = NEW_LABEL(line);
 
-        if (node->nd_pkwargs && !node->nd_pkwrestarg) {
-            const NODE *kw_args = node->nd_pkwargs->nd_head;
-            keys = rb_ary_new_capa(kw_args ? kw_args->nd_alen/2 : 0);
+        if (RNODE_HSHPTN(node)->nd_pkwargs && !RNODE_HSHPTN(node)->nd_pkwrestarg) {
+            const NODE *kw_args = RNODE_HASH(RNODE_HSHPTN(node)->nd_pkwargs)->nd_head;
+            keys = rb_ary_new_capa(kw_args ? RNODE_LIST(kw_args)->as.nd_alen/2 : 0);
             while (kw_args) {
-                rb_ary_push(keys, kw_args->nd_head->nd_lit);
-                kw_args = kw_args->nd_next->nd_next;
+                rb_ary_push(keys, RNODE_LIT(RNODE_LIST(kw_args)->nd_head)->nd_lit);
+                kw_args = RNODE_LIST(RNODE_LIST(kw_args)->nd_next)->nd_next;
             }
         }
 
@@ -6706,28 +6706,28 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
         ADD_INSN1(ret, line_node, checktype, INT2FIX(T_HASH));
         ADD_INSNL(ret, line_node, branchunless, type_error);
 
-        if (node->nd_pkwrestarg) {
+        if (RNODE_HSHPTN(node)->nd_pkwrestarg) {
             ADD_SEND(ret, line_node, rb_intern("dup"), INT2FIX(0));
         }
 
-        if (node->nd_pkwargs) {
+        if (RNODE_HSHPTN(node)->nd_pkwargs) {
             int i;
             int keys_num;
             const NODE *args;
-            args = node->nd_pkwargs->nd_head;
+            args = RNODE_HASH(RNODE_HSHPTN(node)->nd_pkwargs)->nd_head;
             if (args) {
                 DECL_ANCHOR(match_values);
                 INIT_ANCHOR(match_values);
-                keys_num = rb_long2int(args->nd_alen) / 2;
+                keys_num = rb_long2int(RNODE_LIST(args)->as.nd_alen) / 2;
                 for (i = 0; i < keys_num; i++) {
-                    NODE *key_node = args->nd_head;
-                    NODE *value_node = args->nd_next->nd_head;
+                    NODE *key_node = RNODE_LIST(args)->nd_head;
+                    NODE *value_node = RNODE_LIST(RNODE_LIST(args)->nd_next)->nd_head;
                     VALUE key;
 
                     if (!nd_type_p(key_node, NODE_LIT)) {
                         UNKNOWN_NODE("NODE_IN", key_node, COMPILE_NG);
                     }
-                    key = key_node->nd_lit;
+                    key = RNODE_LIT(key_node)->nd_lit;
 
                     ADD_INSN(ret, line_node, dup);
                     ADD_INSN1(ret, line_node, putobject, key);
@@ -6756,9 +6756,9 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
 
                     ADD_INSN(match_values, line_node, dup);
                     ADD_INSN1(match_values, line_node, putobject, key);
-                    ADD_SEND(match_values, line_node, node->nd_pkwrestarg ? rb_intern("delete") : idAREF, INT2FIX(1)); // (8)
+                    ADD_SEND(match_values, line_node, RNODE_HSHPTN(node)->nd_pkwrestarg ? rb_intern("delete") : idAREF, INT2FIX(1)); // (8)
                     CHECK(iseq_compile_pattern_match(iseq, match_values, value_node, match_failed, in_single_pattern, in_alt_pattern, base_index + 1 /* (8) */, false));
-                    args = args->nd_next->nd_next;
+                    args = RNODE_LIST(RNODE_LIST(args)->nd_next)->nd_next;
                 }
                 ADD_SEQ(ret, match_values);
             }
@@ -6772,8 +6772,8 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
             ADD_INSNL(ret, line_node, branchunless, match_failed);
         }
 
-        if (node->nd_pkwrestarg) {
-            if (node->nd_pkwrestarg == NODE_SPECIAL_NO_REST_KEYWORD) {
+        if (RNODE_HSHPTN(node)->nd_pkwrestarg) {
+            if (RNODE_HSHPTN(node)->nd_pkwrestarg == NODE_SPECIAL_NO_REST_KEYWORD) {
                 ADD_INSN(ret, line_node, dup);
                 ADD_SEND(ret, line_node, idEmptyP, INT2FIX(0)); // (10)
                 if (in_single_pattern) {
@@ -6783,7 +6783,7 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
             }
             else {
                 ADD_INSN(ret, line_node, dup); // (11)
-                CHECK(iseq_compile_pattern_match(iseq, ret, node->nd_pkwrestarg, match_failed, in_single_pattern, in_alt_pattern, base_index + 1 /* (11) */, false));
+                CHECK(iseq_compile_pattern_match(iseq, ret, RNODE_HSHPTN(node)->nd_pkwrestarg, match_failed, in_single_pattern, in_alt_pattern, base_index + 1 /* (11) */, false));
             }
         }
 
@@ -6840,7 +6840,7 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
         break;
       case NODE_LASGN: {
         struct rb_iseq_constant_body *const body = ISEQ_BODY(iseq);
-        ID id = node->nd_vid;
+        ID id = RNODE_LASGN(node)->nd_vid;
         int idx = ISEQ_BODY(body->local_iseq)->local_table_size - get_local_var_idx(iseq, id);
 
         if (in_alt_pattern) {
@@ -6858,7 +6858,7 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
       }
       case NODE_DASGN: {
         int idx, lv, ls;
-        ID id = node->nd_vid;
+        ID id = RNODE_DASGN(node)->nd_vid;
 
         idx = get_dyna_var_idx(iseq, id, &lv, &ls);
 
@@ -6884,8 +6884,8 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
       case NODE_UNLESS: {
         LABEL *match_failed;
         match_failed = unmatched;
-        CHECK(iseq_compile_pattern_match(iseq, ret, node->nd_body, unmatched, in_single_pattern, in_alt_pattern, base_index, use_deconstructed_cache));
-        CHECK(COMPILE(ret, "case in if", node->nd_cond));
+        CHECK(iseq_compile_pattern_match(iseq, ret, RNODE_IF(node)->nd_body, unmatched, in_single_pattern, in_alt_pattern, base_index, use_deconstructed_cache));
+        CHECK(COMPILE(ret, "case in if", RNODE_IF(node)->nd_cond));
         if (in_single_pattern) {
             LABEL *match_succeeded;
             match_succeeded = NEW_LABEL(line);
@@ -6922,15 +6922,15 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
         LABEL *match_failed;
         match_failed = NEW_LABEL(line);
 
-        n = node->nd_head;
-        if (! (nd_type_p(n, NODE_LIST) && n->nd_alen == 2)) {
+        n = RNODE_HASH(node)->nd_head;
+        if (! (nd_type_p(n, NODE_LIST) && RNODE_LIST(n)->as.nd_alen == 2)) {
             COMPILE_ERROR(ERROR_ARGS "unexpected node");
             return COMPILE_NG;
         }
 
         ADD_INSN(ret, line_node, dup); // (1)
-        CHECK(iseq_compile_pattern_match(iseq, ret, n->nd_head, match_failed, in_single_pattern, in_alt_pattern, base_index + 1 /* (1) */, use_deconstructed_cache));
-        CHECK(iseq_compile_pattern_each(iseq, ret, n->nd_next->nd_head, matched, match_failed, in_single_pattern, in_alt_pattern, base_index, false));
+        CHECK(iseq_compile_pattern_match(iseq, ret, RNODE_LIST(n)->nd_head, match_failed, in_single_pattern, in_alt_pattern, base_index + 1 /* (1) */, use_deconstructed_cache));
+        CHECK(iseq_compile_pattern_each(iseq, ret, RNODE_LIST(RNODE_LIST(n)->nd_next)->nd_head, matched, match_failed, in_single_pattern, in_alt_pattern, base_index, false));
         ADD_INSN(ret, line_node, putnil);
 
         ADD_LABEL(ret, match_failed);
@@ -6944,13 +6944,13 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
         fin = NEW_LABEL(line);
 
         ADD_INSN(ret, line_node, dup); // (1)
-        CHECK(iseq_compile_pattern_each(iseq, ret, node->nd_1st, match_succeeded, fin, in_single_pattern, true, base_index + 1 /* (1) */, use_deconstructed_cache));
+        CHECK(iseq_compile_pattern_each(iseq, ret, RNODE_OR(node)->nd_1st, match_succeeded, fin, in_single_pattern, true, base_index + 1 /* (1) */, use_deconstructed_cache));
         ADD_LABEL(ret, match_succeeded);
         ADD_INSN(ret, line_node, pop);
         ADD_INSNL(ret, line_node, jump, matched);
         ADD_INSN(ret, line_node, putnil);
         ADD_LABEL(ret, fin);
-        CHECK(iseq_compile_pattern_each(iseq, ret, node->nd_2nd, matched, unmatched, in_single_pattern, true, base_index, use_deconstructed_cache));
+        CHECK(iseq_compile_pattern_each(iseq, ret, RNODE_OR(node)->nd_2nd, matched, unmatched, in_single_pattern, true, base_index, use_deconstructed_cache));
         break;
       }
       default:
@@ -6973,9 +6973,9 @@ iseq_compile_pattern_constant(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NOD
 {
     const NODE *line_node = node;
 
-    if (node->nd_pconst) {
+    if (RNODE_ARYPTN(node)->nd_pconst) {
         ADD_INSN(ret, line_node, dup); // (1)
-        CHECK(COMPILE(ret, "constant", node->nd_pconst)); // (2)
+        CHECK(COMPILE(ret, "constant", RNODE_ARYPTN(node)->nd_pconst)); // (2)
         if (in_single_pattern) {
             ADD_INSN1(ret, line_node, dupn, INT2FIX(2));
         }
@@ -7178,12 +7178,12 @@ compile_case3(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_no
 
     branches = decl_branch_base(iseq, node, "case");
 
