compile.c

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/**********************************************************************

  compile.c - ruby node tree -> VM instruction sequence

  $Author: usa $
  created at: 04/01/01 03:42:15 JST

  Copyright (C) 2004-2007 Koichi Sasada

**********************************************************************/

#include "ruby/ruby.h"
#include "internal.h"
#include <math.h>

#define USE_INSN_STACK_INCREASE 1
#include "vm_core.h"
#include "iseq.h"
#include "insns.inc"
#include "insns_info.inc"

#define FIXNUM_INC(n, i) ((n)+(INT2FIX(i)&~FIXNUM_FLAG))
#define FIXNUM_OR(n, i) ((n)|INT2FIX(i))

typedef struct iseq_link_element {
    enum {
        ISEQ_ELEMENT_NONE,
        ISEQ_ELEMENT_LABEL,
        ISEQ_ELEMENT_INSN,
        ISEQ_ELEMENT_ADJUST
    } type;
    struct iseq_link_element *next;
    struct iseq_link_element *prev;
} LINK_ELEMENT;

typedef struct iseq_link_anchor {
    LINK_ELEMENT anchor;
    LINK_ELEMENT *last;
} LINK_ANCHOR;

typedef struct iseq_label_data {
    LINK_ELEMENT link;
    int label_no;
    int position;
    int sc_state;
    int set;
    int sp;
} LABEL;

typedef struct iseq_insn_data {
    LINK_ELEMENT link;
    enum ruby_vminsn_type insn_id;
    unsigned int line_no;
    int operand_size;
    int sc_state;
    VALUE *operands;
} INSN;

typedef struct iseq_adjust_data {
    LINK_ELEMENT link;
    LABEL *label;
    int line_no;
} ADJUST;

struct ensure_range {
    LABEL *begin;
    LABEL *end;
    struct ensure_range *next;
};

struct iseq_compile_data_ensure_node_stack {
    NODE *ensure_node;
    struct iseq_compile_data_ensure_node_stack *prev;
    struct ensure_range *erange;
};

#ifndef CPDEBUG
#define CPDEBUG 0
#endif

#if CPDEBUG >= 0
#define compile_debug CPDEBUG
#else
#define compile_debug iseq->compile_data->option->debug_level
#endif

#if CPDEBUG

#define compile_debug_print_indent(level) \
    ruby_debug_print_indent((level), compile_debug, gl_node_level * 2)

#define debugp(header, value) (void) \
  (compile_debug_print_indent(1) && \
   ruby_debug_print_value(1, compile_debug, (header), (value)))

#define debugi(header, id)  (void) \
  (compile_debug_print_indent(1) && \
   ruby_debug_print_id(1, compile_debug, (header), (id)))

#define debugp_param(header, value)  (void) \
  (compile_debug_print_indent(1) && \
   ruby_debug_print_value(1, compile_debug, (header), (value)))

#define debugp_verbose(header, value)  (void) \
  (compile_debug_print_indent(2) && \
   ruby_debug_print_value(2, compile_debug, (header), (value)))

#define debugp_verbose_node(header, value)  (void) \
  (compile_debug_print_indent(10) && \
   ruby_debug_print_value(10, compile_debug, (header), (value)))

#define debug_node_start(node)  ((void) \
  (compile_debug_print_indent(1) && \
   (ruby_debug_print_node(1, CPDEBUG, "", (NODE *)(node)), gl_node_level)), \
   gl_node_level++)

#define debug_node_end()  gl_node_level --

#else

static inline ID
r_id(ID id)
{
    return id;
}

static inline VALUE
r_value(VALUE value)
{
    return value;
}

#define debugi(header, id)                 r_id(id)
#define debugp(header, value)              r_value(value)
#define debugp_verbose(header, value)      r_value(value)
#define debugp_verbose_node(header, value) r_value(value)
#define debugp_param(header, value)        r_value(value)
#define debug_node_start(node)             ((void)0)
#define debug_node_end()                   ((void)0)
#endif

#if CPDEBUG > 1 || CPDEBUG < 0
#define debugs if (compile_debug_print_indent(1)) ruby_debug_printf
#define debug_compile(msg, v) ((void)(compile_debug_print_indent(1) && fputs((msg), stderr)), (v))
#else
#define debugs                             if(0)printf
#define debug_compile(msg, v) (v)
#endif


/* create new label */
#define NEW_LABEL(l) new_label_body(iseq, (l))

#define iseq_path(iseq) \
  (((rb_iseq_t*)DATA_PTR(iseq))->location.path)

#define iseq_absolute_path(iseq) \
  (((rb_iseq_t*)DATA_PTR(iseq))->location.absolute_path)

#define NEW_ISEQVAL(node, name, type, line_no)       \
  new_child_iseq(iseq, (node), rb_fstring(name), 0, (type), (line_no))

#define NEW_CHILD_ISEQVAL(node, name, type, line_no)       \
  new_child_iseq(iseq, (node), rb_fstring(name), iseq->self, (type), (line_no))

/* add instructions */
#define ADD_SEQ(seq1, seq2) \
  APPEND_LIST((seq1), (seq2))

/* add an instruction */
#define ADD_INSN(seq, line, insn) \
  ADD_ELEM((seq), (LINK_ELEMENT *) new_insn_body(iseq, (line), BIN(insn), 0))

/* add an instruction with some operands (1, 2, 3, 5) */
#define ADD_INSN1(seq, line, insn, op1) \
  ADD_ELEM((seq), (LINK_ELEMENT *) \
           new_insn_body(iseq, (line), BIN(insn), 1, (VALUE)(op1)))

/* add an instruction with label operand (alias of ADD_INSN1) */
#define ADD_INSNL(seq, line, insn, label) ADD_INSN1(seq, line, insn, label)

#define ADD_INSN2(seq, line, insn, op1, op2) \
  ADD_ELEM((seq), (LINK_ELEMENT *) \
           new_insn_body(iseq, (line), BIN(insn), 2, (VALUE)(op1), (VALUE)(op2)))

#define ADD_INSN3(seq, line, insn, op1, op2, op3) \
  ADD_ELEM((seq), (LINK_ELEMENT *) \
           new_insn_body(iseq, (line), BIN(insn), 3, (VALUE)(op1), (VALUE)(op2), (VALUE)(op3)))

/* Specific Insn factory */
#define ADD_SEND(seq, line, id, argc) \
  ADD_SEND_R((seq), (line), (id), (argc), (VALUE)Qfalse, (VALUE)INT2FIX(0))

#define ADD_CALL_RECEIVER(seq, line) \
  ADD_INSN((seq), (line), putself)

#define ADD_CALL(seq, line, id, argc) \
  ADD_SEND_R((seq), (line), (id), (argc), (VALUE)Qfalse, (VALUE)INT2FIX(VM_CALL_FCALL))

#define ADD_CALL_WITH_BLOCK(seq, line, id, argc, block) \
  ADD_SEND_R((seq), (line), (id), (argc), (block), (VALUE)INT2FIX(VM_CALL_FCALL))

#define ADD_SEND_R(seq, line, id, argc, block, flag) \
  ADD_ELEM((seq), (LINK_ELEMENT *) \
           new_insn_send(iseq, (line), \
                         (VALUE)(id), (VALUE)(argc), (VALUE)(block), (VALUE)(flag)))

#define ADD_TRACE(seq, line, event) \
  do { \
      if ((event) == RUBY_EVENT_LINE && iseq->coverage && \
          (line) != iseq->compile_data->last_coverable_line) { \
          RARRAY_ASET(iseq->coverage, (line) - 1, INT2FIX(0)); \
          iseq->compile_data->last_coverable_line = (line); \
          ADD_INSN1((seq), (line), trace, INT2FIX(RUBY_EVENT_COVERAGE)); \
      } \
      if (iseq->compile_data->option->trace_instruction) { \
          ADD_INSN1((seq), (line), trace, INT2FIX(event)); \
      } \
  } while (0)

/* add label */
#define ADD_LABEL(seq, label) \
  ADD_ELEM((seq), (LINK_ELEMENT *) (label))

#define APPEND_LABEL(seq, before, label) \
  APPEND_ELEM((seq), (before), (LINK_ELEMENT *) (label))

#define ADD_ADJUST(seq, line, label) \
  ADD_ELEM((seq), (LINK_ELEMENT *) new_adjust_body(iseq, (label), (line)))

#define ADD_ADJUST_RESTORE(seq, label) \
  ADD_ELEM((seq), (LINK_ELEMENT *) new_adjust_body(iseq, (label), -1))

#define ADD_CATCH_ENTRY(type, ls, le, iseqv, lc)                \
    (rb_ary_push(iseq->compile_data->catch_table_ary,           \
                 rb_ary_new3(5, (type),                         \
                             (VALUE)(ls) | 1, (VALUE)(le) | 1,  \
                             (VALUE)(iseqv), (VALUE)(lc) | 1)))

/* compile node */
#define COMPILE(anchor, desc, node) \
  (debug_compile("== " desc "\n", \
                 iseq_compile_each(iseq, (anchor), (node), 0)))

/* compile node, this node's value will be popped */
#define COMPILE_POPED(anchor, desc, node)    \
  (debug_compile("== " desc "\n", \
                 iseq_compile_each(iseq, (anchor), (node), 1)))

/* compile node, which is popped when 'poped' is true */
#define COMPILE_(anchor, desc, node, poped)  \
  (debug_compile("== " desc "\n", \
                 iseq_compile_each(iseq, (anchor), (node), (poped))))

#define OPERAND_AT(insn, idx) \
  (((INSN*)(insn))->operands[(idx)])

#define INSN_OF(insn) \
  (((INSN*)(insn))->insn_id)

/* error */
#define COMPILE_ERROR(strs)                        \
{                                                  \
  VALUE tmp = GET_THREAD()->errinfo;               \
  if (compile_debug) rb_compile_bug strs;          \
  GET_THREAD()->errinfo = iseq->compile_data->err_info;  \
  rb_compile_error strs;                           \
  RB_OBJ_WRITE(iseq->self, &iseq->compile_data->err_info, GET_THREAD()->errinfo); \
  GET_THREAD()->errinfo = tmp;                     \
  ret = 0;                                         \
  break;                                           \
}

#define ERROR_ARGS ruby_sourcefile, nd_line(node),


#define COMPILE_OK 1
#define COMPILE_NG 0


/* leave name uninitialized so that compiler warn if INIT_ANCHOR is
 * missing */
#define DECL_ANCHOR(name) \
  LINK_ANCHOR *name, name##_body__ = {{0,},}
#define INIT_ANCHOR(name) \
  (name##_body__.last = &name##_body__.anchor, name = &name##_body__)

#define hide_obj(obj) do {OBJ_FREEZE(obj); RBASIC_CLEAR_CLASS(obj);} while (0)

#include "optinsn.inc"
#if OPT_INSTRUCTIONS_UNIFICATION
#include "optunifs.inc"
#endif

/* for debug */
#if CPDEBUG < 0
#define ISEQ_ARG iseq,
#define ISEQ_ARG_DECLARE rb_iseq_t *iseq,
#else
#define ISEQ_ARG
#define ISEQ_ARG_DECLARE
#endif

#if CPDEBUG
#define gl_node_level iseq->compile_data->node_level
#if 0
static void debug_list(ISEQ_ARG_DECLARE LINK_ANCHOR *anchor);
#endif
#endif

static void dump_disasm_list(LINK_ELEMENT *elem);

static int insn_data_length(INSN *iobj);
static int calc_sp_depth(int depth, INSN *iobj);

static INSN *new_insn_body(rb_iseq_t *iseq, int line_no, int insn_id, int argc, ...);
static LABEL *new_label_body(rb_iseq_t *iseq, long line);
static ADJUST *new_adjust_body(rb_iseq_t *iseq, LABEL *label, int line);

static int iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *anchor, NODE * n, int);
static int iseq_setup(rb_iseq_t *iseq, LINK_ANCHOR *anchor);
static int iseq_optimize(rb_iseq_t *iseq, LINK_ANCHOR *anchor);
static int iseq_insns_unification(rb_iseq_t *iseq, LINK_ANCHOR *anchor);

static int iseq_set_local_table(rb_iseq_t *iseq, ID *tbl);
static int iseq_set_exception_local_table(rb_iseq_t *iseq);
static int iseq_set_arguments(rb_iseq_t *iseq, LINK_ANCHOR *anchor, NODE * node);

static int iseq_set_sequence_stackcaching(rb_iseq_t *iseq, LINK_ANCHOR *anchor);
static int iseq_set_sequence(rb_iseq_t *iseq, LINK_ANCHOR *anchor);
static int iseq_set_exception_table(rb_iseq_t *iseq);
static int iseq_set_optargs_table(rb_iseq_t *iseq);

/*
 * To make Array to LinkedList, use link_anchor
 */

static void
verify_list(ISEQ_ARG_DECLARE const char *info, LINK_ANCHOR *anchor)
{
#if CPDEBUG
    int flag = 0;
    LINK_ELEMENT *list, *plist;

    if (!compile_debug) return;

    list = anchor->anchor.next;
    plist = &anchor->anchor;
    while (list) {
        if (plist != list->prev) {
            flag += 1;
        }
        plist = list;
        list = list->next;
    }

    if (anchor->last != plist && anchor->last != 0) {
        flag |= 0x70000;
    }

    if (flag != 0) {
        rb_bug("list verify error: %08x (%s)", flag, info);
    }
#endif
}
#if CPDEBUG < 0
#define verify_list(info, anchor) verify_list(iseq, (info), (anchor))
#endif

/*
 * elem1, elem2 => elem1, elem2, elem
 */
static void
ADD_ELEM(ISEQ_ARG_DECLARE LINK_ANCHOR *anchor, LINK_ELEMENT *elem)
{
    elem->prev = anchor->last;
    anchor->last->next = elem;
    anchor->last = elem;
    verify_list("add", anchor);
}

/*
 * elem1, before, elem2 => elem1, before, elem, elem2
 */
static void
APPEND_ELEM(ISEQ_ARG_DECLARE LINK_ANCHOR *anchor, LINK_ELEMENT *before, LINK_ELEMENT *elem)
{
    elem->prev = before;
    elem->next = before->next;
    elem->next->prev = elem;
    before->next = elem;
    if (before == anchor->last) anchor->last = elem;
    verify_list("add", anchor);
}
#if CPDEBUG < 0
#define ADD_ELEM(anchor, elem) ADD_ELEM(iseq, (anchor), (elem))
#define APPEND_ELEM(anchor, before, elem) ADD_ELEM(iseq, (anchor), (before), (elem))
#endif

static int
iseq_add_mark_object(rb_iseq_t *iseq, VALUE v)
{
    if (!SPECIAL_CONST_P(v)) {
        rb_iseq_add_mark_object(iseq, v);
    }
    return COMPILE_OK;
}

#define ruby_sourcefile         RSTRING_PTR(iseq->location.path)

static int
iseq_add_mark_object_compile_time(rb_iseq_t *iseq, VALUE v)
{
    if (!SPECIAL_CONST_P(v)) {
        rb_ary_push(iseq->compile_data->mark_ary, v);
    }
    return COMPILE_OK;
}

static int
validate_label(st_data_t name, st_data_t label, st_data_t arg)
{
    rb_iseq_t *iseq = (rb_iseq_t *)arg;
    LABEL *lobj = (LABEL *)label;
    if (!lobj->link.next) {
        do {
            int ret;
            COMPILE_ERROR((ruby_sourcefile, lobj->position,
                           "%s: undefined label", rb_id2name((ID)name)));
            if (ret) break;
        } while (0);
    }
    return ST_CONTINUE;
}

static void
validate_labels(rb_iseq_t *iseq, st_table *labels_table)
{
    st_foreach(labels_table, validate_label, (st_data_t)iseq);
    if (!NIL_P(iseq->compile_data->err_info)) {
        rb_exc_raise(iseq->compile_data->err_info);
    }
}

VALUE
rb_iseq_compile_node(VALUE self, NODE *node)
{
    DECL_ANCHOR(ret);
    rb_iseq_t *iseq;
    INIT_ANCHOR(ret);
    GetISeqPtr(self, iseq);

    if (node == 0) {
        COMPILE(ret, "nil", node);
        iseq_set_local_table(iseq, 0);
    }
    else if (nd_type(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);

        switch (iseq->type) {
          case ISEQ_TYPE_BLOCK:
            {
                LABEL *start = iseq->compile_data->start_label = NEW_LABEL(0);
                LABEL *end = iseq->compile_data->end_label = NEW_LABEL(0);

                ADD_TRACE(ret, FIX2INT(iseq->location.first_lineno), RUBY_EVENT_B_CALL);
                ADD_LABEL(ret, start);
                COMPILE(ret, "block body", node->nd_body);
                ADD_LABEL(ret, end);
                ADD_TRACE(ret, nd_line(node), RUBY_EVENT_B_RETURN);

                /* wide range catch handler must put at last */
                ADD_CATCH_ENTRY(CATCH_TYPE_REDO, start, end, 0, start);
                ADD_CATCH_ENTRY(CATCH_TYPE_NEXT, start, end, 0, end);
                break;
            }
          case ISEQ_TYPE_CLASS:
            {
                ADD_TRACE(ret, FIX2INT(iseq->location.first_lineno), RUBY_EVENT_CLASS);
                COMPILE(ret, "scoped node", node->nd_body);
                ADD_TRACE(ret, nd_line(node), RUBY_EVENT_END);
                break;
            }
          case ISEQ_TYPE_METHOD:
            {
                ADD_TRACE(ret, FIX2INT(iseq->location.first_lineno), RUBY_EVENT_CALL);
                COMPILE(ret, "scoped node", node->nd_body);
                ADD_TRACE(ret, nd_line(node), RUBY_EVENT_RETURN);
                break;
            }
          default: {
            COMPILE(ret, "scoped node", node->nd_body);
            break;
          }
        }
    }
    else if (nd_type(node) == NODE_IFUNC) {
        /* user callback */
        (*node->nd_cfnc)(iseq, ret, node->nd_tval);
    }
    else {
        switch (iseq->type) {
          case ISEQ_TYPE_METHOD:
          case ISEQ_TYPE_CLASS:
          case ISEQ_TYPE_BLOCK:
          case ISEQ_TYPE_EVAL:
          case ISEQ_TYPE_MAIN:
          case ISEQ_TYPE_TOP:
            rb_compile_error(ERROR_ARGS "compile/should not be reached: %s:%d",
                             __FILE__, __LINE__);
            break;
          case ISEQ_TYPE_RESCUE:
            iseq_set_exception_local_table(iseq);
            COMPILE(ret, "rescue", node);
            break;
          case ISEQ_TYPE_ENSURE:
            iseq_set_exception_local_table(iseq);
            COMPILE_POPED(ret, "ensure", node);
            break;
          case ISEQ_TYPE_DEFINED_GUARD:
            iseq_set_local_table(iseq, 0);
            COMPILE(ret, "defined guard", node);
            break;
          default:
            rb_bug("unknown scope");
        }
    }

    if (iseq->type == ISEQ_TYPE_RESCUE || iseq->type == ISEQ_TYPE_ENSURE) {
        ADD_INSN2(ret, 0, getlocal, INT2FIX(2), INT2FIX(0));
        ADD_INSN1(ret, 0, throw, INT2FIX(0) /* continue throw */ );
    }
    else {
        ADD_INSN(ret, iseq->compile_data->last_line, leave);
    }

#if SUPPORT_JOKE
    if (iseq->compile_data->labels_table) {
        validate_labels(iseq, iseq->compile_data->labels_table);
    }
#endif
    return iseq_setup(iseq, ret);
}

int
rb_iseq_translate_threaded_code(rb_iseq_t *iseq)
{
#if OPT_DIRECT_THREADED_CODE || OPT_CALL_THREADED_CODE
    const void * const *table = rb_vm_get_insns_address_table();
    unsigned long i;

    iseq->iseq_encoded = ALLOC_N(VALUE, iseq->iseq_size);
    MEMCPY(iseq->iseq_encoded, iseq->iseq, VALUE, iseq->iseq_size);

    for (i = 0; i < iseq->iseq_size; /* */ ) {
        int insn = (int)iseq->iseq_encoded[i];
        int len = insn_len(insn);
        iseq->iseq_encoded[i] = (VALUE)table[insn];
        i += len;
    }
#else
    iseq->iseq_encoded = iseq->iseq;
#endif
    return COMPILE_OK;
}

/*********************************************/
/* definition of data structure for compiler */
/*********************************************/

/*
 * On 32-bit SPARC, GCC by default generates SPARC V7 code that may require
 * 8-byte word alignment. On the other hand, Oracle Solaris Studio seems to
 * generate SPARCV8PLUS code with unaligned memory accesss instructions.
 * That is why the STRICT_ALIGNMENT is defined only with GCC.
 */
#if defined(__sparc) && SIZEOF_VOIDP == 4 && defined(__GNUC__)
  #define STRICT_ALIGNMENT
#endif

#ifdef STRICT_ALIGNMENT
  #if defined(HAVE_TRUE_LONG_LONG) && SIZEOF_LONG_LONG > SIZEOF_VALUE
    #define ALIGNMENT_SIZE SIZEOF_LONG_LONG
  #else
    #define ALIGNMENT_SIZE SIZEOF_VALUE
  #endif
  #define PADDING_SIZE_MAX    ((size_t)((ALIGNMENT_SIZE) - 1))
  #define ALIGNMENT_SIZE_MASK PADDING_SIZE_MAX
  /* Note: ALIGNMENT_SIZE == (2 ** N) is expected. */
#else
  #define PADDING_SIZE_MAX 0
#endif /* STRICT_ALIGNMENT */

#ifdef STRICT_ALIGNMENT
/* calculate padding size for aligned memory access */
static size_t
calc_padding(void *ptr, size_t size)
{
    size_t mis;
    size_t padding = 0;

    mis = (size_t)ptr & ALIGNMENT_SIZE_MASK;
    if (mis > 0) {
        padding = ALIGNMENT_SIZE - mis;
    }
/*
 * On 32-bit sparc or equivalents, when a single VALUE is requested
 * and padding == sizeof(VALUE), it is clear that no padding is needed.
 */
#if ALIGNMENT_SIZE > SIZEOF_VALUE
    if (size == sizeof(VALUE) && padding == sizeof(VALUE)) {
        padding = 0;
    }
#endif

    return padding;
}
#endif /* STRICT_ALIGNMENT */

static void *
compile_data_alloc(rb_iseq_t *iseq, size_t size)
{
    void *ptr = 0;
    struct iseq_compile_data_storage *storage =
        iseq->compile_data->storage_current;
#ifdef STRICT_ALIGNMENT
    size_t padding = calc_padding((void *)&storage->buff[storage->pos], size);
#else
    const size_t padding = 0; /* expected to be optimized by compiler */
#endif /* STRICT_ALIGNMENT */

    if (storage->pos + size + padding > storage->size) {
        unsigned long alloc_size = storage->size * 2;

      retry:
        if (alloc_size < size + PADDING_SIZE_MAX) {
            alloc_size *= 2;
            goto retry;
        }
        storage->next = (void *)ALLOC_N(char, alloc_size +
                                        sizeof(struct
                                               iseq_compile_data_storage));
        storage = iseq->compile_data->storage_current = storage->next;
        storage->next = 0;
        storage->pos = 0;
        storage->size = alloc_size;
        storage->buff = (char *)(&storage->buff + 1);
#ifdef STRICT_ALIGNMENT
        padding = calc_padding((void *)&storage->buff[storage->pos], size);
#endif /* STRICT_ALIGNMENT */
    }

#ifdef STRICT_ALIGNMENT
    storage->pos += (int)padding;
#endif /* STRICT_ALIGNMENT */

    ptr = (void *)&storage->buff[storage->pos];
    storage->pos += size;
    return ptr;
}

static INSN *
compile_data_alloc_insn(rb_iseq_t *iseq)
{
    return (INSN *)compile_data_alloc(iseq, sizeof(INSN));
}

static LABEL *
compile_data_alloc_label(rb_iseq_t *iseq)
{
    return (LABEL *)compile_data_alloc(iseq, sizeof(LABEL));
}

static ADJUST *
compile_data_alloc_adjust(rb_iseq_t *iseq)
{
    return (ADJUST *)compile_data_alloc(iseq, sizeof(ADJUST));
}

/*
 * elem1, elemX => elem1, elem2, elemX
 */
static void
INSERT_ELEM_NEXT(LINK_ELEMENT *elem1, LINK_ELEMENT *elem2)
{
    elem2->next = elem1->next;
    elem2->prev = elem1;
    elem1->next = elem2;
    if (elem2->next) {
        elem2->next->prev = elem2;
    }
}

