ruby--ruby/vm_insnhelper.c

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

  vm_insnhelper.c - instruction helper functions.

  $Author$

  Copyright (C) 2007 Koichi Sasada

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

/* finish iseq array */
#include "insns.inc"
#include <math.h>
#include "constant.h"
#include "internal.h"
#include "probes.h"
#include "probes_helper.h"
#include "ruby/config.h"
#include "debug_counter.h"

/* control stack frame */

static rb_control_frame_t *vm_get_ruby_level_caller_cfp(const rb_execution_context_t *ec, const rb_control_frame_t *cfp);

VALUE
ruby_vm_special_exception_copy(VALUE exc)
{
    VALUE e = rb_obj_alloc(rb_class_real(RBASIC_CLASS(exc)));
    rb_obj_copy_ivar(e, exc);
    return e;
}

NORETURN(static void threadptr_stack_overflow(rb_thread_t *, int));
static void
threadptr_stack_overflow(rb_thread_t *th, int setup)
{
    VALUE mesg = th->vm->special_exceptions[ruby_error_sysstack];
    th->ec->raised_flag = RAISED_STACKOVERFLOW;
    if (setup) {
	VALUE at = rb_threadptr_backtrace_object(th);
	mesg = ruby_vm_special_exception_copy(mesg);
	rb_ivar_set(mesg, idBt, at);
	rb_ivar_set(mesg, idBt_locations, at);
    }
    th->ec->errinfo = mesg;
    EC_JUMP_TAG(th->ec, TAG_RAISE);
}

static void
vm_stackoverflow(void)
{
    threadptr_stack_overflow(GET_THREAD(), TRUE);
}

NORETURN(void rb_threadptr_stack_overflow(rb_thread_t *th, int crit));
void
rb_threadptr_stack_overflow(rb_thread_t *th, int crit)
{
    if (crit || rb_during_gc()) {
	th->ec->raised_flag = RAISED_STACKOVERFLOW;
	th->ec->errinfo = th->vm->special_exceptions[ruby_error_stackfatal];
	EC_JUMP_TAG(th->ec, TAG_RAISE);
    }
#ifdef USE_SIGALTSTACK
    threadptr_stack_overflow(th, TRUE);
#else
    threadptr_stack_overflow(th, FALSE);
#endif
}


#if VM_CHECK_MODE > 0
static int
callable_class_p(VALUE klass)
{
#if VM_CHECK_MODE >= 2
    if (!klass) return FALSE;
    switch (RB_BUILTIN_TYPE(klass)) {
      case T_ICLASS:
	if (!RB_TYPE_P(RCLASS_SUPER(klass), T_MODULE)) break;
      case T_MODULE:
	return TRUE;
    }
    while (klass) {
	if (klass == rb_cBasicObject) {
	    return TRUE;
	}
	klass = RCLASS_SUPER(klass);
    }
    return FALSE;
#else
    return klass != 0;
#endif
}

static int
callable_method_entry_p(const rb_callable_method_entry_t *me)
{
    if (me == NULL || callable_class_p(me->defined_class)) {
	return TRUE;
    }
    else {
	return FALSE;
    }
}

static void
vm_check_frame_detail(VALUE type, int req_block, int req_me, int req_cref, VALUE specval, VALUE cref_or_me, int is_cframe, const rb_iseq_t *iseq)
{
    unsigned int magic = (unsigned int)(type & VM_FRAME_MAGIC_MASK);
    enum imemo_type cref_or_me_type = imemo_env; /* impossible value */

    if (RB_TYPE_P(cref_or_me, T_IMEMO)) {
	cref_or_me_type = imemo_type(cref_or_me);
    }
    if (type & VM_FRAME_FLAG_BMETHOD) {
	req_me = TRUE;
    }

    if (req_block && (type & VM_ENV_FLAG_LOCAL) == 0) {
	rb_bug("vm_push_frame: specval (%p) should be a block_ptr on %x frame", (void *)specval, magic);
    }
    if (!req_block && (type & VM_ENV_FLAG_LOCAL) != 0) {
	rb_bug("vm_push_frame: specval (%p) should not be a block_ptr on %x frame", (void *)specval, magic);
    }

    if (req_me) {
	if (cref_or_me_type != imemo_ment) {
	    rb_bug("vm_push_frame: (%s) should be method entry on %x frame", rb_obj_info(cref_or_me), magic);
	}
    }
    else {
	if (req_cref && cref_or_me_type != imemo_cref) {
	    rb_bug("vm_push_frame: (%s) should be CREF on %x frame", rb_obj_info(cref_or_me), magic);
	}
	else { /* cref or Qfalse */
	    if (cref_or_me != Qfalse && cref_or_me_type != imemo_cref) {
		if (((type & VM_FRAME_FLAG_LAMBDA) || magic == VM_FRAME_MAGIC_IFUNC) && (cref_or_me_type == imemo_ment)) {
		    /* ignore */
		}
		else {
		    rb_bug("vm_push_frame: (%s) should be false or cref on %x frame", rb_obj_info(cref_or_me), magic);
		}
	    }
	}
    }

    if (cref_or_me_type == imemo_ment) {
	const rb_callable_method_entry_t *me = (const rb_callable_method_entry_t *)cref_or_me;

	if (!callable_method_entry_p(me)) {
	    rb_bug("vm_push_frame: ment (%s) should be callable on %x frame.", rb_obj_info(cref_or_me), magic);
	}
    }

    if ((type & VM_FRAME_MAGIC_MASK) == VM_FRAME_MAGIC_DUMMY) {
	VM_ASSERT(iseq == NULL ||
		  RUBY_VM_NORMAL_ISEQ_P(iseq) /* argument error. it shold be fixed */);
    }
    else {
	VM_ASSERT(is_cframe == !RUBY_VM_NORMAL_ISEQ_P(iseq));
    }
}

static void
vm_check_frame(VALUE type,
	       VALUE specval,
	       VALUE cref_or_me,
	       const rb_iseq_t *iseq)
{
    VALUE given_magic = type & VM_FRAME_MAGIC_MASK;
    VM_ASSERT(FIXNUM_P(type));

#define CHECK(magic, req_block, req_me, req_cref, is_cframe) \
    case magic: \
      vm_check_frame_detail(type, req_block, req_me, req_cref, \
			    specval, cref_or_me, is_cframe, iseq); \
      break
    switch (given_magic) {
	/*                           BLK    ME     CREF   CFRAME */
	CHECK(VM_FRAME_MAGIC_METHOD, TRUE,  TRUE,  FALSE, FALSE);
	CHECK(VM_FRAME_MAGIC_CLASS,  TRUE,  FALSE, TRUE,  FALSE);
	CHECK(VM_FRAME_MAGIC_TOP,    TRUE,  FALSE, TRUE,  FALSE);
	CHECK(VM_FRAME_MAGIC_CFUNC,  TRUE,  TRUE,  FALSE, TRUE);
	CHECK(VM_FRAME_MAGIC_BLOCK,  FALSE, FALSE, FALSE, FALSE);
	CHECK(VM_FRAME_MAGIC_IFUNC,  FALSE, FALSE, FALSE, TRUE);
	CHECK(VM_FRAME_MAGIC_EVAL,   FALSE, FALSE, FALSE, FALSE);
	CHECK(VM_FRAME_MAGIC_RESCUE, FALSE, FALSE, FALSE, FALSE);
	CHECK(VM_FRAME_MAGIC_DUMMY,  TRUE,  FALSE, FALSE, FALSE);
      default:
	rb_bug("vm_push_frame: unknown type (%x)", (unsigned int)given_magic);
    }
#undef CHECK
}
#else
#define vm_check_frame(a, b, c, d)
#endif /* VM_CHECK_MODE > 0 */

static inline rb_control_frame_t *
vm_push_frame(rb_execution_context_t *ec,
	      const rb_iseq_t *iseq,
	      VALUE type,
	      VALUE self,
	      VALUE specval,
	      VALUE cref_or_me,
	      const VALUE *pc,
	      VALUE *sp,
	      int local_size,
	      int stack_max)
{
    rb_control_frame_t *const cfp = ec->cfp - 1;
    int i;

    vm_check_frame(type, specval, cref_or_me, iseq);
    VM_ASSERT(local_size >= 0);

    /* check stack overflow */
    CHECK_VM_STACK_OVERFLOW0(cfp, sp, local_size + stack_max);

    ec->cfp = cfp;

    /* setup new frame */
    cfp->pc = (VALUE *)pc;
    cfp->iseq = (rb_iseq_t *)iseq;
    cfp->self = self;
    cfp->block_code = NULL;

    /* setup vm value stack */

    /* initialize local variables */
    for (i=0; i < local_size; i++) {
	*sp++ = Qnil;
    }

    /* setup ep with managing data */
    VM_ASSERT(VM_ENV_DATA_INDEX_ME_CREF == -2);
    VM_ASSERT(VM_ENV_DATA_INDEX_SPECVAL == -1);
    VM_ASSERT(VM_ENV_DATA_INDEX_FLAGS   == -0);
    *sp++ = cref_or_me; /* ep[-2] / Qnil or T_IMEMO(cref) or T_IMEMO(ment) */
    *sp++ = specval     /* ep[-1] / block handler or prev env ptr */;
    *sp   = type;       /* ep[-0] / ENV_FLAGS */

    cfp->ep = sp;
    cfp->sp = sp + 1;

#if VM_DEBUG_BP_CHECK
    cfp->bp_check = sp + 1;
#endif

    if (VMDEBUG == 2) {
	SDR();
    }

    return cfp;
}

rb_control_frame_t *
rb_vm_push_frame(rb_execution_context_t *ec,
		 const rb_iseq_t *iseq,
		 VALUE type,
		 VALUE self,
		 VALUE specval,
		 VALUE cref_or_me,
		 const VALUE *pc,
		 VALUE *sp,
		 int local_size,
		 int stack_max)
{
    return vm_push_frame(ec, iseq, type, self, specval, cref_or_me, pc, sp, local_size, stack_max);
}

/* return TRUE if the frame is finished */
static inline int
vm_pop_frame(rb_execution_context_t *ec, rb_control_frame_t *cfp, const VALUE *ep)
{
    VALUE flags = ep[VM_ENV_DATA_INDEX_FLAGS];

    if (VM_CHECK_MODE >= 4) rb_gc_verify_internal_consistency();
    if (VMDEBUG == 2)       SDR();

    ec->cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);

    return flags & VM_FRAME_FLAG_FINISH;
}

void
rb_vm_pop_frame(rb_execution_context_t *ec)
{
    vm_pop_frame(ec, ec->cfp, ec->cfp->ep);
}

/* method dispatch */
static inline VALUE
rb_arity_error_new(int argc, int min, int max)
{
    VALUE err_mess = 0;
    if (min == max) {
	err_mess = rb_sprintf("wrong number of arguments (given %d, expected %d)", argc, min);
    }
    else if (max == UNLIMITED_ARGUMENTS) {
	err_mess = rb_sprintf("wrong number of arguments (given %d, expected %d+)", argc, min);
    }
    else {
	err_mess = rb_sprintf("wrong number of arguments (given %d, expected %d..%d)", argc, min, max);
    }
    return rb_exc_new3(rb_eArgError, err_mess);
}

void
rb_error_arity(int argc, int min, int max)
{
    rb_exc_raise(rb_arity_error_new(argc, min, max));
}

/* lvar */

NOINLINE(static void vm_env_write_slowpath(const VALUE *ep, int index, VALUE v));

static void
vm_env_write_slowpath(const VALUE *ep, int index, VALUE v)
{
    /* remember env value forcely */
    rb_gc_writebarrier_remember(VM_ENV_ENVVAL(ep));
    VM_FORCE_WRITE(&ep[index], v);
    VM_ENV_FLAGS_UNSET(ep, VM_ENV_FLAG_WB_REQUIRED);
    RB_DEBUG_COUNTER_INC(lvar_set_slowpath);
}

static inline void
vm_env_write(const VALUE *ep, int index, VALUE v)
{
    VALUE flags = ep[VM_ENV_DATA_INDEX_FLAGS];
    if (LIKELY((flags & VM_ENV_FLAG_WB_REQUIRED) == 0)) {
	VM_STACK_ENV_WRITE(ep, index, v);
    }
    else {
	vm_env_write_slowpath(ep, index, v);
    }
}

void
rb_vm_env_write(const VALUE *ep, int index, VALUE v)
{
    vm_env_write(ep, index, v);
}

VALUE
rb_vm_bh_to_procval(rb_execution_context_t *ec, VALUE block_handler)
{
    if (block_handler == VM_BLOCK_HANDLER_NONE) {
	return Qnil;
    }
    else {
	switch (vm_block_handler_type(block_handler)) {
	  case block_handler_type_iseq:
	  case block_handler_type_ifunc:
	    return rb_vm_make_proc(ec, VM_BH_TO_CAPT_BLOCK(block_handler), rb_cProc);
	  case block_handler_type_symbol:
	    return rb_sym_to_proc(VM_BH_TO_SYMBOL(block_handler));
	  case block_handler_type_proc:
	    return VM_BH_TO_PROC(block_handler);
	  default:
	    VM_UNREACHABLE(rb_vm_bh_to_procval);
	}
    }
}

/* svar */

#if VM_CHECK_MODE > 0
static int
vm_svar_valid_p(VALUE svar)
{
    if (RB_TYPE_P((VALUE)svar, T_IMEMO)) {
	switch (imemo_type(svar)) {
	  case imemo_svar:
	  case imemo_cref:
	  case imemo_ment:
	    return TRUE;
	  default:
	    break;
	}
    }
    rb_bug("vm_svar_valid_p: unknown type: %s", rb_obj_info(svar));
    return FALSE;
}
#endif

static inline struct vm_svar *
lep_svar(rb_thread_t *th, const VALUE *lep)
{
    VALUE svar;

    if (lep && (th == NULL || th->ec->root_lep != lep)) {
	svar = lep[VM_ENV_DATA_INDEX_ME_CREF];
    }
    else {
	svar = th->ec->root_svar;
    }