-    node = node->nd_body;
+    node = RNODE_CASE3(node)->nd_body;
     EXPECT_NODE("NODE_CASE3", node, NODE_IN, COMPILE_NG);
     type = nd_type(node);
     line = nd_line(node);
     line_node = node;
-    single_pattern = !node->nd_next;
+    single_pattern = !RNODE_IN(node)->nd_next;
 
     endlabel = NEW_LABEL(line);
     elselabel = NEW_LABEL(line);
@@ -7197,7 +7197,7 @@ compile_case3(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_no
     }
     ADD_INSN(head, line_node, putnil); /* allocate stack for cached #deconstruct value */
 
-    CHECK(COMPILE(head, "case base", orig_node->nd_head));
+    CHECK(COMPILE(head, "case base", RNODE_CASE3(orig_node)->nd_head));
 
     ADD_SEQ(ret, head);	/* case VAL */
 
@@ -7213,14 +7213,14 @@ compile_case3(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_no
         add_trace_branch_coverage(
             iseq,
             body_seq,
-            node->nd_body ? node->nd_body : node,
+            RNODE_IN(node)->nd_body ? RNODE_IN(node)->nd_body : node,
             branch_id++,
             "in",
             branches);
-        CHECK(COMPILE_(body_seq, "in body", node->nd_body, popped));
+        CHECK(COMPILE_(body_seq, "in body", RNODE_IN(node)->nd_body, popped));
         ADD_INSNL(body_seq, line_node, jump, endlabel);
 
-        pattern = node->nd_head;
+        pattern = RNODE_IN(node)->nd_head;
         if (pattern) {
             int pat_line = nd_line(pattern);
             LABEL *next_pat = NEW_LABEL(pat_line);
@@ -7235,7 +7235,7 @@ compile_case3(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_no
             return COMPILE_NG;
         }
 
-        node = node->nd_next;
+        node = RNODE_IN(node)->nd_next;
         if (!node) {
             break;
         }
@@ -7360,7 +7360,7 @@ compile_loop(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, in
     ISEQ_COMPILE_DATA(iseq)->loopval_popped = 0;
     push_ensure_entry(iseq, &enl, NULL, NULL);
 
-    if (node->nd_state == 1) {
+    if (RNODE_WHILE(node)->nd_state == 1) {
         ADD_INSNL(ret, line_node, jump, next_label);
     }
     else {
@@ -7379,27 +7379,27 @@ compile_loop(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, in
     add_trace_branch_coverage(
         iseq,
         ret,
-        node->nd_body ? node->nd_body : node,
+        RNODE_WHILE(node)->nd_body ? RNODE_WHILE(node)->nd_body : node,
         0,
         "body",
         branches);
-    CHECK(COMPILE_POPPED(ret, "while body", node->nd_body));
+    CHECK(COMPILE_POPPED(ret, "while body", RNODE_WHILE(node)->nd_body));
     ADD_LABEL(ret, next_label);	/* next */
 
     if (type == NODE_WHILE) {
-        compile_branch_condition(iseq, ret, node->nd_cond,
+        compile_branch_condition(iseq, ret, RNODE_WHILE(node)->nd_cond,
                                  redo_label, end_label);
     }
     else {
         /* until */
-        compile_branch_condition(iseq, ret, node->nd_cond,
+        compile_branch_condition(iseq, ret, RNODE_WHILE(node)->nd_cond,
                                  end_label, redo_label);
     }
 
     ADD_LABEL(ret, end_label);
     ADD_ADJUST_RESTORE(ret, adjust_label);
 
-    if (UNDEF_P(node->nd_state)) {
+    if (UNDEF_P(RNODE_WHILE(node)->nd_state)) {
         /* ADD_INSN(ret, line_node, putundef); */
         COMPILE_ERROR(ERROR_ARGS "unsupported: putundef");
         return COMPILE_NG;
@@ -7441,18 +7441,18 @@ compile_iter(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, in
 
     ADD_LABEL(ret, retry_label);
     if (nd_type_p(node, NODE_FOR)) {
-        CHECK(COMPILE(ret, "iter caller (for)", node->nd_iter));
+        CHECK(COMPILE(ret, "iter caller (for)", RNODE_FOR(node)->nd_iter));
 
         ISEQ_COMPILE_DATA(iseq)->current_block = child_iseq =
-            NEW_CHILD_ISEQ(node->nd_body, make_name_for_block(iseq),
+            NEW_CHILD_ISEQ(RNODE_FOR(node)->nd_body, make_name_for_block(iseq),
                            ISEQ_TYPE_BLOCK, line);
         ADD_SEND_WITH_BLOCK(ret, line_node, idEach, INT2FIX(0), child_iseq);
     }
     else {
         ISEQ_COMPILE_DATA(iseq)->current_block = child_iseq =
-            NEW_CHILD_ISEQ(node->nd_body, make_name_for_block(iseq),
+            NEW_CHILD_ISEQ(RNODE_ITER(node)->nd_body, make_name_for_block(iseq),
                            ISEQ_TYPE_BLOCK, line);
-        CHECK(COMPILE(ret, "iter caller", node->nd_iter));
+        CHECK(COMPILE(ret, "iter caller", RNODE_ITER(node)->nd_iter));
     }
 
     {
@@ -7496,7 +7496,7 @@ compile_for_masgn(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const nod
      * (args.length == 1 && Array.try_convert(args[0])) || args
      */
     const NODE *line_node = node;
-    const NODE *var = node->nd_var;
+    const NODE *var = RNODE_FOR_MASGN(node)->nd_var;
     LABEL *not_single = NEW_LABEL(nd_line(var));
     LABEL *not_ary = NEW_LABEL(nd_line(var));
     CHECK(COMPILE(ret, "for var", var));
@@ -7531,7 +7531,7 @@ compile_break(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, i
         LABEL *splabel = NEW_LABEL(0);
         ADD_LABEL(ret, splabel);
         ADD_ADJUST(ret, line_node, ISEQ_COMPILE_DATA(iseq)->redo_label);
-        CHECK(COMPILE_(ret, "break val (while/until)", node->nd_stts,
+        CHECK(COMPILE_(ret, "break val (while/until)", RNODE_BREAK(node)->nd_stts,
                        ISEQ_COMPILE_DATA(iseq)->loopval_popped));
         add_ensure_iseq(ret, iseq, 0);
         ADD_INSNL(ret, line_node, jump, ISEQ_COMPILE_DATA(iseq)->end_label);
@@ -7566,7 +7566,7 @@ compile_break(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, i
             }
 
             /* escape from block */
-            CHECK(COMPILE(ret, "break val (block)", node->nd_stts));
+            CHECK(COMPILE(ret, "break val (block)", RNODE_BREAK(node)->nd_stts));
             ADD_INSN1(ret, line_node, throw, INT2FIX(throw_flag | TAG_BREAK));
             if (popped) {
                 ADD_INSN(ret, line_node, pop);
@@ -7589,7 +7589,7 @@ compile_next(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, in
         LABEL *splabel = NEW_LABEL(0);
         debugs("next in while loop\n");
         ADD_LABEL(ret, splabel);
-        CHECK(COMPILE(ret, "next val/valid syntax?", node->nd_stts));
+        CHECK(COMPILE(ret, "next val/valid syntax?", RNODE_NEXT(node)->nd_stts));
         add_ensure_iseq(ret, iseq, 0);
         ADD_ADJUST(ret, line_node, ISEQ_COMPILE_DATA(iseq)->redo_label);
         ADD_INSNL(ret, line_node, jump, ISEQ_COMPILE_DATA(iseq)->start_label);
@@ -7603,7 +7603,7 @@ compile_next(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, in
         debugs("next in block\n");
         ADD_LABEL(ret, splabel);
         ADD_ADJUST(ret, line_node, ISEQ_COMPILE_DATA(iseq)->start_label);
-        CHECK(COMPILE(ret, "next val", node->nd_stts));
+        CHECK(COMPILE(ret, "next val", RNODE_NEXT(node)->nd_stts));
         add_ensure_iseq(ret, iseq, 0);
         ADD_INSNL(ret, line_node, jump, ISEQ_COMPILE_DATA(iseq)->end_label);
         ADD_ADJUST_RESTORE(ret, splabel);
@@ -7638,7 +7638,7 @@ compile_next(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, in
             ip = ISEQ_BODY(ip)->parent_iseq;
         }
         if (ip != 0) {
-            CHECK(COMPILE(ret, "next val", node->nd_stts));
+            CHECK(COMPILE(ret, "next val", RNODE_NEXT(node)->nd_stts));
             ADD_INSN1(ret, line_node, throw, INT2FIX(throw_flag | TAG_NEXT));
 
             if (popped) {
@@ -7750,7 +7750,7 @@ compile_rescue(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
     LABEL *lstart = NEW_LABEL(line);
     LABEL *lend = NEW_LABEL(line);
     LABEL *lcont = NEW_LABEL(line);
-    const rb_iseq_t *rescue = NEW_CHILD_ISEQ(node->nd_resq,
+    const rb_iseq_t *rescue = NEW_CHILD_ISEQ(RNODE_RESCUE(node)->nd_resq,
                                              rb_str_concat(rb_str_new2("rescue in "),
                                                            ISEQ_BODY(iseq)->location.label),
                                              ISEQ_TYPE_RESCUE, line);
@@ -7762,14 +7762,14 @@ compile_rescue(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
     bool prev_in_rescue = ISEQ_COMPILE_DATA(iseq)->in_rescue;
     ISEQ_COMPILE_DATA(iseq)->in_rescue = true;
     {
-        CHECK(COMPILE(ret, "rescue head", node->nd_head));
+        CHECK(COMPILE(ret, "rescue head", RNODE_RESCUE(node)->nd_head));
     }
     ISEQ_COMPILE_DATA(iseq)->in_rescue = prev_in_rescue;
 
     ADD_LABEL(ret, lend);
-    if (node->nd_else) {
+    if (RNODE_RESCUE(node)->nd_else) {
         ADD_INSN(ret, line_node, pop);
-        CHECK(COMPILE(ret, "rescue else", node->nd_else));
+        CHECK(COMPILE(ret, "rescue else", RNODE_RESCUE(node)->nd_else));
     }
     ADD_INSN(ret, line_node, nop);
     ADD_LABEL(ret, lcont);
@@ -7797,16 +7797,16 @@ compile_resbody(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
         label_miss = NEW_LABEL(line);
         label_hit = NEW_LABEL(line);
 