#if 0 /* unused */
/*
 * elemX, elem1 => elemX, elem2, elem1
 */
static void
INSERT_ELEM_PREV(LINK_ELEMENT *elem1, LINK_ELEMENT *elem2)
{
    elem2->prev = elem1->prev;
    elem2->next = elem1;
    elem1->prev = elem2;
    if (elem2->prev) {
        elem2->prev->next = elem2;
    }
}
#endif

/*
 * elemX, elem1, elemY => elemX, elem2, elemY
 */
static void
REPLACE_ELEM(LINK_ELEMENT *elem1, LINK_ELEMENT *elem2)
{
    elem2->prev = elem1->prev;
    elem2->next = elem1->next;
    if (elem1->prev) {
        elem1->prev->next = elem2;
    }
    if (elem1->next) {
        elem1->next->prev = elem2;
    }
}

static void
REMOVE_ELEM(LINK_ELEMENT *elem)
{
    elem->prev->next = elem->next;
    if (elem->next) {
        elem->next->prev = elem->prev;
    }
}

static LINK_ELEMENT *
FIRST_ELEMENT(LINK_ANCHOR *anchor)
{
    return anchor->anchor.next;
}

#if 0 /* unused */
static LINK_ELEMENT *
LAST_ELEMENT(LINK_ANCHOR *anchor)
{
  return anchor->last;
}
#endif

static LINK_ELEMENT *
POP_ELEMENT(ISEQ_ARG_DECLARE LINK_ANCHOR *anchor)
{
    LINK_ELEMENT *elem = anchor->last;
    anchor->last = anchor->last->prev;
    anchor->last->next = 0;
    verify_list("pop", anchor);
    return elem;
}
#if CPDEBUG < 0
#define POP_ELEMENT(anchor) POP_ELEMENT(iseq, (anchor))
#endif

#if 0 /* unused */
static LINK_ELEMENT *
SHIFT_ELEMENT(LINK_ANCHOR *anchor)
{
    LINK_ELEMENT *elem = anchor->anchor.next;
    if (elem) {
        anchor->anchor.next = elem->next;
    }
    return elem;
}
#endif

#if 0 /* unused */
static int
LIST_SIZE(LINK_ANCHOR *anchor)
{
    LINK_ELEMENT *elem = anchor->anchor.next;
    int size = 0;
    while (elem) {
        size += 1;
        elem = elem->next;
    }
    return size;
}
#endif

static int
LIST_SIZE_ZERO(LINK_ANCHOR *anchor)
{
    if (anchor->anchor.next == 0) {
        return 1;
    }
    else {
        return 0;
    }
}

/*
 * anc1: e1, e2, e3
 * anc2: e4, e5
 *#=>
 * anc1: e1, e2, e3, e4, e5
 * anc2: e4, e5 (broken)
 */
static void
APPEND_LIST(ISEQ_ARG_DECLARE LINK_ANCHOR *anc1, LINK_ANCHOR *anc2)
{
    if (anc2->anchor.next) {
        anc1->last->next = anc2->anchor.next;
        anc2->anchor.next->prev = anc1->last;
        anc1->last = anc2->last;
    }
    verify_list("append", anc1);
}
#if CPDEBUG < 0
#define APPEND_LIST(anc1, anc2) APPEND_LIST(iseq, (anc1), (anc2))
#endif

/*
 * anc1: e1, e2, e3
 * anc2: e4, e5
 *#=>
 * anc1: e4, e5, e1, e2, e3
 * anc2: e4, e5 (broken)
 */
static void
INSERT_LIST(ISEQ_ARG_DECLARE LINK_ANCHOR *anc1, LINK_ANCHOR *anc2)
{
    if (anc2->anchor.next) {
        LINK_ELEMENT *first = anc1->anchor.next;
        anc1->anchor.next = anc2->anchor.next;
        anc1->anchor.next->prev = &anc1->anchor;
        anc2->last->next = first;
        if (first) {
            first->prev = anc2->last;
        }
        else {
            anc1->last = anc2->last;
        }
    }

    verify_list("append", anc1);
}
#if CPDEBUG < 0
#define INSERT_LIST(anc1, anc2) INSERT_LIST(iseq, (anc1), (anc2))
#endif

#if 0 /* unused */
/*
 * anc1: e1, e2, e3
 * anc2: e4, e5
 *#=>
 * anc1: e4, e5
 * anc2: e1, e2, e3
 */
static void
SWAP_LIST(ISEQ_ARG_DECLARE LINK_ANCHOR *anc1, LINK_ANCHOR *anc2)
{
    LINK_ANCHOR tmp = *anc2;

    /* it has bug */
    *anc2 = *anc1;
    *anc1 = tmp;

    verify_list("swap1", anc1);
    verify_list("swap2", anc2);
}
#if CPDEBUG < 0
#define SWAP_LIST(anc1, anc2) SWAP_LIST(iseq, (anc1), (anc2))
#endif

static LINK_ANCHOR *
REVERSE_LIST(ISEQ_ARG_DECLARE LINK_ANCHOR *anc)
{
    LINK_ELEMENT *first, *last, *elem, *e;
    first = &anc->anchor;
    elem = first->next;
    last = anc->last;

    if (elem != 0) {
        anc->anchor.next = last;
        anc->last = elem;
    }
    else {
        /* null list */
        return anc;
    }
    while (elem) {
        e = elem->next;
        elem->next = elem->prev;
        elem->prev = e;
        elem = e;
    }

    first->next = last;
    last->prev = first;
    anc->last->next = 0;

    verify_list("reverse", anc);
    return anc;
}
#if CPDEBUG < 0
#define REVERSE_LIST(anc) REVERSE_LIST(iseq, (anc))
#endif
#endif

#if CPDEBUG && 0
static void
debug_list(ISEQ_ARG_DECLARE LINK_ANCHOR *anchor)
{
    LINK_ELEMENT *list = FIRST_ELEMENT(anchor);
    printf("----\n");
    printf("anch: %p, frst: %p, last: %p\n", &anchor->anchor,
           anchor->anchor.next, anchor->last);
    while (list) {
        printf("curr: %p, next: %p, prev: %p, type: %d\n", list, list->next,
               list->prev, FIX2INT(list->type));
        list = list->next;
    }
    printf("----\n");

    dump_disasm_list(anchor->anchor.next);
    verify_list("debug list", anchor);
}
#if CPDEBUG < 0
#define debug_list(anc) debug_list(iseq, (anc))
#endif
#endif

static LABEL *
new_label_body(rb_iseq_t *iseq, long line)
{
    LABEL *labelobj = compile_data_alloc_label(iseq);

    labelobj->link.type = ISEQ_ELEMENT_LABEL;
    labelobj->link.next = 0;

    labelobj->label_no = iseq->compile_data->label_no++;
    labelobj->sc_state = 0;
    labelobj->sp = -1;
    return labelobj;
}

static ADJUST *
new_adjust_body(rb_iseq_t *iseq, LABEL *label, int line)
{
    ADJUST *adjust = compile_data_alloc_adjust(iseq);
    adjust->link.type = ISEQ_ELEMENT_ADJUST;
    adjust->link.next = 0;
    adjust->label = label;
    adjust->line_no = line;
    return adjust;
}

static INSN *
new_insn_core(rb_iseq_t *iseq, int line_no,
              int insn_id, int argc, VALUE *argv)
{
    INSN *iobj = compile_data_alloc_insn(iseq);
    /* printf("insn_id: %d, line: %d\n", insn_id, line_no); */

    iobj->link.type = ISEQ_ELEMENT_INSN;
    iobj->link.next = 0;
    iobj->insn_id = insn_id;
    iobj->line_no = line_no;
    iobj->operands = argv;
    iobj->operand_size = argc;
    iobj->sc_state = 0;
    return iobj;
}

static INSN *
new_insn_body(rb_iseq_t *iseq, int line_no, int insn_id, int argc, ...)
{
    VALUE *operands = 0;
    va_list argv;
    if (argc > 0) {
        int i;
        va_init_list(argv, argc);
        operands = (VALUE *)compile_data_alloc(iseq, sizeof(VALUE) * argc);
        for (i = 0; i < argc; i++) {
            VALUE v = va_arg(argv, VALUE);
            operands[i] = v;
        }
        va_end(argv);
    }
    return new_insn_core(iseq, line_no, insn_id, argc, operands);
}

static rb_call_info_t *
new_callinfo(rb_iseq_t *iseq, ID mid, int argc, VALUE block, unsigned long flag)
{
    rb_call_info_t *ci = (rb_call_info_t *)compile_data_alloc(iseq, sizeof(rb_call_info_t));
    ci->mid = mid;
    ci->flag = flag;
    ci->orig_argc = argc;
    ci->argc = argc;

    if (block) {
        GetISeqPtr(block, ci->blockiseq);
    }
    else {
        ci->blockiseq = 0;
        if (!(ci->flag & (VM_CALL_ARGS_SPLAT | VM_CALL_ARGS_BLOCKARG))) {
            ci->flag |= VM_CALL_ARGS_SKIP_SETUP;
        }
    }
    ci->method_state = 0;
    ci->class_serial = 0;
    ci->blockptr = 0;
    ci->recv = Qundef;
    ci->call = 0; /* TODO: should set default function? */

    ci->aux.index = iseq->callinfo_size++;

    return ci;
}

static INSN *
new_insn_send(rb_iseq_t *iseq, int line_no, VALUE id, VALUE argc, VALUE block, VALUE flag)
{
    VALUE *operands = (VALUE *)compile_data_alloc(iseq, sizeof(VALUE) * 1);
    operands[0] = (VALUE)new_callinfo(iseq, SYM2ID(id), FIX2INT(argc), block, FIX2INT(flag));
    return new_insn_core(iseq, line_no, BIN(send), 1, operands);
}

static VALUE
new_child_iseq(rb_iseq_t *iseq, NODE *node,
               VALUE name, VALUE parent, enum iseq_type type, int line_no)
{
    VALUE ret;

    debugs("[new_child_iseq]> ---------------------------------------\n");
    ret = rb_iseq_new_with_opt(node, name,
                               iseq_path(iseq->self), iseq_absolute_path(iseq->self),
                               INT2FIX(line_no), parent, type, iseq->compile_data->option);
    debugs("[new_child_iseq]< ---------------------------------------\n");
    iseq_add_mark_object(iseq, ret);
    return ret;
}

static int
iseq_setup(rb_iseq_t *iseq, LINK_ANCHOR *anchor)
{
    /* debugs("[compile step 2] (iseq_array_to_linkedlist)\n"); */

    if (compile_debug > 5)
        dump_disasm_list(FIRST_ELEMENT(anchor));

    debugs("[compile step 3.1 (iseq_optimize)]\n");
    iseq_optimize(iseq, anchor);

    if (compile_debug > 5)
        dump_disasm_list(FIRST_ELEMENT(anchor));

    if (iseq->compile_data->option->instructions_unification) {
        debugs("[compile step 3.2 (iseq_insns_unification)]\n");
        iseq_insns_unification(iseq, anchor);
        if (compile_debug > 5)
            dump_disasm_list(FIRST_ELEMENT(anchor));
    }

    if (iseq->compile_data->option->stack_caching) {
        debugs("[compile step 3.3 (iseq_set_sequence_stackcaching)]\n");
        iseq_set_sequence_stackcaching(iseq, anchor);
        if (compile_debug > 5)
            dump_disasm_list(FIRST_ELEMENT(anchor));
    }

    debugs("[compile step 4.1 (iseq_set_sequence)]\n");
    iseq_set_sequence(iseq, anchor);
    if (compile_debug > 5)
        dump_disasm_list(FIRST_ELEMENT(anchor));

    debugs("[compile step 4.2 (iseq_set_exception_table)]\n");
    iseq_set_exception_table(iseq);

    debugs("[compile step 4.3 (set_optargs_table)] \n");
    iseq_set_optargs_table(iseq);

    debugs("[compile step 5 (iseq_translate_threaded_code)] \n");
    rb_iseq_translate_threaded_code(iseq);

    if (compile_debug > 1) {
        VALUE str = rb_iseq_disasm(iseq->self);
        printf("%s\n", StringValueCStr(str));
        fflush(stdout);
    }
    debugs("[compile step: finish]\n");

    return 0;
}

static int
iseq_set_exception_local_table(rb_iseq_t *iseq)
{
    ID id_dollar_bang;

    CONST_ID(id_dollar_bang, "#$!");
    iseq->local_table = (ID *)ALLOC_N(ID, 1);
    iseq->local_table_size = 1;
    iseq->local_size = iseq->local_table_size + 1;
    iseq->local_table[0] = id_dollar_bang;
    return COMPILE_OK;
}

static int
get_lvar_level(rb_iseq_t *iseq)
{
    int lev = 0;
    while (iseq != iseq->local_iseq) {
        lev++;
        iseq = iseq->parent_iseq;
    }
    return lev;
}

static int
get_dyna_var_idx_at_raw(rb_iseq_t *iseq, ID id)
{
    int i;

    for (i = 0; i < iseq->local_table_size; i++) {
        if (iseq->local_table[i] == id) {
            return i;
        }
    }
    return -1;
}

static int
get_local_var_idx(rb_iseq_t *iseq, ID id)
{
    int idx = get_dyna_var_idx_at_raw(iseq->local_iseq, id);

    if (idx < 0) {
        rb_bug("get_local_var_idx: %d", idx);
    }

    return idx;
}

static int
get_dyna_var_idx(rb_iseq_t *iseq, ID id, int *level, int *ls)
{
    int lv = 0, idx = -1;

    while (iseq) {
        idx = get_dyna_var_idx_at_raw(iseq, id);
        if (idx >= 0) {
            break;
        }
        iseq = iseq->parent_iseq;
        lv++;
    }

    if (idx < 0) {
        rb_bug("get_dyna_var_idx: -1");
    }

    *level = lv;
    *ls = iseq->local_size;
    return idx;
}

static int
iseq_set_arguments(rb_iseq_t *iseq, LINK_ANCHOR *optargs, NODE *node_args)
{
    debugs("iseq_set_arguments: %s\n", node_args ? "" : "0");

    if (node_args) {
        struct rb_args_info *args = node_args->nd_ainfo;
        ID rest_id = 0;
        int last_comma = 0;
        ID block_id = 0;

        if (nd_type(node_args) != NODE_ARGS) {
            rb_bug("iseq_set_arguments: NODE_ARGS is expected, but %s",
                   ruby_node_name(nd_type(node_args)));
        }


        iseq->argc = (int)args->pre_args_num;
        debugs("  - argc: %d\n", iseq->argc);

        rest_id = args->rest_arg;
        if (rest_id == 1) {
            last_comma = 1;
            rest_id = 0;
        }
        block_id = args->block_arg;

        if (args->first_post_arg) {
            iseq->arg_post_start = get_dyna_var_idx_at_raw(iseq, args->first_post_arg);
            iseq->arg_post_len = args->post_args_num;
        }

        if (args->opt_args) {
            NODE *node = args->opt_args;
            LABEL *label;
            VALUE labels = rb_ary_tmp_new(1);
            int i = 0, j;

            while (node) {
                label = NEW_LABEL(nd_line(node));
                rb_ary_push(labels, (VALUE)label | 1);
                ADD_LABEL(optargs, label);
                COMPILE_POPED(optargs, "optarg", node->nd_body);
                node = node->nd_next;
                i += 1;
            }

            /* last label */
            label = NEW_LABEL(nd_line(node_args));
            rb_ary_push(labels, (VALUE)label | 1);
            ADD_LABEL(optargs, label);
            i += 1;

            iseq->arg_opts = i;
            iseq->arg_opt_table = ALLOC_N(VALUE, i);
            MEMCPY(iseq->arg_opt_table, RARRAY_CONST_PTR(labels), VALUE, i);
            for (j = 0; j < i; j++) {
                iseq->arg_opt_table[j] &= ~1;
            }
            rb_ary_clear(labels);
        }
        else {
            iseq->arg_opts = 0;
        }

        if (args->kw_args) {
            NODE *node = args->kw_args;
            VALUE keywords = rb_ary_tmp_new(1);
            VALUE required = 0;
            int i = 0, j, r = 0;

            iseq->arg_keyword = get_dyna_var_idx_at_raw(iseq, args->kw_rest_arg->nd_vid);
            COMPILE(optargs, "kwarg", args->kw_rest_arg);
            while (node) {
                VALUE list = keywords;
                if (node->nd_body->nd_value == (NODE *)-1) {
                    ++r;
                    if (!required) required = rb_ary_tmp_new(1);
                    list = required;
                }
                rb_ary_push(list, INT2FIX(node->nd_body->nd_vid));
                COMPILE_POPED(optargs, "kwarg", node); /* nd_type(node) == NODE_KW_ARG */
                node = node->nd_next;
                i += 1;
            }
            iseq->arg_keyword_check = args->kw_rest_arg->nd_cflag != 0;
            iseq->arg_keywords = i;
            iseq->arg_keyword_required = r;
            iseq->arg_keyword_table = ALLOC_N(ID, i);
            if (r) {
                rb_ary_concat(required, keywords);
                keywords = required;
            }
            for (j = 0; j < i; j++) {
                iseq->arg_keyword_table[j] = FIX2INT(RARRAY_AREF(keywords, j));
            }
            ADD_INSN(optargs, nd_line(args->kw_args), pop);
        }
        else if (args->kw_rest_arg) {
            iseq->arg_keyword = get_dyna_var_idx_at_raw(iseq, args->kw_rest_arg->nd_vid);
            COMPILE(optargs, "kwarg", args->kw_rest_arg);
            ADD_INSN(optargs, nd_line(args->kw_rest_arg), pop);
        }
        else {
            iseq->arg_keyword = -1;
        }

        if (args->pre_init) { /* m_init */
            COMPILE_POPED(optargs, "init arguments (m)", args->pre_init);
        }
        if (args->post_init) { /* p_init */
            COMPILE_POPED(optargs, "init arguments (p)", args->post_init);
        }

        if (rest_id) {
            iseq->arg_rest = get_dyna_var_idx_at_raw(iseq, rest_id);

            if (iseq->arg_rest == -1) {
                rb_bug("arg_rest: -1");
            }

            if (iseq->arg_post_start == 0) {
                iseq->arg_post_start = iseq->arg_rest + 1;
            }
        }

        if (block_id) {
            iseq->arg_block = get_dyna_var_idx_at_raw(iseq, block_id);
        }

        if (iseq->arg_opts != 0 || iseq->arg_post_len != 0 ||
            iseq->arg_rest != -1 || iseq->arg_block != -1 ||
            iseq->arg_keyword != -1) {
            iseq->arg_simple = 0;

            /* set arg_size: size of arguments */
            if (iseq->arg_keyword != -1) {
                iseq->arg_size = iseq->arg_keyword + 1;
            }
            else if (iseq->arg_block != -1) {
                iseq->arg_size = iseq->arg_block + 1;
            }
            else if (iseq->arg_post_len) {
                iseq->arg_size = iseq->arg_post_start + iseq->arg_post_len;
            }
            else if (iseq->arg_rest != -1) {
                iseq->arg_size = iseq->arg_rest + 1;
            }
            else if (iseq->arg_opts) {
                iseq->arg_size = iseq->argc + iseq->arg_opts - 1;
            }
            else {
                iseq->arg_size = iseq->argc;
            }
        }
        else {
            iseq->arg_simple = 1;
            iseq->arg_size = iseq->argc;
        }

        if (iseq->type == ISEQ_TYPE_BLOCK) {
            if (iseq->arg_opts == 0 && iseq->arg_post_len == 0 &&
                iseq->arg_rest == -1 && iseq->arg_keyword == -1) {
                if (iseq->argc == 1 && last_comma == 0) {
                    /* {|a|} */
                    iseq->arg_simple |= 0x02;
                }
            }
        }
    }
    else {
        iseq->arg_simple = 1;
    }

    return COMPILE_OK;
}

static int
iseq_set_local_table(rb_iseq_t *iseq, ID *tbl)
{
    int size;

    if (tbl) {
        size = (int)*tbl;
        tbl++;
    }
    else {
        size = 0;
    }

    if (size > 0) {
        iseq->local_table = (ID *)ALLOC_N(ID, size);
        MEMCPY(iseq->local_table, tbl, ID, size);
    }

    iseq->local_size = iseq->local_table_size = size;
    iseq->local_size += 1;
    /*
      if (lfp == dfp ) { // top, class, method
          dfp[-1]: svar
      else {             // block
          dfp[-1]: cref
      }
     */

    debugs("iseq_set_local_table: %d, %d\n", iseq->local_size, iseq->local_table_size);
    return COMPILE_OK;
}

static int
cdhash_cmp(VALUE val, VALUE lit)
{
    if (val == lit) return 0;
    if (SPECIAL_CONST_P(lit)) {
        return val != lit;
    }
    if (SPECIAL_CONST_P(val) || BUILTIN_TYPE(val) != BUILTIN_TYPE(lit)) {
        return -1;
    }
    if (BUILTIN_TYPE(lit) == T_STRING) {
        return rb_str_hash_cmp(lit, val);
    }
    return !rb_eql(lit, val);
}

static st_index_t
cdhash_hash(VALUE a)
{
    if (SPECIAL_CONST_P(a)) return (st_index_t)a;
    if (RB_TYPE_P(a, T_STRING)) return rb_str_hash(a);
    {
        VALUE hval = rb_hash(a);
        return (st_index_t)FIX2LONG(hval);
    }
}

static const struct st_hash_type cdhash_type = {
    cdhash_cmp,
    cdhash_hash,
};

struct cdhash_set_label_struct {
    VALUE hash;
    int pos;
    int len;
};

static int
cdhash_set_label_i(VALUE key, VALUE val, void *ptr)
{
    struct cdhash_set_label_struct *data = (struct cdhash_set_label_struct *)ptr;
    LABEL *lobj = (LABEL *)(val & ~1);
    rb_hash_aset(data->hash, key, INT2FIX(lobj->position - (data->pos+data->len)));
    return ST_CONTINUE;
}

static int
iseq_set_sequence(rb_iseq_t *iseq, LINK_ANCHOR *anchor)
{
    LABEL *lobj;
    INSN *iobj;
    struct iseq_line_info_entry *line_info_table;
    unsigned int last_line = 0;
    LINK_ELEMENT *list;
    VALUE *generated_iseq;

    int k, pos, sp, stack_max = 0, line = 0;

    /* set label position */
    list = FIRST_ELEMENT(anchor);
    k = pos = 0;
    while (list) {
        switch (list->type) {
          case ISEQ_ELEMENT_INSN:
            {
                iobj = (INSN *)list;
                line = iobj->line_no;
                pos += insn_data_length(iobj);
                k++;
                break;
            }
          case ISEQ_ELEMENT_LABEL:
            {
                lobj = (LABEL *)list;
                lobj->position = pos;
                lobj->set = TRUE;
                break;
            }
          case ISEQ_ELEMENT_NONE:
            {
                /* ignore */
                break;
            }
          case ISEQ_ELEMENT_ADJUST:
            {
                ADJUST *adjust = (ADJUST *)list;
                if (adjust->line_no != -1) {
                    pos += 2 /* insn + 1 operand */;
                    k++;
                }
                break;
            }
          default:
            dump_disasm_list(FIRST_ELEMENT(anchor));
            dump_disasm_list(list);
            rb_compile_error(RSTRING_PTR(iseq->location.path), line,
                             "error: set_sequence");
            break;
        }
        list = list->next;
    }

    /* make instruction sequence */
    generated_iseq = ALLOC_N(VALUE, pos);
    line_info_table = ALLOC_N(struct iseq_line_info_entry, k);
    iseq->is_entries = ALLOC_N(union iseq_inline_storage_entry, iseq->is_size);
    MEMZERO(iseq->is_entries, union iseq_inline_storage_entry, iseq->is_size);
    iseq->callinfo_entries = ALLOC_N(rb_call_info_t, iseq->callinfo_size);
    /* MEMZERO(iseq->callinfo_entries, rb_call_info_t, iseq->callinfo_size); */

    list = FIRST_ELEMENT(anchor);
    k = pos = sp = 0;

    while (list) {
        switch (list->type) {
          case ISEQ_ELEMENT_INSN:
            {
                int j, len, insn;
                const char *types;
                VALUE *operands;

                iobj = (INSN *)list;

                /* update sp */
                sp = calc_sp_depth(sp, iobj);
                if (sp > stack_max) {
                    stack_max = sp;
                }