    VM_ASSERT(svar == Qfalse || vm_svar_valid_p(svar));

    return (struct vm_svar *)svar;
}

static inline void
lep_svar_write(rb_thread_t *th, const VALUE *lep, const struct vm_svar *svar)
{
    VM_ASSERT(vm_svar_valid_p((VALUE)svar));

    if (lep && (th == NULL || th->ec->root_lep != lep)) {
	vm_env_write(lep, VM_ENV_DATA_INDEX_ME_CREF, (VALUE)svar);
    }
    else {
	RB_OBJ_WRITE(th->self, &th->ec->root_svar, svar);
    }
}

static VALUE
lep_svar_get(rb_thread_t *th, const VALUE *lep, rb_num_t key)
{
    const struct vm_svar *svar = lep_svar(th, lep);

    if ((VALUE)svar == Qfalse || imemo_type((VALUE)svar) != imemo_svar) return Qnil;

    switch (key) {
      case VM_SVAR_LASTLINE:
	return svar->lastline;
      case VM_SVAR_BACKREF:
	return svar->backref;
      default: {
	const VALUE ary = svar->others;

	if (NIL_P(ary)) {
	    return Qnil;
	}
	else {
	    return rb_ary_entry(ary, key - VM_SVAR_EXTRA_START);
	}
      }
    }
}

static struct vm_svar *
svar_new(VALUE obj)
{
    return (struct vm_svar *)rb_imemo_new(imemo_svar, Qnil, Qnil, Qnil, obj);
}

static void
lep_svar_set(rb_thread_t *th, const VALUE *lep, rb_num_t key, VALUE val)
{
    struct vm_svar *svar = lep_svar(th, lep);

    if ((VALUE)svar == Qfalse || imemo_type((VALUE)svar) != imemo_svar) {
	lep_svar_write(th, lep, svar = svar_new((VALUE)svar));
    }

    switch (key) {
      case VM_SVAR_LASTLINE:
	RB_OBJ_WRITE(svar, &svar->lastline, val);
	return;
      case VM_SVAR_BACKREF:
	RB_OBJ_WRITE(svar, &svar->backref, val);
	return;
      default: {
	VALUE ary = svar->others;

	if (NIL_P(ary)) {
	    RB_OBJ_WRITE(svar, &svar->others, ary = rb_ary_new());
	}
	rb_ary_store(ary, key - VM_SVAR_EXTRA_START, val);
      }
    }
}

static inline VALUE
vm_getspecial(rb_thread_t *th, const VALUE *lep, rb_num_t key, rb_num_t type)
{
    VALUE val;

    if (type == 0) {
	val = lep_svar_get(th, lep, key);
    }
    else {
	VALUE backref = lep_svar_get(th, lep, VM_SVAR_BACKREF);

	if (type & 0x01) {
	    switch (type >> 1) {
	      case '&':
		val = rb_reg_last_match(backref);
		break;
	      case '`':
		val = rb_reg_match_pre(backref);
		break;
	      case '\'':
		val = rb_reg_match_post(backref);
		break;
	      case '+':
		val = rb_reg_match_last(backref);
		break;
	      default:
		rb_bug("unexpected back-ref");
	    }
	}
	else {
	    val = rb_reg_nth_match((int)(type >> 1), backref);
	}
    }
    return val;
}

PUREFUNC(static rb_callable_method_entry_t *check_method_entry(VALUE obj, int can_be_svar));
static rb_callable_method_entry_t *
check_method_entry(VALUE obj, int can_be_svar)
{
    if (obj == Qfalse) return NULL;

#if VM_CHECK_MODE > 0
    if (!RB_TYPE_P(obj, T_IMEMO)) rb_bug("check_method_entry: unknown type: %s", rb_obj_info(obj));
#endif

    switch (imemo_type(obj)) {
      case imemo_ment:
	return (rb_callable_method_entry_t *)obj;
      case imemo_cref:
	return NULL;
      case imemo_svar:
	if (can_be_svar) {
	    return check_method_entry(((struct vm_svar *)obj)->cref_or_me, FALSE);
	}
      default:
#if VM_CHECK_MODE > 0
	rb_bug("check_method_entry: svar should not be there:");
#endif
	return NULL;
    }
}

const rb_callable_method_entry_t *
rb_vm_frame_method_entry(const rb_control_frame_t *cfp)
{
    const VALUE *ep = cfp->ep;
    rb_callable_method_entry_t *me;

    while (!VM_ENV_LOCAL_P(ep)) {
	if ((me = check_method_entry(ep[VM_ENV_DATA_INDEX_ME_CREF], FALSE)) != NULL) return me;
	ep = VM_ENV_PREV_EP(ep);
    }

    return check_method_entry(ep[VM_ENV_DATA_INDEX_ME_CREF], TRUE);
}

static rb_cref_t *
method_entry_cref(rb_callable_method_entry_t *me)
{
    switch (me->def->type) {
      case VM_METHOD_TYPE_ISEQ:
	return me->def->body.iseq.cref;
      default:
	return NULL;
    }
}

#if VM_CHECK_MODE == 0
PUREFUNC(static rb_cref_t *check_cref(VALUE, int));
#endif
static rb_cref_t *
check_cref(VALUE obj, int can_be_svar)
{
    if (obj == Qfalse) return NULL;

#if VM_CHECK_MODE > 0
    if (!RB_TYPE_P(obj, T_IMEMO)) rb_bug("check_cref: unknown type: %s", rb_obj_info(obj));
#endif

    switch (imemo_type(obj)) {
      case imemo_ment:
	return method_entry_cref((rb_callable_method_entry_t *)obj);
      case imemo_cref:
	return (rb_cref_t *)obj;
      case imemo_svar:
	if (can_be_svar) {
	    return check_cref(((struct vm_svar *)obj)->cref_or_me, FALSE);
	}
      default:
#if VM_CHECK_MODE > 0
	rb_bug("check_method_entry: svar should not be there:");
#endif
	return NULL;
    }
}

static inline rb_cref_t *
vm_env_cref(const VALUE *ep)
{
    rb_cref_t *cref;

    while (!VM_ENV_LOCAL_P(ep)) {
	if ((cref = check_cref(ep[VM_ENV_DATA_INDEX_ME_CREF], FALSE)) != NULL) return cref;
	ep = VM_ENV_PREV_EP(ep);
    }

    return check_cref(ep[VM_ENV_DATA_INDEX_ME_CREF], TRUE);
}

static int
is_cref(const VALUE v, int can_be_svar)
{
    if (RB_TYPE_P(v, T_IMEMO)) {
	switch (imemo_type(v)) {
	  case imemo_cref:
	    return TRUE;
	  case imemo_svar:
	    if (can_be_svar) return is_cref(((struct vm_svar *)v)->cref_or_me, FALSE);
	  default:
	    break;
	}
    }
    return FALSE;
}

static int
vm_env_cref_by_cref(const VALUE *ep)
{
    while (!VM_ENV_LOCAL_P(ep)) {
	if (is_cref(ep[VM_ENV_DATA_INDEX_ME_CREF], FALSE)) return TRUE;
	ep = VM_ENV_PREV_EP(ep);
    }
    return is_cref(ep[VM_ENV_DATA_INDEX_ME_CREF], TRUE);
}

static rb_cref_t *
cref_replace_with_duplicated_cref_each_frame(const VALUE *vptr, int can_be_svar, VALUE parent)
{
    const VALUE v = *vptr;
    rb_cref_t *cref, *new_cref;

    if (RB_TYPE_P(v, T_IMEMO)) {
	switch (imemo_type(v)) {
	  case imemo_cref:
	    cref = (rb_cref_t *)v;
	    new_cref = vm_cref_dup(cref);
	    if (parent) {
		RB_OBJ_WRITE(parent, vptr, new_cref);
	    }
	    else {
		VM_FORCE_WRITE(vptr, (VALUE)new_cref);
	    }
	    return (rb_cref_t *)new_cref;
	  case imemo_svar:
	    if (can_be_svar) {
		return cref_replace_with_duplicated_cref_each_frame((const VALUE *)&((struct vm_svar *)v)->cref_or_me, FALSE, v);
	    }
	  case imemo_ment:
	    rb_bug("cref_replace_with_duplicated_cref_each_frame: unreachable");
	  default:
	    break;
	}
    }
    return FALSE;
}

static rb_cref_t *
vm_cref_replace_with_duplicated_cref(const VALUE *ep)
{
    if (vm_env_cref_by_cref(ep)) {
	rb_cref_t *cref;
	VALUE envval;

	while (!VM_ENV_LOCAL_P(ep)) {
	    envval = VM_ENV_ESCAPED_P(ep) ? VM_ENV_ENVVAL(ep) : Qfalse;
	    if ((cref = cref_replace_with_duplicated_cref_each_frame(&ep[VM_ENV_DATA_INDEX_ME_CREF], FALSE, envval)) != NULL) {
		return cref;
	    }
	    ep = VM_ENV_PREV_EP(ep);
	}
	envval = VM_ENV_ESCAPED_P(ep) ? VM_ENV_ENVVAL(ep) : Qfalse;
	return cref_replace_with_duplicated_cref_each_frame(&ep[VM_ENV_DATA_INDEX_ME_CREF], TRUE, envval);
    }
    else {
	rb_bug("vm_cref_dup: unreachable");
    }
}


static rb_cref_t *
rb_vm_get_cref(const VALUE *ep)
{
    rb_cref_t *cref = vm_env_cref(ep);

    if (cref != NULL) {
	return cref;
    }
    else {
	rb_bug("rb_vm_get_cref: unreachable");
    }
}

static const rb_cref_t *
vm_get_const_key_cref(const VALUE *ep)
{
    const rb_cref_t *cref = rb_vm_get_cref(ep);
    const rb_cref_t *key_cref = cref;

    while (cref) {
	if (FL_TEST(CREF_CLASS(cref), FL_SINGLETON)) {
	    return key_cref;
	}
	cref = CREF_NEXT(cref);
    }

    /* does not include singleton class */
    return NULL;
}

void
rb_vm_rewrite_cref(rb_cref_t *cref, VALUE old_klass, VALUE new_klass, rb_cref_t **new_cref_ptr)
{
    rb_cref_t *new_cref;

    while (cref) {
	if (CREF_CLASS(cref) == old_klass) {
	    new_cref = vm_cref_new_use_prev(new_klass, METHOD_VISI_UNDEF, FALSE, cref, FALSE);
	    *new_cref_ptr = new_cref;
	    return;
	}
	new_cref = vm_cref_new_use_prev(CREF_CLASS(cref), METHOD_VISI_UNDEF, FALSE, cref, FALSE);
	cref = CREF_NEXT(cref);
	*new_cref_ptr = new_cref;
	new_cref_ptr = (rb_cref_t **)&new_cref->next;
    }
    *new_cref_ptr = NULL;
}

static rb_cref_t *
vm_cref_push(rb_thread_t *th, VALUE klass, const VALUE *ep, int pushed_by_eval)
{
    rb_cref_t *prev_cref = NULL;

    if (ep) {
	prev_cref = vm_env_cref(ep);
    }
    else {
	rb_control_frame_t *cfp = vm_get_ruby_level_caller_cfp(th->ec, th->ec->cfp);

	if (cfp) {
	    prev_cref = vm_env_cref(cfp->ep);
	}
    }

    return vm_cref_new(klass, METHOD_VISI_PUBLIC, FALSE, prev_cref, pushed_by_eval);
}

static inline VALUE
vm_get_cbase(const VALUE *ep)
{
    const rb_cref_t *cref = rb_vm_get_cref(ep);
    VALUE klass = Qundef;

    while (cref) {
	if ((klass = CREF_CLASS(cref)) != 0) {
	    break;
	}
	cref = CREF_NEXT(cref);
    }

    return klass;
}

static inline VALUE
vm_get_const_base(const VALUE *ep)
{
    const rb_cref_t *cref = rb_vm_get_cref(ep);
    VALUE klass = Qundef;

    while (cref) {
	if (!CREF_PUSHED_BY_EVAL(cref) &&
	    (klass = CREF_CLASS(cref)) != 0) {
	    break;
	}
	cref = CREF_NEXT(cref);
    }

    return klass;
}

static inline void
vm_check_if_namespace(VALUE klass)
{
    if (!RB_TYPE_P(klass, T_CLASS) && !RB_TYPE_P(klass, T_MODULE)) {
	rb_raise(rb_eTypeError, "%+"PRIsVALUE" is not a class/module", klass);
    }
}

static inline void
vm_ensure_not_refinement_module(VALUE self)
{
    if (RB_TYPE_P(self, T_MODULE) && FL_TEST(self, RMODULE_IS_REFINEMENT)) {
	rb_warn("not defined at the refinement, but at the outer class/module");
    }
}

static inline VALUE
vm_get_iclass(rb_control_frame_t *cfp, VALUE klass)
{
    return klass;
}

static inline VALUE
vm_get_ev_const(rb_thread_t *th, VALUE orig_klass, ID id, int is_defined)
{
    void rb_const_warn_if_deprecated(const rb_const_entry_t *ce, VALUE klass, ID id);
    VALUE val;

    if (orig_klass == Qnil) {
	/* in current lexical scope */
	const rb_cref_t *root_cref = rb_vm_get_cref(th->ec->cfp->ep);
	const rb_cref_t *cref;
	VALUE klass = Qnil;

	while (root_cref && CREF_PUSHED_BY_EVAL(root_cref)) {
	    root_cref = CREF_NEXT(root_cref);
	}
	cref = root_cref;
	while (cref && CREF_NEXT(cref)) {
	    if (CREF_PUSHED_BY_EVAL(cref)) {
		klass = Qnil;
	    }
	    else {
		klass = CREF_CLASS(cref);
	    }
	    cref = CREF_NEXT(cref);

	    if (!NIL_P(klass)) {
		VALUE av, am = 0;
		rb_const_entry_t *ce;
	      search_continue:
		if ((ce = rb_const_lookup(klass, id))) {
		    rb_const_warn_if_deprecated(ce, klass, id);
		    val = ce->value;
		    if (val == Qundef) {
			if (am == klass) break;
			am = klass;
			if (is_defined) return 1;
			if (rb_autoloading_value(klass, id, &av)) return av;
			rb_autoload_load(klass, id);
			goto search_continue;
		    }
		    else {
			if (is_defined) {
			    return 1;
			}
			else {
			    return val;
			}
		    }
		}
	    }
	}

	/* search self */
	if (root_cref && !NIL_P(CREF_CLASS(root_cref))) {
	    klass = vm_get_iclass(th->ec->cfp, CREF_CLASS(root_cref));
	}
	else {
	    klass = CLASS_OF(th->ec->cfp->self);
	}

	if (is_defined) {
	    return rb_const_defined(klass, id);
	}
	else {
	    return rb_const_get(klass, id);
	}
    }
    else {
	vm_check_if_namespace(orig_klass);
	if (is_defined) {
	    return rb_public_const_defined_from(orig_klass, id);
	}
	else {
	    return rb_public_const_get_from(orig_klass, id);
	}
    }
}

static inline VALUE
vm_get_cvar_base(const rb_cref_t *cref, rb_control_frame_t *cfp)
{
    VALUE klass;

    if (!cref) {
	rb_bug("vm_get_cvar_base: no cref");
    }

    while (CREF_NEXT(cref) &&
	   (NIL_P(CREF_CLASS(cref)) || FL_TEST(CREF_CLASS(cref), FL_SINGLETON) ||
	    CREF_PUSHED_BY_EVAL(cref))) {
	cref = CREF_NEXT(cref);
    }
    if (!CREF_NEXT(cref)) {
	rb_warn("class variable access from toplevel");
    }

    klass = vm_get_iclass(cfp, CREF_CLASS(cref));

    if (NIL_P(klass)) {
	rb_raise(rb_eTypeError, "no class variables available");
    }
    return klass;
}

static VALUE
vm_search_const_defined_class(const VALUE cbase, ID id)
{
    if (rb_const_defined_at(cbase, id)) return cbase;
    if (cbase == rb_cObject) {
	VALUE tmp = RCLASS_SUPER(cbase);
	while (tmp) {
	    if (rb_const_defined_at(tmp, id)) return tmp;
	    tmp = RCLASS_SUPER(tmp);
	}
    }
    return 0;
}