-        narg = resq->nd_args;
+        narg = RNODE_RESBODY(resq)->nd_args;
         if (narg) {
             switch (nd_type(narg)) {
               case NODE_LIST:
                 while (narg) {
                     ADD_GETLOCAL(ret, line_node, LVAR_ERRINFO, 0);
-                    CHECK(COMPILE(ret, "rescue arg", narg->nd_head));
+                    CHECK(COMPILE(ret, "rescue arg", RNODE_LIST(narg)->nd_head));
                     ADD_INSN1(ret, line_node, checkmatch, INT2FIX(VM_CHECKMATCH_TYPE_RESCUE));
                     ADD_INSNL(ret, line_node, branchif, label_hit);
-                    narg = narg->nd_next;
+                    narg = RNODE_LIST(narg)->nd_next;
                 }
                 break;
               case NODE_SPLAT:
@@ -7831,14 +7831,14 @@ compile_resbody(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
         ADD_LABEL(ret, label_hit);
         ADD_TRACE(ret, RUBY_EVENT_RESCUE);
 
-        if (nd_type(resq->nd_body) == NODE_BEGIN && resq->nd_body->nd_body == NULL) {
+        if (nd_type(RNODE_RESBODY(resq)->nd_body) == NODE_BEGIN && RNODE_BEGIN(RNODE_RESBODY(resq)->nd_body)->nd_body == NULL) {
             // empty body
-            int lineno = nd_line(resq->nd_body);
+            int lineno = nd_line(RNODE_RESBODY(resq)->nd_body);
             NODE dummy_line_node = generate_dummy_line_node(lineno, -1);
             ADD_INSN(ret, &dummy_line_node, putnil);
         }
         else {
-            CHECK(COMPILE(ret, "resbody body", resq->nd_body));
+            CHECK(COMPILE(ret, "resbody body", RNODE_RESBODY(resq)->nd_body));
         }
 
         if (ISEQ_COMPILE_DATA(iseq)->option->tailcall_optimization) {
@@ -7846,7 +7846,7 @@ compile_resbody(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
         }
         ADD_INSN(ret, line_node, leave);
         ADD_LABEL(ret, label_miss);
-        resq = resq->nd_head;
+        resq = RNODE_RESBODY(resq)->nd_head;
     }
     return COMPILE_OK;
 }
@@ -7857,7 +7857,7 @@ compile_ensure(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
     const int line = nd_line(node);
     const NODE *line_node = node;
     DECL_ANCHOR(ensr);
-    const rb_iseq_t *ensure = NEW_CHILD_ISEQ(node->nd_ensr,
+    const rb_iseq_t *ensure = NEW_CHILD_ISEQ(RNODE_ENSURE(node)->nd_ensr,
                                              rb_str_concat(rb_str_new2 ("ensure in "), ISEQ_BODY(iseq)->location.label),
                                              ISEQ_TYPE_ENSURE, line);
     LABEL *lstart = NEW_LABEL(line);
@@ -7870,17 +7870,17 @@ compile_ensure(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
     struct ensure_range *erange;
 
     INIT_ANCHOR(ensr);
-    CHECK(COMPILE_POPPED(ensr, "ensure ensr", node->nd_ensr));
+    CHECK(COMPILE_POPPED(ensr, "ensure ensr", RNODE_ENSURE(node)->nd_ensr));
     last = ensr->last;
     last_leave = last && IS_INSN(last) && IS_INSN_ID(last, leave);
 
     er.begin = lstart;
     er.end = lend;
     er.next = 0;
-    push_ensure_entry(iseq, &enl, &er, node->nd_ensr);
+    push_ensure_entry(iseq, &enl, &er, RNODE_ENSURE(node)->nd_ensr);
 
     ADD_LABEL(ret, lstart);
-    CHECK(COMPILE_(ret, "ensure head", node->nd_head, (popped | last_leave)));
+    CHECK(COMPILE_(ret, "ensure head", RNODE_ENSURE(node)->nd_head, (popped | last_leave)));
     ADD_LABEL(ret, lend);
     ADD_SEQ(ret, ensr);
     if (!popped && last_leave) ADD_INSN(ret, line_node, putnil);
@@ -7909,7 +7909,7 @@ compile_return(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
         enum rb_iseq_type type = ISEQ_BODY(iseq)->type;
         const rb_iseq_t *is = iseq;
         enum rb_iseq_type t = type;
-        const NODE *retval = node->nd_stts;
+        const NODE *retval = RNODE_RETURN(node)->nd_stts;
         LABEL *splabel = 0;
 
         while (t == ISEQ_TYPE_RESCUE || t == ISEQ_TYPE_ENSURE) {
@@ -8018,13 +8018,13 @@ compile_call_precheck_freeze(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE
     /* optimization shortcut
      *   "literal".freeze -> opt_str_freeze("literal")
      */
-    if (node->nd_recv && nd_type_p(node->nd_recv, NODE_STR) &&
-        (node->nd_mid == idFreeze || node->nd_mid == idUMinus) &&
-        node->nd_args == NULL &&
+    if (RNODE_CALL(node)->nd_recv && nd_type_p(RNODE_CALL(node)->nd_recv, NODE_STR) &&
+        (RNODE_CALL(node)->nd_mid == idFreeze || RNODE_CALL(node)->nd_mid == idUMinus) &&
+        RNODE_CALL(node)->nd_args == NULL &&
         ISEQ_COMPILE_DATA(iseq)->current_block == NULL &&
         ISEQ_COMPILE_DATA(iseq)->option->specialized_instruction) {
-        VALUE str = rb_fstring(node->nd_recv->nd_lit);
-        if (node->nd_mid == idUMinus) {
+        VALUE str = rb_fstring(RNODE_STR(RNODE_CALL(node)->nd_recv)->nd_lit);
+        if (RNODE_CALL(node)->nd_mid == idUMinus) {
             ADD_INSN2(ret, line_node, opt_str_uminus, str,
                       new_callinfo(iseq, idUMinus, 0, 0, NULL, FALSE));
         }
@@ -8041,14 +8041,14 @@ compile_call_precheck_freeze(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE
     /* optimization shortcut
      *   obj["literal"] -> opt_aref_with(obj, "literal")
      */
-    if (node->nd_mid == idAREF && !private_recv_p(node) && node->nd_args &&
-        nd_type_p(node->nd_args, NODE_LIST) && node->nd_args->nd_alen == 1 &&
-        nd_type_p(node->nd_args->nd_head, NODE_STR) &&
+    if (RNODE_CALL(node)->nd_mid == idAREF && !private_recv_p(node) && RNODE_CALL(node)->nd_args &&
+        nd_type_p(RNODE_CALL(node)->nd_args, NODE_LIST) && RNODE_LIST(RNODE_CALL(node)->nd_args)->as.nd_alen == 1 &&
+        nd_type_p(RNODE_LIST(RNODE_CALL(node)->nd_args)->nd_head, NODE_STR) &&
         ISEQ_COMPILE_DATA(iseq)->current_block == NULL &&
         !ISEQ_COMPILE_DATA(iseq)->option->frozen_string_literal &&
         ISEQ_COMPILE_DATA(iseq)->option->specialized_instruction) {
-        VALUE str = rb_fstring(node->nd_args->nd_head->nd_lit);
-        CHECK(COMPILE(ret, "recv", node->nd_recv));
+        VALUE str = rb_fstring(RNODE_STR(RNODE_LIST(RNODE_CALL(node)->nd_args)->nd_head)->nd_lit);
+        CHECK(COMPILE(ret, "recv", RNODE_CALL(node)->nd_recv));
         ADD_INSN2(ret, line_node, opt_aref_with, str,
                   new_callinfo(iseq, idAREF, 1, 0, NULL, FALSE));
         RB_OBJ_WRITTEN(iseq, Qundef, str);
@@ -8091,12 +8091,12 @@ iseq_builtin_function_name(const enum node_type type, const NODE *recv, ID mid)
         if (recv) {
             switch (nd_type(recv)) {
               case NODE_VCALL:
-                if (recv->nd_mid == rb_intern("__builtin")) {
+                if (RNODE_VCALL(recv)->nd_mid == rb_intern("__builtin")) {
                     return name;
                 }
                 break;
               case NODE_CONST:
-                if (recv->nd_vid == rb_intern("Primitive")) {
+                if (RNODE_CONST(recv)->nd_vid == rb_intern("Primitive")) {
                     return name;
                 }
                 break;
@@ -8186,13 +8186,13 @@ compile_builtin_attr(rb_iseq_t *iseq, const NODE *node)
     if (!node) goto no_arg;
     while (node) {
         if (!nd_type_p(node, NODE_LIST)) goto bad_arg;
-        const NODE *next = node->nd_next;
+        const NODE *next = RNODE_LIST(node)->nd_next;
 
-        node = node->nd_head;
+        node = RNODE_LIST(node)->nd_head;
         if (!node) goto no_arg;
         if (!nd_type_p(node, NODE_LIT)) goto bad_arg;
 