                /* fprintf(stderr, "insn: %-16s, sp: %d\n", insn_name(iobj->insn_id), sp); */
                operands = iobj->operands;
                insn = iobj->insn_id;
                generated_iseq[pos] = insn;
                types = insn_op_types(insn);
                len = insn_len(insn);

                /* operand check */
                if (iobj->operand_size != len - 1) {
                    /* printf("operand size miss! (%d, %d)\n", iobj->operand_size, len); */
                    dump_disasm_list(list);
                    rb_compile_error(RSTRING_PTR(iseq->location.path), iobj->line_no,
                                     "operand size miss! (%d for %d)",
                                     iobj->operand_size, len - 1);
                    xfree(generated_iseq);
                    xfree(line_info_table);
                    return 0;
                }

                for (j = 0; types[j]; j++) {
                    char type = types[j];
                    /* printf("--> [%c - (%d-%d)]\n", type, k, j); */
                    switch (type) {
                      case TS_OFFSET:
                        {
                            /* label(destination position) */
                            lobj = (LABEL *)operands[j];
                            if (!lobj->set) {
                                rb_compile_error(RSTRING_PTR(iseq->location.path), iobj->line_no,
                                                 "unknown label");
                            }
                            if (lobj->sp == -1) {
                                lobj->sp = sp;
                            }
                            generated_iseq[pos + 1 + j] = lobj->position - (pos + len);
                            break;
                        }
                      case TS_CDHASH:
                        {
                            VALUE map = operands[j];
                            struct cdhash_set_label_struct data;
                            data.hash = map;
                            data.pos = pos;
                            data.len = len;
                            rb_hash_foreach(map, cdhash_set_label_i, (VALUE)&data);

                            hide_obj(map);
                            generated_iseq[pos + 1 + j] = map;
                            break;
                        }
                      case TS_LINDEX:
                      case TS_NUM:      /* ulong */
                        generated_iseq[pos + 1 + j] = FIX2INT(operands[j]);
                        break;
                      case TS_ISEQ:     /* iseq */
                        {
                            VALUE v = operands[j];
                            rb_iseq_t *block = 0;
                            if (v) {
                                GetISeqPtr(v, block);
                            }
                            generated_iseq[pos + 1 + j] = (VALUE)block;
                            break;
                        }
                      case TS_VALUE:    /* VALUE */
                        {
                            VALUE v = operands[j];
                            generated_iseq[pos + 1 + j] = v;
                            /* to mark ruby object */
                            iseq_add_mark_object(iseq, v);
                            break;
                        }
                      case TS_IC: /* inline cache */
                        {
                            int ic_index = FIX2INT(operands[j]);
                            IC ic = (IC)&iseq->is_entries[ic_index];
                            if (UNLIKELY(ic_index >= iseq->is_size)) {
                                rb_bug("iseq_set_sequence: ic_index overflow: index: %d, size: %d", ic_index, iseq->is_size);
                            }
                            generated_iseq[pos + 1 + j] = (VALUE)ic;
                            break;
                        }
                      case TS_CALLINFO: /* call info */
                        {
                            rb_call_info_t *base_ci = (rb_call_info_t *)operands[j];
                            rb_call_info_t *ci = &iseq->callinfo_entries[base_ci->aux.index];
                            *ci = *base_ci;

                            if (UNLIKELY(base_ci->aux.index >= iseq->callinfo_size)) {
                                rb_bug("iseq_set_sequence: ci_index overflow: index: %d, size: %d", base_ci->argc, iseq->callinfo_size);
                            }
                            generated_iseq[pos + 1 + j] = (VALUE)ci;
                            break;
                        }
                      case TS_ID: /* ID */
                        generated_iseq[pos + 1 + j] = SYM2ID(operands[j]);
                        break;
                      case TS_GENTRY:
                        {
                            struct rb_global_entry *entry =
                                (struct rb_global_entry *)(operands[j] & (~1));
                            generated_iseq[pos + 1 + j] = (VALUE)entry;
                        }
                        break;
                      default:
                        rb_compile_error(RSTRING_PTR(iseq->location.path), iobj->line_no,
                                         "unknown operand type: %c", type);
                        xfree(generated_iseq);
                        xfree(line_info_table);
                        return 0;
                    }
                }
                if (last_line != iobj->line_no) {
                    line_info_table[k].line_no = last_line = iobj->line_no;
                    line_info_table[k].position = pos;
                    k++;
                }
                pos += len;
                break;
            }
          case ISEQ_ELEMENT_LABEL:
            {
                lobj = (LABEL *)list;
                if (lobj->sp == -1) {
                    lobj->sp = sp;
                }
                else {
                    sp = lobj->sp;
                }
                break;
            }
          case ISEQ_ELEMENT_ADJUST:
            {
                ADJUST *adjust = (ADJUST *)list;
                int orig_sp = sp;

                if (adjust->label) {
                    sp = adjust->label->sp;
                }
                else {
                    sp = 0;
                }

                if (adjust->line_no != -1) {
                    if (orig_sp - sp > 0) {
                        if (last_line != (unsigned int)adjust->line_no) {
                            line_info_table[k].line_no = last_line = adjust->line_no;
                            line_info_table[k].position = pos;
                            k++;
                        }
                        generated_iseq[pos++] = BIN(adjuststack);
                        generated_iseq[pos++] = orig_sp - sp;
                    }
                    else if (orig_sp - sp == 0) {
                        /* jump to next insn */
                        if (last_line != (unsigned int)adjust->line_no) {
                            line_info_table[k].line_no = last_line = adjust->line_no;
                            line_info_table[k].position = pos;
                            k++;
                        }
                        generated_iseq[pos++] = BIN(jump);
                        generated_iseq[pos++] = 0;
                    }
                    else {
                        rb_bug("iseq_set_sequence: adjust bug");
                    }
                }
                break;
            }
          default:
            /* ignore */
            break;
        }
        list = list->next;
    }

#if 0 /* XXX */
    /* this check need dead code elimination */
    if (sp != 1) {
        rb_bug("SP is not 0 on %s (%d)\n", RSTRING_PTR(iseq->name), sp);
    }
#endif

    iseq->iseq = (void *)generated_iseq;
    iseq->iseq_size = pos;
    iseq->stack_max = stack_max;

    line_info_table = ruby_xrealloc(line_info_table, k * sizeof(struct iseq_line_info_entry));
    iseq->line_info_table = line_info_table;
    iseq->line_info_size = k;

    return COMPILE_OK;
}

static int
label_get_position(LABEL *lobj)
{
    return lobj->position;
}

static int
label_get_sp(LABEL *lobj)
{
    return lobj->sp;
}

static int
iseq_set_exception_table(rb_iseq_t *iseq)
{
    const VALUE *tptr, *ptr;
    int tlen, i;
    struct iseq_catch_table_entry *entry;

    tlen = (int)RARRAY_LEN(iseq->compile_data->catch_table_ary);
    tptr = RARRAY_CONST_PTR(iseq->compile_data->catch_table_ary);

    iseq->catch_table = tlen ? ALLOC_N(struct iseq_catch_table_entry, tlen) : 0;
    iseq->catch_table_size = tlen;

    for (i = 0; i < tlen; i++) {
        ptr = RARRAY_CONST_PTR(tptr[i]);
        entry = &iseq->catch_table[i];
        entry->type = (enum catch_type)(ptr[0] & 0xffff);
        entry->start = label_get_position((LABEL *)(ptr[1] & ~1));
        entry->end = label_get_position((LABEL *)(ptr[2] & ~1));
        entry->iseq = ptr[3];

        /* register iseq as mark object */
        if (entry->iseq != 0) {
            iseq_add_mark_object(iseq, entry->iseq);
        }

        /* stack depth */
        if (ptr[4]) {
            LABEL *lobj = (LABEL *)(ptr[4] & ~1);
            entry->cont = label_get_position(lobj);
            entry->sp = label_get_sp(lobj);

            /* TODO: Dirty Hack!  Fix me */
            if (entry->type == CATCH_TYPE_RESCUE ||
                entry->type == CATCH_TYPE_BREAK ||
                entry->type == CATCH_TYPE_NEXT) {
                entry->sp--;
            }
        }
        else {
            entry->cont = 0;
        }
    }

    RB_OBJ_WRITE(iseq->self, &iseq->compile_data->catch_table_ary, 0); /* free */
    return COMPILE_OK;
}

/*
 * set optional argument table
 *   def foo(a, b=expr1, c=expr2)
 *   =>
 *    b:
 *      expr1
 *    c:
 *      expr2
 */
static int
iseq_set_optargs_table(rb_iseq_t *iseq)
{
    int i;

    if (iseq->arg_opts != 0) {
        for (i = 0; i < iseq->arg_opts; i++) {
            iseq->arg_opt_table[i] =
                label_get_position((LABEL *)iseq->arg_opt_table[i]);
        }
    }
    return COMPILE_OK;
}

static LINK_ELEMENT *
get_destination_insn(INSN *iobj)
{
    LABEL *lobj = (LABEL *)OPERAND_AT(iobj, 0);
    LINK_ELEMENT *list;

    list = lobj->link.next;
    while (list) {
        if (list->type == ISEQ_ELEMENT_INSN || list->type == ISEQ_ELEMENT_ADJUST) {
            break;
        }
        list = list->next;
    }
    return list;
}

static LINK_ELEMENT *
get_next_insn(INSN *iobj)
{
    LINK_ELEMENT *list = iobj->link.next;

    while (list) {
        if (list->type == ISEQ_ELEMENT_INSN || list->type == ISEQ_ELEMENT_ADJUST) {
            return list;
        }
        list = list->next;
    }
    return 0;
}

static LINK_ELEMENT *
get_prev_insn(INSN *iobj)
{
    LINK_ELEMENT *list = iobj->link.prev;

    while (list) {
        if (list->type == ISEQ_ELEMENT_INSN || list->type == ISEQ_ELEMENT_ADJUST) {
            return list;
        }
        list = list->prev;
    }
    return 0;
}

static int
iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcallopt)
{
    INSN *iobj = (INSN *)list;
  again:
    if (iobj->insn_id == BIN(jump)) {
        INSN *niobj, *diobj, *piobj;
        /*
         *  useless jump elimination:
         *     jump LABEL1
         *     ...
         *   LABEL1:
         *     jump LABEL2
         *
         *   => in this case, first jump instruction should jump to
         *      LABEL2 directly
         */
        diobj = (INSN *)get_destination_insn(iobj);
        niobj = (INSN *)get_next_insn(iobj);

        if (diobj == niobj) {
            /*
             *   jump LABEL
             *  LABEL:
             * =>
             *   LABEL:
             */
            REMOVE_ELEM(&iobj->link);
        }
        else if (iobj != diobj && diobj->insn_id == BIN(jump)) {
            if (OPERAND_AT(iobj, 0) != OPERAND_AT(diobj, 0)) {
                OPERAND_AT(iobj, 0) = OPERAND_AT(diobj, 0);
                goto again;
            }
        }
        else if (diobj->insn_id == BIN(leave)) {
            /*
             *  jump LABEL
             *  ...
             * LABEL:
             *  leave
             * =>
             *  leave
             *  ...
             * LABEL:
             *  leave
             */
            INSN *eiobj = new_insn_core(iseq, iobj->line_no, BIN(leave),
                                        diobj->operand_size, diobj->operands);
            INSN *popiobj = new_insn_core(iseq, iobj->line_no,
                                          BIN(pop), 0, 0);
            /* replace */
            REPLACE_ELEM((LINK_ELEMENT *)iobj, (LINK_ELEMENT *)eiobj);
            INSERT_ELEM_NEXT((LINK_ELEMENT *)eiobj, (LINK_ELEMENT *)popiobj);
            iobj = popiobj;
        }
        /*
         * useless jump elimination (if/unless destination):
         *   if   L1
         *   jump L2
         * L1:
         *   ...
         * L2:
         *
         * ==>
         *   unless L2
         * L1:
         *   ...
         * L2:
         */
        else if ((piobj = (INSN *)get_prev_insn(iobj)) != 0 &&
                 (piobj->insn_id == BIN(branchif) ||
                  piobj->insn_id == BIN(branchunless))) {
            if (niobj == (INSN *)get_destination_insn(piobj)) {
                piobj->insn_id = (piobj->insn_id == BIN(branchif))
                  ? BIN(branchunless) : BIN(branchif);
                OPERAND_AT(piobj, 0) = OPERAND_AT(iobj, 0);
                REMOVE_ELEM(&iobj->link);
            }
        }
    }

    if (iobj->insn_id == BIN(branchif) ||
        iobj->insn_id == BIN(branchunless)) {
        /*
         *   if L1
         *   ...
         * L1:
         *   jump L2
         * =>
         *   if L2
         */
        INSN *nobj = (INSN *)get_destination_insn(iobj);
        if (nobj->insn_id == BIN(jump)) {
            OPERAND_AT(iobj, 0) = OPERAND_AT(nobj, 0);
        }
    }

    if (do_tailcallopt && iobj->insn_id == BIN(leave)) {
        /*
         *  send ...
         *  leave
         * =>
         *  send ..., ... | VM_CALL_TAILCALL, ...
         *  leave # unreachable
         */
        INSN *piobj = (INSN *)get_prev_insn((INSN *)list);
        enum ruby_vminsn_type previ = piobj->insn_id;

        if (previ == BIN(send) || previ == BIN(opt_send_simple) || previ == BIN(invokesuper)) {
            rb_call_info_t *ci = (rb_call_info_t *)piobj->operands[0];
            if (ci->blockiseq == 0) {
                ci->flag |= VM_CALL_TAILCALL;
            }
        }
    }
    return COMPILE_OK;
}

static int
insn_set_specialized_instruction(rb_iseq_t *iseq, INSN *iobj, int insn_id)
{
    int old_opsize = iobj->operand_size;
    iobj->insn_id = insn_id;
    iobj->operand_size = insn_len(insn_id) - 1;

    if (iobj->operand_size > old_opsize) {
        VALUE *old_operands = iobj->operands;
        if (insn_id != BIN(opt_neq)) {
            rb_bug("insn_set_specialized_instruction: unknown insn: %d", insn_id);
        }
        iobj->operands = (VALUE *)compile_data_alloc(iseq, iobj->operand_size * sizeof(VALUE));
        iobj->operands[0] = old_operands[0];
        iobj->operands[1] = (VALUE)new_callinfo(iseq, idEq, 1, 0, 0);
    }

    return COMPILE_OK;
}

static int
iseq_specialized_instruction(rb_iseq_t *iseq, INSN *iobj)
{
    if (iobj->insn_id == BIN(send)) {
        rb_call_info_t *ci = (rb_call_info_t *)OPERAND_AT(iobj, 0);

#define SP_INSN(opt) insn_set_specialized_instruction(iseq, iobj, BIN(opt_##opt))
        if (ci->blockiseq == 0 && (ci->flag & ~VM_CALL_ARGS_SKIP_SETUP) == 0) {
            switch (ci->orig_argc) {
              case 0:
                switch (ci->mid) {
                  case idLength: SP_INSN(length); return COMPILE_OK;
                  case idSize:   SP_INSN(size);   return COMPILE_OK;
                  case idEmptyP: SP_INSN(empty_p);return COMPILE_OK;
                  case idSucc:   SP_INSN(succ);   return COMPILE_OK;
                  case idNot:    SP_INSN(not);    return COMPILE_OK;
                }
                break;
              case 1:
                switch (ci->mid) {
                  case idPLUS:   SP_INSN(plus);   return COMPILE_OK;
                  case idMINUS:  SP_INSN(minus);  return COMPILE_OK;
                  case idMULT:   SP_INSN(mult);   return COMPILE_OK;
                  case idDIV:    SP_INSN(div);    return COMPILE_OK;
                  case idMOD:    SP_INSN(mod);    return COMPILE_OK;
                  case idEq:     SP_INSN(eq);     return COMPILE_OK;
                  case idNeq:    SP_INSN(neq);    return COMPILE_OK;
                  case idLT:     SP_INSN(lt);     return COMPILE_OK;
                  case idLE:     SP_INSN(le);     return COMPILE_OK;
                  case idGT:     SP_INSN(gt);     return COMPILE_OK;
                  case idGE:     SP_INSN(ge);     return COMPILE_OK;
                  case idLTLT:   SP_INSN(ltlt);   return COMPILE_OK;
                  case idAREF:   SP_INSN(aref);   return COMPILE_OK;
                }
                break;
              case 2:
                switch (ci->mid) {
                  case idASET:   SP_INSN(aset);   return COMPILE_OK;
                }
                break;
            }
        }
        if (ci->flag & VM_CALL_ARGS_SKIP_SETUP) {
            iobj->insn_id = BIN(opt_send_simple);
        }
    }
#undef SP_INSN

    return COMPILE_OK;
}

static int
iseq_optimize(rb_iseq_t *iseq, LINK_ANCHOR *anchor)
{
    LINK_ELEMENT *list;
    const int do_peepholeopt = iseq->compile_data->option->peephole_optimization;
    const int do_tailcallopt = iseq->compile_data->option->tailcall_optimization;
    const int do_si = iseq->compile_data->option->specialized_instruction;
    const int do_ou = iseq->compile_data->option->operands_unification;
    list = FIRST_ELEMENT(anchor);

    while (list) {
        if (list->type == ISEQ_ELEMENT_INSN) {
            if (do_peepholeopt) {
                iseq_peephole_optimize(iseq, list, do_tailcallopt);
            }
            if (do_si) {
                iseq_specialized_instruction(iseq, (INSN *)list);
            }
            if (do_ou) {
                insn_operands_unification((INSN *)list);
            }
        }
        list = list->next;
    }
    return COMPILE_OK;
}

#if OPT_INSTRUCTIONS_UNIFICATION
static INSN *
new_unified_insn(rb_iseq_t *iseq,
                 int insn_id, int size, LINK_ELEMENT *seq_list)
{
    INSN *iobj = 0;
    LINK_ELEMENT *list = seq_list;
    int i, argc = 0;
    VALUE *operands = 0, *ptr = 0;


    /* count argc */
    for (i = 0; i < size; i++) {
        iobj = (INSN *)list;
        argc += iobj->operand_size;
        list = list->next;
    }

    if (argc > 0) {
        ptr = operands =
            (VALUE *)compile_data_alloc(iseq, sizeof(VALUE) * argc);
    }

    /* copy operands */
    list = seq_list;
    for (i = 0; i < size; i++) {
        iobj = (INSN *)list;
        MEMCPY(ptr, iobj->operands, VALUE, iobj->operand_size);
        ptr += iobj->operand_size;
        list = list->next;
    }

    return new_insn_core(iseq, iobj->line_no, insn_id, argc, operands);
}
#endif

/*
 * This scheme can get more performance if do this optimize with
 * label address resolving.
 * It's future work (if compile time was bottle neck).
 */
static int
iseq_insns_unification(rb_iseq_t *iseq, LINK_ANCHOR *anchor)
{
#if OPT_INSTRUCTIONS_UNIFICATION
    LINK_ELEMENT *list;
    INSN *iobj, *niobj;
    int id, k;
    intptr_t j;

    list = FIRST_ELEMENT(anchor);
    while (list) {
        if (list->type == ISEQ_ELEMENT_INSN) {
            iobj = (INSN *)list;
            id = iobj->insn_id;
            if (unified_insns_data[id] != 0) {
                const int *const *entry = unified_insns_data[id];
                for (j = 1; j < (intptr_t)entry[0]; j++) {
                    const int *unified = entry[j];
                    LINK_ELEMENT *li = list->next;
                    for (k = 2; k < unified[1]; k++) {
                        if (li->type != ISEQ_ELEMENT_INSN ||
                            ((INSN *)li)->insn_id != unified[k]) {
                            goto miss;
                        }
                        li = li->next;
                    }
                    /* matched */
                    niobj =
                        new_unified_insn(iseq, unified[0], unified[1] - 1,
                                         list);

                    /* insert to list */
                    niobj->link.prev = (LINK_ELEMENT *)iobj->link.prev;
                    niobj->link.next = li;
                    if (li) {
                        li->prev = (LINK_ELEMENT *)niobj;
                    }

                    list->prev->next = (LINK_ELEMENT *)niobj;
                    list = (LINK_ELEMENT *)niobj;
                    break;
                  miss:;
                }
            }
        }
        list = list->next;
    }
#endif
    return COMPILE_OK;
}

#if OPT_STACK_CACHING

#define SC_INSN(insn, stat) sc_insn_info[(insn)][(stat)]
#define SC_NEXT(insn)       sc_insn_next[(insn)]

#include "opt_sc.inc"

static int
insn_set_sc_state(rb_iseq_t *iseq, INSN *iobj, int state)
{
    int nstate;
    int insn_id;

    insn_id = iobj->insn_id;
    iobj->insn_id = SC_INSN(insn_id, state);
    nstate = SC_NEXT(iobj->insn_id);

    if (insn_id == BIN(jump) ||
        insn_id == BIN(branchif) || insn_id == BIN(branchunless)) {
        LABEL *lobj = (LABEL *)OPERAND_AT(iobj, 0);

        if (lobj->sc_state != 0) {
            if (lobj->sc_state != nstate) {
                dump_disasm_list((LINK_ELEMENT *)iobj);
                dump_disasm_list((LINK_ELEMENT *)lobj);
                printf("\n-- %d, %d\n", lobj->sc_state, nstate);
                rb_compile_error(RSTRING_PTR(iseq->location.path), iobj->line_no,
                                 "insn_set_sc_state error\n");
                return 0;
            }
        }
        else {
            lobj->sc_state = nstate;
        }
        if (insn_id == BIN(jump)) {
            nstate = SCS_XX;
        }
    }
    else if (insn_id == BIN(leave)) {
        nstate = SCS_XX;
    }

    return nstate;
}

static int
label_set_sc_state(LABEL *lobj, int state)
{
    if (lobj->sc_state != 0) {
        if (lobj->sc_state != state) {
            state = lobj->sc_state;
        }
    }
    else {
        lobj->sc_state = state;
    }

    return state;
}


#endif

static int
iseq_set_sequence_stackcaching(rb_iseq_t *iseq, LINK_ANCHOR *anchor)
{
#if OPT_STACK_CACHING
    LINK_ELEMENT *list;
    int state, insn_id;

    /* initialize */
    state = SCS_XX;
    list = FIRST_ELEMENT(anchor);
    /* dump_disasm_list(list); */

    /* for each list element */
    while (list) {
      redo_point:
        switch (list->type) {
          case ISEQ_ELEMENT_INSN:
            {
                INSN *iobj = (INSN *)list;
                insn_id = iobj->insn_id;

                /* dump_disasm_list(list); */

                switch (insn_id) {
                  case BIN(nop):
                    {
                        /* exception merge point */
                        if (state != SCS_AX) {
                            INSN *rpobj =
                                new_insn_body(iseq, 0, BIN(reput), 0);

                            /* replace this insn */
                            REPLACE_ELEM(list, (LINK_ELEMENT *)rpobj);
                            list = (LINK_ELEMENT *)rpobj;
                            goto redo_point;
                        }
                        break;
                    }
                  case BIN(swap):
                    {
                        if (state == SCS_AB || state == SCS_BA) {
                            state = (state == SCS_AB ? SCS_BA : SCS_AB);