#ifndef USE_IC_FOR_IVAR
#define USE_IC_FOR_IVAR 1
#endif

ALWAYS_INLINE(static VALUE vm_getivar(VALUE, ID, IC, struct rb_call_cache *, int));
static inline VALUE
vm_getivar(VALUE obj, ID id, IC ic, struct rb_call_cache *cc, int is_attr)
{
#if USE_IC_FOR_IVAR
    if (LIKELY(RB_TYPE_P(obj, T_OBJECT))) {
	VALUE val = Qundef;
	if (LIKELY(is_attr ?
		   RB_DEBUG_COUNTER_INC_UNLESS(ivar_get_ic_miss_unset, cc->aux.index > 0) :
		   RB_DEBUG_COUNTER_INC_UNLESS(ivar_get_ic_miss_serial,
					       ic->ic_serial == RCLASS_SERIAL(RBASIC(obj)->klass)))) {
	    st_index_t index = !is_attr ? ic->ic_value.index : (cc->aux.index - 1);
	    if (LIKELY(index < ROBJECT_NUMIV(obj))) {
		val = ROBJECT_IVPTR(obj)[index];
	    }
	  undef_check:
	    if (UNLIKELY(val == Qundef)) {
		if (!is_attr && RTEST(ruby_verbose))
		    rb_warning("instance variable %"PRIsVALUE" not initialized", QUOTE_ID(id));
		val = Qnil;
	    }
	    RB_DEBUG_COUNTER_INC(ivar_get_ic_hit);
	    return val;
	}
	else {
	    st_data_t index;
	    struct st_table *iv_index_tbl = ROBJECT_IV_INDEX_TBL(obj);

	    if (iv_index_tbl) {
		if (st_lookup(iv_index_tbl, id, &index)) {
		    if (index < ROBJECT_NUMIV(obj)) {
			val = ROBJECT_IVPTR(obj)[index];
		    }
		    if (!is_attr) {
			ic->ic_value.index = index;
			ic->ic_serial = RCLASS_SERIAL(RBASIC(obj)->klass);
		    }
		    else { /* call_info */
			cc->aux.index = (int)index + 1;
		    }
		}
	    }
	    goto undef_check;
	}
    }
    else {
	RB_DEBUG_COUNTER_INC(ivar_get_ic_miss_noobject);
    }
#endif	/* USE_IC_FOR_IVAR */
    RB_DEBUG_COUNTER_INC(ivar_get_ic_miss);

    if (is_attr)
	return rb_attr_get(obj, id);
    return rb_ivar_get(obj, id);
}

static inline VALUE
vm_setivar(VALUE obj, ID id, VALUE val, IC ic, struct rb_call_cache *cc, int is_attr)
{
#if USE_IC_FOR_IVAR
    rb_check_frozen(obj);

    if (LIKELY(RB_TYPE_P(obj, T_OBJECT))) {
	VALUE klass = RBASIC(obj)->klass;
	st_data_t index;

	if (LIKELY(
	    (!is_attr && RB_DEBUG_COUNTER_INC_UNLESS(ivar_set_ic_miss_serial, ic->ic_serial == RCLASS_SERIAL(klass))) ||
	    ( is_attr && RB_DEBUG_COUNTER_INC_UNLESS(ivar_set_ic_miss_unset, cc->aux.index > 0)))) {
	    VALUE *ptr = ROBJECT_IVPTR(obj);
	    index = !is_attr ? ic->ic_value.index : cc->aux.index-1;

	    if (RB_DEBUG_COUNTER_INC_UNLESS(ivar_set_ic_miss_oorange, index < ROBJECT_NUMIV(obj))) {
		RB_OBJ_WRITE(obj, &ptr[index], val);
		RB_DEBUG_COUNTER_INC(ivar_set_ic_hit);
		return val; /* inline cache hit */
	    }
	}
	else {
	    struct st_table *iv_index_tbl = ROBJECT_IV_INDEX_TBL(obj);

	    if (iv_index_tbl && st_lookup(iv_index_tbl, (st_data_t)id, &index)) {
		if (!is_attr) {
		    ic->ic_value.index = index;
		    ic->ic_serial = RCLASS_SERIAL(klass);
		}
		else if (index >= INT_MAX) {
		    rb_raise(rb_eArgError, "too many instance variables");
		}
		else {
		    cc->aux.index = (int)(index + 1);
		}
	    }
	    /* fall through */
	}
    }
    else {
	RB_DEBUG_COUNTER_INC(ivar_set_ic_miss_noobject);
    }
#endif	/* USE_IC_FOR_IVAR */
    RB_DEBUG_COUNTER_INC(ivar_set_ic_miss);
    return rb_ivar_set(obj, id, val);
}

static inline VALUE
vm_getinstancevariable(VALUE obj, ID id, IC ic)
{
    return vm_getivar(obj, id, ic, 0, 0);
}

static inline void
vm_setinstancevariable(VALUE obj, ID id, VALUE val, IC ic)
{
    vm_setivar(obj, id, val, ic, 0, 0);
}

static VALUE
vm_throw_continue(rb_thread_t *th, VALUE err)
{
    /* continue throw */

    if (FIXNUM_P(err)) {
	th->ec->tag->state = FIX2INT(err);
    }
    else if (SYMBOL_P(err)) {
	th->ec->tag->state = TAG_THROW;
    }
    else if (THROW_DATA_P(err)) {
	th->ec->tag->state = THROW_DATA_STATE((struct vm_throw_data *)err);
    }
    else {
	th->ec->tag->state = TAG_RAISE;
    }
    return err;
}

static VALUE
vm_throw_start(rb_thread_t *const th, rb_control_frame_t *const reg_cfp, enum ruby_tag_type state,
	       const int flag, const rb_num_t level, const VALUE throwobj)
{
    const rb_control_frame_t *escape_cfp = NULL;
    const rb_control_frame_t * const eocfp = RUBY_VM_END_CONTROL_FRAME(th->ec); /* end of control frame pointer */

    if (flag != 0) {
	/* do nothing */
    }
    else if (state == TAG_BREAK) {
	int is_orphan = 1;
	const VALUE *ep = GET_EP();
	const rb_iseq_t *base_iseq = GET_ISEQ();
	escape_cfp = reg_cfp;

	while (base_iseq->body->type != ISEQ_TYPE_BLOCK) {
	    if (escape_cfp->iseq->body->type == ISEQ_TYPE_CLASS) {
		escape_cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(escape_cfp);
		ep = escape_cfp->ep;
		base_iseq = escape_cfp->iseq;
	    }
	    else {
		ep = VM_ENV_PREV_EP(ep);
		base_iseq = base_iseq->body->parent_iseq;
		escape_cfp = rb_vm_search_cf_from_ep(th->ec, escape_cfp, ep);
		VM_ASSERT(escape_cfp->iseq == base_iseq);
	    }
	}

	if (VM_FRAME_LAMBDA_P(escape_cfp)) {
	    /* lambda{... break ...} */
	    is_orphan = 0;
	    state = TAG_RETURN;
	}
	else {
	    ep = VM_ENV_PREV_EP(ep);

	    while (escape_cfp < eocfp) {
		if (escape_cfp->ep == ep) {
		    const rb_iseq_t *const iseq = escape_cfp->iseq;
		    const VALUE epc = escape_cfp->pc - iseq->body->iseq_encoded;
		    const struct iseq_catch_table *const ct = iseq->body->catch_table;
		    unsigned int i;

		    if (!ct) break;
		    for (i=0; i < ct->size; i++) {
			const struct iseq_catch_table_entry * const entry = &ct->entries[i];

			if (entry->type == CATCH_TYPE_BREAK &&
			    entry->iseq == base_iseq &&
			    entry->start < epc && entry->end >= epc) {
			    if (entry->cont == epc) { /* found! */
				is_orphan = 0;
			    }
			    break;
			}
		    }
		    break;
		}

		escape_cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(escape_cfp);
	    }
	}

	if (is_orphan) {
	    rb_vm_localjump_error("break from proc-closure", throwobj, TAG_BREAK);
	}
    }
    else if (state == TAG_RETRY) {
	rb_num_t i;
	const VALUE *ep = VM_ENV_PREV_EP(GET_EP());

	for (i = 0; i < level; i++) {
	    ep = VM_ENV_PREV_EP(ep);
	}

	escape_cfp = rb_vm_search_cf_from_ep(th->ec, reg_cfp, ep);
    }
    else if (state == TAG_RETURN) {
	const VALUE *current_ep = GET_EP();
	const VALUE *target_lep = VM_EP_LEP(current_ep);
	int in_class_frame = 0;
	int toplevel = 1;
	escape_cfp = reg_cfp;

	while (escape_cfp < eocfp) {
	    const VALUE *lep = VM_CF_LEP(escape_cfp);

	    if (!target_lep) {
		target_lep = lep;
	    }

	    if (lep == target_lep &&
		VM_FRAME_RUBYFRAME_P(escape_cfp) &&
		escape_cfp->iseq->body->type == ISEQ_TYPE_CLASS) {
		in_class_frame = 1;
		target_lep = 0;
	    }

	    if (lep == target_lep) {
		if (VM_FRAME_LAMBDA_P(escape_cfp)) {
		    toplevel = 0;
		    if (in_class_frame) {
			/* lambda {class A; ... return ...; end} */
			goto valid_return;
		    }
		    else {
			const VALUE *tep = current_ep;

			while (target_lep != tep) {
			    if (escape_cfp->ep == tep) {
				/* in lambda */
				goto valid_return;
			    }
			    tep = VM_ENV_PREV_EP(tep);
			}
		    }
		}
		else if (VM_FRAME_RUBYFRAME_P(escape_cfp)) {
		    switch (escape_cfp->iseq->body->type) {
		      case ISEQ_TYPE_TOP:
		      case ISEQ_TYPE_MAIN:
			if (toplevel) goto valid_return;
			break;
		      case ISEQ_TYPE_EVAL:
		      case ISEQ_TYPE_CLASS:
			toplevel = 0;
			break;
		      default:
			break;
		    }
		}
	    }

	    if (escape_cfp->ep == target_lep && escape_cfp->iseq->body->type == ISEQ_TYPE_METHOD) {
		goto valid_return;
	    }

	    escape_cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(escape_cfp);
	}
	rb_vm_localjump_error("unexpected return", throwobj, TAG_RETURN);

      valid_return:;
	/* do nothing */
    }
    else {
	rb_bug("isns(throw): unsupport throw type");
    }

    th->ec->tag->state = state;
    return (VALUE)THROW_DATA_NEW(throwobj, escape_cfp, state);
}

static VALUE
vm_throw(rb_thread_t *th, rb_control_frame_t *reg_cfp,
	 rb_num_t throw_state, VALUE throwobj)
{
    const int state = (int)(throw_state & VM_THROW_STATE_MASK);
    const int flag = (int)(throw_state & VM_THROW_NO_ESCAPE_FLAG);
    const rb_num_t level = throw_state >> VM_THROW_LEVEL_SHIFT;

    if (state != 0) {
	return vm_throw_start(th, reg_cfp, state, flag, level, throwobj);
    }
    else {
	return vm_throw_continue(th, throwobj);
    }
}

static inline void
vm_expandarray(rb_control_frame_t *cfp, VALUE ary, rb_num_t num, int flag)
{
    int is_splat = flag & 0x01;
    rb_num_t space_size = num + is_splat;
    VALUE *base = cfp->sp;
    const VALUE *ptr;
    rb_num_t len;

    if (!RB_TYPE_P(ary, T_ARRAY)) {
	ary = rb_ary_to_ary(ary);
    }

    cfp->sp += space_size;

    ptr = RARRAY_CONST_PTR(ary);
    len = (rb_num_t)RARRAY_LEN(ary);

    if (flag & 0x02) {
	/* post: ..., nil ,ary[-1], ..., ary[0..-num] # top */
	rb_num_t i = 0, j;

	if (len < num) {
	    for (i=0; i<num-len; i++) {
		*base++ = Qnil;
	    }
	}
	for (j=0; i<num; i++, j++) {
	    VALUE v = ptr[len - j - 1];
	    *base++ = v;
	}
	if (is_splat) {
	    *base = rb_ary_new4(len - j, ptr);
	}
    }
    else {
	/* normal: ary[num..-1], ary[num-2], ary[num-3], ..., ary[0] # top */
	rb_num_t i;
	VALUE *bptr = &base[space_size - 1];

	for (i=0; i<num; i++) {
	    if (len <= i) {
		for (; i<num; i++) {
		    *bptr-- = Qnil;
		}
		break;
	    }
	    *bptr-- = ptr[i];
	}
	if (is_splat) {
	    if (num > len) {
		*bptr = rb_ary_new();
	    }
	    else {
		*bptr = rb_ary_new4(len - num, ptr + num);
	    }
	}
    }
    RB_GC_GUARD(ary);
}

static VALUE vm_call_general(rb_thread_t *th, rb_control_frame_t *reg_cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc);

static void
vm_search_method(const struct rb_call_info *ci, struct rb_call_cache *cc, VALUE recv)
{
    VALUE klass = CLASS_OF(recv);

#if OPT_INLINE_METHOD_CACHE
    if (LIKELY(RB_DEBUG_COUNTER_INC_UNLESS(mc_global_state_miss,
					   GET_GLOBAL_METHOD_STATE() == cc->method_state) &&
	       RB_DEBUG_COUNTER_INC_UNLESS(mc_class_serial_miss,
					   RCLASS_SERIAL(klass) == cc->class_serial))) {
	/* cache hit! */
	VM_ASSERT(cc->call != NULL);
	RB_DEBUG_COUNTER_INC(mc_inline_hit);
	return;
    }
    RB_DEBUG_COUNTER_INC(mc_inline_miss);
#endif
    cc->me = rb_callable_method_entry(klass, ci->mid);
    VM_ASSERT(callable_method_entry_p(cc->me));
    cc->call = vm_call_general;
#if OPT_INLINE_METHOD_CACHE
    cc->method_state = GET_GLOBAL_METHOD_STATE();
    cc->class_serial = RCLASS_SERIAL(klass);
#endif
}

static inline int
check_cfunc(const rb_callable_method_entry_t *me, VALUE (*func)())
{
    if (me && me->def->type == VM_METHOD_TYPE_CFUNC &&
	me->def->body.cfunc.func == func) {
	return 1;
    }
    else {
	return 0;
    }
}

static inline int
vm_method_cfunc_is(CALL_INFO ci, CALL_CACHE cc,
		   VALUE recv, VALUE (*func)())
{
    vm_search_method(ci, cc, recv);
    return check_cfunc(cc->me, func);
}

static VALUE
opt_equal_fallback(VALUE recv, VALUE obj, CALL_INFO ci, CALL_CACHE cc)
{
    if (vm_method_cfunc_is(ci, cc, recv, rb_obj_equal)) {
	return recv == obj ? Qtrue : Qfalse;
    }

    return Qundef;
}

#define BUILTIN_CLASS_P(x, k) (!SPECIAL_CONST_P(x) && RBASIC_CLASS(x) == k)
#define EQ_UNREDEFINED_P(t) BASIC_OP_UNREDEFINED_P(BOP_EQ, t##_REDEFINED_OP_FLAG)