-        symbol = node->nd_lit;
+        symbol = RNODE_LIT(node)->nd_lit;
         if (!SYMBOL_P(symbol)) goto non_symbol_arg;
 
         string = rb_sym_to_s(symbol);
@@ -8226,11 +8226,11 @@ compile_builtin_arg(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, c
 {
     if (!node) goto no_arg;
     if (!nd_type_p(node, NODE_LIST)) goto bad_arg;
-    if (node->nd_next) goto too_many_arg;
-    node = node->nd_head;
+    if (RNODE_LIST(node)->nd_next) goto too_many_arg;
+    node = RNODE_LIST(node)->nd_head;
     if (!node) goto no_arg;
     if (!nd_type_p(node, NODE_LIT)) goto bad_arg;
-    VALUE name = node->nd_lit;
+    VALUE name = RNODE_LIT(node)->nd_lit;
     if (!SYMBOL_P(name)) goto non_symbol_arg;
     if (!popped) {
         compile_lvar(iseq, ret, line_node, SYM2ID(name));
@@ -8254,8 +8254,8 @@ static NODE *
 mandatory_node(const rb_iseq_t *iseq, const NODE *cond_node)
 {
     const NODE *node = ISEQ_COMPILE_DATA(iseq)->root_node;
-    if (nd_type(node) == NODE_IF && node->nd_cond == cond_node) {
-        return node->nd_body;
+    if (nd_type(node) == NODE_IF && RNODE_IF(node)->nd_cond == cond_node) {
+        return RNODE_IF(node)->nd_body;
     }
     else {
         rb_bug("mandatory_node: can't find mandatory node");
@@ -8269,8 +8269,11 @@ compile_builtin_mandatory_only_method(rb_iseq_t *iseq, const NODE *node, const N
     struct rb_args_info args = {
         .pre_args_num = ISEQ_BODY(iseq)->param.lead_num,
     };
-    NODE args_node;
-    rb_node_init(&args_node, NODE_ARGS, 0, 0, (VALUE)&args);
+    rb_node_args_t args_node;
+    rb_node_init(RNODE(&args_node), NODE_ARGS);
+    args_node.not_used = 0;
+    args_node.not_used2 = 0;
+    args_node.nd_ainfo = &args;
 
     // local table without non-mandatory parameters
     const int skip_local_size = ISEQ_BODY(iseq)->param.size - ISEQ_BODY(iseq)->param.lead_num;
@@ -8291,11 +8294,14 @@ compile_builtin_mandatory_only_method(rb_iseq_t *iseq, const NODE *node, const N
         tbl->ids[i] = ISEQ_BODY(iseq)->local_table[i + skip_local_size];
     }
 
-    NODE scope_node;
-    rb_node_init(&scope_node, NODE_SCOPE, (VALUE)tbl, (VALUE)mandatory_node(iseq, node), (VALUE)&args_node);
+    rb_node_scope_t scope_node;
+    rb_node_init(RNODE(&scope_node), NODE_SCOPE);
+    scope_node.nd_tbl = tbl;
+    scope_node.nd_body = mandatory_node(iseq, node);
+    scope_node.nd_args = RNODE(&args_node);
 
     rb_ast_body_t ast = {
-        .root = &scope_node,
+        .root = RNODE(&scope_node),
         .frozen_string_literal = -1,
         .coverage_enabled = -1,
         .script_lines = ISEQ_BODY(iseq)->variable.script_lines,
@@ -8315,7 +8321,7 @@ static int
 compile_builtin_function_call(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, const NODE *line_node, int popped,
                               const rb_iseq_t *parent_block, LINK_ANCHOR *args, const char *builtin_func)
 {
-    NODE *args_node = node->nd_args;
+    NODE *args_node = RNODE_QCALL(node)->nd_args;
 
     if (parent_block != NULL) {
         COMPILE_ERROR(ERROR_ARGS_AT(line_node) "should not call builtins here.");
@@ -8418,7 +8424,7 @@ compile_call(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, co
      */
     DECL_ANCHOR(recv);
     DECL_ANCHOR(args);
-    ID mid = node->nd_mid;
+    ID mid = RNODE_CALL(node)->nd_mid;
     VALUE argc;
     unsigned int flag = 0;
     struct rb_callinfo_kwarg *keywords = NULL;
@@ -8497,7 +8503,7 @@ compile_call(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, co
 
     const char *builtin_func;
     if (UNLIKELY(iseq_has_builtin_function_table(iseq)) &&
-        (builtin_func = iseq_builtin_function_name(type, node->nd_recv, mid)) != NULL) {
+        (builtin_func = iseq_builtin_function_name(type, RNODE_CALL(node)->nd_recv, mid)) != NULL) {
         return compile_builtin_function_call(iseq, ret, node, line_node, popped, parent_block, args, builtin_func);
     }
 
@@ -8507,16 +8513,16 @@ compile_call(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, co
             int idx, level;
 
             if (mid == idCall &&
-                nd_type_p(node->nd_recv, NODE_LVAR) &&
-                iseq_block_param_id_p(iseq, node->nd_recv->nd_vid, &idx, &level)) {
-                ADD_INSN2(recv, node->nd_recv, getblockparamproxy, INT2FIX(idx + VM_ENV_DATA_SIZE - 1), INT2FIX(level));
+                nd_type_p(RNODE_CALL(node)->nd_recv, NODE_LVAR) &&
+                iseq_block_param_id_p(iseq, RNODE_LVAR(RNODE_CALL(node)->nd_recv)->nd_vid, &idx, &level)) {
+                ADD_INSN2(recv, RNODE_CALL(node)->nd_recv, getblockparamproxy, INT2FIX(idx + VM_ENV_DATA_SIZE - 1), INT2FIX(level));
             }
             else if (private_recv_p(node)) {
                 ADD_INSN(recv, node, putself);
                 flag |= VM_CALL_FCALL;
             }
             else {
-                CHECK(COMPILE(recv, "recv", node->nd_recv));
+                CHECK(COMPILE(recv, "recv", RNODE_CALL(node)->nd_recv));
             }
 
             if (type == NODE_QCALL) {
@@ -8530,7 +8536,7 @@ compile_call(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, co
 
     /* args */
     if (type != NODE_VCALL) {
-        argc = setup_args(iseq, args, node->nd_args, &flag, &keywords);
+        argc = setup_args(iseq, args, RNODE_CALL(node)->nd_args, &flag, &keywords);
         CHECK(!NIL_P(argc));
     }
     else {
@@ -8567,7 +8573,7 @@ compile_op_asgn1(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
     VALUE argc;
     unsigned int flag = 0;
     int asgnflag = 0;
-    ID id = node->nd_mid;
+    ID id = RNODE_OP_ASGN1(node)->nd_mid;
     int boff = 0;
 
     /*
@@ -8596,9 +8602,9 @@ compile_op_asgn1(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
     if (!popped) {
         ADD_INSN(ret, node, putnil);
     }
-    asgnflag = COMPILE_RECV(ret, "NODE_OP_ASGN1 recv", node);
+    asgnflag = COMPILE_RECV(ret, "NODE_OP_ASGN1 recv", node, RNODE_OP_ASGN1(node)->nd_recv);
     CHECK(asgnflag != -1);
-    switch (nd_type(node->nd_args->nd_head)) {
+    switch (nd_type(RNODE_OP_ASGN1(node)->nd_args->nd_head)) {
       case NODE_ZLIST:
         argc = INT2FIX(0);
         break;
@@ -8606,7 +8612,7 @@ compile_op_asgn1(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
         boff = 1;
         /* fall through */
       default:
-        argc = setup_args(iseq, ret, node->nd_args->nd_head, &flag, NULL);
+        argc = setup_args(iseq, ret, RNODE_OP_ASGN1(node)->nd_args->nd_head, &flag, NULL);
         CHECK(!NIL_P(argc));
     }
     ADD_INSN1(ret, node, dupn, FIXNUM_INC(argc, 1 + boff));
@@ -8634,7 +8640,7 @@ compile_op_asgn1(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
         }
         ADD_INSN(ret, node, pop);
 
-        CHECK(COMPILE(ret, "NODE_OP_ASGN1 args->body: ", node->nd_args->nd_body));
+        CHECK(COMPILE(ret, "NODE_OP_ASGN1 args->body: ", RNODE_OP_ASGN1(node)->nd_args->nd_body));
         if (!popped) {
             ADD_INSN1(ret, node, setn, FIXNUM_INC(argc, 2+boff));
         }
@@ -8668,7 +8674,7 @@ compile_op_asgn1(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
         ADD_LABEL(ret, lfin);
     }
     else {
-        CHECK(COMPILE(ret, "NODE_OP_ASGN1 args->body: ", node->nd_args->nd_body));
+        CHECK(COMPILE(ret, "NODE_OP_ASGN1 args->body: ", RNODE_OP_ASGN1(node)->nd_args->nd_body));
         ADD_SEND(ret, node, id, INT2FIX(1));
         if (!popped) {
             ADD_INSN1(ret, node, setn, FIXNUM_INC(argc, 2+boff));
@@ -8702,8 +8708,8 @@ static int
 compile_op_asgn2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int popped)
 {
     const int line = nd_line(node);
-    ID atype = node->nd_next->nd_mid;
-    ID vid = node->nd_next->nd_vid, aid = rb_id_attrset(vid);
+    ID atype = RNODE_OP_ASGN2(node)->nd_next->nd_mid;
+    ID vid = RNODE_OP_ASGN2(node)->nd_next->nd_vid, aid = rb_id_attrset(vid);
     int asgnflag;
     LABEL *lfin = NEW_LABEL(line);
     LABEL *lcfin = NEW_LABEL(line);
@@ -8761,9 +8767,9 @@ compile_op_asgn2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
 
     */
 
-    asgnflag = COMPILE_RECV(ret, "NODE_OP_ASGN2#recv", node);
+    asgnflag = COMPILE_RECV(ret, "NODE_OP_ASGN2#recv", node, RNODE_OP_ASGN2(node)->nd_recv);
     CHECK(asgnflag != -1);
-    if (node->nd_next->nd_aid) {
+    if (RNODE_OP_ASGN2(node)->nd_next->nd_aid) {
         lskip = NEW_LABEL(line);
         ADD_INSN(ret, node, dup);
         ADD_INSNL(ret, node, branchnil, lskip);
@@ -8784,7 +8790,7 @@ compile_op_asgn2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
         if (!popped) {
             ADD_INSN(ret, node, pop);
         }
-        CHECK(COMPILE(ret, "NODE_OP_ASGN2 val", node->nd_value));
+        CHECK(COMPILE(ret, "NODE_OP_ASGN2 val", RNODE_OP_ASGN2(node)->nd_value));
         if (!popped) {
             ADD_INSN(ret, node, swap);
             ADD_INSN1(ret, node, topn, INT2FIX(1));
@@ -8800,7 +8806,7 @@ compile_op_asgn2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
         ADD_LABEL(ret, lfin);
     }
     else {
-        CHECK(COMPILE(ret, "NODE_OP_ASGN2 val", node->nd_value));
+        CHECK(COMPILE(ret, "NODE_OP_ASGN2 val", RNODE_OP_ASGN2(node)->nd_value));
         ADD_SEND(ret, node, atype, INT2FIX(1));
         if (!popped) {
             ADD_INSN(ret, node, swap);
@@ -8826,21 +8832,21 @@ compile_op_cdecl(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
     LABEL *lassign = 0;
     ID mid;
 