                            REMOVE_ELEM(list);
                            list = list->next;
                            goto redo_point;
                        }
                        break;
                    }
                  case BIN(pop):
                    {
                        switch (state) {
                          case SCS_AX:
                          case SCS_BX:
                            state = SCS_XX;
                            break;
                          case SCS_AB:
                            state = SCS_AX;
                            break;
                          case SCS_BA:
                            state = SCS_BX;
                            break;
                          case SCS_XX:
                            goto normal_insn;
                          default:
                            rb_compile_error(RSTRING_PTR(iseq->location.path), iobj->line_no,
                                             "unreachable");
                        }
                        /* remove useless pop */
                        REMOVE_ELEM(list);
                        list = list->next;
                        goto redo_point;
                    }
                  default:;
                    /* none */
                }               /* end of switch */
              normal_insn:
                state = insn_set_sc_state(iseq, iobj, state);
                break;
            }
          case ISEQ_ELEMENT_LABEL:
            {
                LABEL *lobj;
                lobj = (LABEL *)list;

                state = label_set_sc_state(lobj, state);
            }
          default:
            break;
        }
        list = list->next;
    }
#endif
    return COMPILE_OK;
}

static int
compile_dstr_fragments(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE *node, int *cntp)
{
    NODE *list = node->nd_next;
    VALUE lit = node->nd_lit;
    int cnt = 0;

    debugp_param("nd_lit", lit);
    if (!NIL_P(lit)) {
        cnt++;
        if (RB_TYPE_P(lit, T_STRING))
            lit = node->nd_lit = rb_fstring(node->nd_lit);
        ADD_INSN1(ret, nd_line(node), putobject, lit);
    }

    while (list) {
        node = list->nd_head;
        if (nd_type(node) == NODE_STR) {
            node->nd_lit = rb_fstring(node->nd_lit);
            ADD_INSN1(ret, nd_line(node), putobject, node->nd_lit);
        }
        else {
            COMPILE(ret, "each string", node);
        }
        cnt++;
        list = list->nd_next;
    }
    *cntp = cnt;

    return COMPILE_OK;
}

static int
compile_dstr(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node)
{
    int cnt;
    compile_dstr_fragments(iseq, ret, node, &cnt);
    ADD_INSN1(ret, nd_line(node), concatstrings, INT2FIX(cnt));
    return COMPILE_OK;
}

static int
compile_dregx(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node)
{
    int cnt;
    compile_dstr_fragments(iseq, ret, node, &cnt);
    ADD_INSN2(ret, nd_line(node), toregexp, INT2FIX(node->nd_cflag), INT2FIX(cnt));
    return COMPILE_OK;
}

static int
compile_branch_condition(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * cond,
                         LABEL *then_label, LABEL *else_label)
{
    switch (nd_type(cond)) {
      case NODE_AND:
        {
            LABEL *label = NEW_LABEL(nd_line(cond));
            compile_branch_condition(iseq, ret, cond->nd_1st, label,
                                     else_label);
            ADD_LABEL(ret, label);
            compile_branch_condition(iseq, ret, cond->nd_2nd, then_label,
                                     else_label);
            break;
        }
      case NODE_OR:
        {
            LABEL *label = NEW_LABEL(nd_line(cond));
            compile_branch_condition(iseq, ret, cond->nd_1st, then_label,
                                     label);
            ADD_LABEL(ret, label);
            compile_branch_condition(iseq, ret, cond->nd_2nd, then_label,
                                     else_label);
            break;
        }
      case NODE_LIT:            /* NODE_LIT is always not true */
      case NODE_TRUE:
      case NODE_STR:
        /* printf("useless condition eliminate (%s)\n",  ruby_node_name(nd_type(cond))); */
        ADD_INSNL(ret, nd_line(cond), jump, then_label);
        break;
      case NODE_FALSE:
      case NODE_NIL:
        /* printf("useless condition eliminate (%s)\n", ruby_node_name(nd_type(cond))); */
        ADD_INSNL(ret, nd_line(cond), jump, else_label);
        break;
      default:
        COMPILE(ret, "branch condition", cond);
        ADD_INSNL(ret, nd_line(cond), branchunless, else_label);
        ADD_INSNL(ret, nd_line(cond), jump, then_label);
        break;
    }
    return COMPILE_OK;
}

enum compile_array_type_t {
    COMPILE_ARRAY_TYPE_ARRAY,
    COMPILE_ARRAY_TYPE_HASH,
    COMPILE_ARRAY_TYPE_ARGS
};

static int
compile_array_(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE* node_root,
               enum compile_array_type_t type, int poped)
{
    NODE *node = node_root;
    int line = (int)nd_line(node);
    int len = 0;

    if (nd_type(node) == NODE_ZARRAY) {
        if (!poped) {
            switch (type) {
              case COMPILE_ARRAY_TYPE_ARRAY: ADD_INSN1(ret, line, newarray, INT2FIX(0)); break;
              case COMPILE_ARRAY_TYPE_HASH: ADD_INSN1(ret, line, newhash, INT2FIX(0)); break;
              case COMPILE_ARRAY_TYPE_ARGS: /* do nothing */ break;
            }
        }
    }
    else {
        int opt_p = 1;
        int first = 1, i;

        while (node) {
            NODE *start_node = node, *end_node;
            NODE *kw = 0;
            const int max = 0x100;
            DECL_ANCHOR(anchor);
            INIT_ANCHOR(anchor);

            for (i=0; i<max && node; i++, len++, node = node->nd_next) {
                if (CPDEBUG > 0 && nd_type(node) != NODE_ARRAY) {
                    rb_bug("compile_array: This node is not NODE_ARRAY, but %s", ruby_node_name(nd_type(node)));
                }

                if (type == COMPILE_ARRAY_TYPE_HASH && !node->nd_head) {
                    opt_p = 0;
                    kw = node->nd_next;
                    node = kw->nd_next;
                    kw = kw->nd_head;
                    break;
                }
                if (opt_p && nd_type(node->nd_head) != NODE_LIT) {
                    opt_p = 0;
                }

                COMPILE_(anchor, "array element", node->nd_head, poped);
            }

            if (opt_p && type != COMPILE_ARRAY_TYPE_ARGS) {
                if (!poped) {
                    VALUE ary = rb_ary_tmp_new(i);

                    end_node = node;
                    node = start_node;

                    while (node != end_node) {
                        rb_ary_push(ary, node->nd_head->nd_lit);
                        node = node->nd_next;
                    }
                    while (node && nd_type(node->nd_head) == NODE_LIT &&
                           node->nd_next && nd_type(node->nd_next->nd_head) == NODE_LIT) {
                        rb_ary_push(ary, node->nd_head->nd_lit);
                        node = node->nd_next;
                        rb_ary_push(ary, node->nd_head->nd_lit);
                        node = node->nd_next;
                        len++;
                    }

                    OBJ_FREEZE(ary);

                    iseq_add_mark_object_compile_time(iseq, ary);

                    if (first) {
                        first = 0;
                        if (type == COMPILE_ARRAY_TYPE_ARRAY) {
                            ADD_INSN1(ret, line, duparray, ary);
                        }
                        else { /* COMPILE_ARRAY_TYPE_HASH */
                            ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
                            ADD_INSN1(ret, line, putobject, ary);
                            ADD_SEND(ret, line, ID2SYM(id_core_hash_from_ary), INT2FIX(1));
                        }
                    }
                    else {
                        if (type == COMPILE_ARRAY_TYPE_ARRAY) {
                            ADD_INSN1(ret, line, putobject, ary);
                            ADD_INSN(ret, line, concatarray);
                        }
                        else {
                            ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
                            ADD_INSN1(ret, line, putobject, ary);
                            ADD_SEND(ret, line, ID2SYM(id_core_hash_merge_ary), INT2FIX(1));
                        }
                    }
                }
            }
            else {
                if (!poped) {
                    switch (type) {
                      case COMPILE_ARRAY_TYPE_ARRAY:
                        ADD_INSN1(anchor, line, newarray, INT2FIX(i));

                        if (first) {
                            first = 0;
                        }
                        else {
                            ADD_INSN(anchor, line, concatarray);
                        }

                        APPEND_LIST(ret, anchor);
                        break;
                      case COMPILE_ARRAY_TYPE_HASH:
                        if (i > 0) {
                            if (first) {
                                ADD_INSN1(anchor, line, newhash, INT2FIX(i));
                                APPEND_LIST(ret, anchor);
                            }
                            else {
                                ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
                                ADD_INSN(ret, line, swap);
                                APPEND_LIST(ret, anchor);
                                ADD_SEND(ret, line, ID2SYM(id_core_hash_merge_ptr), INT2FIX(i + 1));
                            }
                        }
                        if (kw) {
                            VALUE nhash = (i > 0 || !first) ? INT2FIX(2) : INT2FIX(1);
                            ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
                            if (i > 0 || !first) ADD_INSN(ret, line, swap);
                            COMPILE(ret, "keyword splat", kw);
                            ADD_SEND(ret, line, ID2SYM(id_core_hash_merge_kwd), nhash);
                            if (nhash == INT2FIX(1)) ADD_SEND(ret, line, ID2SYM(rb_intern("dup")), INT2FIX(0));
                        }
                        first = 0;
                        break;
                      case COMPILE_ARRAY_TYPE_ARGS:
                        APPEND_LIST(ret, anchor);
                        break;
                    }
                }
                else {
                    /* poped */
                    APPEND_LIST(ret, anchor);
                }
            }
        }
    }
    return len;
}

static VALUE
compile_array(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE* node_root, enum compile_array_type_t type)
{
    return compile_array_(iseq, ret, node_root, type, 0);
}

static VALUE
case_when_optimizable_literal(NODE * node)
{
    switch (nd_type(node)) {
      case NODE_LIT: {
        VALUE v = node->nd_lit;
        double ival;
        if (RB_TYPE_P(v, T_FLOAT) &&
            modf(RFLOAT_VALUE(v), &ival) == 0.0) {
            return FIXABLE(ival) ? LONG2FIX((long)ival) : rb_dbl2big(ival);
        }
        if (SYMBOL_P(v) || rb_obj_is_kind_of(v, rb_cNumeric)) {
            return v;
        }
        break;
      }
      case NODE_STR:
        return node->nd_lit = rb_fstring(node->nd_lit);
    }
    return Qundef;
}

static int
when_vals(rb_iseq_t *iseq, LINK_ANCHOR *cond_seq, NODE *vals, LABEL *l1, int only_special_literals, VALUE literals)
{
    while (vals) {
        NODE* val = vals->nd_head;
        VALUE lit = case_when_optimizable_literal(val);

        if (lit == Qundef) {
            only_special_literals = 0;
        }
        else {
            if (rb_hash_lookup(literals, lit) != Qnil) {
                rb_compile_warning(RSTRING_PTR(iseq->location.path), nd_line(val), "duplicated when clause is ignored");
            }
            else {
                rb_hash_aset(literals, lit, (VALUE)(l1) | 1);
            }
        }

        ADD_INSN(cond_seq, nd_line(val), dup); /* dup target */

        if (nd_type(val) == NODE_STR) {
            val->nd_lit = rb_fstring(val->nd_lit);
            debugp_param("nd_lit", val->nd_lit);
            ADD_INSN1(cond_seq, nd_line(val), putobject, val->nd_lit);
        }
        else {
            COMPILE(cond_seq, "when cond", val);
        }

        ADD_INSN1(cond_seq, nd_line(vals), checkmatch, INT2FIX(VM_CHECKMATCH_TYPE_CASE));
        ADD_INSNL(cond_seq, nd_line(val), branchif, l1);
        vals = vals->nd_next;
    }
    return only_special_literals;
}

static int
compile_massign_lhs(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE *node)
{
    switch (nd_type(node)) {
      case NODE_ATTRASGN: {
        INSN *iobj;
        rb_call_info_t *ci;
        VALUE dupidx;

        COMPILE_POPED(ret, "masgn lhs (NODE_ATTRASGN)", node);

        POP_ELEMENT(ret);        /* pop pop insn */
        iobj = (INSN *)POP_ELEMENT(ret); /* pop send insn */
        ci = (rb_call_info_t *)iobj->operands[0];
        ci->orig_argc += 1; ci->argc = ci->orig_argc;
        dupidx = INT2FIX(ci->orig_argc);

        ADD_INSN1(ret, nd_line(node), topn, dupidx);
        ADD_ELEM(ret, (LINK_ELEMENT *)iobj);
        ADD_INSN(ret, nd_line(node), pop);      /* result */
        ADD_INSN(ret, nd_line(node), pop);      /* rhs    */
        break;
      }
      case NODE_MASGN: {
        DECL_ANCHOR(anchor);
        INIT_ANCHOR(anchor);
        COMPILE_POPED(anchor, "nest masgn lhs", node);
        REMOVE_ELEM(FIRST_ELEMENT(anchor));
        ADD_SEQ(ret, anchor);
        break;
      }
      default: {
        DECL_ANCHOR(anchor);
        INIT_ANCHOR(anchor);
        COMPILE_POPED(anchor, "masgn lhs", node);
        REMOVE_ELEM(FIRST_ELEMENT(anchor));
        ADD_SEQ(ret, anchor);
      }
    }

    return COMPILE_OK;
}

static void
compile_massign_opt_lhs(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE *lhsn)
{
    if (lhsn) {
        compile_massign_opt_lhs(iseq, ret, lhsn->nd_next);
        compile_massign_lhs(iseq, ret, lhsn->nd_head);
    }
}

static int
compile_massign_opt(rb_iseq_t *iseq, LINK_ANCHOR *ret,
                    NODE *rhsn, NODE *orig_lhsn)
{
    VALUE mem[64];
    const int memsize = numberof(mem);
    int memindex = 0;
    int llen = 0, rlen = 0;
    int i;
    NODE *lhsn = orig_lhsn;

#define MEMORY(v) { \
    int i; \
    if (memindex == memsize) return 0; \
    for (i=0; i<memindex; i++) { \
        if (mem[i] == (v)) return 0; \
    } \
    mem[memindex++] = (v); \
}

    if (rhsn == 0 || nd_type(rhsn) != NODE_ARRAY) {
        return 0;
    }

    while (lhsn) {
        NODE *ln = lhsn->nd_head;
        switch (nd_type(ln)) {
          case NODE_LASGN:
            MEMORY(ln->nd_vid);
            break;
          case NODE_DASGN:
          case NODE_DASGN_CURR:
          case NODE_IASGN:
          case NODE_IASGN2:
          case NODE_CVASGN:
            MEMORY(ln->nd_vid);
            break;
          default:
            return 0;
        }
        lhsn = lhsn->nd_next;
        llen++;
    }

    while (rhsn) {
        if (llen <= rlen) {
            COMPILE_POPED(ret, "masgn val (popped)", rhsn->nd_head);
        }
        else {
            COMPILE(ret, "masgn val", rhsn->nd_head);
        }
        rhsn = rhsn->nd_next;
        rlen++;
    }

    if (llen > rlen) {
        for (i=0; i<llen-rlen; i++) {
            ADD_INSN(ret, nd_line(orig_lhsn), putnil);
        }
    }

    compile_massign_opt_lhs(iseq, ret, orig_lhsn);
    return 1;
}

static int
compile_massign(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE *node, int poped)
{
    NODE *rhsn = node->nd_value;
    NODE *splatn = node->nd_args;
    NODE *lhsn = node->nd_head;
    int lhs_splat = (splatn && (VALUE)splatn != (VALUE)-1) ? 1 : 0;

    if (!poped || splatn || !compile_massign_opt(iseq, ret, rhsn, lhsn)) {
        int llen = 0;
        DECL_ANCHOR(lhsseq);

        INIT_ANCHOR(lhsseq);

        while (lhsn) {
            compile_massign_lhs(iseq, lhsseq, lhsn->nd_head);
            llen += 1;
            lhsn = lhsn->nd_next;
        }

        COMPILE(ret, "normal masgn rhs", rhsn);

        if (!poped) {
            ADD_INSN(ret, nd_line(node), dup);
        }

        ADD_INSN2(ret, nd_line(node), expandarray,
                  INT2FIX(llen), INT2FIX(lhs_splat));
        ADD_SEQ(ret, lhsseq);

        if (lhs_splat) {
            if (nd_type(splatn) == NODE_POSTARG) {
                /*a, b, *r, p1, p2 */
                NODE *postn = splatn->nd_2nd;
                NODE *restn = splatn->nd_1st;
                int num = (int)postn->nd_alen;
                int flag = 0x02 | (((VALUE)restn == (VALUE)-1) ? 0x00 : 0x01);

                ADD_INSN2(ret, nd_line(splatn), expandarray,
                          INT2FIX(num), INT2FIX(flag));

                if ((VALUE)restn != (VALUE)-1) {
                    compile_massign_lhs(iseq, ret, restn);
                }
                while (postn) {
                    compile_massign_lhs(iseq, ret, postn->nd_head);
                    postn = postn->nd_next;
                }
            }
            else {
                /* a, b, *r */
                compile_massign_lhs(iseq, ret, splatn);
            }
        }
    }
    return COMPILE_OK;
}

static int
compile_colon2(rb_iseq_t *iseq, NODE * node,
               LINK_ANCHOR *pref, LINK_ANCHOR *body)
{
    switch (nd_type(node)) {
      case NODE_CONST:
        debugi("compile_colon2 - colon", node->nd_vid);
        ADD_INSN1(body, nd_line(node), getconstant, ID2SYM(node->nd_vid));
        break;
      case NODE_COLON3:
        debugi("compile_colon2 - colon3", node->nd_mid);
        ADD_INSN(body, nd_line(node), pop);
        ADD_INSN1(body, nd_line(node), putobject, rb_cObject);
        ADD_INSN1(body, nd_line(node), getconstant, ID2SYM(node->nd_mid));
        break;
      case NODE_COLON2:
        compile_colon2(iseq, node->nd_head, pref, body);
        debugi("compile_colon2 - colon2", node->nd_mid);
        ADD_INSN1(body, nd_line(node), getconstant, ID2SYM(node->nd_mid));
        break;
      default:
        COMPILE(pref, "const colon2 prefix", node);
        break;
    }
    return COMPILE_OK;
}

static VALUE
compile_cpath(LINK_ANCHOR *ret, rb_iseq_t *iseq, NODE *cpath)
{
    if (nd_type(cpath) == NODE_COLON3) {
        /* toplevel class ::Foo */
        ADD_INSN1(ret, nd_line(cpath), putobject, rb_cObject);
        return Qfalse;
    }
    else if (cpath->nd_head) {
        /* Bar::Foo */
        COMPILE(ret, "nd_else->nd_head", cpath->nd_head);
        return Qfalse;
    }
    else {
        /* class at cbase Foo */
        ADD_INSN1(ret, nd_line(cpath), putspecialobject,
                  INT2FIX(VM_SPECIAL_OBJECT_CONST_BASE));
        return Qtrue;
    }
}

#define defined_expr defined_expr0
static int
defined_expr(rb_iseq_t *iseq, LINK_ANCHOR *ret,
             NODE *node, LABEL **lfinish, VALUE needstr)
{
    enum defined_type expr_type = 0;
    enum node_type type;

    switch (type = nd_type(node)) {

        /* easy literals */
      case NODE_NIL:
        expr_type = DEFINED_NIL;
        break;
      case NODE_SELF:
        expr_type = DEFINED_SELF;
        break;
      case NODE_TRUE:
        expr_type = DEFINED_TRUE;
        break;
      case NODE_FALSE:
        expr_type = DEFINED_FALSE;
        break;

      case NODE_ARRAY:{
        NODE *vals = node;

        do {
            defined_expr(iseq, ret, vals->nd_head, lfinish, Qfalse);

            if (!lfinish[1]) {
                lfinish[1] = NEW_LABEL(nd_line(node));
            }
            ADD_INSNL(ret, nd_line(node), branchunless, lfinish[1]);
        } while ((vals = vals->nd_next) != NULL);
      }
      case NODE_STR:
      case NODE_LIT:
      case NODE_ZARRAY:
      case NODE_AND:
      case NODE_OR:
      default:
        expr_type = DEFINED_EXPR;
        break;

        /* variables */
      case NODE_LVAR:
      case NODE_DVAR:
        expr_type = DEFINED_LVAR;
        break;

      case NODE_IVAR:
        ADD_INSN(ret, nd_line(node), putnil);
        ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_IVAR),
                  ID2SYM(node->nd_vid), needstr);
        return 1;

      case NODE_GVAR:
        ADD_INSN(ret, nd_line(node), putnil);
        ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_GVAR),
                  ID2SYM(node->nd_entry->id), needstr);
        return 1;

      case NODE_CVAR:
        ADD_INSN(ret, nd_line(node), putnil);
        ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_CVAR),
                  ID2SYM(node->nd_vid), needstr);
        return 1;

      case NODE_CONST:
        ADD_INSN(ret, nd_line(node), putnil);
        ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_CONST),
                  ID2SYM(node->nd_vid), needstr);
        return 1;
      case NODE_COLON2:
        if (!lfinish[1]) {
            lfinish[1] = NEW_LABEL(nd_line(node));
        }
        defined_expr(iseq, ret, node->nd_head, lfinish, Qfalse);
        ADD_INSNL(ret, nd_line(node), branchunless, lfinish[1]);

        if (rb_is_const_id(node->nd_mid)) {
            COMPILE(ret, "defined/colon2#nd_head", node->nd_head);
            ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_CONST),
                      ID2SYM(node->nd_mid), needstr);
        }
        else {
            COMPILE(ret, "defined/colon2#nd_head", node->nd_head);
            ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_METHOD),
                      ID2SYM(node->nd_mid), needstr);
        }
        return 1;
      case NODE_COLON3:
        ADD_INSN1(ret, nd_line(node), putobject, rb_cObject);
        ADD_INSN3(ret, nd_line(node), defined,
                  INT2FIX(DEFINED_CONST), ID2SYM(node->nd_mid), needstr);
        return 1;

        /* method dispatch */
      case NODE_CALL:
      case NODE_VCALL:
      case NODE_FCALL:
      case NODE_ATTRASGN:{
        int self = TRUE;

        switch (type) {
          case NODE_ATTRASGN:
            if (node->nd_recv == (NODE *)1) break;
          case NODE_CALL:
            self = FALSE;
            break;
          default:
            /* through */;
        }
        if (!lfinish[1]) {
            lfinish[1] = NEW_LABEL(nd_line(node));
        }
        if (node->nd_args) {
            defined_expr(iseq, ret, node->nd_args, lfinish, Qfalse);
            ADD_INSNL(ret, nd_line(node), branchunless, lfinish[1]);
        }
        if (!self) {
            defined_expr(iseq, ret, node->nd_recv, lfinish, Qfalse);
            ADD_INSNL(ret, nd_line(node), branchunless, lfinish[1]);
            COMPILE(ret, "defined/recv", node->nd_recv);
            ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_METHOD),
                      ID2SYM(node->nd_mid), needstr);
        }
        else {
            ADD_INSN(ret, nd_line(node), putself);
            ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_FUNC),
                      ID2SYM(node->nd_mid), needstr);
        }
        return 1;
      }

      case NODE_YIELD:
        ADD_INSN(ret, nd_line(node), putnil);
        ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_YIELD), 0,
                  needstr);
        return 1;

      case NODE_BACK_REF:
      case NODE_NTH_REF:
        ADD_INSN(ret, nd_line(node), putnil);
        ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_REF),
                  INT2FIX((node->nd_nth << 1) | (type == NODE_BACK_REF)),
                  needstr);
        return 1;

      case NODE_SUPER:
      case NODE_ZSUPER:
        ADD_INSN(ret, nd_line(node), putnil);
        ADD_INSN3(ret, nd_line(node), defined, INT2FIX(DEFINED_ZSUPER), 0,
                  needstr);
        return 1;

      case NODE_OP_ASGN1:
      case NODE_OP_ASGN2:
      case NODE_OP_ASGN_OR:
      case NODE_OP_ASGN_AND:
      case NODE_MASGN:
      case NODE_LASGN:
      case NODE_DASGN:
      case NODE_DASGN_CURR:
      case NODE_GASGN:
      case NODE_IASGN:
      case NODE_CDECL:
      case NODE_CVDECL:
      case NODE_CVASGN:
        expr_type = DEFINED_ASGN;
        break;
    }

    if (expr_type) {
        if (needstr != Qfalse) {
            VALUE str = rb_iseq_defined_string(expr_type);
            ADD_INSN1(ret, nd_line(node), putobject, str);
        }
        else {
            ADD_INSN1(ret, nd_line(node), putobject, Qtrue);
        }
        return 1;
    }
    return 0;
}
#undef defined_expr

static int
defined_expr(rb_iseq_t *iseq, LINK_ANCHOR *ret,
             NODE *node, LABEL **lfinish, VALUE needstr)
{
    LINK_ELEMENT *lcur = ret->last;
    int done = defined_expr0(iseq, ret, node, lfinish, needstr);
    if (lfinish[1]) {
        int line = nd_line(node);
        LABEL *lstart = NEW_LABEL(line);
        LABEL *lend = NEW_LABEL(line);
        VALUE rescue = NEW_CHILD_ISEQVAL(NEW_NIL(),
                                         rb_str_concat(rb_str_new2
                                                       ("defined guard in "),
                                                       iseq->location.label),
                                         ISEQ_TYPE_DEFINED_GUARD, 0);
        APPEND_LABEL(ret, lcur, lstart);
        ADD_LABEL(ret, lend);
        ADD_CATCH_ENTRY(CATCH_TYPE_RESCUE, lstart, lend, rescue, lfinish[1]);
    }
    return done;
}