/* 1: compare by identity, 0: not applicable, -1: redefined */
static inline int
comparable_by_identity(VALUE recv, VALUE obj)
{
    if (FIXNUM_2_P(recv, obj)) {
	return (EQ_UNREDEFINED_P(INTEGER) != 0) * 2 - 1;
    }
    if (FLONUM_2_P(recv, obj)) {
	return (EQ_UNREDEFINED_P(FLOAT) != 0) * 2 - 1;
    }
    if (SYMBOL_P(recv) && SYMBOL_P(obj)) {
	return (EQ_UNREDEFINED_P(SYMBOL) != 0) * 2 - 1;
    }
    return 0;
}

static
#ifndef NO_BIG_INLINE
inline
#endif
VALUE
opt_eq_func(VALUE recv, VALUE obj, CALL_INFO ci, CALL_CACHE cc)
{
    switch (comparable_by_identity(recv, obj)) {
      case 1:
	return (recv == obj) ? Qtrue : Qfalse;
      case -1:
	goto fallback;
    }
    if (0) {
    }
    else if (BUILTIN_CLASS_P(recv, rb_cFloat)) {
	if (EQ_UNREDEFINED_P(FLOAT)) {
	    return rb_float_equal(recv, obj);
	}
    }
    else if (BUILTIN_CLASS_P(recv, rb_cString)) {
	if (EQ_UNREDEFINED_P(STRING)) {
	    return rb_str_equal(recv, obj);
	}
    }

  fallback:
    return opt_equal_fallback(recv, obj, ci, cc);
}

static
#ifndef NO_BIG_INLINE
inline
#endif
VALUE
opt_eql_func(VALUE recv, VALUE obj, CALL_INFO ci, CALL_CACHE cc)
{
    switch (comparable_by_identity(recv, obj)) {
      case 1:
	return (recv == obj) ? Qtrue : Qfalse;
      case -1:
	goto fallback;
    }
    if (0) {
    }
    else if (BUILTIN_CLASS_P(recv, rb_cFloat)) {
	if (EQ_UNREDEFINED_P(FLOAT)) {
	    return rb_float_eql(recv, obj);
	}
    }
    else if (BUILTIN_CLASS_P(recv, rb_cString)) {
	if (EQ_UNREDEFINED_P(STRING)) {
	    return rb_str_eql(recv, obj);
	}
    }

  fallback:
    return opt_equal_fallback(recv, obj, ci, cc);
}
#undef BUILTIN_CLASS_P
#undef EQ_UNREDEFINED_P

VALUE
rb_equal_opt(VALUE obj1, VALUE obj2)
{
    struct rb_call_info ci;
    struct rb_call_cache cc;

    ci.mid = idEq;
    cc.method_state = 0;
    cc.class_serial = 0;
    cc.me = NULL;
    return opt_eq_func(obj1, obj2, &ci, &cc);
}

VALUE
rb_eql_opt(VALUE obj1, VALUE obj2)
{
    struct rb_call_info ci;
    struct rb_call_cache cc;

    ci.mid = idEqlP;
    cc.method_state = 0;
    cc.class_serial = 0;
    cc.me = NULL;
    return opt_eql_func(obj1, obj2, &ci, &cc);
}

static VALUE vm_call0(rb_thread_t*, VALUE, ID, int, const VALUE*, const rb_callable_method_entry_t *);

static VALUE
check_match(VALUE pattern, VALUE target, enum vm_check_match_type type)
{
    switch (type) {
      case VM_CHECKMATCH_TYPE_WHEN:
	return pattern;
      case VM_CHECKMATCH_TYPE_RESCUE:
	if (!rb_obj_is_kind_of(pattern, rb_cModule)) {
	    rb_raise(rb_eTypeError, "class or module required for rescue clause");
	}
	/* fall through */
      case VM_CHECKMATCH_TYPE_CASE: {
	const rb_callable_method_entry_t *me =
	    rb_callable_method_entry_with_refinements(CLASS_OF(pattern), idEqq, NULL);
	if (me) {
	    return vm_call0(GET_THREAD(), pattern, idEqq, 1, &target, me);
	}
	else {
	    /* fallback to funcall (e.g. method_missing) */
	    return rb_funcallv(pattern, idEqq, 1, &target);
	}
      }
      default:
	rb_bug("check_match: unreachable");
    }
}


#if defined(_MSC_VER) && _MSC_VER < 1300
#define CHECK_CMP_NAN(a, b) if (isnan(a) || isnan(b)) return Qfalse;
#else
#define CHECK_CMP_NAN(a, b) /* do nothing */
#endif

static inline VALUE
double_cmp_lt(double a, double b)
{
    CHECK_CMP_NAN(a, b);
    return a < b ? Qtrue : Qfalse;
}

static inline VALUE
double_cmp_le(double a, double b)
{
    CHECK_CMP_NAN(a, b);
    return a <= b ? Qtrue : Qfalse;
}

static inline VALUE
double_cmp_gt(double a, double b)
{
    CHECK_CMP_NAN(a, b);
    return a > b ? Qtrue : Qfalse;
}

static inline VALUE
double_cmp_ge(double a, double b)
{
    CHECK_CMP_NAN(a, b);
    return a >= b ? Qtrue : Qfalse;
}

static VALUE *
vm_base_ptr(const rb_control_frame_t *cfp)
{
    const rb_control_frame_t *prev_cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);

    if (cfp->iseq && VM_FRAME_RUBYFRAME_P(cfp)) {
	VALUE *bp = prev_cfp->sp + cfp->iseq->body->local_table_size + VM_ENV_DATA_SIZE;
	if (cfp->iseq->body->type == ISEQ_TYPE_METHOD) {
	    /* adjust `self' */
	    bp += 1;
	}
#if VM_DEBUG_BP_CHECK
	if (bp != cfp->bp_check) {
	    fprintf(stderr, "bp_check: %ld, bp: %ld\n",
		    (long)(cfp->bp_check - GET_EC()->vm_stack),
		    (long)(bp - GET_EC()->vm_stack));
	    rb_bug("vm_base_ptr: unreachable");
	}
#endif
	return bp;
    }
    else {
	return NULL;
    }
}

/* method call processes with call_info */

#include "vm_args.c"

static inline VALUE vm_call_iseq_setup_2(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc, int opt_pc, int param_size, int local_size);
static inline VALUE vm_call_iseq_setup_normal(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc, int opt_pc, int param_size, int local_size);
static inline VALUE vm_call_iseq_setup_tailcall(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc, int opt_pc);
static VALUE vm_call_super_method(rb_thread_t *th, rb_control_frame_t *reg_cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc);
static VALUE vm_call_method_nome(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc);
static VALUE vm_call_method_each_type(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc);
static inline VALUE vm_call_method(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc);

static vm_call_handler vm_call_iseq_setup_func(const struct rb_call_info *ci, const int param_size, const int local_size);

static rb_method_definition_t *method_definition_create(rb_method_type_t type, ID mid);
static void method_definition_set(const rb_method_entry_t *me, rb_method_definition_t *def, void *opts);
static int rb_method_definition_eq(const rb_method_definition_t *d1, const rb_method_definition_t *d2);

static const rb_iseq_t *
def_iseq_ptr(rb_method_definition_t *def)
{
#if VM_CHECK_MODE > 0
    if (def->type != VM_METHOD_TYPE_ISEQ) rb_bug("def_iseq_ptr: not iseq (%d)", def->type);
#endif
    return rb_iseq_check(def->body.iseq.iseqptr);
}

static VALUE
vm_call_iseq_setup_tailcall_0start(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    return vm_call_iseq_setup_tailcall(th, cfp, calling, ci, cc, 0);
}

static VALUE
vm_call_iseq_setup_normal_0start(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    const rb_iseq_t *iseq = def_iseq_ptr(cc->me->def);
    int param = iseq->body->param.size;
    int local = iseq->body->local_table_size;
    return vm_call_iseq_setup_normal(th, cfp, calling, ci, cc, 0, param, local);
}

static inline int
simple_iseq_p(const rb_iseq_t *iseq)
{
    return iseq->body->param.flags.has_opt == FALSE &&
           iseq->body->param.flags.has_rest == FALSE &&
	   iseq->body->param.flags.has_post == FALSE &&
	   iseq->body->param.flags.has_kw == FALSE &&
	   iseq->body->param.flags.has_kwrest == FALSE &&
	   iseq->body->param.flags.has_block == FALSE;
}

static inline int
vm_callee_setup_arg(rb_thread_t *th, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc,
		    const rb_iseq_t *iseq, VALUE *argv, int param_size, int local_size)
{
    if (LIKELY(simple_iseq_p(iseq) && !(ci->flag & VM_CALL_KW_SPLAT))) {
	rb_control_frame_t *cfp = th->ec->cfp;

	CALLER_SETUP_ARG(cfp, calling, ci); /* splat arg */

	if (calling->argc != iseq->body->param.lead_num) {
	    argument_arity_error(th, iseq, calling->argc, iseq->body->param.lead_num, iseq->body->param.lead_num);
	}

	CI_SET_FASTPATH(cc, vm_call_iseq_setup_func(ci, param_size, local_size),
			(!IS_ARGS_SPLAT(ci) && !IS_ARGS_KEYWORD(ci) &&
			 !(METHOD_ENTRY_VISI(cc->me) == METHOD_VISI_PROTECTED)));
	return 0;
    }
    else {
	return setup_parameters_complex(th, iseq, calling, ci, argv, arg_setup_method);
    }
}

static VALUE
vm_call_iseq_setup(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    const rb_iseq_t *iseq = def_iseq_ptr(cc->me->def);
    const int param_size = iseq->body->param.size;
    const int local_size = iseq->body->local_table_size;
    const int opt_pc = vm_callee_setup_arg(th, calling, ci, cc, def_iseq_ptr(cc->me->def), cfp->sp - calling->argc, param_size, local_size);
    return vm_call_iseq_setup_2(th, cfp, calling, ci, cc, opt_pc, param_size, local_size);
}

static inline VALUE
vm_call_iseq_setup_2(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc,
		     int opt_pc, int param_size, int local_size)
{
    if (LIKELY(!(ci->flag & VM_CALL_TAILCALL))) {
	return vm_call_iseq_setup_normal(th, cfp, calling, ci, cc, opt_pc, param_size, local_size);
    }
    else {
	return vm_call_iseq_setup_tailcall(th, cfp, calling, ci, cc, opt_pc);
    }
}

static inline VALUE
vm_call_iseq_setup_normal(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc,
			  int opt_pc, int param_size, int local_size)
{
    const rb_callable_method_entry_t *me = cc->me;
    const rb_iseq_t *iseq = def_iseq_ptr(me->def);
    VALUE *argv = cfp->sp - calling->argc;
    VALUE *sp = argv + param_size;
    cfp->sp = argv - 1 /* recv */;

    vm_push_frame(th->ec, iseq, VM_FRAME_MAGIC_METHOD | VM_ENV_FLAG_LOCAL, calling->recv,
		  calling->block_handler, (VALUE)me,
		  iseq->body->iseq_encoded + opt_pc, sp,
		  local_size - param_size,
		  iseq->body->stack_max);
    return Qundef;
}

static inline VALUE
vm_call_iseq_setup_tailcall(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc,
			    int opt_pc)
{
    unsigned int i;
    VALUE *argv = cfp->sp - calling->argc;
    const rb_callable_method_entry_t *me = cc->me;
    const rb_iseq_t *iseq = def_iseq_ptr(me->def);
    VALUE *src_argv = argv;
    VALUE *sp_orig, *sp;
    VALUE finish_flag = VM_FRAME_FINISHED_P(cfp) ? VM_FRAME_FLAG_FINISH : 0;

    if (VM_BH_FROM_CFP_P(calling->block_handler, cfp)) {
	struct rb_captured_block *dst_captured = VM_CFP_TO_CAPTURED_BLOCK(RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp));
	const struct rb_captured_block *src_captured = VM_BH_TO_CAPT_BLOCK(calling->block_handler);
	dst_captured->code.val = src_captured->code.val;
	if (VM_BH_ISEQ_BLOCK_P(calling->block_handler)) {
	    calling->block_handler = VM_BH_FROM_ISEQ_BLOCK(dst_captured);
	}
	else {
	    calling->block_handler = VM_BH_FROM_IFUNC_BLOCK(dst_captured);
	}
    }

    vm_pop_frame(th->ec, cfp, cfp->ep);
    cfp = th->ec->cfp;

    sp_orig = sp = cfp->sp;

    /* push self */
    sp[0] = calling->recv;
    sp++;

    /* copy arguments */
    for (i=0; i < iseq->body->param.size; i++) {
	*sp++ = src_argv[i];
    }

    vm_push_frame(th->ec, iseq, VM_FRAME_MAGIC_METHOD | VM_ENV_FLAG_LOCAL | finish_flag,
		  calling->recv, calling->block_handler, (VALUE)me,
		  iseq->body->iseq_encoded + opt_pc, sp,
		  iseq->body->local_table_size - iseq->body->param.size,
		  iseq->body->stack_max);

    cfp->sp = sp_orig;
    RUBY_VM_CHECK_INTS(th);

    return Qundef;
}

static VALUE
call_cfunc_m2(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, rb_ary_new4(argc, argv));
}

static VALUE
call_cfunc_m1(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(argc, argv, recv);
}

static VALUE
call_cfunc_0(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv);
}

static VALUE
call_cfunc_1(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0]);
}

static VALUE
call_cfunc_2(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1]);
}

static VALUE
call_cfunc_3(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2]);
}

static VALUE
call_cfunc_4(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3]);
}

static VALUE
call_cfunc_5(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4]);
}

static VALUE
call_cfunc_6(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4], argv[5]);
}

static VALUE
call_cfunc_7(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4], argv[5], argv[6]);
}

static VALUE
call_cfunc_8(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4], argv[5], argv[6], argv[7]);
}

static VALUE
call_cfunc_9(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4], argv[5], argv[6], argv[7], argv[8]);
}

static VALUE
call_cfunc_10(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4], argv[5], argv[6], argv[7], argv[8], argv[9]);
}

static VALUE
call_cfunc_11(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4], argv[5], argv[6], argv[7], argv[8], argv[9], argv[10]);
}

static VALUE
call_cfunc_12(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4], argv[5], argv[6], argv[7], argv[8], argv[9], argv[10], argv[11]);
}

static VALUE
call_cfunc_13(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4], argv[5], argv[6], argv[7], argv[8], argv[9], argv[10], argv[11], argv[12]);
}

static VALUE
call_cfunc_14(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4], argv[5], argv[6], argv[7], argv[8], argv[9], argv[10], argv[11], argv[12], argv[13]);
}

static VALUE
call_cfunc_15(VALUE (*func)(ANYARGS), VALUE recv, int argc, const VALUE *argv)
{
    return (*func)(recv, argv[0], argv[1], argv[2], argv[3], argv[4], argv[5], argv[6], argv[7], argv[8], argv[9], argv[10], argv[11], argv[12], argv[13], argv[14]);
}