-    switch (nd_type(node->nd_head)) {
+    switch (nd_type(RNODE_OP_CDECL(node)->nd_head)) {
       case NODE_COLON3:
         ADD_INSN1(ret, node, putobject, rb_cObject);
         break;
       case NODE_COLON2:
-        CHECK(COMPILE(ret, "NODE_OP_CDECL/colon2#nd_head", node->nd_head->nd_head));
+        CHECK(COMPILE(ret, "NODE_OP_CDECL/colon2#nd_head", RNODE_COLON2(RNODE_OP_CDECL(node)->nd_head)->nd_head));
         break;
       default:
         COMPILE_ERROR(ERROR_ARGS "%s: invalid node in NODE_OP_CDECL",
-                      ruby_node_name(nd_type(node->nd_head)));
+                      ruby_node_name(nd_type(RNODE_OP_CDECL(node)->nd_head)));
         return COMPILE_NG;
     }
-    mid = node->nd_head->nd_mid;
+    mid = RNODE_COLON2(RNODE_OP_CDECL(node)->nd_head)->nd_mid;
     /* cref */
-    if (node->nd_aid == idOROP) {
+    if (RNODE_OP_CDECL(node)->nd_aid == idOROP) {
         lassign = NEW_LABEL(line);
         ADD_INSN(ret, node, dup); /* cref cref */
         ADD_INSN3(ret, node, defined, INT2FIX(DEFINED_CONST_FROM),
@@ -8851,17 +8857,17 @@ compile_op_cdecl(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
     ADD_INSN1(ret, node, putobject, Qtrue);
     ADD_INSN1(ret, node, getconstant, ID2SYM(mid)); /* cref obj */
 
-    if (node->nd_aid == idOROP || node->nd_aid == idANDOP) {
+    if (RNODE_OP_CDECL(node)->nd_aid == idOROP || RNODE_OP_CDECL(node)->nd_aid == idANDOP) {
         lfin = NEW_LABEL(line);
         if (!popped) ADD_INSN(ret, node, dup); /* cref [obj] obj */
-        if (node->nd_aid == idOROP)
+        if (RNODE_OP_CDECL(node)->nd_aid == idOROP)
             ADD_INSNL(ret, node, branchif, lfin);
         else /* idANDOP */
             ADD_INSNL(ret, node, branchunless, lfin);
         /* cref [obj] */
         if (!popped) ADD_INSN(ret, node, pop); /* cref */
         if (lassign) ADD_LABEL(ret, lassign);
-        CHECK(COMPILE(ret, "NODE_OP_CDECL#nd_value", node->nd_value));
+        CHECK(COMPILE(ret, "NODE_OP_CDECL#nd_value", RNODE_OP_CDECL(node)->nd_value));
         /* cref value */
         if (popped)
             ADD_INSN1(ret, node, topn, INT2FIX(1)); /* cref value cref */
@@ -8875,9 +8881,9 @@ compile_op_cdecl(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
         ADD_INSN(ret, node, pop); /* [value] */
     }
     else {
-        CHECK(COMPILE(ret, "NODE_OP_CDECL#nd_value", node->nd_value));
+        CHECK(COMPILE(ret, "NODE_OP_CDECL#nd_value", RNODE_OP_CDECL(node)->nd_value));
         /* cref obj value */
-        ADD_CALL(ret, node, node->nd_aid, INT2FIX(1));
+        ADD_CALL(ret, node, RNODE_OP_CDECL(node)->nd_aid, INT2FIX(1));
         /* cref value */
         ADD_INSN(ret, node, swap); /* value cref */
         if (!popped) {
@@ -8896,11 +8902,11 @@ compile_op_log(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
     LABEL *lfin = NEW_LABEL(line);
     LABEL *lassign;
 
-    if (type == NODE_OP_ASGN_OR && !nd_type_p(node->nd_head, NODE_IVAR)) {
+    if (type == NODE_OP_ASGN_OR && !nd_type_p(RNODE_OP_ASGN_OR(node)->nd_head, NODE_IVAR)) {
         LABEL *lfinish[2];
         lfinish[0] = lfin;
         lfinish[1] = 0;
-        defined_expr(iseq, ret, node->nd_head, lfinish, Qfalse);
+        defined_expr(iseq, ret, RNODE_OP_ASGN_OR(node)->nd_head, lfinish, Qfalse);
         lassign = lfinish[1];
         if (!lassign) {
             lassign = NEW_LABEL(line);
@@ -8911,7 +8917,7 @@ compile_op_log(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
         lassign = NEW_LABEL(line);
     }
 
-    CHECK(COMPILE(ret, "NODE_OP_ASGN_AND/OR#nd_head", node->nd_head));
+    CHECK(COMPILE(ret, "NODE_OP_ASGN_AND/OR#nd_head", RNODE_OP_ASGN_OR(node)->nd_head));
 
     if (!popped) {
         ADD_INSN(ret, node, dup);
@@ -8929,7 +8935,7 @@ compile_op_log(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
     }
 
     ADD_LABEL(ret, lassign);
-    CHECK(COMPILE_(ret, "NODE_OP_ASGN_AND/OR#nd_value", node->nd_value, popped));
+    CHECK(COMPILE_(ret, "NODE_OP_ASGN_AND/OR#nd_value", RNODE_OP_ASGN_OR(node)->nd_value, popped));
     ADD_LABEL(ret, lfin);
     return COMPILE_OK;
 }
@@ -8947,7 +8953,7 @@ compile_super(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, i
     INIT_ANCHOR(args);
     ISEQ_COMPILE_DATA(iseq)->current_block = NULL;
     if (type == NODE_SUPER) {
-        VALUE vargc = setup_args(iseq, args, node->nd_args, &flag, &keywords);
+        VALUE vargc = setup_args(iseq, args, RNODE_SUPER(node)->nd_args, &flag, &keywords);
         CHECK(!NIL_P(vargc));
         argc = FIX2INT(vargc);
     }
@@ -9079,8 +9085,8 @@ compile_yield(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, i
       default: /* valid */;
     }
 
-    if (node->nd_head) {
-        argc = setup_args(iseq, args, node->nd_head, &flag, &keywords);
+    if (RNODE_YIELD(node)->nd_head) {
+        argc = setup_args(iseq, args, RNODE_YIELD(node)->nd_head, &flag, &keywords);
         CHECK(!NIL_P(argc));
     }
     else {
@@ -9114,17 +9120,17 @@ compile_match(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, i
     INIT_ANCHOR(val);
     switch ((int)type) {
       case NODE_MATCH:
-        ADD_INSN1(recv, node, putobject, node->nd_lit);
+        ADD_INSN1(recv, node, putobject, RNODE_MATCH(node)->nd_lit);
         ADD_INSN2(val, node, getspecial, INT2FIX(0),
                   INT2FIX(0));
         break;
       case NODE_MATCH2:
-        CHECK(COMPILE(recv, "receiver", node->nd_recv));
-        CHECK(COMPILE(val, "value", node->nd_value));
+        CHECK(COMPILE(recv, "receiver", RNODE_MATCH2(node)->nd_recv));
+        CHECK(COMPILE(val, "value", RNODE_MATCH2(node)->nd_value));
         break;
       case NODE_MATCH3:
-        CHECK(COMPILE(recv, "receiver", node->nd_value));
-        CHECK(COMPILE(val, "value", node->nd_recv));
+        CHECK(COMPILE(recv, "receiver", RNODE_MATCH3(node)->nd_value));
+        CHECK(COMPILE(val, "value", RNODE_MATCH3(node)->nd_recv));
         break;
     }
 
@@ -9132,8 +9138,8 @@ compile_match(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, i
     ADD_SEQ(ret, val);
     ADD_SEND(ret, node, idEqTilde, INT2FIX(1));
 
-    if (node->nd_args) {
-        compile_named_capture_assign(iseq, ret, node->nd_args);
+    if (RNODE_MATCH2(node)->nd_args) {
+        compile_named_capture_assign(iseq, ret, RNODE_MATCH2(node)->nd_args);
     }
 
     if (popped) {
@@ -9145,7 +9151,7 @@ compile_match(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, i
 static int
 compile_colon2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int popped)
 {
-    if (rb_is_const_id(node->nd_mid)) {
+    if (rb_is_const_id(RNODE_COLON2(node)->nd_mid)) {
         /* constant */
         VALUE segments;
         if (ISEQ_COMPILE_DATA(iseq)->option->inline_const_cache &&
@@ -9175,8 +9181,8 @@ compile_colon2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
     else {
         /* function call */
         ADD_CALL_RECEIVER(ret, node);
-        CHECK(COMPILE(ret, "colon2#nd_head", node->nd_head));
-        ADD_CALL(ret, node, node->nd_mid, INT2FIX(1));
+        CHECK(COMPILE(ret, "colon2#nd_head", RNODE_COLON2(node)->nd_head));
+        ADD_CALL(ret, node, RNODE_COLON2(node)->nd_mid, INT2FIX(1));
     }
     if (popped) {
         ADD_INSN(ret, node, pop);
@@ -9187,19 +9193,19 @@ compile_colon2(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
 static int
 compile_colon3(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int popped)
 {
-    debugi("colon3#nd_mid", node->nd_mid);
+    debugi("colon3#nd_mid", RNODE_COLON3(node)->nd_mid);
 