#define BUFSIZE 0x100

static VALUE
make_name_for_block(rb_iseq_t *iseq)
{
    int level = 1;
    rb_iseq_t *ip = iseq;

    if (iseq->parent_iseq != 0) {
        while (ip->local_iseq != ip) {
            if (ip->type == ISEQ_TYPE_BLOCK) {
                level++;
            }
            ip = ip->parent_iseq;
        }
    }

    if (level == 1) {
        return rb_sprintf("block in %"PRIsVALUE, ip->location.label);
    }
    else {
        return rb_sprintf("block (%d levels) in %"PRIsVALUE, level, ip->location.label);
    }
}

static void
push_ensure_entry(rb_iseq_t *iseq,
                  struct iseq_compile_data_ensure_node_stack *enl,
                  struct ensure_range *er, NODE *node)
{
    enl->ensure_node = node;
    enl->prev = iseq->compile_data->ensure_node_stack;  /* prev */
    enl->erange = er;
    iseq->compile_data->ensure_node_stack = enl;
}

static void
add_ensure_range(rb_iseq_t *iseq, struct ensure_range *erange,
                 LABEL *lstart, LABEL *lend)
{
    struct ensure_range *ne =
        compile_data_alloc(iseq, sizeof(struct ensure_range));

    while (erange->next != 0) {
        erange = erange->next;
    }
    ne->next = 0;
    ne->begin = lend;
    ne->end = erange->end;
    erange->end = lstart;

    erange->next = ne;
}

static void
add_ensure_iseq(LINK_ANCHOR *ret, rb_iseq_t *iseq, int is_return)
{
    struct iseq_compile_data_ensure_node_stack *enlp =
        iseq->compile_data->ensure_node_stack;
    struct iseq_compile_data_ensure_node_stack *prev_enlp = enlp;
    DECL_ANCHOR(ensure);

    INIT_ANCHOR(ensure);
    while (enlp) {
        if (enlp->erange != 0) {
            DECL_ANCHOR(ensure_part);
            LABEL *lstart = NEW_LABEL(0);
            LABEL *lend = NEW_LABEL(0);
            INIT_ANCHOR(ensure_part);

            add_ensure_range(iseq, enlp->erange, lstart, lend);

            iseq->compile_data->ensure_node_stack = enlp->prev;
            ADD_LABEL(ensure_part, lstart);
            COMPILE_POPED(ensure_part, "ensure part", enlp->ensure_node);
            ADD_LABEL(ensure_part, lend);
            ADD_SEQ(ensure, ensure_part);
        }
        else {
            if (!is_return) {
                break;
            }
        }
        enlp = enlp->prev;
    }
    iseq->compile_data->ensure_node_stack = prev_enlp;
    ADD_SEQ(ret, ensure);
}

static VALUE
setup_args(rb_iseq_t *iseq, LINK_ANCHOR *args, NODE *argn, VALUE *flag)
{
    VALUE argc = INT2FIX(0);
    int nsplat = 0;
    DECL_ANCHOR(arg_block);
    DECL_ANCHOR(args_splat);

    INIT_ANCHOR(arg_block);
    INIT_ANCHOR(args_splat);
    if (argn && nd_type(argn) == NODE_BLOCK_PASS) {
        COMPILE(arg_block, "block", argn->nd_body);
        *flag |= VM_CALL_ARGS_BLOCKARG;
        argn = argn->nd_head;
    }

  setup_argn:
    if (argn) {
        switch (nd_type(argn)) {
          case NODE_SPLAT: {
            COMPILE(args, "args (splat)", argn->nd_head);
            argc = INT2FIX(1);
            nsplat++;
            *flag |= VM_CALL_ARGS_SPLAT;
            break;
          }
          case NODE_ARGSCAT:
          case NODE_ARGSPUSH: {
            int next_is_array = (nd_type(argn->nd_head) == NODE_ARRAY);
            DECL_ANCHOR(tmp);

            INIT_ANCHOR(tmp);
            COMPILE(tmp, "args (cat: splat)", argn->nd_body);
            if (next_is_array && nsplat == 0) {
                /* none */
            }
            else {
                if (nd_type(argn) == NODE_ARGSCAT) {
                    ADD_INSN1(tmp, nd_line(argn), splatarray, Qfalse);
                }
                else {
                    ADD_INSN1(tmp, nd_line(argn), newarray, INT2FIX(1));
                }
            }
            INSERT_LIST(args_splat, tmp);
            nsplat++;
            *flag |= VM_CALL_ARGS_SPLAT;

            if (next_is_array) {
                argc = INT2FIX(compile_array(iseq, args, argn->nd_head, COMPILE_ARRAY_TYPE_ARGS) + 1);
            }
            else {
                argn = argn->nd_head;
                goto setup_argn;
            }
            break;
          }
          case NODE_ARRAY: {
            argc = INT2FIX(compile_array(iseq, args, argn, COMPILE_ARRAY_TYPE_ARGS));
            break;
          }
          default: {
            rb_bug("setup_arg: unknown node: %s\n", ruby_node_name(nd_type(argn)));
          }
        }
    }

    if (nsplat > 1) {
        int i;
        for (i=1; i<nsplat; i++) {
            ADD_INSN(args_splat, nd_line(args), concatarray);
        }
    }

    if (!LIST_SIZE_ZERO(args_splat)) {
        ADD_SEQ(args, args_splat);
    }

    if (*flag & VM_CALL_ARGS_BLOCKARG) {
        ADD_SEQ(args, arg_block);
    }
    return argc;
}

static VALUE
build_postexe_iseq(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE *body)
{
    int line = nd_line(body);
    VALUE argc = INT2FIX(0);
    VALUE block = NEW_CHILD_ISEQVAL(body, make_name_for_block(iseq->parent_iseq), ISEQ_TYPE_BLOCK, line);
    ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
    ADD_CALL_WITH_BLOCK(ret, line, ID2SYM(id_core_set_postexe), argc, block);
    iseq_set_local_table(iseq, 0);
    return Qnil;
}

static int
iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
{
    enum node_type type;
    LINK_ELEMENT *saved_last_element = 0;
    int line;

    if (node == 0) {
        if (!poped) {
            debugs("node: NODE_NIL(implicit)\n");
            ADD_INSN(ret, iseq->compile_data->last_line, putnil);
        }
        return COMPILE_OK;
    }

    line = (int)nd_line(node);

    if (iseq->compile_data->last_line == line) {
        /* ignore */
    }
    else {
        if (node->flags & NODE_FL_NEWLINE) {
            iseq->compile_data->last_line = line;
            ADD_TRACE(ret, line, RUBY_EVENT_LINE);
            saved_last_element = ret->last;
        }
    }

    debug_node_start(node);

    type = nd_type(node);

    switch (type) {
      case NODE_BLOCK:{
        while (node && nd_type(node) == NODE_BLOCK) {
            COMPILE_(ret, "BLOCK body", node->nd_head,
                     (node->nd_next == 0 && poped == 0) ? 0 : 1);
            node = node->nd_next;
        }
        if (node) {
            COMPILE_(ret, "BLOCK next", node->nd_next, poped);
        }
        break;
      }
      case NODE_IF:{
        DECL_ANCHOR(cond_seq);
        DECL_ANCHOR(then_seq);
        DECL_ANCHOR(else_seq);
        LABEL *then_label, *else_label, *end_label;

        INIT_ANCHOR(cond_seq);
        INIT_ANCHOR(then_seq);
        INIT_ANCHOR(else_seq);
        then_label = NEW_LABEL(line);
        else_label = NEW_LABEL(line);
        end_label = NEW_LABEL(line);

        compile_branch_condition(iseq, cond_seq, node->nd_cond,
                                 then_label, else_label);
        COMPILE_(then_seq, "then", node->nd_body, poped);
        COMPILE_(else_seq, "else", node->nd_else, poped);

        ADD_SEQ(ret, cond_seq);

        ADD_LABEL(ret, then_label);
        ADD_SEQ(ret, then_seq);
        ADD_INSNL(ret, line, jump, end_label);

        ADD_LABEL(ret, else_label);
        ADD_SEQ(ret, else_seq);

        ADD_LABEL(ret, end_label);

        break;
      }
      case NODE_CASE:{
        NODE *vals;
        NODE *tempnode = node;
        LABEL *endlabel, *elselabel;
        DECL_ANCHOR(head);
        DECL_ANCHOR(body_seq);
        DECL_ANCHOR(cond_seq);
        int only_special_literals = 1;
        VALUE literals = rb_hash_new();

        INIT_ANCHOR(head);
        INIT_ANCHOR(body_seq);
        INIT_ANCHOR(cond_seq);

        rb_hash_tbl_raw(literals)->type = &cdhash_type;

        if (node->nd_head == 0) {
            COMPILE_(ret, "when", node->nd_body, poped);
            break;
        }
        COMPILE(head, "case base", node->nd_head);

        node = node->nd_body;
        type = nd_type(node);
        line = nd_line(node);

        if (type != NODE_WHEN) {
            COMPILE_ERROR((ERROR_ARGS "NODE_CASE: unexpected node. must be NODE_WHEN, but %s", ruby_node_name(type)));
        }

        endlabel = NEW_LABEL(line);
        elselabel = NEW_LABEL(line);

        ADD_SEQ(ret, head);     /* case VAL */

        while (type == NODE_WHEN) {
            LABEL *l1;

            l1 = NEW_LABEL(line);
            ADD_LABEL(body_seq, l1);
            ADD_INSN(body_seq, line, pop);
            COMPILE_(body_seq, "when body", node->nd_body, poped);
            ADD_INSNL(body_seq, line, jump, endlabel);

            vals = node->nd_head;
            if (vals) {
                switch (nd_type(vals)) {
                  case NODE_ARRAY:
                    only_special_literals = when_vals(iseq, cond_seq, vals, l1, only_special_literals, literals);
                    break;
                  case NODE_SPLAT:
                  case NODE_ARGSCAT:
                  case NODE_ARGSPUSH:
                    only_special_literals = 0;
                    ADD_INSN (cond_seq, nd_line(vals), dup);
                    COMPILE(cond_seq, "when/cond splat", vals);
                    ADD_INSN1(cond_seq, nd_line(vals), checkmatch, INT2FIX(VM_CHECKMATCH_TYPE_CASE | VM_CHECKMATCH_ARRAY));
                    ADD_INSNL(cond_seq, nd_line(vals), branchif, l1);
                    break;
                  default:
                    rb_bug("NODE_CASE: unknown node (%s)",
                           ruby_node_name(nd_type(vals)));
                }
            }
            else {
                rb_bug("NODE_CASE: must be NODE_ARRAY, but 0");
            }

            node = node->nd_next;
            if (!node) {
                break;
            }
            type = nd_type(node);
            line = nd_line(node);
        }
        /* else */
        if (node) {
            ADD_LABEL(cond_seq, elselabel);
            ADD_INSN(cond_seq, line, pop);
            COMPILE_(cond_seq, "else", node, poped);
            ADD_INSNL(cond_seq, line, jump, endlabel);
        }
        else {
            debugs("== else (implicit)\n");
            ADD_LABEL(cond_seq, elselabel);
            ADD_INSN(cond_seq, nd_line(tempnode), pop);
            if (!poped) {
                ADD_INSN(cond_seq, nd_line(tempnode), putnil);
            }
            ADD_INSNL(cond_seq, nd_line(tempnode), jump, endlabel);
        }

        if (only_special_literals) {
            iseq_add_mark_object(iseq, literals);

            ADD_INSN(ret, nd_line(tempnode), dup);
            ADD_INSN2(ret, nd_line(tempnode), opt_case_dispatch, literals, elselabel);
        }

        ADD_SEQ(ret, cond_seq);
        ADD_SEQ(ret, body_seq);
        ADD_LABEL(ret, endlabel);
        break;
      }
      case NODE_WHEN:{
        NODE *vals;
        NODE *val;
        NODE *orig_node = node;
        LABEL *endlabel;
        DECL_ANCHOR(body_seq);

        INIT_ANCHOR(body_seq);
        endlabel = NEW_LABEL(line);

        while (node && nd_type(node) == NODE_WHEN) {
            LABEL *l1 = NEW_LABEL(line = nd_line(node));
            ADD_LABEL(body_seq, l1);
            COMPILE_(body_seq, "when", node->nd_body, poped);
            ADD_INSNL(body_seq, line, jump, endlabel);

            vals = node->nd_head;
            if (!vals) {
                rb_bug("NODE_WHEN: must be NODE_ARRAY, but 0");
            }
            switch (nd_type(vals)) {
              case NODE_ARRAY:
                while (vals) {
                    val = vals->nd_head;
                    COMPILE(ret, "when2", val);
                    ADD_INSNL(ret, nd_line(val), branchif, l1);
                    vals = vals->nd_next;
                }
                break;
              case NODE_SPLAT:
              case NODE_ARGSCAT:
              case NODE_ARGSPUSH:
                ADD_INSN(ret, nd_line(vals), putnil);
                COMPILE(ret, "when2/cond splat", vals);
                ADD_INSN1(ret, nd_line(vals), checkmatch, INT2FIX(VM_CHECKMATCH_TYPE_WHEN | VM_CHECKMATCH_ARRAY));
                ADD_INSNL(ret, nd_line(vals), branchif, l1);
                break;
              default:
                rb_bug("NODE_WHEN: unknown node (%s)",
                       ruby_node_name(nd_type(vals)));
            }
            node = node->nd_next;
        }
        /* else */
        COMPILE_(ret, "else", node, poped);
        ADD_INSNL(ret, nd_line(orig_node), jump, endlabel);

        ADD_SEQ(ret, body_seq);
        ADD_LABEL(ret, endlabel);

        break;
      }
      case NODE_OPT_N:
      case NODE_WHILE:
      case NODE_UNTIL:{
        LABEL *prev_start_label = iseq->compile_data->start_label;
        LABEL *prev_end_label = iseq->compile_data->end_label;
        LABEL *prev_redo_label = iseq->compile_data->redo_label;
        int prev_loopval_popped = iseq->compile_data->loopval_popped;

        struct iseq_compile_data_ensure_node_stack enl;

        LABEL *next_label = iseq->compile_data->start_label = NEW_LABEL(line);  /* next  */
        LABEL *redo_label = iseq->compile_data->redo_label = NEW_LABEL(line);   /* redo  */
        LABEL *break_label = iseq->compile_data->end_label = NEW_LABEL(line);   /* break */
        LABEL *end_label = NEW_LABEL(line);

        LABEL *next_catch_label = NEW_LABEL(line);
        LABEL *tmp_label = NULL;

        iseq->compile_data->loopval_popped = 0;
        push_ensure_entry(iseq, &enl, 0, 0);

        if (type == NODE_OPT_N || node->nd_state == 1) {
            ADD_INSNL(ret, line, jump, next_label);
        }
        else {
            tmp_label = NEW_LABEL(line);
            ADD_INSNL(ret, line, jump, tmp_label);
        }
        ADD_INSN(ret, line, putnil);
        ADD_LABEL(ret, next_catch_label);
        ADD_INSN(ret, line, pop);
        ADD_INSNL(ret, line, jump, next_label);
        if (tmp_label) ADD_LABEL(ret, tmp_label);

        ADD_LABEL(ret, redo_label);
        COMPILE_POPED(ret, "while body", node->nd_body);
        ADD_LABEL(ret, next_label);     /* next */

        if (type == NODE_WHILE) {
            compile_branch_condition(iseq, ret, node->nd_cond,
                                     redo_label, end_label);
        }
        else if (type == NODE_UNTIL) {
            /* until */
            compile_branch_condition(iseq, ret, node->nd_cond,
                                     end_label, redo_label);
        }
        else {
            ADD_CALL_RECEIVER(ret, line);
            ADD_CALL(ret, line, ID2SYM(idGets), INT2FIX(0));
            ADD_INSNL(ret, line, branchif, redo_label);
            /* opt_n */
        }

        ADD_LABEL(ret, end_label);

        if (node->nd_state == Qundef) {
            /* ADD_INSN(ret, line, putundef); */
            rb_bug("unsupported: putundef");
        }
        else {
            ADD_INSN(ret, line, putnil);
        }

        ADD_LABEL(ret, break_label);    /* break */

        if (poped) {
            ADD_INSN(ret, line, pop);
        }

        ADD_CATCH_ENTRY(CATCH_TYPE_BREAK, redo_label, break_label,
                        0, break_label);
        ADD_CATCH_ENTRY(CATCH_TYPE_NEXT, redo_label, break_label, 0,
                        next_catch_label);
        ADD_CATCH_ENTRY(CATCH_TYPE_REDO, redo_label, break_label, 0,
                        iseq->compile_data->redo_label);

        iseq->compile_data->start_label = prev_start_label;
        iseq->compile_data->end_label = prev_end_label;
        iseq->compile_data->redo_label = prev_redo_label;
        iseq->compile_data->loopval_popped = prev_loopval_popped;
        iseq->compile_data->ensure_node_stack = iseq->compile_data->ensure_node_stack->prev;
        break;
      }
      case NODE_ITER:
      case NODE_FOR:{
        VALUE prevblock = iseq->compile_data->current_block;
        LABEL *retry_label = NEW_LABEL(line);
        LABEL *retry_end_l = NEW_LABEL(line);

        ADD_LABEL(ret, retry_label);
        if (nd_type(node) == NODE_FOR) {
            COMPILE(ret, "iter caller (for)", node->nd_iter);

            iseq->compile_data->current_block =
                NEW_CHILD_ISEQVAL(node->nd_body, make_name_for_block(iseq),
                                  ISEQ_TYPE_BLOCK, line);

            ADD_SEND_R(ret, line, ID2SYM(idEach), INT2FIX(0),
                       iseq->compile_data->current_block, INT2FIX(0));
        }
        else {
            iseq->compile_data->current_block =
                NEW_CHILD_ISEQVAL(node->nd_body, make_name_for_block(iseq),
                                  ISEQ_TYPE_BLOCK, line);
            COMPILE(ret, "iter caller", node->nd_iter);
        }
        ADD_LABEL(ret, retry_end_l);

        if (poped) {
            ADD_INSN(ret, line, pop);
        }

        iseq->compile_data->current_block = prevblock;

        ADD_CATCH_ENTRY(CATCH_TYPE_BREAK, retry_label, retry_end_l, 0, retry_end_l);

        break;
      }
      case NODE_BREAK:{
        unsigned long level = 0;

        if (iseq->compile_data->redo_label != 0) {
            /* while/until */
            LABEL *splabel = NEW_LABEL(0);
            ADD_LABEL(ret, splabel);
            ADD_ADJUST(ret, line, iseq->compile_data->redo_label);
            COMPILE_(ret, "break val (while/until)", node->nd_stts, iseq->compile_data->loopval_popped);
            add_ensure_iseq(ret, iseq, 0);
            ADD_INSNL(ret, line, jump, iseq->compile_data->end_label);
            ADD_ADJUST_RESTORE(ret, splabel);

            if (!poped) {
                ADD_INSN(ret, line, putnil);
            }
        }
        else if (iseq->type == ISEQ_TYPE_BLOCK) {
          break_by_insn:
            /* escape from block */
            COMPILE(ret, "break val (block)", node->nd_stts);
            ADD_INSN1(ret, line, throw, INT2FIX(level | 0x02) /* TAG_BREAK */ );
            if (poped) {
                ADD_INSN(ret, line, pop);
            }
        }
        else if (iseq->type == ISEQ_TYPE_EVAL) {
          break_in_eval:
            COMPILE_ERROR((ERROR_ARGS "Can't escape from eval with break"));
        }
        else {
            rb_iseq_t *ip = iseq->parent_iseq;
            while (ip) {
                if (!ip->compile_data) {
                    ip = 0;
                    break;
                }

                level++;
                if (ip->compile_data->redo_label != 0) {
                    level = 0x8000;
                    if (ip->compile_data->loopval_popped == 0) {
                        /* need value */
                        level |= 0x4000;
                    }
                    goto break_by_insn;
                }
                else if (ip->type == ISEQ_TYPE_BLOCK) {
                    level <<= 16;
                    goto break_by_insn;
                }
                else if (ip->type == ISEQ_TYPE_EVAL) {
                    goto break_in_eval;
                }

                ip = ip->parent_iseq;
            }
            COMPILE_ERROR((ERROR_ARGS "Invalid break"));
        }
        break;
      }
      case NODE_NEXT:{
        unsigned long level = 0;

        if (iseq->compile_data->redo_label != 0) {
            LABEL *splabel = NEW_LABEL(0);
            debugs("next in while loop\n");
            ADD_LABEL(ret, splabel);
            COMPILE(ret, "next val/valid syntax?", node->nd_stts);
            add_ensure_iseq(ret, iseq, 0);
            ADD_ADJUST(ret, line, iseq->compile_data->redo_label);
            ADD_INSNL(ret, line, jump, iseq->compile_data->start_label);
            ADD_ADJUST_RESTORE(ret, splabel);
            if (!poped) {
                ADD_INSN(ret, line, putnil);
            }
        }
        else if (iseq->compile_data->end_label) {
            LABEL *splabel = NEW_LABEL(0);
            debugs("next in block\n");
            ADD_LABEL(ret, splabel);
            ADD_ADJUST(ret, line, iseq->compile_data->start_label);
            COMPILE(ret, "next val", node->nd_stts);
            add_ensure_iseq(ret, iseq, 0);
            ADD_INSNL(ret, line, jump, iseq->compile_data->end_label);
            ADD_ADJUST_RESTORE(ret, splabel);

            if (!poped) {
                ADD_INSN(ret, line, putnil);
            }
        }
        else if (iseq->type == ISEQ_TYPE_EVAL) {
          next_in_eval:
            COMPILE_ERROR((ERROR_ARGS "Can't escape from eval with next"));
        }
        else {
            rb_iseq_t *ip;
            ip = iseq;
            while (ip) {
                if (!ip->compile_data) {
                    ip = 0;
                    break;
                }

                level = 0x8000 | 0x4000;
                if (ip->compile_data->redo_label != 0) {
                    /* while loop */
                    break;
                }
                else if (ip->type == ISEQ_TYPE_BLOCK) {
                    break;
                }
                else if (ip->type == ISEQ_TYPE_EVAL) {
                    goto next_in_eval;
                }

                ip = ip->parent_iseq;
            }
            if (ip != 0) {
                COMPILE(ret, "next val", node->nd_stts);
                ADD_INSN1(ret, line, throw, INT2FIX(level | 0x03) /* TAG_NEXT */ );

                if (poped) {
                    ADD_INSN(ret, line, pop);
                }
            }
            else {
                COMPILE_ERROR((ERROR_ARGS "Invalid next"));
            }
        }
        break;
      }
      case NODE_REDO:{
        if (iseq->compile_data->redo_label) {
            LABEL *splabel = NEW_LABEL(0);
            debugs("redo in while");
            ADD_LABEL(ret, splabel);
            ADD_ADJUST(ret, line, iseq->compile_data->redo_label);
            add_ensure_iseq(ret, iseq, 0);
            ADD_INSNL(ret, line, jump, iseq->compile_data->redo_label);
            ADD_ADJUST_RESTORE(ret, splabel);
            if (!poped) {
                ADD_INSN(ret, line, putnil);
            }
        }
        else if (iseq->type == ISEQ_TYPE_EVAL) {
          redo_in_eval:
            COMPILE_ERROR((ERROR_ARGS "Can't escape from eval with redo"));
        }
        else if (iseq->compile_data->start_label) {
            LABEL *splabel = NEW_LABEL(0);

            debugs("redo in block");
            ADD_LABEL(ret, splabel);
            add_ensure_iseq(ret, iseq, 0);
            ADD_ADJUST(ret, line, iseq->compile_data->start_label);
            ADD_INSNL(ret, line, jump, iseq->compile_data->start_label);
            ADD_ADJUST_RESTORE(ret, splabel);

            if (!poped) {
                ADD_INSN(ret, line, putnil);
            }
        }
        else {
            rb_iseq_t *ip;
            unsigned long level;
            level = 0x8000 | 0x4000;
            ip = iseq;
            while (ip) {
                if (!ip->compile_data) {
                    ip = 0;
                    break;
                }

                if (ip->compile_data->redo_label != 0) {
                    break;
                }
                else if (ip->type == ISEQ_TYPE_BLOCK) {
                    break;
                }
                else if (ip->type == ISEQ_TYPE_EVAL) {
                    goto redo_in_eval;
                }

                ip = ip->parent_iseq;
            }
            if (ip != 0) {
                ADD_INSN(ret, line, putnil);
                ADD_INSN1(ret, line, throw, INT2FIX(level | 0x05) /* TAG_REDO */ );

                if (poped) {
                    ADD_INSN(ret, line, pop);
                }
            }
            else {
                COMPILE_ERROR((ERROR_ARGS "Invalid redo"));
            }
        }
        break;
      }
      case NODE_RETRY:{
        if (iseq->type == ISEQ_TYPE_RESCUE) {
            ADD_INSN(ret, line, putnil);
            ADD_INSN1(ret, line, throw, INT2FIX(0x04) /* TAG_RETRY */ );

            if (poped) {
                ADD_INSN(ret, line, pop);
            }
        }
        else {
            COMPILE_ERROR((ERROR_ARGS "Invalid retry"));
        }
        break;
      }
      case NODE_BEGIN:{
        COMPILE_(ret, "NODE_BEGIN", node->nd_body, poped);
        break;
      }
      case NODE_RESCUE:{
        LABEL *lstart = NEW_LABEL(line);
        LABEL *lend = NEW_LABEL(line);
        LABEL *lcont = NEW_LABEL(line);
        VALUE rescue = NEW_CHILD_ISEQVAL(
            node->nd_resq,
            rb_str_concat(rb_str_new2("rescue in "), iseq->location.label),
            ISEQ_TYPE_RESCUE, line);