#ifndef VM_PROFILE
#define VM_PROFILE 0
#endif

#if VM_PROFILE
enum {
    VM_PROFILE_R2C_CALL,
    VM_PROFILE_R2C_POPF,
    VM_PROFILE_C2C_CALL,
    VM_PROFILE_C2C_POPF,
    VM_PROFILE_COUNT
};
static int vm_profile_counter[VM_PROFILE_COUNT];
#define VM_PROFILE_UP(x) (vm_profile_counter[VM_PROFILE_##x]++)
#define VM_PROFILE_ATEXIT() atexit(vm_profile_show_result)
static void
vm_profile_show_result(void)
{
    fprintf(stderr, "VM Profile results: \n");
    fprintf(stderr, "r->c call: %d\n", vm_profile_counter[VM_PROFILE_R2C_CALL]);
    fprintf(stderr, "r->c popf: %d\n", vm_profile_counter[VM_PROFILE_R2C_POPF]);
    fprintf(stderr, "c->c call: %d\n", vm_profile_counter[VM_PROFILE_C2C_CALL]);
    fprintf(stderr, "c->c popf: %d\n", vm_profile_counter[VM_PROFILE_C2C_POPF]);
}
#else
#define VM_PROFILE_UP(x)
#define VM_PROFILE_ATEXIT()
#endif

static inline int
vm_cfp_consistent_p(rb_thread_t *th, const rb_control_frame_t *reg_cfp)
{
    const int ov_flags = RAISED_STACKOVERFLOW;
    if (LIKELY(reg_cfp == th->ec->cfp + 1)) return TRUE;
    if (rb_thread_raised_p(th, ov_flags)) {
	rb_thread_raised_reset(th, ov_flags);
	return TRUE;
    }
    return FALSE;
}

#define CHECK_CFP_CONSISTENCY(func) \
    (LIKELY(vm_cfp_consistent_p(th, reg_cfp)) ? (void)0 : \
     rb_bug(func ": cfp consistency error (%p, %p)", reg_cfp, th->ec->cfp+1))

static inline
const rb_method_cfunc_t *
vm_method_cfunc_entry(const rb_callable_method_entry_t *me)
{
#if VM_DEBUG_VERIFY_METHOD_CACHE
    switch (me->def->type) {
      case VM_METHOD_TYPE_CFUNC:
      case VM_METHOD_TYPE_NOTIMPLEMENTED:
	break;
# define METHOD_BUG(t) case VM_METHOD_TYPE_##t: rb_bug("wrong method type: " #t)
	METHOD_BUG(ISEQ);
	METHOD_BUG(ATTRSET);
	METHOD_BUG(IVAR);
	METHOD_BUG(BMETHOD);
	METHOD_BUG(ZSUPER);
	METHOD_BUG(UNDEF);
	METHOD_BUG(OPTIMIZED);
	METHOD_BUG(MISSING);
	METHOD_BUG(REFINED);
	METHOD_BUG(ALIAS);
# undef METHOD_BUG
      default:
	rb_bug("wrong method type: %d", me->def->type);
    }
#endif
    return &me->def->body.cfunc;
}

static VALUE
vm_call_cfunc_with_frame(rb_thread_t *th, rb_control_frame_t *reg_cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    VALUE val;
    const rb_callable_method_entry_t *me = cc->me;
    const rb_method_cfunc_t *cfunc = vm_method_cfunc_entry(me);
    int len = cfunc->argc;

    VALUE recv = calling->recv;
    VALUE block_handler = calling->block_handler;
    int argc = calling->argc;

    RUBY_DTRACE_CMETHOD_ENTRY_HOOK(th, me->owner, me->def->original_id);
    EXEC_EVENT_HOOK(th, RUBY_EVENT_C_CALL, recv, me->def->original_id, ci->mid, me->owner, Qundef);

    vm_push_frame(th->ec, NULL, VM_FRAME_MAGIC_CFUNC | VM_FRAME_FLAG_CFRAME | VM_ENV_FLAG_LOCAL, recv,
		  block_handler, (VALUE)me,
		  0, th->ec->cfp->sp, 0, 0);

    if (len >= 0) rb_check_arity(argc, len, len);

    reg_cfp->sp -= argc + 1;
    VM_PROFILE_UP(R2C_CALL);
    val = (*cfunc->invoker)(cfunc->func, recv, argc, reg_cfp->sp + 1);

    CHECK_CFP_CONSISTENCY("vm_call_cfunc");

    rb_vm_pop_frame(th->ec);

    EXEC_EVENT_HOOK(th, RUBY_EVENT_C_RETURN, recv, me->def->original_id, ci->mid, me->owner, val);
    RUBY_DTRACE_CMETHOD_RETURN_HOOK(th, me->owner, me->def->original_id);

    return val;
}

static VALUE
vm_call_cfunc(rb_thread_t *th, rb_control_frame_t *reg_cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    CALLER_SETUP_ARG(reg_cfp, calling, ci);
    return vm_call_cfunc_with_frame(th, reg_cfp, calling, ci, cc);
}

static VALUE
vm_call_ivar(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    cfp->sp -= 1;
    return vm_getivar(calling->recv, cc->me->def->body.attr.id, NULL, cc, 1);
}

static VALUE
vm_call_attrset(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    VALUE val = *(cfp->sp - 1);
    cfp->sp -= 2;
    return vm_setivar(calling->recv, cc->me->def->body.attr.id, val, NULL, cc, 1);
}

static inline VALUE
vm_call_bmethod_body(rb_thread_t *th, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc, const VALUE *argv)
{
    rb_proc_t *proc;
    VALUE val;

    /* control block frame */
    th->passed_bmethod_me = cc->me;
    GetProcPtr(cc->me->def->body.proc, proc);
    val = vm_invoke_bmethod(th, proc, calling->recv, calling->argc, argv, calling->block_handler);

    return val;
}

static VALUE
vm_call_bmethod(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    VALUE *argv;
    int argc;

    CALLER_SETUP_ARG(cfp, calling, ci);
    argc = calling->argc;
    argv = ALLOCA_N(VALUE, argc);
    MEMCPY(argv, cfp->sp - argc, VALUE, argc);
    cfp->sp += - argc - 1;

    return vm_call_bmethod_body(th, calling, ci, cc, argv);
}

static enum method_missing_reason
ci_missing_reason(const struct rb_call_info *ci)
{
    enum method_missing_reason stat = MISSING_NOENTRY;
    if (ci->flag & VM_CALL_VCALL) stat |= MISSING_VCALL;
    if (ci->flag & VM_CALL_FCALL) stat |= MISSING_FCALL;
    if (ci->flag & VM_CALL_SUPER) stat |= MISSING_SUPER;
    return stat;
}

static VALUE
vm_call_opt_send(rb_thread_t *th, rb_control_frame_t *reg_cfp, struct rb_calling_info *calling, const struct rb_call_info *orig_ci, struct rb_call_cache *orig_cc)
{
    int i;
    VALUE sym;
    struct rb_call_info *ci;
    struct rb_call_info_with_kwarg ci_entry;
    struct rb_call_cache cc_entry, *cc;

    CALLER_SETUP_ARG(reg_cfp, calling, orig_ci);

    i = calling->argc - 1;

    if (calling->argc == 0) {
	rb_raise(rb_eArgError, "no method name given");
    }

    /* setup new ci */
    if (orig_ci->flag & VM_CALL_KWARG) {
	ci = (struct rb_call_info *)&ci_entry;
	ci_entry = *(struct rb_call_info_with_kwarg *)orig_ci;
    }
    else {
	ci = &ci_entry.ci;
	ci_entry.ci = *orig_ci;
    }
    ci->flag = ci->flag & ~VM_CALL_KWARG; /* TODO: delegate kw_arg without making a Hash object */

    /* setup new cc */
    cc_entry = *orig_cc;
    cc = &cc_entry;

    sym = TOPN(i);

    if (!(ci->mid = rb_check_id(&sym))) {
	if (rb_method_basic_definition_p(CLASS_OF(calling->recv), idMethodMissing)) {
	    VALUE exc = make_no_method_exception(rb_eNoMethodError, 0, calling->recv,
						 rb_long2int(calling->argc), &TOPN(i),
						 ci->flag & (VM_CALL_FCALL|VM_CALL_VCALL));
	    rb_exc_raise(exc);
	}
	TOPN(i) = rb_str_intern(sym);
	ci->mid = idMethodMissing;
	th->method_missing_reason = cc->aux.method_missing_reason = ci_missing_reason(ci);
    }
    else {
	/* shift arguments */
	if (i > 0) {
	    MEMMOVE(&TOPN(i), &TOPN(i-1), VALUE, i);
	}
	calling->argc -= 1;
	DEC_SP(1);
    }

    cc->me = rb_callable_method_entry_with_refinements(CLASS_OF(calling->recv), ci->mid, NULL);
    ci->flag = VM_CALL_FCALL | VM_CALL_OPT_SEND;
    return vm_call_method(th, reg_cfp, calling, ci, cc);
}

static VALUE
vm_call_opt_call(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    rb_proc_t *proc;
    int argc;
    VALUE *argv;

    CALLER_SETUP_ARG(cfp, calling, ci);

    argc = calling->argc;
    argv = ALLOCA_N(VALUE, argc);
    GetProcPtr(calling->recv, proc);
    MEMCPY(argv, cfp->sp - argc, VALUE, argc);
    cfp->sp -= argc + 1;

    return rb_vm_invoke_proc(th, proc, argc, argv, calling->block_handler);
}

static VALUE
vm_call_method_missing(rb_thread_t *th, rb_control_frame_t *reg_cfp, struct rb_calling_info *calling, const struct rb_call_info *orig_ci, struct rb_call_cache *orig_cc)
{
    VALUE *argv = STACK_ADDR_FROM_TOP(calling->argc);
    struct rb_call_info ci_entry;
    const struct rb_call_info *ci;
    struct rb_call_cache cc_entry, *cc;
    unsigned int argc;

    CALLER_SETUP_ARG(reg_cfp, calling, orig_ci);
    argc = calling->argc+1;

    ci_entry.flag = VM_CALL_FCALL | VM_CALL_OPT_SEND;
    ci_entry.mid = idMethodMissing;
    ci_entry.orig_argc = argc;
    ci = &ci_entry;

    cc_entry = *orig_cc;
    cc_entry.me =
	rb_callable_method_entry_without_refinements(CLASS_OF(calling->recv),
						     idMethodMissing, NULL);
    cc = &cc_entry;

    calling->argc = argc;

    /* shift arguments: m(a, b, c) #=> method_missing(:m, a, b, c) */
    CHECK_VM_STACK_OVERFLOW(reg_cfp, 1);
    if (argc > 1) {
	MEMMOVE(argv+1, argv, VALUE, argc-1);
    }
    argv[0] = ID2SYM(orig_ci->mid);
    INC_SP(1);

    th->method_missing_reason = orig_cc->aux.method_missing_reason;
    return vm_call_method(th, reg_cfp, calling, ci, cc);
}

static const rb_callable_method_entry_t *refined_method_callable_without_refinement(const rb_callable_method_entry_t *me);
static VALUE
vm_call_zsuper(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc, VALUE klass)
{
    klass = RCLASS_SUPER(klass);
    cc->me = klass ? rb_callable_method_entry(klass, ci->mid) : NULL;

    if (!cc->me) {
	return vm_call_method_nome(th, cfp, calling, ci, cc);
    }
    if (cc->me->def->type == VM_METHOD_TYPE_REFINED &&
	cc->me->def->body.refined.orig_me) {
	cc->me = refined_method_callable_without_refinement(cc->me);
    }
    return vm_call_method_each_type(th, cfp, calling, ci, cc);
}

static inline VALUE
find_refinement(VALUE refinements, VALUE klass)
{
    if (NIL_P(refinements)) {
	return Qnil;
    }
    return rb_hash_lookup(refinements, klass);
}

PUREFUNC(static rb_control_frame_t * current_method_entry(rb_thread_t *th, rb_control_frame_t *cfp));
static rb_control_frame_t *
current_method_entry(rb_thread_t *th, rb_control_frame_t *cfp)
{
    rb_control_frame_t *top_cfp = cfp;

    if (cfp->iseq && cfp->iseq->body->type == ISEQ_TYPE_BLOCK) {
	const rb_iseq_t *local_iseq = cfp->iseq->body->local_iseq;

	do {
	    cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);
	    if (RUBY_VM_CONTROL_FRAME_STACK_OVERFLOW_P(th->ec, cfp)) {
		/* TODO: orphan block */
		return top_cfp;
	    }
	} while (cfp->iseq != local_iseq);
    }
    return cfp;
}

static VALUE
find_defined_class_by_owner(VALUE current_class, VALUE target_owner)
{
    VALUE klass = current_class;

    /* for prepended Module, then start from cover class */
    if (RB_TYPE_P(klass, T_ICLASS) && FL_TEST(klass, RICLASS_IS_ORIGIN)) klass = RBASIC_CLASS(klass);

    while (RTEST(klass)) {
	VALUE owner = RB_TYPE_P(klass, T_ICLASS) ? RBASIC_CLASS(klass) : klass;
	if (owner == target_owner) {
	    return klass;
	}
	klass = RCLASS_SUPER(klass);
    }

    return current_class; /* maybe module function */
}

static const rb_callable_method_entry_t *
aliased_callable_method_entry(const rb_callable_method_entry_t *me)
{
    const rb_method_entry_t *orig_me = me->def->body.alias.original_me;
    const rb_callable_method_entry_t *cme;

    if (orig_me->defined_class == 0) {
	VALUE defined_class = find_defined_class_by_owner(me->defined_class, orig_me->owner);
	VM_ASSERT(RB_TYPE_P(orig_me->owner, T_MODULE));
	cme = rb_method_entry_complement_defined_class(orig_me, me->called_id, defined_class);

	if (me->def->alias_count + me->def->complemented_count == 0) {
	    RB_OBJ_WRITE(me, &me->def->body.alias.original_me, cme);
	}
	else {
	    method_definition_set((rb_method_entry_t *)me,
				  method_definition_create(VM_METHOD_TYPE_ALIAS, me->def->original_id),
				  (void *)cme);
	}
    }
    else {
	cme = (const rb_callable_method_entry_t *)orig_me;
    }

    VM_ASSERT(callable_method_entry_p(cme));
    return cme;
}

static const rb_callable_method_entry_t *
refined_method_callable_without_refinement(const rb_callable_method_entry_t *me)
{
    const rb_method_entry_t *orig_me = me->def->body.refined.orig_me;
    const rb_callable_method_entry_t *cme;

    if (orig_me->defined_class == 0) {
	cme = NULL;
	rb_notimplement();
    }
    else {
	cme = (const rb_callable_method_entry_t *)orig_me;
    }