     /* add cache insn */
     if (ISEQ_COMPILE_DATA(iseq)->option->inline_const_cache) {
         ISEQ_BODY(iseq)->ic_size++;
-        VALUE segments = rb_ary_new_from_args(2, ID2SYM(idNULL), ID2SYM(node->nd_mid));
+        VALUE segments = rb_ary_new_from_args(2, ID2SYM(idNULL), ID2SYM(RNODE_COLON3(node)->nd_mid));
         ADD_INSN1(ret, node, opt_getconstant_path, segments);
         RB_OBJ_WRITTEN(iseq, Qundef, segments);
     }
     else {
         ADD_INSN1(ret, node, putobject, rb_cObject);
         ADD_INSN1(ret, node, putobject, Qtrue);
-        ADD_INSN1(ret, node, getconstant, ID2SYM(node->nd_mid));
+        ADD_INSN1(ret, node, getconstant, ID2SYM(RNODE_COLON3(node)->nd_mid));
     }
 
     if (popped) {
@@ -9212,13 +9218,13 @@ static int
 compile_dots(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int popped, const int excl)
 {
     VALUE flag = INT2FIX(excl);
-    const NODE *b = node->nd_beg;
-    const NODE *e = node->nd_end;
+    const NODE *b = RNODE_DOT2(node)->nd_beg;
+    const NODE *e = RNODE_DOT2(node)->nd_end;
 
     if (optimizable_range_item_p(b) && optimizable_range_item_p(e)) {
         if (!popped) {
-            VALUE bv = nd_type_p(b, NODE_LIT) ? b->nd_lit : Qnil;
-            VALUE ev = nd_type_p(e, NODE_LIT) ? e->nd_lit : Qnil;
+            VALUE bv = nd_type_p(b, NODE_LIT) ? RNODE_LIT(b)->nd_lit : Qnil;
+            VALUE ev = nd_type_p(e, NODE_LIT) ? RNODE_LIT(e)->nd_lit : Qnil;
             VALUE val = rb_range_new(bv, ev, excl);
             ADD_INSN1(ret, node, putobject, val);
             RB_OBJ_WRITTEN(iseq, Qundef, val);
@@ -9267,7 +9273,7 @@ compile_kw_arg(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
 {
     struct rb_iseq_constant_body *const body = ISEQ_BODY(iseq);
     LABEL *end_label = NEW_LABEL(nd_line(node));
-    const NODE *default_value = node->nd_body->nd_value;
+    const NODE *default_value = RNODE_DASGN(RNODE_KW_ARG(node)->nd_body)->nd_value;
 
     if (default_value == NODE_SPECIAL_REQUIRED_KEYWORD) {
         /* required argument. do nothing */
@@ -9291,7 +9297,7 @@ compile_kw_arg(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node,
 
         ADD_INSN2(ret, node, checkkeyword, INT2FIX(kw_bits_idx + VM_ENV_DATA_SIZE - 1), INT2FIX(keyword_idx));
         ADD_INSNL(ret, node, branchif, end_label);
-        CHECK(COMPILE_POPPED(ret, "keyword default argument", node->nd_body));
+        CHECK(COMPILE_POPPED(ret, "keyword default argument", RNODE_KW_ARG(node)->nd_body));
         ADD_LABEL(ret, end_label);
     }
     return COMPILE_OK;
@@ -9303,7 +9309,7 @@ compile_attrasgn(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
     DECL_ANCHOR(recv);
     DECL_ANCHOR(args);
     unsigned int flag = 0;
-    ID mid = node->nd_mid;
+    ID mid = RNODE_ATTRASGN(node)->nd_mid;
     VALUE argc;
     LABEL *else_label = NULL;
     VALUE branches = Qfalse;
@@ -9311,16 +9317,16 @@ compile_attrasgn(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
     /* optimization shortcut
      *   obj["literal"] = value -> opt_aset_with(obj, "literal", value)
      */
-    if (mid == idASET && !private_recv_p(node) && node->nd_args &&
-        nd_type_p(node->nd_args, NODE_LIST) && node->nd_args->nd_alen == 2 &&
-        nd_type_p(node->nd_args->nd_head, NODE_STR) &&
+    if (mid == idASET && !private_recv_p(node) && RNODE_ATTRASGN(node)->nd_args &&
+        nd_type_p(RNODE_ATTRASGN(node)->nd_args, NODE_LIST) && RNODE_LIST(RNODE_ATTRASGN(node)->nd_args)->as.nd_alen == 2 &&
+        nd_type_p(RNODE_LIST(RNODE_ATTRASGN(node)->nd_args)->nd_head, NODE_STR) &&
         ISEQ_COMPILE_DATA(iseq)->current_block == NULL &&
         !ISEQ_COMPILE_DATA(iseq)->option->frozen_string_literal &&
         ISEQ_COMPILE_DATA(iseq)->option->specialized_instruction)
     {
-        VALUE str = rb_fstring(node->nd_args->nd_head->nd_lit);
-        CHECK(COMPILE(ret, "recv", node->nd_recv));
-        CHECK(COMPILE(ret, "value", node->nd_args->nd_next->nd_head));
+        VALUE str = rb_fstring(RNODE_STR(RNODE_LIST(RNODE_ATTRASGN(node)->nd_args)->nd_head)->nd_lit);
+        CHECK(COMPILE(ret, "recv", RNODE_ATTRASGN(node)->nd_recv));
+        CHECK(COMPILE(ret, "value", RNODE_LIST(RNODE_LIST(RNODE_ATTRASGN(node)->nd_args)->nd_next)->nd_head));
         if (!popped) {
             ADD_INSN(ret, node, swap);
             ADD_INSN1(ret, node, topn, INT2FIX(1));
@@ -9334,10 +9340,10 @@ compile_attrasgn(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node
 
     INIT_ANCHOR(recv);
     INIT_ANCHOR(args);
-    argc = setup_args(iseq, args, node->nd_args, &flag, NULL);
+    argc = setup_args(iseq, args, RNODE_ATTRASGN(node)->nd_args, &flag, NULL);
     CHECK(!NIL_P(argc));
 
-    int asgnflag = COMPILE_RECV(recv, "recv", node);
+    int asgnflag = COMPILE_RECV(recv, "recv", node, RNODE_ATTRASGN(node)->nd_recv);
     CHECK(asgnflag != -1);
     flag |= (unsigned int)asgnflag;
 
@@ -9474,7 +9480,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         CHECK(compile_retry(iseq, ret, node, popped));
         break;
       case NODE_BEGIN:{
-        CHECK(COMPILE_(ret, "NODE_BEGIN", node->nd_body, popped));
+        CHECK(COMPILE_(ret, "NODE_BEGIN", RNODE_BEGIN(node)->nd_body, popped));
         break;
       }
       case NODE_RESCUE:
@@ -9490,7 +9496,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       case NODE_AND:
       case NODE_OR:{
         LABEL *end_label = NEW_LABEL(line);
-        CHECK(COMPILE(ret, "nd_1st", node->nd_1st));
+        CHECK(COMPILE(ret, "nd_1st", RNODE_OR(node)->nd_1st));
         if (!popped) {
             ADD_INSN(ret, node, dup);
         }
@@ -9503,7 +9509,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         if (!popped) {
             ADD_INSN(ret, node, pop);
         }
-        CHECK(COMPILE_(ret, "nd_2nd", node->nd_2nd, popped));
+        CHECK(COMPILE_(ret, "nd_2nd", RNODE_OR(node)->nd_2nd, popped));
         ADD_LABEL(ret, end_label);
         break;
       }
@@ -9514,11 +9520,11 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       }
 
       case NODE_LASGN:{
-        ID id = node->nd_vid;
+        ID id = RNODE_LASGN(node)->nd_vid;
         int idx = ISEQ_BODY(body->local_iseq)->local_table_size - get_local_var_idx(iseq, id);
 
         debugs("lvar: %s idx: %d\n", rb_id2name(id), idx);
-        CHECK(COMPILE(ret, "rvalue", node->nd_value));
+        CHECK(COMPILE(ret, "rvalue", RNODE_LASGN(node)->nd_value));
 
         if (!popped) {
             ADD_INSN(ret, node, dup);
@@ -9528,8 +9534,8 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       }
       case NODE_DASGN: {
         int idx, lv, ls;
-        ID id = node->nd_vid;
-        CHECK(COMPILE(ret, "dvalue", node->nd_value));
+        ID id = RNODE_DASGN(node)->nd_vid;
+        CHECK(COMPILE(ret, "dvalue", RNODE_DASGN(node)->nd_value));
         debugi("dassn id", rb_id2str(id) ? id : '*');
 
         if (!popped) {
@@ -9547,27 +9553,27 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         break;
       }
       case NODE_GASGN:{
-        CHECK(COMPILE(ret, "lvalue", node->nd_value));
+        CHECK(COMPILE(ret, "lvalue", RNODE_GASGN(node)->nd_value));
 
         if (!popped) {
             ADD_INSN(ret, node, dup);
         }
-        ADD_INSN1(ret, node, setglobal, ID2SYM(node->nd_vid));
+        ADD_INSN1(ret, node, setglobal, ID2SYM(RNODE_GASGN(node)->nd_vid));
         break;
       }
       case NODE_IASGN:{
-        CHECK(COMPILE(ret, "lvalue", node->nd_value));
+        CHECK(COMPILE(ret, "lvalue", RNODE_IASGN(node)->nd_value));
         if (!popped) {
             ADD_INSN(ret, node, dup);
         }
         ADD_INSN2(ret, node, setinstancevariable,
-                  ID2SYM(node->nd_vid),
-                  get_ivar_ic_value(iseq,node->nd_vid));
+                  ID2SYM(RNODE_IASGN(node)->nd_vid),
+                  get_ivar_ic_value(iseq,RNODE_IASGN(node)->nd_vid));
         break;
       }
       case NODE_CDECL:{
-        if (node->nd_vid) {
-            CHECK(COMPILE(ret, "lvalue", node->nd_value));
+        if (RNODE_CDECL(node)->nd_vid) {
+            CHECK(COMPILE(ret, "lvalue", RNODE_CDECL(node)->nd_value));
 
             if (!popped) {
                 ADD_INSN(ret, node, dup);
@@ -9575,11 +9581,11 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
 