        ADD_LABEL(ret, lstart);
        COMPILE(ret, "rescue head", node->nd_head);
        ADD_LABEL(ret, lend);
        if (node->nd_else) {
            ADD_INSN(ret, line, pop);
            COMPILE(ret, "rescue else", node->nd_else);
        }
        ADD_INSN(ret, line, nop);
        ADD_LABEL(ret, lcont);

        if (poped) {
            ADD_INSN(ret, line, pop);
        }

        /* register catch entry */
        ADD_CATCH_ENTRY(CATCH_TYPE_RESCUE, lstart, lend, rescue, lcont);
        ADD_CATCH_ENTRY(CATCH_TYPE_RETRY, lend, lcont, 0, lstart);
        break;
      }
      case NODE_RESBODY:{
        NODE *resq = node;
        NODE *narg;
        LABEL *label_miss, *label_hit;

        while (resq) {
            label_miss = NEW_LABEL(line);
            label_hit = NEW_LABEL(line);

            narg = resq->nd_args;
            if (narg) {
                switch (nd_type(narg)) {
                  case NODE_ARRAY:
                    while (narg) {
                        ADD_INSN2(ret, line, getlocal, INT2FIX(2), INT2FIX(0));
                        COMPILE(ret, "rescue arg", narg->nd_head);
                        ADD_INSN1(ret, line, checkmatch, INT2FIX(VM_CHECKMATCH_TYPE_RESCUE));
                        ADD_INSNL(ret, line, branchif, label_hit);
                        narg = narg->nd_next;
                    }
                    break;
                  case NODE_SPLAT:
                  case NODE_ARGSCAT:
                  case NODE_ARGSPUSH:
                    ADD_INSN2(ret, line, getlocal, INT2FIX(2), INT2FIX(0));
                    COMPILE(ret, "rescue/cond splat", narg);
                    ADD_INSN1(ret, line, checkmatch, INT2FIX(VM_CHECKMATCH_TYPE_RESCUE | VM_CHECKMATCH_ARRAY));
                    ADD_INSNL(ret, line, branchif, label_hit);
                    break;
                  default:
                    rb_bug("NODE_RESBODY: unknown node (%s)",
                           ruby_node_name(nd_type(narg)));
                }
            }
            else {
                ADD_INSN2(ret, line, getlocal, INT2FIX(2), INT2FIX(0));
                ADD_INSN1(ret, line, putobject, rb_eStandardError);
                ADD_INSN1(ret, line, checkmatch, INT2FIX(VM_CHECKMATCH_TYPE_RESCUE));
                ADD_INSNL(ret, line, branchif, label_hit);
            }
            ADD_INSNL(ret, line, jump, label_miss);
            ADD_LABEL(ret, label_hit);
            COMPILE(ret, "resbody body", resq->nd_body);
            if (iseq->compile_data->option->tailcall_optimization) {
                ADD_INSN(ret, line, nop);
            }
            ADD_INSN(ret, line, leave);
            ADD_LABEL(ret, label_miss);
            resq = resq->nd_head;
        }
        break;
      }
      case NODE_ENSURE:{
        DECL_ANCHOR(ensr);
        VALUE ensure = NEW_CHILD_ISEQVAL(node->nd_ensr,
                                         rb_str_concat(rb_str_new2
                                                       ("ensure in "),
                                                       iseq->location.label),
                                         ISEQ_TYPE_ENSURE, line);
        LABEL *lstart = NEW_LABEL(line);
        LABEL *lend = NEW_LABEL(line);
        LABEL *lcont = NEW_LABEL(line);
        struct ensure_range er;
        struct iseq_compile_data_ensure_node_stack enl;
        struct ensure_range *erange;

        INIT_ANCHOR(ensr);
        COMPILE_POPED(ensr, "ensure ensr", node->nd_ensr);

        er.begin = lstart;
        er.end = lend;
        er.next = 0;
        push_ensure_entry(iseq, &enl, &er, node->nd_ensr);

        ADD_LABEL(ret, lstart);
        COMPILE_(ret, "ensure head", node->nd_head, poped);
        ADD_LABEL(ret, lend);
        if (ensr->anchor.next == 0) {
            ADD_INSN(ret, line, nop);
        }
        else {
            ADD_SEQ(ret, ensr);
        }
        ADD_LABEL(ret, lcont);

        erange = iseq->compile_data->ensure_node_stack->erange;
        while (erange) {
            ADD_CATCH_ENTRY(CATCH_TYPE_ENSURE, erange->begin, erange->end,
                            ensure, lcont);
            erange = erange->next;
        }

        iseq->compile_data->ensure_node_stack = enl.prev;
        break;
      }

      case NODE_AND:
      case NODE_OR:{
        LABEL *end_label = NEW_LABEL(line);
        COMPILE(ret, "nd_1st", node->nd_1st);
        if (!poped) {
            ADD_INSN(ret, line, dup);
        }
        if (type == NODE_AND) {
            ADD_INSNL(ret, line, branchunless, end_label);
        }
        else {
            ADD_INSNL(ret, line, branchif, end_label);
        }
        if (!poped) {
            ADD_INSN(ret, line, pop);
        }
        COMPILE_(ret, "nd_2nd", node->nd_2nd, poped);
        ADD_LABEL(ret, end_label);
        break;
      }

      case NODE_MASGN:{
        compile_massign(iseq, ret, node, poped);
        break;
      }

      case NODE_LASGN:{
        ID id = node->nd_vid;
        int idx = iseq->local_iseq->local_size - get_local_var_idx(iseq, id);

        debugs("lvar: %s idx: %d\n", rb_id2name(id), idx);
        COMPILE(ret, "rvalue", node->nd_value);

        if (!poped) {
            ADD_INSN(ret, line, dup);
        }
        ADD_INSN2(ret, line, setlocal, INT2FIX(idx), INT2FIX(get_lvar_level(iseq)));

        break;
      }
      case NODE_DASGN:
      case NODE_DASGN_CURR:{
        int idx, lv, ls;
        COMPILE(ret, "dvalue", node->nd_value);
        debugp_param("dassn id", rb_str_new2(rb_id2name(node->nd_vid) ? rb_id2name(node->nd_vid) : "*"));

        if (!poped) {
            ADD_INSN(ret, line, dup);
        }

        idx = get_dyna_var_idx(iseq, node->nd_vid, &lv, &ls);

        if (idx < 0) {
            rb_bug("NODE_DASGN(_CURR): unknown id (%s)", rb_id2name(node->nd_vid));
        }

        ADD_INSN2(ret, line, setlocal, INT2FIX(ls - idx), INT2FIX(lv));
        break;
      }
      case NODE_GASGN:{
        COMPILE(ret, "lvalue", node->nd_value);

        if (!poped) {
            ADD_INSN(ret, line, dup);
        }
        ADD_INSN1(ret, line, setglobal,
                  ((VALUE)node->nd_entry | 1));
        break;
      }
      case NODE_IASGN:
      case NODE_IASGN2:{
        COMPILE(ret, "lvalue", node->nd_value);
        if (!poped) {
            ADD_INSN(ret, line, dup);
        }
        ADD_INSN2(ret, line, setinstancevariable,
                  ID2SYM(node->nd_vid), INT2FIX(iseq->is_size++));
        break;
      }
      case NODE_CDECL:{
        COMPILE(ret, "lvalue", node->nd_value);

        if (!poped) {
            ADD_INSN(ret, line, dup);
        }

        if (node->nd_vid) {
            ADD_INSN1(ret, line, putspecialobject,
                      INT2FIX(VM_SPECIAL_OBJECT_CONST_BASE));
            ADD_INSN1(ret, line, setconstant, ID2SYM(node->nd_vid));
        }
        else {
            compile_cpath(ret, iseq, node->nd_else);
            ADD_INSN1(ret, line, setconstant, ID2SYM(node->nd_else->nd_mid));
        }
        break;
      }
      case NODE_CVASGN:{
        COMPILE(ret, "cvasgn val", node->nd_value);
        if (!poped) {
            ADD_INSN(ret, line, dup);
        }
        ADD_INSN1(ret, line, setclassvariable,
                  ID2SYM(node->nd_vid));
        break;
      }
      case NODE_OP_ASGN1: {
        DECL_ANCHOR(args);
        VALUE argc;
        VALUE flag = 0;
        ID id = node->nd_mid;
        int boff = 0;

        /*
         * a[x] (op)= y
         *
         * nil       # nil
         * eval a    # nil a
         * eval x    # nil a x
         * dupn 2    # nil a x a x
         * send :[]  # nil a x a[x]
         * eval y    # nil a x a[x] y
         * send op   # nil a x ret
         * setn 3    # ret a x ret
         * send []=  # ret ?
         * pop       # ret
         */

        /*
         * nd_recv[nd_args->nd_body] (nd_mid)= nd_args->nd_head;
         * NODE_OP_ASGN nd_recv
         *              nd_args->nd_head
         *              nd_args->nd_body
         *              nd_mid
         */

        if (!poped) {
            ADD_INSN(ret, line, putnil);
        }
        COMPILE(ret, "NODE_OP_ASGN1 recv", node->nd_recv);
        switch (nd_type(node->nd_args->nd_head)) {
          case NODE_ZARRAY:
            argc = INT2FIX(0);
            break;
          case NODE_BLOCK_PASS:
            boff = 1;
          default:
            INIT_ANCHOR(args);
            argc = setup_args(iseq, args, node->nd_args->nd_head, &flag);
            ADD_SEQ(ret, args);
        }
        ADD_INSN1(ret, line, dupn, FIXNUM_INC(argc, 1 + boff));
        ADD_SEND_R(ret, line, ID2SYM(idAREF), argc, Qfalse, LONG2FIX(flag));

        if (id == 0 || id == 1) {
            /* 0: or, 1: and
               a[x] ||= y

               unless/if a[x]
               a[x]= y
               else
               nil
               end
            */
            LABEL *label = NEW_LABEL(line);
            LABEL *lfin = NEW_LABEL(line);

            ADD_INSN(ret, line, dup);
            if (id == 0) {
                /* or */
                ADD_INSNL(ret, line, branchif, label);
            }
            else {
                /* and */
                ADD_INSNL(ret, line, branchunless, label);
            }
            ADD_INSN(ret, line, pop);

            COMPILE(ret, "NODE_OP_ASGN1 args->body: ", node->nd_args->nd_body);
            if (!poped) {
                ADD_INSN1(ret, line, setn, FIXNUM_INC(argc, 2+boff));
            }
            if (flag & VM_CALL_ARGS_SPLAT) {
                ADD_INSN1(ret, line, newarray, INT2FIX(1));
                if (boff > 0) {
                    ADD_INSN1(ret, line, dupn, INT2FIX(3));
                    ADD_INSN(ret, line, swap);
                    ADD_INSN(ret, line, pop);
                }
                ADD_INSN(ret, line, concatarray);
                if (boff > 0) {
                    ADD_INSN1(ret, line, setn, INT2FIX(3));
                    ADD_INSN(ret, line, pop);
                    ADD_INSN(ret, line, pop);
                }
                ADD_SEND_R(ret, line, ID2SYM(idASET),
                           argc, Qfalse, LONG2FIX(flag));
            }
            else {
                if (boff > 0)
                    ADD_INSN(ret, line, swap);
                ADD_SEND_R(ret, line, ID2SYM(idASET),
                           FIXNUM_INC(argc, 1), Qfalse, LONG2FIX(flag));
            }
            ADD_INSN(ret, line, pop);
            ADD_INSNL(ret, line, jump, lfin);
            ADD_LABEL(ret, label);
            if (!poped) {
                ADD_INSN1(ret, line, setn, FIXNUM_INC(argc, 2+boff));
            }
            ADD_INSN1(ret, line, adjuststack, FIXNUM_INC(argc, 2+boff));
            ADD_LABEL(ret, lfin);
        }
        else {
            COMPILE(ret, "NODE_OP_ASGN1 args->body: ", node->nd_args->nd_body);
            ADD_SEND(ret, line, ID2SYM(id), INT2FIX(1));
            if (!poped) {
                ADD_INSN1(ret, line, setn, FIXNUM_INC(argc, 2+boff));
            }
            if (flag & VM_CALL_ARGS_SPLAT) {
                ADD_INSN1(ret, line, newarray, INT2FIX(1));
                if (boff > 0) {
                    ADD_INSN1(ret, line, dupn, INT2FIX(3));
                    ADD_INSN(ret, line, swap);
                    ADD_INSN(ret, line, pop);
                }
                ADD_INSN(ret, line, concatarray);
                if (boff > 0) {
                    ADD_INSN1(ret, line, setn, INT2FIX(3));
                    ADD_INSN(ret, line, pop);
                    ADD_INSN(ret, line, pop);
                }
                ADD_SEND_R(ret, line, ID2SYM(idASET),
                           argc, Qfalse, LONG2FIX(flag));
            }
            else {
                if (boff > 0)
                    ADD_INSN(ret, line, swap);
                ADD_SEND_R(ret, line, ID2SYM(idASET),
                           FIXNUM_INC(argc, 1), Qfalse, LONG2FIX(flag));
            }
            ADD_INSN(ret, line, pop);
        }

        break;
      }
      case NODE_OP_ASGN2:{
        ID atype = node->nd_next->nd_mid;
        LABEL *lfin = NEW_LABEL(line);
        LABEL *lcfin = NEW_LABEL(line);
        /*
          class C; attr_accessor :c; end
          r = C.new
          r.a &&= v # asgn2

          eval r    # r
          dup       # r r
          eval r.a  # r o

          # or
          dup       # r o o
          if lcfin  # r o
          pop       # r
          eval v    # r v
          swap      # v r
          topn 1    # v r v
          send a=   # v ?
          jump lfin # v ?

          lcfin:      # r o
          swap      # o r

          lfin:       # o ?
          pop       # o

          # and
          dup       # r o o
          unless lcfin
          pop       # r
          eval v    # r v
          swap      # v r
          topn 1    # v r v
          send a=   # v ?
          jump lfin # v ?

          # others
          eval v    # r o v
          send ??   # r w
          send a=   # w

        */

        COMPILE(ret, "NODE_OP_ASGN2#recv", node->nd_recv);
        ADD_INSN(ret, line, dup);
        ADD_SEND(ret, line, ID2SYM(node->nd_next->nd_vid),
                 INT2FIX(0));

        if (atype == 0 || atype == 1) { /* 0: OR or 1: AND */
            ADD_INSN(ret, line, dup);
            if (atype == 0) {
                ADD_INSNL(ret, line, branchif, lcfin);
            }
            else {
                ADD_INSNL(ret, line, branchunless, lcfin);
            }
            ADD_INSN(ret, line, pop);
            COMPILE(ret, "NODE_OP_ASGN2 val", node->nd_value);
            ADD_INSN(ret, line, swap);
            ADD_INSN1(ret, line, topn, INT2FIX(1));
            ADD_SEND(ret, line, ID2SYM(node->nd_next->nd_aid),
                     INT2FIX(1));
            ADD_INSNL(ret, line, jump, lfin);

            ADD_LABEL(ret, lcfin);
            ADD_INSN(ret, line, swap);

            ADD_LABEL(ret, lfin);
            ADD_INSN(ret, line, pop);
            if (poped) {
                /* we can apply more optimize */
                ADD_INSN(ret, line, pop);
            }
        }
        else {
            COMPILE(ret, "NODE_OP_ASGN2 val", node->nd_value);
            ADD_SEND(ret, line, ID2SYM(node->nd_next->nd_mid),
                     INT2FIX(1));
            if (!poped) {
                ADD_INSN(ret, line, swap);
                ADD_INSN1(ret, line, topn, INT2FIX(1));
            }
            ADD_SEND(ret, line, ID2SYM(node->nd_next->nd_aid),
                     INT2FIX(1));
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_OP_CDECL: {
        LABEL *lfin = 0;
        LABEL *lassign = 0;
        ID mid;

        switch (nd_type(node->nd_head)) {
          case NODE_COLON3:
            ADD_INSN1(ret, line, putobject, rb_cObject);
            break;
          case NODE_COLON2:
            COMPILE(ret, "NODE_OP_CDECL/colon2#nd_head", node->nd_head->nd_head);
            break;
          default:
            do {
                COMPILE_ERROR((ERROR_ARGS "%s: invalid node in NODE_OP_CDECL",
                               ruby_node_name(nd_type(node->nd_head))));
            } while (0);
            return COMPILE_NG;
        }
        mid = node->nd_head->nd_mid;
        /* cref */
        if (node->nd_aid == 0) {
            lassign = NEW_LABEL(line);
            ADD_INSN(ret, line, dup); /* cref cref */
            ADD_INSN3(ret, line, defined, INT2FIX(DEFINED_CONST),
                      ID2SYM(mid), Qfalse); /* cref bool */
            ADD_INSNL(ret, line, branchunless, lassign); /* cref */
        }
        ADD_INSN(ret, line, dup); /* cref cref */
        ADD_INSN1(ret, line, getconstant, ID2SYM(mid)); /* cref obj */

        if (node->nd_aid == 0 || node->nd_aid == 1) {
            lfin = NEW_LABEL(line);
            if (!poped) ADD_INSN(ret, line, dup); /* cref [obj] obj */
            if (node->nd_aid == 0)
                ADD_INSNL(ret, line, branchif, lfin);
            else
                ADD_INSNL(ret, line, branchunless, lfin);
            /* cref [obj] */
            if (!poped) ADD_INSN(ret, line, pop); /* cref */
            if (lassign) ADD_LABEL(ret, lassign);
            COMPILE(ret, "NODE_OP_CDECL#nd_value", node->nd_value);
            /* cref value */
            if (poped)
                ADD_INSN1(ret, line, topn, INT2FIX(1)); /* cref value cref */
            else {
                ADD_INSN1(ret, line, dupn, INT2FIX(2)); /* cref value cref value */
                ADD_INSN(ret, line, swap); /* cref value value cref */
            }
            ADD_INSN1(ret, line, setconstant, ID2SYM(mid)); /* cref [value] */
            ADD_LABEL(ret, lfin);                           /* cref [value] */
            if (!poped) ADD_INSN(ret, line, swap); /* [value] cref */
            ADD_INSN(ret, line, pop); /* [value] */
        }
        else {
            COMPILE(ret, "NODE_OP_CDECL#nd_value", node->nd_value);
            /* cref obj value */
            ADD_CALL(ret, line, ID2SYM(node->nd_aid), INT2FIX(1));
            /* cref value */
            ADD_INSN(ret, line, swap); /* value cref */
            if (!poped) {
                ADD_INSN1(ret, line, topn, INT2FIX(1)); /* value cref value */
                ADD_INSN(ret, line, swap); /* value value cref */
            }
            ADD_INSN1(ret, line, setconstant, ID2SYM(mid));
        }
        break;
      }
      case NODE_OP_ASGN_AND:
      case NODE_OP_ASGN_OR:{
        LABEL *lfin = NEW_LABEL(line);
        LABEL *lassign;

        if (nd_type(node) == NODE_OP_ASGN_OR) {
            LABEL *lfinish[2];
            lfinish[0] = lfin;
            lfinish[1] = 0;
            defined_expr(iseq, ret, node->nd_head, lfinish, Qfalse);
            lassign = lfinish[1];
            if (!lassign) {
                lassign = NEW_LABEL(line);
            }
            ADD_INSNL(ret, line, branchunless, lassign);
        }
        else {
            lassign = NEW_LABEL(line);
        }

        COMPILE(ret, "NODE_OP_ASGN_AND/OR#nd_head", node->nd_head);
        ADD_INSN(ret, line, dup);

        if (nd_type(node) == NODE_OP_ASGN_AND) {
            ADD_INSNL(ret, line, branchunless, lfin);
        }
        else {
            ADD_INSNL(ret, line, branchif, lfin);
        }

        ADD_INSN(ret, line, pop);
        ADD_LABEL(ret, lassign);
        COMPILE(ret, "NODE_OP_ASGN_AND/OR#nd_value", node->nd_value);
        ADD_LABEL(ret, lfin);

        if (poped) {
            /* we can apply more optimize */
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_CALL:
        if (node->nd_recv && nd_type(node->nd_recv) == NODE_STR &&
            node->nd_mid == idFreeze && node->nd_args == NULL)
        {
            VALUE str = rb_fstring(node->nd_recv->nd_lit);
            iseq_add_mark_object(iseq, str);
            ADD_INSN1(ret, line, opt_str_freeze, str);
            if (poped) {
                ADD_INSN(ret, line, pop);
            }
            break;
        }
      case NODE_FCALL:
      case NODE_VCALL:{         /* VCALL: variable or call */
        /*
          call:  obj.method(...)
          fcall: func(...)
          vcall: func
        */
        DECL_ANCHOR(recv);
        DECL_ANCHOR(args);
        ID mid = node->nd_mid;
        VALUE argc;
        VALUE flag = 0;
        VALUE parent_block = iseq->compile_data->current_block;
        iseq->compile_data->current_block = Qfalse;

        INIT_ANCHOR(recv);
        INIT_ANCHOR(args);
#if SUPPORT_JOKE
        if (nd_type(node) == NODE_VCALL) {
            ID id_bitblt;
            ID id_answer;

            CONST_ID(id_bitblt, "bitblt");
            CONST_ID(id_answer, "the_answer_to_life_the_universe_and_everything");

            if (mid == id_bitblt) {
                ADD_INSN(ret, line, bitblt);
                break;
            }
            else if (mid == id_answer) {
                ADD_INSN(ret, line, answer);
                break;
            }
        }
        /* only joke */
        {
            ID goto_id;
            ID label_id;

            CONST_ID(goto_id, "__goto__");
            CONST_ID(label_id, "__label__");

            if (nd_type(node) == NODE_FCALL &&
                (mid == goto_id || mid == label_id)) {
                LABEL *label;
                st_data_t data;
                st_table *labels_table = iseq->compile_data->labels_table;
                ID label_name;

                if (!labels_table) {
                    labels_table = st_init_numtable();
                    iseq->compile_data->labels_table = labels_table;
                }
                if (nd_type(node->nd_args->nd_head) == NODE_LIT &&
                    SYMBOL_P(node->nd_args->nd_head->nd_lit)) {

                    label_name = SYM2ID(node->nd_args->nd_head->nd_lit);
                    if (!st_lookup(labels_table, (st_data_t)label_name, &data)) {
                        label = NEW_LABEL(line);
                        label->position = line;
                        st_insert(labels_table, (st_data_t)label_name, (st_data_t)label);
                    }
                    else {
                        label = (LABEL *)data;
                    }
                }
                else {
                    COMPILE_ERROR((ERROR_ARGS "invalid goto/label format"));
                }


                if (mid == goto_id) {
                    ADD_INSNL(ret, line, jump, label);
                }
                else {
                    ADD_LABEL(ret, label);
                }
                break;
            }
        }
#endif
        /* receiver */
        if (type == NODE_CALL) {
            COMPILE(recv, "recv", node->nd_recv);
        }
        else if (type == NODE_FCALL || type == NODE_VCALL) {
            ADD_CALL_RECEIVER(recv, line);
        }

        /* args */
        if (nd_type(node) != NODE_VCALL) {
            argc = setup_args(iseq, args, node->nd_args, &flag);
        }
        else {
            argc = INT2FIX(0);
        }

        ADD_SEQ(ret, recv);
        ADD_SEQ(ret, args);

        debugp_param("call args argc", argc);
        debugp_param("call method", ID2SYM(mid));

        switch (nd_type(node)) {
          case NODE_VCALL:
            flag |= VM_CALL_VCALL;
            /* VCALL is funcall, so fall through */
          case NODE_FCALL:
            flag |= VM_CALL_FCALL;
        }

        ADD_SEND_R(ret, line, ID2SYM(mid),
                   argc, parent_block, LONG2FIX(flag));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_SUPER:
      case NODE_ZSUPER:{
        DECL_ANCHOR(args);
        int argc;
        VALUE flag = 0;
        VALUE parent_block = iseq->compile_data->current_block;