    VM_ASSERT(callable_method_entry_p(cme));

    if (UNDEFINED_METHOD_ENTRY_P(cme)) {
	cme = NULL;
    }

    return cme;
}

static VALUE
vm_call_method_each_type(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    switch (cc->me->def->type) {
      case VM_METHOD_TYPE_ISEQ:
	CI_SET_FASTPATH(cc, vm_call_iseq_setup, TRUE);
	return vm_call_iseq_setup(th, cfp, calling, ci, cc);

      case VM_METHOD_TYPE_NOTIMPLEMENTED:
      case VM_METHOD_TYPE_CFUNC:
	CI_SET_FASTPATH(cc, vm_call_cfunc, TRUE);
	return vm_call_cfunc(th, cfp, calling, ci, cc);

      case VM_METHOD_TYPE_ATTRSET:
	CALLER_SETUP_ARG(cfp, calling, ci);
	rb_check_arity(calling->argc, 1, 1);
	cc->aux.index = 0;
	CI_SET_FASTPATH(cc, vm_call_attrset, !((ci->flag & VM_CALL_ARGS_SPLAT) || (ci->flag & VM_CALL_KWARG)));
	return vm_call_attrset(th, cfp, calling, ci, cc);

      case VM_METHOD_TYPE_IVAR:
	CALLER_SETUP_ARG(cfp, calling, ci);
	rb_check_arity(calling->argc, 0, 0);
	cc->aux.index = 0;
	CI_SET_FASTPATH(cc, vm_call_ivar, !(ci->flag & VM_CALL_ARGS_SPLAT));
	return vm_call_ivar(th, cfp, calling, ci, cc);

      case VM_METHOD_TYPE_MISSING:
	cc->aux.method_missing_reason = 0;
	CI_SET_FASTPATH(cc, vm_call_method_missing, TRUE);
	return vm_call_method_missing(th, cfp, calling, ci, cc);

      case VM_METHOD_TYPE_BMETHOD:
	CI_SET_FASTPATH(cc, vm_call_bmethod, TRUE);
	return vm_call_bmethod(th, cfp, calling, ci, cc);

      case VM_METHOD_TYPE_ALIAS:
	cc->me = aliased_callable_method_entry(cc->me);
	VM_ASSERT(cc->me != NULL);
	return vm_call_method_each_type(th, cfp, calling, ci, cc);

      case VM_METHOD_TYPE_OPTIMIZED:
	switch (cc->me->def->body.optimize_type) {
	  case OPTIMIZED_METHOD_TYPE_SEND:
	    CI_SET_FASTPATH(cc, vm_call_opt_send, TRUE);
	    return vm_call_opt_send(th, cfp, calling, ci, cc);
	  case OPTIMIZED_METHOD_TYPE_CALL:
	    CI_SET_FASTPATH(cc, vm_call_opt_call, TRUE);
	    return vm_call_opt_call(th, cfp, calling, ci, cc);
	  default:
	    rb_bug("vm_call_method: unsupported optimized method type (%d)",
		   cc->me->def->body.optimize_type);
	}

      case VM_METHOD_TYPE_UNDEF:
	break;

      case VM_METHOD_TYPE_ZSUPER:
	return vm_call_zsuper(th, cfp, calling, ci, cc, RCLASS_ORIGIN(cc->me->owner));

      case VM_METHOD_TYPE_REFINED: {
	const rb_cref_t *cref = rb_vm_get_cref(cfp->ep);
	VALUE refinements = cref ? CREF_REFINEMENTS(cref) : Qnil;
	VALUE refinement;
	const rb_callable_method_entry_t *ref_me;

	refinement = find_refinement(refinements, cc->me->owner);

	if (NIL_P(refinement)) {
	    goto no_refinement_dispatch;
	}
	ref_me = rb_callable_method_entry(refinement, ci->mid);

	if (ref_me) {
	    if (cc->call == vm_call_super_method) {
		const rb_control_frame_t *top_cfp = current_method_entry(th, cfp);
		const rb_callable_method_entry_t *top_me = rb_vm_frame_method_entry(top_cfp);
		if (top_me && rb_method_definition_eq(ref_me->def, top_me->def)) {
		    goto no_refinement_dispatch;
		}
	    }
	    cc->me = ref_me;
	    if (ref_me->def->type != VM_METHOD_TYPE_REFINED) {
		return vm_call_method(th, cfp, calling, ci, cc);
	    }
	}
	else {
	    cc->me = NULL;
	    return vm_call_method_nome(th, cfp, calling, ci, cc);
	}

      no_refinement_dispatch:
	if (cc->me->def->body.refined.orig_me) {
	    cc->me = refined_method_callable_without_refinement(cc->me);
	}
	else {
	    VALUE klass = RCLASS_SUPER(cc->me->owner);
	    cc->me = klass ? rb_callable_method_entry(klass, ci->mid) : NULL;
	}
	return vm_call_method(th, cfp, calling, ci, cc);
      }
    }

    rb_bug("vm_call_method: unsupported method type (%d)", cc->me->def->type);
}

static VALUE
vm_call_method_nome(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    /* method missing */
    const int stat = ci_missing_reason(ci);

    if (ci->mid == idMethodMissing) {
	rb_control_frame_t *reg_cfp = cfp;
	VALUE *argv = STACK_ADDR_FROM_TOP(calling->argc);
	rb_raise_method_missing(th, calling->argc, argv, calling->recv, stat);
    }
    else {
	cc->aux.method_missing_reason = stat;
	CI_SET_FASTPATH(cc, vm_call_method_missing, 1);
	return vm_call_method_missing(th, cfp, calling, ci, cc);
    }
}

static inline VALUE
vm_call_method(rb_thread_t *th, rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    VM_ASSERT(callable_method_entry_p(cc->me));

    if (cc->me != NULL) {
	switch (METHOD_ENTRY_VISI(cc->me)) {
	  case METHOD_VISI_PUBLIC: /* likely */
	    return vm_call_method_each_type(th, cfp, calling, ci, cc);

	  case METHOD_VISI_PRIVATE:
	    if (!(ci->flag & VM_CALL_FCALL)) {
		enum method_missing_reason stat = MISSING_PRIVATE;
		if (ci->flag & VM_CALL_VCALL) stat |= MISSING_VCALL;

		cc->aux.method_missing_reason = stat;
		CI_SET_FASTPATH(cc, vm_call_method_missing, 1);
		return vm_call_method_missing(th, cfp, calling, ci, cc);
	    }
	    return vm_call_method_each_type(th, cfp, calling, ci, cc);

	  case METHOD_VISI_PROTECTED:
	    if (!(ci->flag & VM_CALL_OPT_SEND)) {
		if (!rb_obj_is_kind_of(cfp->self, cc->me->defined_class)) {
		    cc->aux.method_missing_reason = MISSING_PROTECTED;
		    return vm_call_method_missing(th, cfp, calling, ci, cc);
		}
		else {
		    /* caching method info to dummy cc */
		    struct rb_call_cache cc_entry;
		    cc_entry = *cc;
		    cc = &cc_entry;

		    VM_ASSERT(cc->me != NULL);
		    return vm_call_method_each_type(th, cfp, calling, ci, cc);
		}
	    }
	    return vm_call_method_each_type(th, cfp, calling, ci, cc);

	  default:
	    rb_bug("unreachable");
	}
    }
    else {
	return vm_call_method_nome(th, cfp, calling, ci, cc);
    }
}

static VALUE
vm_call_general(rb_thread_t *th, rb_control_frame_t *reg_cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    return vm_call_method(th, reg_cfp, calling, ci, cc);
}

static VALUE
vm_call_super_method(rb_thread_t *th, rb_control_frame_t *reg_cfp, struct rb_calling_info *calling, const struct rb_call_info *ci, struct rb_call_cache *cc)
{
    /* this check is required to distinguish with other functions. */
    if (cc->call != vm_call_super_method) rb_bug("bug");
    return vm_call_method(th, reg_cfp, calling, ci, cc);
}

/* super */

static inline VALUE
vm_search_normal_superclass(VALUE klass)
{
    if (BUILTIN_TYPE(klass) == T_ICLASS &&
	FL_TEST(RBASIC(klass)->klass, RMODULE_IS_REFINEMENT)) {
	klass = RBASIC(klass)->klass;
    }
    klass = RCLASS_ORIGIN(klass);
    return RCLASS_SUPER(klass);
}

static void
vm_super_outside(void)
{
    rb_raise(rb_eNoMethodError, "super called outside of method");
}

static void
vm_search_super_method(rb_thread_t *th, rb_control_frame_t *reg_cfp,
		       struct rb_calling_info *calling, struct rb_call_info *ci, struct rb_call_cache *cc)
{
    VALUE current_defined_class, klass;
    VALUE sigval = TOPN(calling->argc);
    const rb_callable_method_entry_t *me = rb_vm_frame_method_entry(reg_cfp);

    if (!me) {
	vm_super_outside();
    }

    current_defined_class = me->defined_class;

    if (!NIL_P(RCLASS_REFINED_CLASS(current_defined_class))) {
	current_defined_class = RCLASS_REFINED_CLASS(current_defined_class);
    }

    if (BUILTIN_TYPE(current_defined_class) != T_MODULE &&
	BUILTIN_TYPE(current_defined_class) != T_ICLASS && /* bound UnboundMethod */
	!FL_TEST(current_defined_class, RMODULE_INCLUDED_INTO_REFINEMENT) &&
	!rb_obj_is_kind_of(calling->recv, current_defined_class)) {
	VALUE m = RB_TYPE_P(current_defined_class, T_ICLASS) ?
	    RBASIC(current_defined_class)->klass : current_defined_class;

	rb_raise(rb_eTypeError,
		 "self has wrong type to call super in this context: "
		 "%"PRIsVALUE" (expected %"PRIsVALUE")",
		 rb_obj_class(calling->recv), m);
    }

    if (me->def->type == VM_METHOD_TYPE_BMETHOD && !sigval) {
	rb_raise(rb_eRuntimeError,
		 "implicit argument passing of super from method defined"
		 " by define_method() is not supported."
		 " Specify all arguments explicitly.");
    }

    ci->mid = me->def->original_id;
    klass = vm_search_normal_superclass(me->defined_class);

    if (!klass) {
	/* bound instance method of module */
	cc->aux.method_missing_reason = MISSING_SUPER;
	CI_SET_FASTPATH(cc, vm_call_method_missing, 1);
    }
    else {
	/* TODO: use inline cache */
	cc->me = rb_callable_method_entry(klass, ci->mid);
	CI_SET_FASTPATH(cc, vm_call_super_method, 1);
    }
}

/* yield */

static inline int
block_proc_is_lambda(const VALUE procval)
{
    rb_proc_t *proc;

    if (procval) {
	GetProcPtr(procval, proc);
	return proc->is_lambda;
    }
    else {
	return 0;
    }
}

static VALUE
vm_block_handler_to_proc(rb_thread_t *th, VALUE block_handler)
{
    VALUE blockarg = Qnil;

    if (block_handler != VM_BLOCK_HANDLER_NONE) {
	switch (vm_block_handler_type(block_handler)) {
	  case block_handler_type_proc:
	    blockarg = block_handler;
	    break;
	  case block_handler_type_symbol:
	    blockarg = rb_sym_to_proc(block_handler);
	    break;
	  case block_handler_type_iseq:
	  case block_handler_type_ifunc:
	    blockarg = rb_vm_make_proc(th->ec, VM_BH_TO_CAPT_BLOCK(block_handler), rb_cProc);
	    break;
	}
    }

    return blockarg;
}

static VALUE
vm_yield_with_cfunc(rb_thread_t *th,
		    const struct rb_captured_block *captured,
		    VALUE self, int argc, const VALUE *argv, VALUE block_handler)
{
    int is_lambda = FALSE; /* TODO */
    VALUE val, arg, blockarg;
    const struct vm_ifunc *ifunc = captured->code.ifunc;
    const rb_callable_method_entry_t *me = th->passed_bmethod_me;
    th->passed_bmethod_me = NULL;

    if (is_lambda) {
	arg = rb_ary_new4(argc, argv);
    }
    else if (argc == 0) {
	arg = Qnil;
    }
    else {
	arg = argv[0];
    }

    blockarg = vm_block_handler_to_proc(th, block_handler);

    vm_push_frame(th->ec, (const rb_iseq_t *)captured->code.ifunc,
		  VM_FRAME_MAGIC_IFUNC | VM_FRAME_FLAG_CFRAME,
		  self,
		  VM_GUARDED_PREV_EP(captured->ep),
		  (VALUE)me,
		  0, th->ec->cfp->sp, 0, 0);
    val = (*ifunc->func)(arg, ifunc->data, argc, argv, blockarg);
    rb_vm_pop_frame(th->ec);

    return val;
}

static VALUE
vm_yield_with_symbol(rb_thread_t *th,  VALUE symbol, int argc, const VALUE *argv, VALUE block_handler)
{
    return rb_sym_proc_call(SYM2ID(symbol), argc, argv, vm_block_handler_to_proc(th, block_handler));
}

static inline int
vm_callee_setup_block_arg_arg0_splat(rb_control_frame_t *cfp, const rb_iseq_t *iseq, VALUE *argv, VALUE ary)
{
    int i;
    long len = RARRAY_LEN(ary);

    CHECK_VM_STACK_OVERFLOW(cfp, iseq->body->param.lead_num);

    for (i=0; i<len && i<iseq->body->param.lead_num; i++) {
	argv[i] = RARRAY_AREF(ary, i);
    }

    return i;
}

static inline VALUE
vm_callee_setup_block_arg_arg0_check(VALUE *argv)
{
    VALUE ary, arg0 = argv[0];
    ary = rb_check_array_type(arg0);
#if 0
    argv[0] = arg0;
#else
    VM_ASSERT(argv[0] == arg0);
#endif
    return ary;
}

static int
vm_callee_setup_block_arg(rb_thread_t *th, struct rb_calling_info *calling, const struct rb_call_info *ci, const rb_iseq_t *iseq, VALUE *argv, const enum arg_setup_type arg_setup_type)
{
    if (simple_iseq_p(iseq)) {
	rb_control_frame_t *cfp = th->ec->cfp;
	VALUE arg0;