             ADD_INSN1(ret, node, putspecialobject,
                       INT2FIX(VM_SPECIAL_OBJECT_CONST_BASE));
-            ADD_INSN1(ret, node, setconstant, ID2SYM(node->nd_vid));
+            ADD_INSN1(ret, node, setconstant, ID2SYM(RNODE_CDECL(node)->nd_vid));
         }
         else {
-            compile_cpath(ret, iseq, node->nd_else);
-            CHECK(COMPILE(ret, "lvalue", node->nd_value));
+            compile_cpath(ret, iseq, RNODE_CDECL(node)->nd_else);
+            CHECK(COMPILE(ret, "lvalue", RNODE_CDECL(node)->nd_value));
             ADD_INSN(ret, node, swap);
 
             if (!popped) {
@@ -9587,18 +9593,18 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
                 ADD_INSN(ret, node, swap);
             }
 
-            ADD_INSN1(ret, node, setconstant, ID2SYM(node->nd_else->nd_mid));
+            ADD_INSN1(ret, node, setconstant, ID2SYM(RNODE_COLON2(RNODE_CDECL(node)->nd_else)->nd_mid));
         }
         break;
       }
       case NODE_CVASGN:{
-        CHECK(COMPILE(ret, "cvasgn val", node->nd_value));
+        CHECK(COMPILE(ret, "cvasgn val", RNODE_CVASGN(node)->nd_value));
         if (!popped) {
             ADD_INSN(ret, node, dup);
         }
         ADD_INSN2(ret, node, setclassvariable,
-                  ID2SYM(node->nd_vid),
-                  get_cvar_ic_value(iseq,node->nd_vid));
+                  ID2SYM(RNODE_CVASGN(node)->nd_vid),
+                  get_cvar_ic_value(iseq, RNODE_CVASGN(node)->nd_vid));
         break;
       }
       case NODE_OP_ASGN1:
@@ -9646,10 +9652,10 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
             COMPILE_ERROR(ERROR_ARGS "NODE_VALUES: must not be popped");
         }
         while (n) {
-            CHECK(COMPILE(ret, "values item", n->nd_head));
-            n = n->nd_next;
+            CHECK(COMPILE(ret, "values item", RNODE_VALUES(n)->nd_head));
+            n = RNODE_VALUES(n)->nd_next;
         }
-        ADD_INSN1(ret, node, newarray, INT2FIX(node->nd_alen));
+        ADD_INSN1(ret, node, newarray, INT2FIX(RNODE_VALUES(node)->nd_alen));
         break;
       }
       case NODE_HASH:
@@ -9663,18 +9669,18 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         break;
       case NODE_LVAR:{
         if (!popped) {
-            compile_lvar(iseq, ret, node, node->nd_vid);
+            compile_lvar(iseq, ret, node, RNODE_LVAR(node)->nd_vid);
         }
         break;
       }
       case NODE_DVAR:{
         int lv, idx, ls;
-        debugi("nd_vid", node->nd_vid);
+        debugi("nd_vid", RNODE_DVAR(node)->nd_vid);
         if (!popped) {
-            idx = get_dyna_var_idx(iseq, node->nd_vid, &lv, &ls);
+            idx = get_dyna_var_idx(iseq, RNODE_DVAR(node)->nd_vid, &lv, &ls);
             if (idx < 0) {
                 COMPILE_ERROR(ERROR_ARGS "unknown dvar (%"PRIsVALUE")",
-                              rb_id2str(node->nd_vid));
+                              rb_id2str(RNODE_DVAR(node)->nd_vid));
                 goto ng;
             }
             ADD_GETLOCAL(ret, node, ls - idx, lv);
@@ -9682,34 +9688,34 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         break;
       }
       case NODE_GVAR:{
-        ADD_INSN1(ret, node, getglobal, ID2SYM(node->nd_vid));
+        ADD_INSN1(ret, node, getglobal, ID2SYM(RNODE_GVAR(node)->nd_vid));
         if (popped) {
             ADD_INSN(ret, node, pop);
         }
         break;
       }
       case NODE_IVAR:{
-        debugi("nd_vid", node->nd_vid);
+        debugi("nd_vid", RNODE_IVAR(node)->nd_vid);
         if (!popped) {
             ADD_INSN2(ret, node, getinstancevariable,
-                      ID2SYM(node->nd_vid),
-                      get_ivar_ic_value(iseq,node->nd_vid));
+                      ID2SYM(RNODE_IVAR(node)->nd_vid),
+                      get_ivar_ic_value(iseq, RNODE_IVAR(node)->nd_vid));
         }
         break;
       }
       case NODE_CONST:{
-        debugi("nd_vid", node->nd_vid);
+        debugi("nd_vid", RNODE_CONST(node)->nd_vid);
 
         if (ISEQ_COMPILE_DATA(iseq)->option->inline_const_cache) {
             body->ic_size++;
-            VALUE segments = rb_ary_new_from_args(1, ID2SYM(node->nd_vid));
+            VALUE segments = rb_ary_new_from_args(1, ID2SYM(RNODE_CONST(node)->nd_vid));
             ADD_INSN1(ret, node, opt_getconstant_path, segments);
             RB_OBJ_WRITTEN(iseq, Qundef, segments);
         }
         else {
             ADD_INSN(ret, node, putnil);
             ADD_INSN1(ret, node, putobject, Qtrue);
-            ADD_INSN1(ret, node, getconstant, ID2SYM(node->nd_vid));
+            ADD_INSN1(ret, node, getconstant, ID2SYM(RNODE_CONST(node)->nd_vid));
         }
 
         if (popped) {
@@ -9720,26 +9726,26 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       case NODE_CVAR:{
         if (!popped) {
             ADD_INSN2(ret, node, getclassvariable,
-                      ID2SYM(node->nd_vid),
-                      get_cvar_ic_value(iseq,node->nd_vid));
+                      ID2SYM(RNODE_CVAR(node)->nd_vid),
+                      get_cvar_ic_value(iseq, RNODE_CVAR(node)->nd_vid));
         }
         break;
       }
       case NODE_NTH_REF:{
         if (!popped) {
-            if (!node->nd_nth) {
+            if (!RNODE_NTH_REF(node)->nd_nth) {
                 ADD_INSN(ret, node, putnil);
                 break;
             }
             ADD_INSN2(ret, node, getspecial, INT2FIX(1) /* '~'  */,
-                      INT2FIX(node->nd_nth << 1));
+                      INT2FIX(RNODE_NTH_REF(node)->nd_nth << 1));
         }
         break;
       }
       case NODE_BACK_REF:{
         if (!popped) {
             ADD_INSN2(ret, node, getspecial, INT2FIX(1) /* '~' */,
-                      INT2FIX(0x01 | (node->nd_nth << 1)));
+                      INT2FIX(0x01 | (RNODE_BACK_REF(node)->nd_nth << 1)));
         }
         break;
       }
@@ -9749,17 +9755,17 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         CHECK(compile_match(iseq, ret, node, popped, type));
         break;
       case NODE_LIT:{
-        debugp_param("lit", node->nd_lit);
+        debugp_param("lit", RNODE_LIT(node)->nd_lit);
         if (!popped) {
-            ADD_INSN1(ret, node, putobject, node->nd_lit);
-            RB_OBJ_WRITTEN(iseq, Qundef, node->nd_lit);
+            ADD_INSN1(ret, node, putobject, RNODE_LIT(node)->nd_lit);
+            RB_OBJ_WRITTEN(iseq, Qundef, RNODE_LIT(node)->nd_lit);
         }
         break;
       }
       case NODE_STR:{
-        debugp_param("nd_lit", node->nd_lit);
+        debugp_param("nd_lit", RNODE_STR(node)->nd_lit);
         if (!popped) {
-            VALUE lit = node->nd_lit;
+            VALUE lit = RNODE_STR(node)->nd_lit;
             if (!ISEQ_COMPILE_DATA(iseq)->option->frozen_string_literal) {
                 lit = rb_fstring(lit);
                 ADD_INSN1(ret, node, putstring, lit);
@@ -9791,7 +9797,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       }
       case NODE_XSTR:{
         ADD_CALL_RECEIVER(ret, node);
-        VALUE str = rb_fstring(node->nd_lit);
+        VALUE str = rb_fstring(RNODE_XSTR(node)->nd_lit);
         ADD_INSN1(ret, node, putobject, str);
         RB_OBJ_WRITTEN(iseq, Qundef, str);
         ADD_CALL(ret, node, idBackquote, INT2FIX(1));
@@ -9812,7 +9818,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         break;
       }
       case NODE_EVSTR:
-        CHECK(compile_evstr(iseq, ret, node->nd_body, popped));
+        CHECK(compile_evstr(iseq, ret, RNODE_EVSTR(node)->nd_body, popped));
         break;
       case NODE_DREGX:{
         compile_dregx(iseq, ret, node);
@@ -9825,7 +9831,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       case NODE_ONCE:{
         int ic_index = body->ise_size++;
         const rb_iseq_t *block_iseq;
-        block_iseq = NEW_CHILD_ISEQ(node->nd_body, make_name_for_block(iseq), ISEQ_TYPE_PLAIN, line);
+        block_iseq = NEW_CHILD_ISEQ(RNODE_ONCE(node)->nd_body, make_name_for_block(iseq), ISEQ_TYPE_PLAIN, line);
 