        INIT_ANCHOR(args);
        iseq->compile_data->current_block = Qfalse;
        if (nd_type(node) == NODE_SUPER) {
            VALUE vargc = setup_args(iseq, args, node->nd_args, &flag);
            argc = FIX2INT(vargc);
        }
        else {
            /* NODE_ZSUPER */
            int i;
            rb_iseq_t *liseq = iseq->local_iseq;
            int lvar_level = get_lvar_level(iseq);

            argc = liseq->argc;

            /* normal arguments */
            for (i = 0; i < liseq->argc; i++) {
                int idx = liseq->local_size - i;
                ADD_INSN2(args, line, getlocal, INT2FIX(idx), INT2FIX(lvar_level));
            }

            if (!liseq->arg_simple) {
                if (liseq->arg_opts) {
                    /* optional arguments */
                    int j;
                    for (j = 0; j < liseq->arg_opts - 1; j++) {
                        int idx = liseq->local_size - (i + j);
                        ADD_INSN2(args, line, getlocal, INT2FIX(idx), INT2FIX(lvar_level));
                    }
                    i += j;
                    argc = i;
                }

                if (liseq->arg_rest != -1) {
                    /* rest argument */
                    int idx = liseq->local_size - liseq->arg_rest;
                    ADD_INSN2(args, line, getlocal, INT2FIX(idx), INT2FIX(lvar_level));
                    argc = liseq->arg_rest + 1;
                    flag |= VM_CALL_ARGS_SPLAT;
                }

                if (liseq->arg_post_len) {
                    /* post arguments */
                    int post_len = liseq->arg_post_len;
                    int post_start = liseq->arg_post_start;

                    if (liseq->arg_rest != -1) {
                        int j;
                        for (j=0; j<post_len; j++) {
                            int idx = liseq->local_size - (post_start + j);
                            ADD_INSN2(args, line, getlocal, INT2FIX(idx), INT2FIX(lvar_level));
                        }
                        ADD_INSN1(args, line, newarray, INT2FIX(j));
                        ADD_INSN (args, line, concatarray);
                        /* argc is settled at above */
                    }
                    else {
                        int j;
                        for (j=0; j<post_len; j++) {
                            int idx = liseq->local_size - (post_start + j);
                            ADD_INSN2(args, line, getlocal, INT2FIX(idx), INT2FIX(lvar_level));
                        }
                        argc = post_len + post_start;
                    }
                }

                if (liseq->arg_keyword >= 0) {
                    int local_size = liseq->local_size;
                    int idx = local_size - liseq->arg_keyword;
                    argc++;
                    ADD_INSN1(args, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
                    ADD_INSN2(args, line, getlocal, INT2FIX(idx), INT2FIX(lvar_level));
                    ADD_SEND (args, line, ID2SYM(rb_intern("dup")), INT2FIX(0));
                    for (i = 0; i < liseq->arg_keywords; ++i) {
                        ID id = liseq->arg_keyword_table[i];
                        idx = local_size - get_local_var_idx(liseq, id);
                        ADD_INSN1(args, line, putobject, ID2SYM(id));
                        ADD_INSN2(args, line, getlocal, INT2FIX(idx), INT2FIX(lvar_level));
                    }
                    ADD_SEND(args, line, ID2SYM(id_core_hash_merge_ptr), INT2FIX(i * 2 + 1));
                    if (liseq->arg_rest != -1) {
                        ADD_INSN1(args, line, newarray, INT2FIX(1));
                        ADD_INSN (args, line, concatarray);
                        --argc;
                    }
                }
            }
        }

        /* dummy receiver */
        ADD_INSN1(ret, line, putobject, nd_type(node) == NODE_ZSUPER ? Qfalse : Qtrue);
        ADD_SEQ(ret, args);
        ADD_INSN1(ret, line, invokesuper, new_callinfo(iseq, 0, argc, parent_block,
                                                                flag | VM_CALL_SUPER | VM_CALL_FCALL));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_ARRAY:{
        compile_array_(iseq, ret, node, COMPILE_ARRAY_TYPE_ARRAY, poped);
        break;
      }
      case NODE_ZARRAY:{
        if (!poped) {
            ADD_INSN1(ret, line, newarray, INT2FIX(0));
        }
        break;
      }
      case NODE_VALUES:{
        NODE *n = node;
        while (n) {
            COMPILE(ret, "values item", n->nd_head);
            n = n->nd_next;
        }
        ADD_INSN1(ret, line, newarray, INT2FIX(node->nd_alen));
        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_HASH:{
        DECL_ANCHOR(list);
        int type = node->nd_head ? nd_type(node->nd_head) : NODE_ZARRAY;

        INIT_ANCHOR(list);
        switch (type) {
          case NODE_ARRAY:
            compile_array(iseq, list, node->nd_head, COMPILE_ARRAY_TYPE_HASH);
            ADD_SEQ(ret, list);
            break;

          case NODE_ZARRAY:
            ADD_INSN1(ret, line, newhash, INT2FIX(0));
            break;

          default:
            rb_bug("can't make hash with this node: %s", ruby_node_name(type));
        }

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_RETURN:{
        rb_iseq_t *is = iseq;

        if (is) {
            if (is->type == ISEQ_TYPE_TOP) {
                COMPILE_ERROR((ERROR_ARGS "Invalid return"));
            }
            else {
                LABEL *splabel = 0;

                if (is->type == ISEQ_TYPE_METHOD) {
                    splabel = NEW_LABEL(0);
                    ADD_LABEL(ret, splabel);
                    ADD_ADJUST(ret, line, 0);
                }

                COMPILE(ret, "return nd_stts (return val)", node->nd_stts);

                if (is->type == ISEQ_TYPE_METHOD) {
                    add_ensure_iseq(ret, iseq, 1);
                    ADD_TRACE(ret, line, RUBY_EVENT_RETURN);
                    ADD_INSN(ret, line, leave);
                    ADD_ADJUST_RESTORE(ret, splabel);

                    if (!poped) {
                        ADD_INSN(ret, line, putnil);
                    }
                }
                else {
                    ADD_INSN1(ret, line, throw, INT2FIX(0x01) /* TAG_RETURN */ );
                    if (poped) {
                        ADD_INSN(ret, line, pop);
                    }
                }
            }
        }
        break;
      }
      case NODE_YIELD:{
        DECL_ANCHOR(args);
        VALUE argc;
        VALUE flag = 0;

        INIT_ANCHOR(args);
        if (iseq->type == ISEQ_TYPE_TOP) {
            COMPILE_ERROR((ERROR_ARGS "Invalid yield"));
        }

        if (node->nd_head) {
            argc = setup_args(iseq, args, node->nd_head, &flag);
        }
        else {
            argc = INT2FIX(0);
        }

        ADD_SEQ(ret, args);
        ADD_INSN1(ret, line, invokeblock, new_callinfo(iseq, 0, FIX2INT(argc), 0, flag));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_LVAR:{
        if (!poped) {
            ID id = node->nd_vid;
            int idx = iseq->local_iseq->local_size - get_local_var_idx(iseq, id);

            debugs("id: %s idx: %d\n", rb_id2name(id), idx);
            ADD_INSN2(ret, line, getlocal, INT2FIX(idx), INT2FIX(get_lvar_level(iseq)));
        }
        break;
      }
      case NODE_DVAR:{
        int lv, idx, ls;
        debugi("nd_vid", node->nd_vid);
        if (!poped) {
            idx = get_dyna_var_idx(iseq, node->nd_vid, &lv, &ls);
            if (idx < 0) {
                rb_bug("unknown dvar (%s)", rb_id2name(node->nd_vid));
            }
            ADD_INSN2(ret, line, getlocal, INT2FIX(ls - idx), INT2FIX(lv));
        }
        break;
      }
      case NODE_GVAR:{
        ADD_INSN1(ret, line, getglobal,
                  ((VALUE)node->nd_entry | 1));
        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_IVAR:{
        debugi("nd_vid", node->nd_vid);
        if (!poped) {
            ADD_INSN2(ret, line, getinstancevariable,
                      ID2SYM(node->nd_vid), INT2FIX(iseq->is_size++));
        }
        break;
      }
      case NODE_CONST:{
        debugi("nd_vid", node->nd_vid);

        if (iseq->compile_data->option->inline_const_cache) {
            LABEL *lend = NEW_LABEL(line);
            int ic_index = iseq->is_size++;

            ADD_INSN2(ret, line, getinlinecache, lend, INT2FIX(ic_index));
            ADD_INSN1(ret, line, getconstant, ID2SYM(node->nd_vid));
            ADD_INSN1(ret, line, setinlinecache, INT2FIX(ic_index));
            ADD_LABEL(ret, lend);
        }
        else {
            ADD_INSN(ret, line, putnil);
            ADD_INSN1(ret, line, getconstant, ID2SYM(node->nd_vid));
        }

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_CVAR:{
        if (!poped) {
            ADD_INSN1(ret, line, getclassvariable,
                      ID2SYM(node->nd_vid));
        }
        break;
      }
      case NODE_NTH_REF:{
        if (!poped) {
            if (!node->nd_nth) {
                ADD_INSN(ret, line, putnil);
                break;
            }
            ADD_INSN2(ret, line, getspecial, INT2FIX(1) /* '~'  */,
                      INT2FIX(node->nd_nth << 1));
        }
        break;
      }
      case NODE_BACK_REF:{
        if (!poped) {
            ADD_INSN2(ret, line, getspecial, INT2FIX(1) /* '~' */,
                      INT2FIX(0x01 | (node->nd_nth << 1)));
        }
        break;
      }
      case NODE_MATCH:
      case NODE_MATCH2:
      case NODE_MATCH3:{
        DECL_ANCHOR(recv);
        DECL_ANCHOR(val);

        INIT_ANCHOR(recv);
        INIT_ANCHOR(val);
        switch (nd_type(node)) {
          case NODE_MATCH:
            ADD_INSN1(recv, line, putobject, node->nd_lit);
            ADD_INSN2(val, line, getspecial, INT2FIX(0),
                      INT2FIX(0));
            break;
          case NODE_MATCH2:
            COMPILE(recv, "receiver", node->nd_recv);
            COMPILE(val, "value", node->nd_value);
            break;
          case NODE_MATCH3:
            COMPILE(recv, "receiver", node->nd_value);
            COMPILE(val, "value", node->nd_recv);
            break;
        }

        if (iseq->compile_data->option->specialized_instruction) {
            /* TODO: detect by node */
            if (recv->last == recv->anchor.next &&
                INSN_OF(recv->last) == BIN(putobject) &&
                nd_type(node) == NODE_MATCH2) {
                ADD_SEQ(ret, val);
                ADD_INSN1(ret, line, opt_regexpmatch1,
                          OPERAND_AT(recv->last, 0));
            }
            else {
                ADD_SEQ(ret, recv);
                ADD_SEQ(ret, val);
                ADD_INSN1(ret, line, opt_regexpmatch2, new_callinfo(iseq, idEqTilde, 1, 0, 0));
            }
        }
        else {
            ADD_SEQ(ret, recv);
            ADD_SEQ(ret, val);
            ADD_SEND(ret, line, ID2SYM(idEqTilde), INT2FIX(1));
        }

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_LIT:{
        debugp_param("lit", node->nd_lit);
        if (!poped) {
            ADD_INSN1(ret, line, putobject, node->nd_lit);
        }
        break;
      }
      case NODE_STR:{
        node->nd_lit = rb_fstring(node->nd_lit);
        debugp_param("nd_lit", node->nd_lit);
        if (!poped) {
            ADD_INSN1(ret, line, putstring, node->nd_lit);
        }
        break;
      }
      case NODE_DSTR:{
        compile_dstr(iseq, ret, node);

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_XSTR:{
        node->nd_lit = rb_fstring(node->nd_lit);
        ADD_CALL_RECEIVER(ret, line);
        ADD_INSN1(ret, line, putobject, node->nd_lit);
        ADD_CALL(ret, line, ID2SYM(idBackquote), INT2FIX(1));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_DXSTR:{
        ADD_CALL_RECEIVER(ret, line);
        compile_dstr(iseq, ret, node);
        ADD_CALL(ret, line, ID2SYM(idBackquote), INT2FIX(1));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_EVSTR:{
        COMPILE(ret, "nd_body", node->nd_body);

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        else {
            ADD_INSN(ret, line, tostring);
        }
        break;
      }
      case NODE_DREGX:{
        compile_dregx(iseq, ret, node);

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_DREGX_ONCE:{
        int ic_index = iseq->is_size++;
        NODE *dregx_node = NEW_NODE(NODE_DREGX, node->u1.value, node->u2.value, node->u3.value);
        NODE *block_node = NEW_NODE(NODE_SCOPE, 0, dregx_node, 0);
        VALUE block_iseq = NEW_CHILD_ISEQVAL(block_node, make_name_for_block(iseq), ISEQ_TYPE_BLOCK, line);

        ADD_INSN2(ret, line, once, block_iseq, INT2FIX(ic_index));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_ARGSCAT:{
        if (poped) {
            COMPILE(ret, "argscat head", node->nd_head);
            ADD_INSN1(ret, line, splatarray, Qfalse);
            ADD_INSN(ret, line, pop);
            COMPILE(ret, "argscat body", node->nd_body);
            ADD_INSN1(ret, line, splatarray, Qfalse);
            ADD_INSN(ret, line, pop);
        }
        else {
            COMPILE(ret, "argscat head", node->nd_head);
            COMPILE(ret, "argscat body", node->nd_body);
            ADD_INSN(ret, line, concatarray);
        }
        break;
      }
      case NODE_ARGSPUSH:{
        if (poped) {
            COMPILE(ret, "arsgpush head", node->nd_head);
            ADD_INSN1(ret, line, splatarray, Qfalse);
            ADD_INSN(ret, line, pop);
            COMPILE_(ret, "argspush body", node->nd_body, poped);
        }
        else {
            COMPILE(ret, "arsgpush head", node->nd_head);
            COMPILE_(ret, "argspush body", node->nd_body, poped);
            ADD_INSN1(ret, line, newarray, INT2FIX(1));
            ADD_INSN(ret, line, concatarray);
        }
        break;
      }
      case NODE_SPLAT:{
        COMPILE(ret, "splat", node->nd_head);
        ADD_INSN1(ret, line, splatarray, Qtrue);

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_DEFN:{
        VALUE iseqval = NEW_ISEQVAL(node->nd_defn,
                                    rb_id2str(node->nd_mid),
                                    ISEQ_TYPE_METHOD, line);

        debugp_param("defn/iseq", iseqval);

        ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
        ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_CBASE));
        ADD_INSN1(ret, line, putobject, ID2SYM(node->nd_mid));
        ADD_INSN1(ret, line, putiseq, iseqval);
        ADD_SEND (ret, line, ID2SYM(id_core_define_method), INT2FIX(3));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }

        debugp_param("defn", iseqval);
        break;
      }
      case NODE_DEFS:{
        VALUE iseqval = NEW_ISEQVAL(node->nd_defn,
                                    rb_id2str(node->nd_mid),
                                    ISEQ_TYPE_METHOD, line);

        debugp_param("defs/iseq", iseqval);

        ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
        COMPILE(ret, "defs: recv", node->nd_recv);
        ADD_INSN1(ret, line, putobject, ID2SYM(node->nd_mid));
        ADD_INSN1(ret, line, putiseq, iseqval);
        ADD_SEND (ret, line, ID2SYM(id_core_define_singleton_method), INT2FIX(3));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_ALIAS:{
        ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
        ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_CBASE));
        COMPILE(ret, "alias arg1", node->u1.node);
        COMPILE(ret, "alias arg2", node->u2.node);
        ADD_SEND(ret, line, ID2SYM(id_core_set_method_alias), INT2FIX(3));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_VALIAS:{
        ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
        ADD_INSN1(ret, line, putobject, ID2SYM(node->u1.id));
        ADD_INSN1(ret, line, putobject, ID2SYM(node->u2.id));
        ADD_SEND(ret, line, ID2SYM(id_core_set_variable_alias), INT2FIX(2));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_UNDEF:{
        ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
        ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_CBASE));
        COMPILE(ret, "undef arg", node->u2.node);
        ADD_SEND(ret, line, ID2SYM(id_core_undef_method), INT2FIX(2));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_CLASS:{
        VALUE iseqval =
            NEW_CHILD_ISEQVAL(
                node->nd_body,
                rb_sprintf("<class:%s>", rb_id2name(node->nd_cpath->nd_mid)),
                ISEQ_TYPE_CLASS, line);
        VALUE noscope = compile_cpath(ret, iseq, node->nd_cpath);
        int flags = VM_DEFINECLASS_TYPE_CLASS;
        if (!noscope) flags |= VM_DEFINECLASS_FLAG_SCOPED;
        if (node->nd_super) flags |= VM_DEFINECLASS_FLAG_HAS_SUPERCLASS;
        COMPILE(ret, "super", node->nd_super);
        ADD_INSN3(ret, line, defineclass,
                  ID2SYM(node->nd_cpath->nd_mid), iseqval, INT2FIX(flags));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_MODULE:{
        VALUE iseqval = NEW_CHILD_ISEQVAL(
            node->nd_body,
            rb_sprintf("<module:%s>", rb_id2name(node->nd_cpath->nd_mid)),
            ISEQ_TYPE_CLASS, line);

        VALUE noscope = compile_cpath(ret, iseq, node->nd_cpath);
        int flags = VM_DEFINECLASS_TYPE_MODULE;
        if (!noscope) flags |= VM_DEFINECLASS_FLAG_SCOPED;
        ADD_INSN (ret, line, putnil); /* dummy */
        ADD_INSN3(ret, line, defineclass,
                  ID2SYM(node->nd_cpath->nd_mid), iseqval, INT2FIX(flags));
        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_SCLASS:{
        ID singletonclass;
        VALUE iseqval =
            NEW_ISEQVAL(node->nd_body, rb_str_new2("singleton class"),
                        ISEQ_TYPE_CLASS, line);

        COMPILE(ret, "sclass#recv", node->nd_recv);
        ADD_INSN (ret, line, putnil);
        CONST_ID(singletonclass, "singletonclass");
        ADD_INSN3(ret, line, defineclass,
                  ID2SYM(singletonclass), iseqval,
                  INT2FIX(VM_DEFINECLASS_TYPE_SINGLETON_CLASS));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_COLON2:{
        if (rb_is_const_id(node->nd_mid)) {
            /* constant */
            LABEL *lend = NEW_LABEL(line);
            int ic_index = iseq->is_size++;

            DECL_ANCHOR(pref);
            DECL_ANCHOR(body);

            INIT_ANCHOR(pref);
            INIT_ANCHOR(body);
            compile_colon2(iseq, node, pref, body);
            if (LIST_SIZE_ZERO(pref)) {
                if (iseq->compile_data->option->inline_const_cache) {
                    ADD_INSN2(ret, line, getinlinecache, lend, INT2FIX(ic_index));
                }
                else {
                    ADD_INSN(ret, line, putnil);
                }

                ADD_SEQ(ret, body);

                if (iseq->compile_data->option->inline_const_cache) {
                    ADD_INSN1(ret, line, setinlinecache, INT2FIX(ic_index));
                    ADD_LABEL(ret, lend);
                }
            }
            else {
                ADD_SEQ(ret, pref);
                ADD_SEQ(ret, body);
            }
        }
        else {
            /* function call */
            ADD_CALL_RECEIVER(ret, line);
            COMPILE(ret, "colon2#nd_head", node->nd_head);
            ADD_CALL(ret, line, ID2SYM(node->nd_mid),
                     INT2FIX(1));
        }
        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_COLON3:{
        LABEL *lend = NEW_LABEL(line);
        int ic_index = iseq->is_size++;

        debugi("colon3#nd_mid", node->nd_mid);

        /* add cache insn */
        if (iseq->compile_data->option->inline_const_cache) {
            ADD_INSN2(ret, line, getinlinecache, lend, INT2FIX(ic_index));
            ADD_INSN(ret, line, pop);
        }

        ADD_INSN1(ret, line, putobject, rb_cObject);
        ADD_INSN1(ret, line, getconstant, ID2SYM(node->nd_mid));

        if (iseq->compile_data->option->inline_const_cache) {
            ADD_INSN1(ret, line, setinlinecache, INT2FIX(ic_index));
            ADD_LABEL(ret, lend);
        }

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_DOT2:
      case NODE_DOT3:{
        VALUE flag = type == NODE_DOT2 ? INT2FIX(0) : INT2FIX(1);
        COMPILE(ret, "min", (NODE *) node->nd_beg);
        COMPILE(ret, "max", (NODE *) node->nd_end);
        if (poped) {
            ADD_INSN(ret, line, pop);
            ADD_INSN(ret, line, pop);
        }
        else {
            ADD_INSN1(ret, line, newrange, flag);
        }
        break;
      }
      case NODE_FLIP2:
      case NODE_FLIP3:{
        LABEL *lend = NEW_LABEL(line);
        LABEL *lfin = NEW_LABEL(line);
        LABEL *ltrue = NEW_LABEL(line);
        rb_iseq_t *local_iseq = iseq->local_iseq;
        rb_num_t cnt;
        VALUE key;

        cnt = local_iseq->flip_cnt++ + DEFAULT_SPECIAL_VAR_COUNT;
        key = INT2FIX(cnt);

        ADD_INSN2(ret, line, getspecial, key, INT2FIX(0));
        ADD_INSNL(ret, line, branchif, lend);

        /* *flip == 0 */
        COMPILE(ret, "flip2 beg", node->nd_beg);
        ADD_INSN(ret, line, dup);
        ADD_INSNL(ret, line, branchunless, lfin);
        if (nd_type(node) == NODE_FLIP3) {
            ADD_INSN(ret, line, dup);
            ADD_INSN1(ret, line, setspecial, key);
            ADD_INSNL(ret, line, jump, lfin);
        }
        else {
            ADD_INSN1(ret, line, setspecial, key);
        }

        /* *flip == 1 */
        ADD_LABEL(ret, lend);
        COMPILE(ret, "flip2 end", node->nd_end);
        ADD_INSNL(ret, line, branchunless, ltrue);
        ADD_INSN1(ret, line, putobject, Qfalse);
        ADD_INSN1(ret, line, setspecial, key);

        ADD_LABEL(ret, ltrue);
        ADD_INSN1(ret, line, putobject, Qtrue);

        ADD_LABEL(ret, lfin);
        break;
      }
      case NODE_SELF:{
        if (!poped) {
            ADD_INSN(ret, line, putself);
        }
        break;
      }
      case NODE_NIL:{
        if (!poped) {
            ADD_INSN(ret, line, putnil);
        }
        break;
      }
      case NODE_TRUE:{
        if (!poped) {
            ADD_INSN1(ret, line, putobject, Qtrue);
        }
        break;
      }
      case NODE_FALSE:{
        if (!poped) {
            ADD_INSN1(ret, line, putobject, Qfalse);
        }
        break;
      }
      case NODE_ERRINFO:{
        if (!poped) {
            if (iseq->type == ISEQ_TYPE_RESCUE) {
                ADD_INSN2(ret, line, getlocal, INT2FIX(2), INT2FIX(0));
            }
            else {
                rb_iseq_t *ip = iseq;
                int level = 0;
                while (ip) {
                    if (ip->type == ISEQ_TYPE_RESCUE) {
                        break;
                    }
                    ip = ip->parent_iseq;
                    level++;
                }
                if (ip) {
                    ADD_INSN2(ret, line, getlocal, INT2FIX(2), INT2FIX(level));
                }
                else {
                    ADD_INSN(ret, line, putnil);
                }
            }
        }
        break;
      }
      case NODE_DEFINED:{
        if (poped) break;
        if (!node->nd_head) {
            VALUE str = rb_iseq_defined_string(DEFINED_NIL);
            ADD_INSN1(ret, nd_line(node), putobject, str);
        }
        else {
            LABEL *lfinish[2];
            lfinish[0] = NEW_LABEL(line);
            lfinish[1] = 0;
            ADD_INSN(ret, line, putnil);
            defined_expr(iseq, ret, node->nd_head, lfinish, Qtrue);
            ADD_INSN(ret, line, swap);
            ADD_INSN(ret, line, pop);
            if (lfinish[1]) {
                ADD_LABEL(ret, lfinish[1]);
            }
            ADD_LABEL(ret, lfinish[0]);
        }
        break;
      }
      case NODE_POSTEXE:{
        /* compiled to:
         *   ONCE{ rb_mRubyVMFrozenCore::core#set_postexe{ ... } }
         */
        int is_index = iseq->is_size++;
        VALUE once_iseq = NEW_CHILD_ISEQVAL(
            NEW_IFUNC(build_postexe_iseq, node->nd_body),
            make_name_for_block(iseq), ISEQ_TYPE_BLOCK, line);