	CALLER_SETUP_ARG(cfp, calling, ci); /* splat arg */

	if (arg_setup_type == arg_setup_block &&
	    calling->argc == 1 &&
	    iseq->body->param.flags.has_lead &&
	    !iseq->body->param.flags.ambiguous_param0 &&
	    !NIL_P(arg0 = vm_callee_setup_block_arg_arg0_check(argv))) {
	    calling->argc = vm_callee_setup_block_arg_arg0_splat(cfp, iseq, argv, arg0);
	}

	if (calling->argc != iseq->body->param.lead_num) {
	    if (arg_setup_type == arg_setup_block) {
		if (calling->argc < iseq->body->param.lead_num) {
		    int i;
		    CHECK_VM_STACK_OVERFLOW(cfp, iseq->body->param.lead_num);
		    for (i=calling->argc; i<iseq->body->param.lead_num; i++) argv[i] = Qnil;
		    calling->argc = iseq->body->param.lead_num; /* fill rest parameters */
		}
		else if (calling->argc > iseq->body->param.lead_num) {
		    calling->argc = iseq->body->param.lead_num; /* simply truncate arguments */
		}
	    }
	    else {
		argument_arity_error(th, iseq, calling->argc, iseq->body->param.lead_num, iseq->body->param.lead_num);
	    }
	}

	return 0;
    }
    else {
	return setup_parameters_complex(th, iseq, calling, ci, argv, arg_setup_type);
    }
}

static int
vm_yield_setup_args(rb_thread_t *th, const rb_iseq_t *iseq, const int argc, VALUE *argv, VALUE block_handler, enum arg_setup_type arg_setup_type)
{
    struct rb_calling_info calling_entry, *calling;
    struct rb_call_info ci_entry, *ci;

    calling = &calling_entry;
    calling->argc = argc;
    calling->block_handler = block_handler;

    ci_entry.flag = 0;
    ci = &ci_entry;

    return vm_callee_setup_block_arg(th, calling, ci, iseq, argv, arg_setup_type);
}

/* ruby iseq -> ruby block */

static VALUE
vm_invoke_iseq_block(rb_thread_t *th, rb_control_frame_t *reg_cfp,
		     struct rb_calling_info *calling, const struct rb_call_info *ci,
		     int is_lambda, const struct rb_captured_block *captured)
{
    const rb_iseq_t *iseq = rb_iseq_check(captured->code.iseq);
    const int arg_size = iseq->body->param.size;
    VALUE * const rsp = GET_SP() - calling->argc;
    int opt_pc = vm_callee_setup_block_arg(th, calling, ci, iseq, rsp, is_lambda ? arg_setup_method : arg_setup_block);

    SET_SP(rsp);

    vm_push_frame(th->ec, iseq,
		  VM_FRAME_MAGIC_BLOCK | (is_lambda ? VM_FRAME_FLAG_LAMBDA : 0),
		  captured->self,
		  VM_GUARDED_PREV_EP(captured->ep), 0,
		  iseq->body->iseq_encoded + opt_pc,
		  rsp + arg_size,
		  iseq->body->local_table_size - arg_size, iseq->body->stack_max);

    return Qundef;
}

static VALUE
vm_invoke_symbol_block(rb_thread_t *th, rb_control_frame_t *reg_cfp,
		       struct rb_calling_info *calling, const struct rb_call_info *ci,
		       VALUE symbol)
{
    VALUE val;
    int argc;
    CALLER_SETUP_ARG(th->ec->cfp, calling, ci);
    argc = calling->argc;
    val = vm_yield_with_symbol(th, symbol, argc, STACK_ADDR_FROM_TOP(argc), VM_BLOCK_HANDLER_NONE);
    POPN(argc);
    return val;
}

static VALUE
vm_invoke_ifunc_block(rb_thread_t *th, rb_control_frame_t *reg_cfp,
		      struct rb_calling_info *calling, const struct rb_call_info *ci,
		      const struct rb_captured_block *captured)
{
    VALUE val;
    int argc;
    CALLER_SETUP_ARG(th->ec->cfp, calling, ci);
    argc = calling->argc;
    val = vm_yield_with_cfunc(th, captured, captured->self, argc, STACK_ADDR_FROM_TOP(argc), VM_BLOCK_HANDLER_NONE);
    POPN(argc); /* TODO: should put before C/yield? */
    return val;
}

static VALUE
vm_proc_to_block_handler(VALUE procval)
{
    const struct rb_block *block = vm_proc_block(procval);

    switch (vm_block_type(block)) {
      case block_type_iseq:
	return VM_BH_FROM_ISEQ_BLOCK(&block->as.captured);
      case block_type_ifunc:
	return VM_BH_FROM_IFUNC_BLOCK(&block->as.captured);
      case block_type_symbol:
	return VM_BH_FROM_SYMBOL(block->as.symbol);
      case block_type_proc:
	return VM_BH_FROM_PROC(block->as.proc);
    }
    VM_UNREACHABLE(vm_yield_with_proc);
    return Qundef;
}

static VALUE
vm_invoke_block(rb_thread_t *th, rb_control_frame_t *reg_cfp, struct rb_calling_info *calling, const struct rb_call_info *ci)
{
    VALUE block_handler = VM_CF_BLOCK_HANDLER(reg_cfp);
    VALUE type = GET_ISEQ()->body->local_iseq->body->type;
    int is_lambda = FALSE;

    if ((type != ISEQ_TYPE_METHOD && type != ISEQ_TYPE_CLASS) ||
	block_handler == VM_BLOCK_HANDLER_NONE) {
	rb_vm_localjump_error("no block given (yield)", Qnil, 0);
    }

  again:
    switch (vm_block_handler_type(block_handler)) {
      case block_handler_type_iseq:
	{
	    const struct rb_captured_block *captured = VM_BH_TO_ISEQ_BLOCK(block_handler);
	    return vm_invoke_iseq_block(th, reg_cfp, calling, ci, is_lambda, captured);
	}
      case block_handler_type_ifunc:
	{
	    const struct rb_captured_block *captured = VM_BH_TO_IFUNC_BLOCK(block_handler);
	    return vm_invoke_ifunc_block(th, reg_cfp, calling, ci, captured);
	}
      case block_handler_type_proc:
	is_lambda = block_proc_is_lambda(VM_BH_TO_PROC(block_handler));
	block_handler = vm_proc_to_block_handler(VM_BH_TO_PROC(block_handler));
	goto again;
      case block_handler_type_symbol:
	return vm_invoke_symbol_block(th, reg_cfp, calling, ci, VM_BH_TO_SYMBOL(block_handler));
    }
    VM_UNREACHABLE(vm_invoke_block: unreachable);
    return Qnil;
}

static VALUE
vm_make_proc_with_iseq(const rb_iseq_t *blockiseq)
{
    const rb_execution_context_t *ec = GET_EC();
    const rb_control_frame_t *cfp = rb_vm_get_ruby_level_next_cfp(ec, ec->cfp);
    struct rb_captured_block *captured;

    if (cfp == 0) {
	rb_bug("vm_make_proc_with_iseq: unreachable");
    }

    captured = VM_CFP_TO_CAPTURED_BLOCK(cfp);
    captured->code.iseq = blockiseq;

    return rb_vm_make_proc(ec, captured, rb_cProc);
}

static VALUE
vm_once_exec(VALUE iseq)
{
    VALUE proc = vm_make_proc_with_iseq((rb_iseq_t *)iseq);
    return rb_proc_call_with_block(proc, 0, 0, Qnil);
}

static VALUE
vm_once_clear(VALUE data)
{
    union iseq_inline_storage_entry *is = (union iseq_inline_storage_entry *)data;
    is->once.running_thread = NULL;
    return Qnil;
}

rb_control_frame_t *
FUNC_FASTCALL(rb_vm_opt_struct_aref)(rb_thread_t *th, rb_control_frame_t *reg_cfp)
{
    TOPN(0) = rb_struct_aref(GET_SELF(), TOPN(0));
    return reg_cfp;
}

rb_control_frame_t *
FUNC_FASTCALL(rb_vm_opt_struct_aset)(rb_thread_t *th, rb_control_frame_t *reg_cfp)
{
    rb_struct_aset(GET_SELF(), TOPN(0), TOPN(1));
    return reg_cfp;
}

/* defined insn */

static enum defined_type
check_respond_to_missing(VALUE obj, VALUE v)
{
    VALUE args[2];
    VALUE r;

    args[0] = obj; args[1] = Qfalse;
    r = rb_check_funcall(v, idRespond_to_missing, 2, args);
    if (r != Qundef && RTEST(r)) {
	return DEFINED_METHOD;
    }
    else {
	return 0;
    }
}

static VALUE
vm_defined(rb_thread_t *th, rb_control_frame_t *reg_cfp, rb_num_t op_type, VALUE obj, VALUE needstr, VALUE v)
{
    VALUE klass;
    enum defined_type expr_type = 0;
    enum defined_type type = (enum defined_type)op_type;

    switch (type) {
      case DEFINED_IVAR:
	if (rb_ivar_defined(GET_SELF(), SYM2ID(obj))) {
	    expr_type = DEFINED_IVAR;
	}
	break;
      case DEFINED_IVAR2:
	klass = vm_get_cbase(GET_EP());
	break;
      case DEFINED_GVAR:
	if (rb_gvar_defined(rb_global_entry(SYM2ID(obj)))) {
	    expr_type = DEFINED_GVAR;
	}
	break;
      case DEFINED_CVAR: {
	const rb_cref_t *cref = rb_vm_get_cref(GET_EP());
	klass = vm_get_cvar_base(cref, GET_CFP());
	if (rb_cvar_defined(klass, SYM2ID(obj))) {
	    expr_type = DEFINED_CVAR;
	}
	break;
      }
      case DEFINED_CONST:
	klass = v;
	if (vm_get_ev_const(th, klass, SYM2ID(obj), 1)) {
	    expr_type = DEFINED_CONST;
	}
	break;
      case DEFINED_FUNC:
	klass = CLASS_OF(v);
	if (rb_method_boundp(klass, SYM2ID(obj), 0)) {
	    expr_type = DEFINED_METHOD;
	}
	else {
	    expr_type = check_respond_to_missing(obj, v);
	}
	break;
      case DEFINED_METHOD:{
	VALUE klass = CLASS_OF(v);
	const rb_method_entry_t *me = rb_method_entry(klass, SYM2ID(obj));

	if (me) {
	    switch (METHOD_ENTRY_VISI(me)) {
	      case METHOD_VISI_PRIVATE:
		break;
	      case METHOD_VISI_PROTECTED:
		if (!rb_obj_is_kind_of(GET_SELF(), rb_class_real(klass))) {
		    break;
		}
	      case METHOD_VISI_PUBLIC:
		expr_type = DEFINED_METHOD;
		break;
	      default:
		rb_bug("vm_defined: unreachable: %u", (unsigned int)METHOD_ENTRY_VISI(me));
	    }
	}
	else {
	    expr_type = check_respond_to_missing(obj, v);
	}
	break;
      }
      case DEFINED_YIELD:
	if (GET_BLOCK_HANDLER() != VM_BLOCK_HANDLER_NONE) {
	    expr_type = DEFINED_YIELD;
	}
	break;
      case DEFINED_ZSUPER:
	{
	    const rb_callable_method_entry_t *me = rb_vm_frame_method_entry(GET_CFP());

	    if (me) {
		VALUE klass = vm_search_normal_superclass(me->defined_class);
		ID id = me->def->original_id;

		if (rb_method_boundp(klass, id, 0)) {
		    expr_type = DEFINED_ZSUPER;
		}
	    }
	}
	break;
      case DEFINED_REF:{
	if (vm_getspecial(th, GET_LEP(), Qfalse, FIX2INT(obj)) != Qnil) {
	    expr_type = DEFINED_GVAR;
	}
	break;
      }
      default:
	rb_bug("unimplemented defined? type (VM)");
	break;
    }

    if (expr_type != 0) {
	if (needstr != Qfalse) {
	    return rb_iseq_defined_string(expr_type);
	}
	else {
	    return Qtrue;
	}
    }
    else {
	return Qnil;
    }
}

static const VALUE *
vm_get_ep(const VALUE *const reg_ep, rb_num_t lv)
{
    rb_num_t i;
    const VALUE *ep = reg_ep;
    for (i = 0; i < lv; i++) {
	ep = GET_PREV_EP(ep);
    }
    return ep;
}

static VALUE
vm_get_special_object(const VALUE *const reg_ep,
		      enum vm_special_object_type type)
{
    switch (type) {
      case VM_SPECIAL_OBJECT_VMCORE:
	return rb_mRubyVMFrozenCore;
      case VM_SPECIAL_OBJECT_CBASE:
	return vm_get_cbase(reg_ep);
      case VM_SPECIAL_OBJECT_CONST_BASE:
	return vm_get_const_base(reg_ep);
      default:
	rb_bug("putspecialobject insn: unknown value_type %d", type);
    }
}

static void
vm_freezestring(VALUE str, VALUE debug)
{
    if (!NIL_P(debug)) {
	rb_ivar_set(str, id_debug_created_info, debug);
    }
    rb_str_freeze(str);
}

static VALUE
vm_concat_array(VALUE ary1, VALUE ary2st)
{
    const VALUE ary2 = ary2st;
    VALUE tmp1 = rb_check_convert_type_with_id(ary1, T_ARRAY, "Array", idTo_a);
    VALUE tmp2 = rb_check_convert_type_with_id(ary2, T_ARRAY, "Array", idTo_a);

    if (NIL_P(tmp1)) {
	tmp1 = rb_ary_new3(1, ary1);
    }

    if (NIL_P(tmp2)) {
	tmp2 = rb_ary_new3(1, ary2);
    }

    if (tmp1 == ary1) {
	tmp1 = rb_ary_dup(ary1);
    }
    return rb_ary_concat(tmp1, tmp2);
}

static VALUE
vm_splat_array(VALUE flag, VALUE ary)
{
    VALUE tmp = rb_check_convert_type_with_id(ary, T_ARRAY, "Array", idTo_a);
    if (NIL_P(tmp)) {
	return rb_ary_new3(1, ary);
    }
    else if (RTEST(flag)) {
	return rb_ary_dup(tmp);
    }
    else {
	return tmp;
    }
}

static VALUE
vm_check_match(VALUE target, VALUE pattern, rb_num_t flag)
{
    enum vm_check_match_type type = ((int)flag) & VM_CHECKMATCH_TYPE_MASK;

    if (flag & VM_CHECKMATCH_ARRAY) {
	long i;
	const long n = RARRAY_LEN(pattern);

	for (i = 0; i < n; i++) {
	    VALUE v = RARRAY_AREF(pattern, i);
	    VALUE c = check_match(v, target, type);

	    if (RTEST(c)) {
		return c;
	    }
	}
	return Qfalse;
    }
    else {
	return check_match(pattern, target, type);
    }
}

static VALUE
vm_check_keyword(lindex_t bits, lindex_t idx, const VALUE *ep)
{
    const VALUE kw_bits = *(ep - bits);

    if (FIXNUM_P(kw_bits)) {
	int b = FIX2INT(kw_bits);
	return (b & (0x01 << idx)) ? Qfalse : Qtrue;
    }
    else {
	VM_ASSERT(RB_TYPE_P(kw_bits, T_HASH));
	return rb_hash_has_key(kw_bits, INT2FIX(idx));
    }
}

static void
vm_dtrace(rb_event_flag_t flag, rb_thread_t *th)
{
    if (RUBY_DTRACE_METHOD_ENTRY_ENABLED() ||
	RUBY_DTRACE_METHOD_RETURN_ENABLED() ||
	RUBY_DTRACE_CMETHOD_ENTRY_ENABLED() ||
	RUBY_DTRACE_CMETHOD_RETURN_ENABLED()) {