         ADD_INSN2(ret, node, once, block_iseq, INT2FIX(ic_index));
         RB_OBJ_WRITTEN(iseq, Qundef, (VALUE)block_iseq);
@@ -9837,36 +9843,36 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       }
       case NODE_ARGSCAT:{
         if (popped) {
-            CHECK(COMPILE(ret, "argscat head", node->nd_head));
+            CHECK(COMPILE(ret, "argscat head", RNODE_ARGSCAT(node)->nd_head));
             ADD_INSN1(ret, node, splatarray, Qfalse);
             ADD_INSN(ret, node, pop);
-            CHECK(COMPILE(ret, "argscat body", node->nd_body));
+            CHECK(COMPILE(ret, "argscat body", RNODE_ARGSCAT(node)->nd_body));
             ADD_INSN1(ret, node, splatarray, Qfalse);
             ADD_INSN(ret, node, pop);
         }
         else {
-            CHECK(COMPILE(ret, "argscat head", node->nd_head));
-            CHECK(COMPILE(ret, "argscat body", node->nd_body));
+            CHECK(COMPILE(ret, "argscat head", RNODE_ARGSCAT(node)->nd_head));
+            CHECK(COMPILE(ret, "argscat body", RNODE_ARGSCAT(node)->nd_body));
             ADD_INSN(ret, node, concatarray);
         }
         break;
       }
       case NODE_ARGSPUSH:{
         if (popped) {
-            CHECK(COMPILE(ret, "argspush head", node->nd_head));
+            CHECK(COMPILE(ret, "argspush head", RNODE_ARGSPUSH(node)->nd_head));
             ADD_INSN1(ret, node, splatarray, Qfalse);
             ADD_INSN(ret, node, pop);
-            CHECK(COMPILE_(ret, "argspush body", node->nd_body, popped));
+            CHECK(COMPILE_(ret, "argspush body", RNODE_ARGSPUSH(node)->nd_body, popped));
         }
         else {
-            CHECK(COMPILE(ret, "argspush head", node->nd_head));
-            CHECK(compile_array_1(iseq, ret, node->nd_body));
+            CHECK(COMPILE(ret, "argspush head", RNODE_ARGSPUSH(node)->nd_head));
+            CHECK(compile_array_1(iseq, ret, RNODE_ARGSPUSH(node)->nd_body));
             ADD_INSN(ret, node, concatarray);
         }
         break;
       }
       case NODE_SPLAT:{
-        CHECK(COMPILE(ret, "splat", node->nd_head));
+        CHECK(COMPILE(ret, "splat", RNODE_SPLAT(node)->nd_head));
         ADD_INSN1(ret, node, splatarray, Qtrue);
 
         if (popped) {
@@ -9875,8 +9881,8 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         break;
       }
       case NODE_DEFN:{
-        ID mid = node->nd_mid;
-        const rb_iseq_t *method_iseq = NEW_ISEQ(node->nd_defn,
+        ID mid = RNODE_DEFN(node)->nd_mid;
+        const rb_iseq_t *method_iseq = NEW_ISEQ(RNODE_DEFN(node)->nd_defn,
                                                 rb_id2str(mid),
                                                 ISEQ_TYPE_METHOD, line);
 
@@ -9891,13 +9897,13 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         break;
       }
       case NODE_DEFS:{
-        ID mid = node->nd_mid;
-        const rb_iseq_t * singleton_method_iseq = NEW_ISEQ(node->nd_defn,
+        ID mid = RNODE_DEFS(node)->nd_mid;
+        const rb_iseq_t * singleton_method_iseq = NEW_ISEQ(RNODE_DEFS(node)->nd_defn,
                                                            rb_id2str(mid),
                                                            ISEQ_TYPE_METHOD, line);
 
         debugp_param("defs/iseq", rb_iseqw_new(singleton_method_iseq));
-        CHECK(COMPILE(ret, "defs: recv", node->nd_recv));
+        CHECK(COMPILE(ret, "defs: recv", RNODE_DEFS(node)->nd_recv));
         ADD_INSN2(ret, node, definesmethod, ID2SYM(mid), singleton_method_iseq);
         RB_OBJ_WRITTEN(iseq, Qundef, (VALUE)singleton_method_iseq);
 
@@ -9909,8 +9915,8 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       case NODE_ALIAS:{
         ADD_INSN1(ret, node, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
         ADD_INSN1(ret, node, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_CBASE));
-        CHECK(COMPILE(ret, "alias arg1", node->nd_1st));
-        CHECK(COMPILE(ret, "alias arg2", node->nd_2nd));
+        CHECK(COMPILE(ret, "alias arg1", RNODE_ALIAS(node)->nd_1st));
+        CHECK(COMPILE(ret, "alias arg2", RNODE_ALIAS(node)->nd_2nd));
         ADD_SEND(ret, node, id_core_set_method_alias, INT2FIX(3));
 
         if (popped) {
@@ -9920,8 +9926,8 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       }
       case NODE_VALIAS:{
         ADD_INSN1(ret, node, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
-        ADD_INSN1(ret, node, putobject, ID2SYM(node->nd_alias));
-        ADD_INSN1(ret, node, putobject, ID2SYM(node->nd_orig));
+        ADD_INSN1(ret, node, putobject, ID2SYM(RNODE_VALIAS(node)->nd_alias));
+        ADD_INSN1(ret, node, putobject, ID2SYM(RNODE_VALIAS(node)->nd_orig));
         ADD_SEND(ret, node, id_core_set_variable_alias, INT2FIX(2));
 
         if (popped) {
@@ -9932,7 +9938,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       case NODE_UNDEF:{
         ADD_INSN1(ret, node, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
         ADD_INSN1(ret, node, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_CBASE));
-        CHECK(COMPILE(ret, "undef arg", node->nd_undef));
+        CHECK(COMPILE(ret, "undef arg", RNODE_UNDEF(node)->nd_undef));
         ADD_SEND(ret, node, id_core_undef_method, INT2FIX(2));
 
         if (popped) {
@@ -9941,15 +9947,15 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         break;
       }
       case NODE_CLASS:{
-        const rb_iseq_t *class_iseq = NEW_CHILD_ISEQ(node->nd_body,
-                                                     rb_str_freeze(rb_sprintf("<class:%"PRIsVALUE">", rb_id2str(node->nd_cpath->nd_mid))),
+        const rb_iseq_t *class_iseq = NEW_CHILD_ISEQ(RNODE_CLASS(node)->nd_body,
+                                                     rb_str_freeze(rb_sprintf("<class:%"PRIsVALUE">", rb_id2str(RNODE_COLON2(RNODE_CLASS(node)->nd_cpath)->nd_mid))),
                                                      ISEQ_TYPE_CLASS, line);
         const int flags = VM_DEFINECLASS_TYPE_CLASS |
-            (node->nd_super ? VM_DEFINECLASS_FLAG_HAS_SUPERCLASS : 0) |
-            compile_cpath(ret, iseq, node->nd_cpath);
+            (RNODE_CLASS(node)->nd_super ? VM_DEFINECLASS_FLAG_HAS_SUPERCLASS : 0) |
+            compile_cpath(ret, iseq, RNODE_CLASS(node)->nd_cpath);
 
-        CHECK(COMPILE(ret, "super", node->nd_super));
-        ADD_INSN3(ret, node, defineclass, ID2SYM(node->nd_cpath->nd_mid), class_iseq, INT2FIX(flags));
+        CHECK(COMPILE(ret, "super", RNODE_CLASS(node)->nd_super));
+        ADD_INSN3(ret, node, defineclass, ID2SYM(RNODE_COLON2(RNODE_CLASS(node)->nd_cpath)->nd_mid), class_iseq, INT2FIX(flags));
         RB_OBJ_WRITTEN(iseq, Qundef, (VALUE)class_iseq);
 
         if (popped) {
@@ -9958,14 +9964,14 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         break;
       }
       case NODE_MODULE:{
-        const rb_iseq_t *module_iseq = NEW_CHILD_ISEQ(node->nd_body,
-                                                      rb_str_freeze(rb_sprintf("<module:%"PRIsVALUE">", rb_id2str(node->nd_cpath->nd_mid))),
+        const rb_iseq_t *module_iseq = NEW_CHILD_ISEQ(RNODE_MODULE(node)->nd_body,
+                                                      rb_str_freeze(rb_sprintf("<module:%"PRIsVALUE">", rb_id2str(RNODE_COLON2(RNODE_MODULE(node)->nd_cpath)->nd_mid))),
                                                       ISEQ_TYPE_CLASS, line);
         const int flags = VM_DEFINECLASS_TYPE_MODULE |
-            compile_cpath(ret, iseq, node->nd_cpath);
+            compile_cpath(ret, iseq, RNODE_MODULE(node)->nd_cpath);
 
         ADD_INSN (ret, node, putnil); /* dummy */
-        ADD_INSN3(ret, node, defineclass, ID2SYM(node->nd_cpath->nd_mid), module_iseq, INT2FIX(flags));
+        ADD_INSN3(ret, node, defineclass, ID2SYM(RNODE_COLON2(RNODE_MODULE(node)->nd_cpath)->nd_mid), module_iseq, INT2FIX(flags));
         RB_OBJ_WRITTEN(iseq, Qundef, (VALUE)module_iseq);
 
         if (popped) {
@@ -9975,10 +9981,10 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
       }
       case NODE_SCLASS:{
         ID singletonclass;
-        const rb_iseq_t *singleton_class = NEW_ISEQ(node->nd_body, rb_fstring_lit("singleton class"),
+        const rb_iseq_t *singleton_class = NEW_ISEQ(RNODE_SCLASS(node)->nd_body, rb_fstring_lit("singleton class"),
                                                     ISEQ_TYPE_CLASS, line);
 
-        CHECK(COMPILE(ret, "sclass#recv", node->nd_recv));
+        CHECK(COMPILE(ret, "sclass#recv", RNODE_SCLASS(node)->nd_recv));
         ADD_INSN (ret, node, putnil);
         CONST_ID(singletonclass, "singletonclass");
         ADD_INSN3(ret, node, defineclass,
@@ -10056,7 +10062,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
          */
         int is_index = body->ise_size++;
         struct rb_iseq_new_with_callback_callback_func *ifunc =
-            rb_iseq_new_with_callback_new_callback(build_postexe_iseq, node->nd_body);
+            rb_iseq_new_with_callback_new_callback(build_postexe_iseq, RNODE_POSTEXE(node)->nd_body);
         const rb_iseq_t *once_iseq =
             new_child_iseq_with_callback(iseq, ifunc,
                                  rb_fstring(make_name_for_block(iseq)), iseq, ISEQ_TYPE_BLOCK, line);
@@ -10087,7 +10093,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
         break;
       case NODE_LAMBDA:{
         /* compile same as lambda{...} */
-        const rb_iseq_t *block = NEW_CHILD_ISEQ(node->nd_body, make_name_for_block(iseq), ISEQ_TYPE_BLOCK, line);
+        const rb_iseq_t *block = NEW_CHILD_ISEQ(RNODE_LAMBDA(node)->nd_body, make_name_for_block(iseq), ISEQ_TYPE_BLOCK, line);
         VALUE argc = INT2FIX(0);
 
         ADD_INSN1(ret, node, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));