        ADD_INSN2(ret, line, once, once_iseq, INT2FIX(is_index));

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_KW_ARG:{
        LABEL *default_label = NEW_LABEL(line);
        LABEL *end_label = 0;
        int idx, lv, ls;
        ID id = node->nd_body->nd_vid;

        ADD_INSN(ret, line, dup);
        ADD_INSN1(ret, line, putobject, ID2SYM(id));
        ADD_SEND(ret, line, ID2SYM(rb_intern("key?")), INT2FIX(1));
        ADD_INSNL(ret, line, branchunless, default_label);
        ADD_INSN(ret, line, dup);
        ADD_INSN1(ret, line, putobject, ID2SYM(id));
        ADD_SEND(ret, line, ID2SYM(rb_intern("delete")), INT2FIX(1));
        switch (nd_type(node->nd_body)) {
          case NODE_LASGN:
            idx = iseq->local_iseq->local_size - get_local_var_idx(iseq, id);
            ADD_INSN2(ret, line, setlocal, INT2FIX(idx), INT2FIX(get_lvar_level(iseq)));
            break;
          case NODE_DASGN:
          case NODE_DASGN_CURR:
            idx = get_dyna_var_idx(iseq, id, &lv, &ls);
            ADD_INSN2(ret, line, setlocal, INT2FIX(ls - idx), INT2FIX(lv));
            break;
          default:
            rb_bug("iseq_compile_each (NODE_KW_ARG): unknown node: %s", ruby_node_name(nd_type(node->nd_body)));
        }
        if (node->nd_body->nd_value != (NODE *)-1) {
            end_label = NEW_LABEL(nd_line(node));
            ADD_INSNL(ret, nd_line(node), jump, end_label);
        }
        ADD_LABEL(ret, default_label);
        if (node->nd_body->nd_value != (NODE *)-1) {
            COMPILE_POPED(ret, "keyword default argument", node->nd_body);
            ADD_LABEL(ret, end_label);
        }
        break;
      }
      case NODE_DSYM:{
        compile_dstr(iseq, ret, node);
        if (!poped) {
            ADD_SEND(ret, line, ID2SYM(idIntern), INT2FIX(0));
        }
        else {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      case NODE_ATTRASGN:{
        DECL_ANCHOR(recv);
        DECL_ANCHOR(args);
        VALUE flag = 0;
        VALUE argc;

        INIT_ANCHOR(recv);
        INIT_ANCHOR(args);
        argc = setup_args(iseq, args, node->nd_args, &flag);

        if (node->nd_recv == (NODE *) 1) {
            flag |= VM_CALL_FCALL;
            ADD_INSN(recv, line, putself);
        }
        else {
            COMPILE(recv, "recv", node->nd_recv);
        }

        debugp_param("argc", argc);
        debugp_param("nd_mid", ID2SYM(node->nd_mid));

        if (!poped) {
            ADD_INSN(ret, line, putnil);
            ADD_SEQ(ret, recv);
            ADD_SEQ(ret, args);

            if (flag & VM_CALL_ARGS_BLOCKARG) {
                ADD_INSN1(ret, line, topn, INT2FIX(1));
                if (flag & VM_CALL_ARGS_SPLAT) {
                    ADD_INSN1(ret, line, putobject, INT2FIX(-1));
                    ADD_SEND(ret, line, ID2SYM(idAREF), INT2FIX(1));
                }
                ADD_INSN1(ret, line, setn, FIXNUM_INC(argc, 3));
                ADD_INSN (ret, line, pop);
            }
            else if (flag & VM_CALL_ARGS_SPLAT) {
                ADD_INSN(ret, line, dup);
                ADD_INSN1(ret, line, putobject, INT2FIX(-1));
                ADD_SEND(ret, line, ID2SYM(idAREF), INT2FIX(1));
                ADD_INSN1(ret, line, setn, FIXNUM_INC(argc, 2));
                ADD_INSN (ret, line, pop);
            }
            else {
                ADD_INSN1(ret, line, setn, FIXNUM_INC(argc, 1));
            }
        }
        else {
            ADD_SEQ(ret, recv);
            ADD_SEQ(ret, args);
        }
        ADD_SEND_R(ret, line, ID2SYM(node->nd_mid), argc, 0, LONG2FIX(flag));
        ADD_INSN(ret, line, pop);

        break;
      }
      case NODE_PRELUDE:{
        COMPILE_POPED(ret, "prelude", node->nd_head);
        COMPILE_(ret, "body", node->nd_body, poped);
        break;
      }
      case NODE_LAMBDA:{
        /* compile same as lambda{...} */
        VALUE block = NEW_CHILD_ISEQVAL(node->nd_body, make_name_for_block(iseq), ISEQ_TYPE_BLOCK, line);
        VALUE argc = INT2FIX(0);
        ADD_INSN1(ret, line, putspecialobject, INT2FIX(VM_SPECIAL_OBJECT_VMCORE));
        ADD_CALL_WITH_BLOCK(ret, line, ID2SYM(idLambda), argc, block);

        if (poped) {
            ADD_INSN(ret, line, pop);
        }
        break;
      }
      default:
        rb_bug("iseq_compile_each: unknown node: %s", ruby_node_name(type));
        return COMPILE_NG;
    }

    /* check & remove redundant trace(line) */
    if (saved_last_element && ret /* ret can be 0 when error */ &&
        ret->last == saved_last_element &&
        ((INSN *)saved_last_element)->insn_id == BIN(trace)) {
        POP_ELEMENT(ret);
    }

    debug_node_end();
    return COMPILE_OK;
}

/***************************/
/* instruction information */
/***************************/

static int
insn_data_length(INSN *iobj)
{
    return insn_len(iobj->insn_id);
}

static int
calc_sp_depth(int depth, INSN *insn)
{
    return insn_stack_increase(depth, insn->insn_id, insn->operands);
}

static VALUE
opobj_inspect(VALUE obj)
{
    struct RBasic *r = (struct RBasic *) obj;
    if (!SPECIAL_CONST_P(r)  && r->klass == 0) {
        switch (BUILTIN_TYPE(r)) {
          case T_STRING:
            obj = rb_str_new_cstr(RSTRING_PTR(obj));
            break;
          case T_ARRAY:
            obj = rb_ary_dup(obj);
            break;
        }
    }
    return rb_inspect(obj);
}



static VALUE
insn_data_to_s_detail(INSN *iobj)
{
    VALUE str = rb_sprintf("%-20s ", insn_name(iobj->insn_id));

    if (iobj->operands) {
        const char *types = insn_op_types(iobj->insn_id);
        int j;

        for (j = 0; types[j]; j++) {
            char type = types[j];

            switch (type) {
              case TS_OFFSET:   /* label(destination position) */
                {
                    LABEL *lobj = (LABEL *)OPERAND_AT(iobj, j);
                    rb_str_catf(str, "<L%03d>", lobj->label_no);
                    break;
                }
                break;
              case TS_ISEQ:     /* iseq */
                {
                    rb_iseq_t *iseq = (rb_iseq_t *)OPERAND_AT(iobj, j);
                    VALUE val = Qnil;
                    if (0 && iseq) { /* TODO: invalidate now */
                        val = iseq->self;
                    }
                    rb_str_concat(str, opobj_inspect(val));
                }
                break;
              case TS_LINDEX:
              case TS_NUM:      /* ulong */
              case TS_VALUE:    /* VALUE */
                {
                    VALUE v = OPERAND_AT(iobj, j);
                    rb_str_concat(str, opobj_inspect(v));
                    break;
                }
              case TS_ID:       /* ID */
                rb_str_concat(str, opobj_inspect(OPERAND_AT(iobj, j)));
                break;
              case TS_GENTRY:
                {
                    struct rb_global_entry *entry = (struct rb_global_entry *)
                      (OPERAND_AT(iobj, j) & (~1));
                    rb_str_cat2(str, rb_id2name(entry->id));
                    break;
                }
              case TS_IC:       /* inline cache */
                rb_str_catf(str, "<ic:%d>", FIX2INT(OPERAND_AT(iobj, j)));
                break;
              case TS_CALLINFO: /* call info */
                {
                    rb_call_info_t *ci = (rb_call_info_t *)OPERAND_AT(iobj, j);
                    rb_str_catf(str, "<callinfo:%s, %d>", ci->mid ? rb_id2name(ci->mid) : "", ci->orig_argc);
                    break;
                }
              case TS_CDHASH:   /* case/when condition cache */
                rb_str_cat2(str, "<ch>");
                break;
              default:{
                rb_raise(rb_eSyntaxError, "unknown operand type: %c", type);
              }
            }
            if (types[j + 1]) {
                rb_str_cat2(str, ", ");
            }
        }
    }
    return str;
}

static void
dump_disasm_list(struct iseq_link_element *link)
{
    int pos = 0;
    INSN *iobj;
    LABEL *lobj;
    VALUE str;

    printf("-- raw disasm--------\n");

    while (link) {
        switch (link->type) {
          case ISEQ_ELEMENT_INSN:
            {
                iobj = (INSN *)link;
                str = insn_data_to_s_detail(iobj);
                printf("%04d %-65s(%4d)\n", pos, StringValueCStr(str), iobj->line_no);
                pos += insn_data_length(iobj);
                break;
            }
          case ISEQ_ELEMENT_LABEL:
            {
                lobj = (LABEL *)link;
                printf("<L%03d>\n", lobj->label_no);
                break;
            }
          case ISEQ_ELEMENT_NONE:
            {
                printf("[none]\n");
                break;
            }
          case ISEQ_ELEMENT_ADJUST:
            {
                ADJUST *adjust = (ADJUST *)link;
                printf("adjust: [label: %d]\n", adjust->label ? adjust->label->label_no : -1);
                break;
            }
          default:
            /* ignore */
            rb_raise(rb_eSyntaxError, "dump_disasm_list error: %ld\n", FIX2LONG(link->type));
        }
        link = link->next;
    }
    printf("---------------------\n");
}

const char *
rb_insns_name(int i)
{
    return insn_name_info[i];
}

VALUE
rb_insns_name_array(void)
{
    VALUE ary = rb_ary_new();
    int i;
    for (i = 0; i < numberof(insn_name_info); i++) {
        rb_ary_push(ary, rb_fstring(rb_str_new2(insn_name_info[i])));
    }
    return rb_obj_freeze(ary);
}

static LABEL *
register_label(rb_iseq_t *iseq, struct st_table *labels_table, VALUE obj)
{
    LABEL *label = 0;
    st_data_t tmp;
    obj = rb_convert_type(obj, T_SYMBOL, "Symbol", "to_sym");

    if (st_lookup(labels_table, obj, &tmp) == 0) {
        label = NEW_LABEL(0);
        st_insert(labels_table, obj, (st_data_t)label);
    }
    else {
        label = (LABEL *)tmp;
    }
    return label;
}

static VALUE
get_exception_sym2type(VALUE sym)
{
#undef rb_intern
#define rb_intern(str) rb_intern_const(str)
    VALUE sym_inspect;
    static VALUE symRescue, symEnsure, symRetry;
    static VALUE symBreak, symRedo, symNext;

    if (symRescue == 0) {
        symRescue = ID2SYM(rb_intern("rescue"));
        symEnsure = ID2SYM(rb_intern("ensure"));
        symRetry  = ID2SYM(rb_intern("retry"));
        symBreak  = ID2SYM(rb_intern("break"));
        symRedo   = ID2SYM(rb_intern("redo"));
        symNext   = ID2SYM(rb_intern("next"));
    }

    if (sym == symRescue) return CATCH_TYPE_RESCUE;
    if (sym == symEnsure) return CATCH_TYPE_ENSURE;
    if (sym == symRetry)  return CATCH_TYPE_RETRY;
    if (sym == symBreak)  return CATCH_TYPE_BREAK;
    if (sym == symRedo)   return CATCH_TYPE_REDO;
    if (sym == symNext)   return CATCH_TYPE_NEXT;
    sym_inspect = rb_inspect(sym);
    rb_raise(rb_eSyntaxError, "invalid exception symbol: %s",
             StringValuePtr(sym_inspect));
    return 0;
}

static int
iseq_build_from_ary_exception(rb_iseq_t *iseq, struct st_table *labels_table,
                     VALUE exception)
{
    int i;

    for (i=0; i<RARRAY_LEN(exception); i++) {
        VALUE v, type, eiseqval;
        const VALUE *ptr;
        LABEL *lstart, *lend, *lcont;
        int sp;

        RB_GC_GUARD(v) = rb_convert_type(RARRAY_AREF(exception, i), T_ARRAY,
                                         "Array", "to_ary");
        if (RARRAY_LEN(v) != 6) {
            rb_raise(rb_eSyntaxError, "wrong exception entry");
        }
        ptr  = RARRAY_CONST_PTR(v);
        type = get_exception_sym2type(ptr[0]);
        if (ptr[1] == Qnil) {
            eiseqval = 0;
        }
        else {
            eiseqval = rb_iseq_load(ptr[1], iseq->self, Qnil);
        }

        lstart = register_label(iseq, labels_table, ptr[2]);
        lend   = register_label(iseq, labels_table, ptr[3]);
        lcont  = register_label(iseq, labels_table, ptr[4]);
        sp     = NUM2INT(ptr[5]);

        (void)sp;

        ADD_CATCH_ENTRY(type, lstart, lend, eiseqval, lcont);
    }
    return COMPILE_OK;
}

static struct st_table *
insn_make_insn_table(void)
{
    struct st_table *table;
    int i;
    table = st_init_numtable();

    for (i=0; i<VM_INSTRUCTION_SIZE; i++) {
        st_insert(table, ID2SYM(rb_intern(insn_name(i))), i);
    }

    return table;
}

static VALUE
iseq_build_load_iseq(rb_iseq_t *iseq, VALUE op)
{
    VALUE iseqval;
    if (RB_TYPE_P(op, T_ARRAY)) {
        iseqval = rb_iseq_load(op, iseq->self, Qnil);
    }
    else if (CLASS_OF(op) == rb_cISeq) {
        iseqval = op;
    }
    else {
        rb_raise(rb_eSyntaxError, "ISEQ is required");
    }
    iseq_add_mark_object(iseq, iseqval);
    return iseqval;
}

static int
iseq_build_from_ary_body(rb_iseq_t *iseq, LINK_ANCHOR *anchor,
                VALUE body, struct st_table *labels_table)
{
    /* TODO: body should be frozen */
    const VALUE *ptr = RARRAY_CONST_PTR(body);
    long i, len = RARRAY_LEN(body);
    int j;
    int line_no = 0;

    /*
     * index -> LABEL *label
     */
    static struct st_table *insn_table;

    if (insn_table == 0) {
        insn_table = insn_make_insn_table();
    }

    for (i=0; i<len; i++) {
        VALUE obj = ptr[i];

        if (SYMBOL_P(obj)) {
            LABEL *label = register_label(iseq, labels_table, obj);
            ADD_LABEL(anchor, label);
        }
        else if (FIXNUM_P(obj)) {
            line_no = NUM2INT(obj);
        }
        else if (RB_TYPE_P(obj, T_ARRAY)) {
            VALUE *argv = 0;
            int argc = RARRAY_LENINT(obj) - 1;
            st_data_t insn_id;
            VALUE insn;

            insn = (argc < 0) ? Qnil : RARRAY_AREF(obj, 0);
            if (st_lookup(insn_table, (st_data_t)insn, &insn_id) == 0) {
                /* TODO: exception */
                RB_GC_GUARD(insn) = rb_inspect(insn);
                rb_compile_error(RSTRING_PTR(iseq->location.path), line_no,
                                 "unknown instruction: %s", RSTRING_PTR(insn));
            }

            if (argc != insn_len((VALUE)insn_id)-1) {
                rb_compile_error(RSTRING_PTR(iseq->location.path), line_no,
                                 "operand size mismatch");
            }

            if (argc > 0) {
                argv = compile_data_alloc(iseq, sizeof(VALUE) * argc);
                for (j=0; j<argc; j++) {
                    VALUE op = rb_ary_entry(obj, j+1);
                    switch (insn_op_type((VALUE)insn_id, j)) {
                      case TS_OFFSET: {
                        LABEL *label = register_label(iseq, labels_table, op);
                        argv[j] = (VALUE)label;
                        break;
                      }
                      case TS_LINDEX:
                      case TS_NUM:
                        (void)NUM2INT(op);
                        argv[j] = op;
                        break;
                      case TS_VALUE:
                        argv[j] = op;
                        iseq_add_mark_object(iseq, op);
                        break;
                      case TS_ISEQ:
                        {
                            if (op != Qnil) {
                                argv[j] = iseq_build_load_iseq(iseq, op);
                            }
                            else {
                                argv[j] = 0;
                            }
                        }
                        break;
                      case TS_GENTRY:
                        op = rb_convert_type(op, T_SYMBOL, "Symbol", "to_sym");
                        argv[j] = (VALUE)rb_global_entry(SYM2ID(op));
                        break;
                      case TS_IC:
                        argv[j] = op;
                        if (NUM2INT(op) >= iseq->is_size) {
                            iseq->is_size = NUM2INT(op) + 1;
                        }
                        break;
                      case TS_CALLINFO:
                        {
                            ID mid = 0;
                            int orig_argc = 0;
                            VALUE block = 0;
                            unsigned long flag = 0;

                            if (!NIL_P(op)) {
                                VALUE vmid = rb_hash_aref(op, ID2SYM(rb_intern("mid")));
                                VALUE vflag = rb_hash_aref(op, ID2SYM(rb_intern("flag")));
                                VALUE vorig_argc = rb_hash_aref(op, ID2SYM(rb_intern("orig_argc")));
                                VALUE vblock = rb_hash_aref(op, ID2SYM(rb_intern("blockptr")));

                                if (!NIL_P(vmid)) mid = SYM2ID(vmid);
                                if (!NIL_P(vflag)) flag = NUM2ULONG(vflag);
                                if (!NIL_P(vorig_argc)) orig_argc = FIX2INT(vorig_argc);
                                if (!NIL_P(vblock)) block = iseq_build_load_iseq(iseq, vblock);
                            }
                            argv[j] = (VALUE)new_callinfo(iseq, mid, orig_argc, block, flag);
                        }
                        break;
                      case TS_ID:
                        argv[j] = rb_convert_type(op, T_SYMBOL,
                                                  "Symbol", "to_sym");
                        break;
                      case TS_CDHASH:
                        {
                            int i;
                            op = rb_convert_type(op, T_ARRAY, "Array", "to_ary");
                            op = rb_ary_dup(op);
                            for (i=0; i<RARRAY_LEN(op); i+=2) {
                                VALUE sym = rb_ary_entry(op, i+1);
                                LABEL *label =
                                  register_label(iseq, labels_table, sym);
                                rb_ary_store(op, i+1, (VALUE)label | 1);
                            }
                            argv[j] = op;
                            iseq_add_mark_object_compile_time(iseq, op);
                        }
                        break;
                      default:
                        rb_raise(rb_eSyntaxError, "unknown operand: %c", insn_op_type((VALUE)insn_id, j));
                    }
                }
            }
            ADD_ELEM(anchor,
                     (LINK_ELEMENT*)new_insn_core(iseq, line_no,
                                                  (enum ruby_vminsn_type)insn_id, argc, argv));
        }
        else {
            rb_raise(rb_eTypeError, "unexpected object for instruction");
        }
    }
    validate_labels(iseq, labels_table);
    st_free_table(labels_table);
    iseq_setup(iseq, anchor);
    return COMPILE_OK;
}

#define CHECK_ARRAY(v)   rb_convert_type((v), T_ARRAY, "Array", "to_ary")
#define CHECK_STRING(v)  rb_convert_type((v), T_STRING, "String", "to_str")
#define CHECK_SYMBOL(v)  rb_convert_type((v), T_SYMBOL, "Symbol", "to_sym")
static inline VALUE CHECK_INTEGER(VALUE v) {(void)NUM2LONG(v); return v;}

VALUE
rb_iseq_build_from_ary(rb_iseq_t *iseq, VALUE locals, VALUE args,
                         VALUE exception, VALUE body)
{
    int i;
    ID *tbl;
    struct st_table *labels_table = st_init_numtable();
    DECL_ANCHOR(anchor);
    INIT_ANCHOR(anchor);

    iseq->local_table_size = RARRAY_LENINT(locals);
    iseq->local_table = tbl = (ID *)ALLOC_N(ID, iseq->local_table_size);
    iseq->local_size = iseq->local_table_size + 1;

    for (i=0; i<RARRAY_LEN(locals); i++) {
        VALUE lv = RARRAY_AREF(locals, i);
        tbl[i] = FIXNUM_P(lv) ? (ID)FIX2LONG(lv) : SYM2ID(CHECK_SYMBOL(lv));
    }

    /* args */
    if (FIXNUM_P(args)) {
        iseq->arg_size = iseq->argc = FIX2INT(args);
        iseq->arg_simple = 1;
    }
    else {
        int i = 0;
        VALUE argc = CHECK_INTEGER(rb_ary_entry(args, i++));
        VALUE arg_opt_labels = CHECK_ARRAY(rb_ary_entry(args, i++));
        VALUE arg_post_len = CHECK_INTEGER(rb_ary_entry(args, i++));
        VALUE arg_post_start = CHECK_INTEGER(rb_ary_entry(args, i++));
        VALUE arg_rest = CHECK_INTEGER(rb_ary_entry(args, i++));
        VALUE arg_block = CHECK_INTEGER(rb_ary_entry(args, i++));
        VALUE arg_simple = CHECK_INTEGER(rb_ary_entry(args, i++));

        iseq->argc = FIX2INT(argc);
        iseq->arg_rest = FIX2INT(arg_rest);
        iseq->arg_post_len = FIX2INT(arg_post_len);
        iseq->arg_post_start = FIX2INT(arg_post_start);
        iseq->arg_block = FIX2INT(arg_block);
        iseq->arg_opts = RARRAY_LENINT(arg_opt_labels);
        iseq->arg_opt_table = (VALUE *)ALLOC_N(VALUE, iseq->arg_opts);

        if (iseq->arg_block != -1) {
            iseq->arg_size = iseq->arg_block + 1;
        }
        else if (iseq->arg_post_len) {
            iseq->arg_size = iseq->arg_post_start + iseq->arg_post_len;
        }
        else if (iseq->arg_rest != -1) {
            iseq->arg_size = iseq->arg_rest + 1;
        }
        else {
            iseq->arg_size = iseq->argc + (iseq->arg_opts ? iseq->arg_opts - 1 : 0);
        }

        for (i=0; i<RARRAY_LEN(arg_opt_labels); i++) {
            iseq->arg_opt_table[i] =
              (VALUE)register_label(iseq, labels_table,
                                    rb_ary_entry(arg_opt_labels, i));
        }

        iseq->arg_simple = NUM2INT(arg_simple);
    }

    /* exception */
    iseq_build_from_ary_exception(iseq, labels_table, exception);

    /* body */
    iseq_build_from_ary_body(iseq, anchor, body, labels_table);
    return iseq->self;
}

/* for parser */

int
rb_dvar_defined(ID id)
{
    rb_thread_t *th = GET_THREAD();
    rb_iseq_t *iseq;
    if (th->base_block && (iseq = th->base_block->iseq)) {
        while (iseq->type == ISEQ_TYPE_BLOCK ||
               iseq->type == ISEQ_TYPE_RESCUE ||
               iseq->type == ISEQ_TYPE_ENSURE ||
               iseq->type == ISEQ_TYPE_EVAL ||
               iseq->type == ISEQ_TYPE_MAIN
               ) {
            int i;

            for (i = 0; i < iseq->local_table_size; i++) {
                if (iseq->local_table[i] == id) {
                    return 1;
                }
            }
            iseq = iseq->parent_iseq;
        }
    }
    return 0;
}

int
rb_local_defined(ID id)
{
    rb_thread_t *th = GET_THREAD();
    rb_iseq_t *iseq;

    if (th->base_block && th->base_block->iseq) {
        int i;
        iseq = th->base_block->iseq->local_iseq;

        for (i=0; i<iseq->local_table_size; i++) {
            if (iseq->local_table[i] == id) {
                return 1;
            }
        }
    }
    return 0;
}

int
rb_parse_in_eval(void)
{
    return GET_THREAD()->parse_in_eval > 0;
}

int
rb_parse_in_main(void)
{
    return GET_THREAD()->parse_in_eval < 0;
}

---