	switch (flag) {
	  case RUBY_EVENT_CALL:
	    RUBY_DTRACE_METHOD_ENTRY_HOOK(th, 0, 0);
	    return;
	  case RUBY_EVENT_C_CALL:
	    RUBY_DTRACE_CMETHOD_ENTRY_HOOK(th, 0, 0);
	    return;
	  case RUBY_EVENT_RETURN:
	    RUBY_DTRACE_METHOD_RETURN_HOOK(th, 0, 0);
	    return;
	  case RUBY_EVENT_C_RETURN:
	    RUBY_DTRACE_CMETHOD_RETURN_HOOK(th, 0, 0);
	    return;
	}
    }
}

static VALUE
vm_const_get_under(ID id, rb_num_t flags, VALUE cbase)
{
    VALUE ns;

    if ((ns = vm_search_const_defined_class(cbase, id)) == 0) {
	return ns;
    }
    else if (VM_DEFINECLASS_SCOPED_P(flags)) {
	return rb_public_const_get_at(ns, id);
    }
    else {
	return rb_const_get_at(ns, id);
    }
}

static VALUE
vm_check_if_class(ID id, rb_num_t flags, VALUE super, VALUE klass)
{
    if (!RB_TYPE_P(klass, T_CLASS)) {
	rb_raise(rb_eTypeError, "%"PRIsVALUE" is not a class", rb_id2str(id));
    }
    else if (VM_DEFINECLASS_HAS_SUPERCLASS_P(flags)) {
	VALUE tmp = rb_class_real(RCLASS_SUPER(klass));

	if (tmp != super) {
	    rb_raise(rb_eTypeError,
		     "superclass mismatch for class %"PRIsVALUE"",
		     rb_id2str(id));
	}
	else {
	    return klass;
	}
    }
    else {
	return klass;
    }
}

static VALUE
vm_check_if_module(ID id, VALUE mod)
{
    if (!RB_TYPE_P(mod, T_MODULE)) {
	rb_raise(rb_eTypeError, "%"PRIsVALUE" is not a module", rb_id2str(id));
    }
    else {
	return mod;
    }
}

static VALUE
vm_declare_class(ID id, rb_num_t flags, VALUE cbase, VALUE super)
{
    /* new class declaration */
    VALUE s = VM_DEFINECLASS_HAS_SUPERCLASS_P(flags) ? super : rb_cObject;
    VALUE c = rb_define_class_id(id, s);

    rb_set_class_path_string(c, cbase, rb_id2str(id));
    rb_const_set(cbase, id, c);
    rb_class_inherited(s, c);
    return c;
}

static VALUE
vm_declare_module(ID id, VALUE cbase)
{
    /* new module declaration */
    VALUE mod = rb_define_module_id(id);
    rb_set_class_path_string(mod, cbase, rb_id2str(id));
    rb_const_set(cbase, id, mod);
    return mod;
}

static VALUE
vm_define_class(ID id, rb_num_t flags, VALUE cbase, VALUE super)
{
    VALUE klass;

    if (VM_DEFINECLASS_HAS_SUPERCLASS_P(flags) && !RB_TYPE_P(super, T_CLASS)) {
	rb_raise(rb_eTypeError,
		 "superclass must be a Class (%"PRIsVALUE" given)",
		 rb_obj_class(super));
    }

    vm_check_if_namespace(cbase);

    /* find klass */
    rb_autoload_load(cbase, id);
    if ((klass = vm_const_get_under(id, flags, cbase)) != 0) {
	return vm_check_if_class(id, flags, super, klass);
    }
    else {
	return vm_declare_class(id, flags, cbase, super);
    }
}

static VALUE
vm_define_module(ID id, rb_num_t flags, VALUE cbase)
{
    VALUE mod;

    vm_check_if_namespace(cbase);
    if ((mod = vm_const_get_under(id, flags, cbase)) != 0) {
	return vm_check_if_module(id, mod);
    }
    else {
	return vm_declare_module(id, cbase);
    }
}

static VALUE
vm_find_or_create_class_by_id(ID id,
			      rb_num_t flags,
			      VALUE cbase,
			      VALUE super)
{
    rb_vm_defineclass_type_t type = VM_DEFINECLASS_TYPE(flags);

    switch (type) {
      case VM_DEFINECLASS_TYPE_CLASS:
	/* classdef returns class scope value */
	return vm_define_class(id, flags, cbase, super);

      case VM_DEFINECLASS_TYPE_SINGLETON_CLASS:
	/* classdef returns class scope value */
	return rb_singleton_class(cbase);

      case VM_DEFINECLASS_TYPE_MODULE:
	/* classdef returns class scope value */
	return vm_define_module(id, flags, cbase);

      default:
	rb_bug("unknown defineclass type: %d", (int)type);
    }
}

/* this macro is mandatory to use OPTIMIZED_CMP. What a design! */
#define id_cmp idCmp

static VALUE
vm_opt_newarray_max(rb_num_t num, const VALUE *ptr)
{
    if (BASIC_OP_UNREDEFINED_P(BOP_MAX, ARRAY_REDEFINED_OP_FLAG)) {
	if (num == 0) {
	    return Qnil;
	}
	else {
	    struct cmp_opt_data cmp_opt = { 0, 0 };
	    VALUE result = Qundef;
	    rb_num_t i = num - 1;
	    result = ptr[i];
	    while (i-- > 0) {
		const VALUE v = ptr[i];
		if (result == Qundef || OPTIMIZED_CMP(v, result, cmp_opt) > 0) {
		    result = v;
		}
	    }
	    return result == Qundef ? Qnil : result;
	}
    }
    else {
	VALUE ary = rb_ary_new4(num, ptr);
	return rb_funcall(ary, idMax, 0);
    }
}

static VALUE
vm_opt_newarray_min(rb_num_t num, const VALUE *ptr)
{
    if (BASIC_OP_UNREDEFINED_P(BOP_MIN, ARRAY_REDEFINED_OP_FLAG)) {
	if (num == 0) {
	    return Qnil;
	}
	else {
	    struct cmp_opt_data cmp_opt = { 0, 0 };
	    VALUE result = Qundef;
	    rb_num_t i = num - 1;
	    result = ptr[i];
	    while (i-- > 0) {
		const VALUE v = ptr[i];
		if (result == Qundef || OPTIMIZED_CMP(v, result, cmp_opt) < 0) {
		    result = v;
		}
	    }
	    return result == Qundef ? Qnil : result;
	}
    }
    else {
	VALUE ary = rb_ary_new4(num, ptr);
	return rb_funcall(ary, idMin, 0);
    }
}

#undef id_cmp

static VALUE
vm_ic_hit_p(IC ic, const VALUE *reg_ep)
{
    if (ic->ic_serial == GET_GLOBAL_CONSTANT_STATE() &&
	(ic->ic_cref == NULL || ic->ic_cref == rb_vm_get_cref(reg_ep))) {
	return ic->ic_value.value;
    }
    else {
	return Qnil;
    }
}

static void
vm_ic_update(IC ic, VALUE val, const VALUE *reg_ep)
{
    VM_ASSERT(ic->ic_value.value != Qundef);
    ic->ic_value.value = val;
    ic->ic_serial = GET_GLOBAL_CONSTANT_STATE() - ruby_vm_const_missing_count;
    ic->ic_cref = vm_get_const_key_cref(reg_ep);
    ruby_vm_const_missing_count = 0;
}

static VALUE
vm_once_dispatch(ISEQ iseq, IC ic, rb_thread_t *th)
{
    rb_thread_t *const RUNNING_THREAD_ONCE_DONE = (rb_thread_t *)(0x1);
    union iseq_inline_storage_entry *const is = (union iseq_inline_storage_entry *)ic;

  again:
    if (is->once.running_thread == RUNNING_THREAD_ONCE_DONE) {
	return is->once.value;
    }
    else if (is->once.running_thread == NULL) {
	VALUE val;
	is->once.running_thread = th;
	val = is->once.value = rb_ensure(vm_once_exec, (VALUE)iseq, vm_once_clear, (VALUE)is);
	/* is->once.running_thread is cleared by vm_once_clear() */
	is->once.running_thread = RUNNING_THREAD_ONCE_DONE; /* success */
	rb_iseq_add_mark_object(th->ec->cfp->iseq, val);
	return val;
    }
    else if (is->once.running_thread == th) {
	/* recursive once */
	return vm_once_exec((VALUE)iseq);
    }
    else {
	/* waiting for finish */
	RUBY_VM_CHECK_INTS(th);
	rb_thread_schedule();
	goto again;
    }
}

static OFFSET
vm_case_dispatch(CDHASH hash, OFFSET else_offset, VALUE key)
{
    switch (OBJ_BUILTIN_TYPE(key)) {
      case -1:
      case T_FLOAT:
      case T_SYMBOL:
      case T_BIGNUM:
      case T_STRING:
	if (BASIC_OP_UNREDEFINED_P(BOP_EQQ,
				   SYMBOL_REDEFINED_OP_FLAG |
				   INTEGER_REDEFINED_OP_FLAG |
				   FLOAT_REDEFINED_OP_FLAG |
				   NIL_REDEFINED_OP_FLAG    |
				   TRUE_REDEFINED_OP_FLAG   |
				   FALSE_REDEFINED_OP_FLAG  |
				   STRING_REDEFINED_OP_FLAG)) {
	    st_data_t val;
	    if (RB_FLOAT_TYPE_P(key)) {
		double kval = RFLOAT_VALUE(key);
		if (!isinf(kval) && modf(kval, &kval) == 0.0) {
		    key = FIXABLE(kval) ? LONG2FIX((long)kval) : rb_dbl2big(kval);
		}
	    }
	    if (st_lookup(RHASH_TBL_RAW(hash), key, &val)) {
		return FIX2INT((VALUE)val);
	    }
	    else {
		return else_offset;
	    }
	}
    }
    return 0;
}

NORETURN(static void
	 vm_stack_consistency_error(rb_thread_t *,
				    const rb_control_frame_t *,
				    const VALUE *));
static void
vm_stack_consistency_error(rb_thread_t *th,
			   const rb_control_frame_t *cfp,
			   const VALUE *bp)
{
    const ptrdiff_t nsp = VM_SP_CNT(th, cfp->sp);
    const ptrdiff_t nbp = VM_SP_CNT(th, bp);
    static const char stack_consistency_error[] =
	"Stack consistency error (sp: %"PRIdPTRDIFF", bp: %"PRIdPTRDIFF")";
#if defined RUBY_DEVEL
    VALUE mesg = rb_sprintf(stack_consistency_error, nsp, nbp);
    rb_str_cat_cstr(mesg, "\n");
    rb_str_append(mesg, rb_iseq_disasm(cfp->iseq));
    rb_exc_fatal(rb_exc_new3(rb_eFatal, mesg));
#else
    rb_bug(stack_consistency_error, nsp, nbp);
#endif
}

enum binop_operands_type {
    bot_others = 0,
    bot_fixnum,
    bot_flonum,
    bot_float
};

static enum binop_operands_type
vm_opt_binop_dispatch(VALUE recv, VALUE obj, enum ruby_basic_operators BOP)
{
    if (FIXNUM_2_P(recv, obj) &&
	BASIC_OP_UNREDEFINED_P(BOP, INTEGER_REDEFINED_OP_FLAG)) {
	return bot_fixnum;
    }
    else if (FLONUM_2_P(recv, obj) &&
	     BASIC_OP_UNREDEFINED_P(BOP, FLOAT_REDEFINED_OP_FLAG)) {
	return bot_flonum;
    }
    else if (SPECIAL_CONST_P(recv) || SPECIAL_CONST_P(obj)) {
	return bot_others;
    }
    else if (RBASIC_CLASS(recv) == rb_cFloat &&
	     RBASIC_CLASS(obj)  == rb_cFloat &&
	     BASIC_OP_UNREDEFINED_P(BOP, FLOAT_REDEFINED_OP_FLAG)) {
	return bot_float;
    }
    else {
	return bot_others;
    }
}

static VALUE
vm_opt_plus(VALUE recv, VALUE obj)
{
    switch (vm_opt_binop_dispatch(recv, obj, BOP_PLUS)) {
      case bot_float:
      case bot_flonum: return DBL2NUM(RFLOAT_VALUE(recv) + RFLOAT_VALUE(obj));
      case bot_fixnum: return rb_fix_plus_fix(recv, obj);
      default:
	if (SPECIAL_CONST_P(recv) || SPECIAL_CONST_P(obj)) {
	    return Qundef;
	}
	else if (RBASIC_CLASS(recv) == rb_cString &&
		 RBASIC_CLASS(obj) == rb_cString &&
		 BASIC_OP_UNREDEFINED_P(BOP_PLUS, STRING_REDEFINED_OP_FLAG)) {
	    return rb_str_plus(recv, obj);
	}
	else if (RBASIC_CLASS(recv) == rb_cArray &&
		 BASIC_OP_UNREDEFINED_P(BOP_PLUS, ARRAY_REDEFINED_OP_FLAG)) {
	    return rb_ary_plus(recv, obj);
	}
	else {
	    return Qundef;
	}
    }
}

static VALUE
vm_opt_minus(VALUE recv, VALUE obj)
{
    switch (vm_opt_binop_dispatch(recv, obj, BOP_MINUS)) {
      case bot_float:
      case bot_flonum: return DBL2NUM(RFLOAT_VALUE(recv) - RFLOAT_VALUE(obj));
      case bot_fixnum: return rb_fix_minus_fix(recv, obj);
      default:         return Qundef;
    }
}

static VALUE
vm_opt_mult(VALUE recv, VALUE obj)
{
    switch (vm_opt_binop_dispatch(recv, obj, BOP_MULT)) {
      case bot_float:
      case bot_flonum: return DBL2NUM(RFLOAT_VALUE(recv) * RFLOAT_VALUE(obj));
      case bot_fixnum: return rb_fix_mul_fix(recv, obj);
      default:         return Qundef;
    }
}

static VALUE
vm_opt_div(VALUE recv, VALUE obj)
{
    switch (vm_opt_binop_dispatch(recv, obj, BOP_DIV)) {
      case bot_float:
      case bot_flonum:
	return DBL2NUM(RFLOAT_VALUE(recv) / RFLOAT_VALUE(obj));
      case bot_fixnum:
	return (FIX2LONG(obj) == 0) ? Qundef : rb_fix_div_fix(recv, obj);
      default:
	return Qundef;
    }
}

static VALUE
vm_opt_mod(VALUE recv, VALUE obj)
{
    switch (vm_opt_binop_dispatch(recv, obj, BOP_MOD)) {
      case bot_float:
      case bot_flonum:
	return DBL2NUM(ruby_float_mod(RFLOAT_VALUE(recv), RFLOAT_VALUE(obj)));
      case bot_fixnum:
	return (FIX2LONG(obj) == 0) ? Qundef : rb_fix_mod_fix(recv, obj);
      default:
	return Qundef;
    }
}

static VALUE
vm_opt_neq(CALL_INFO ci, CALL_CACHE cc,
	   CALL_INFO ci_eq, CALL_CACHE cc_eq,
	   VALUE recv, VALUE obj)
{
    if (vm_method_cfunc_is(ci, cc, recv, rb_obj_not_equal)) {
	VALUE val = opt_eq_func(recv, obj, ci_eq, cc_eq);

	if (val != Qundef) {
	    return RTEST(val) ? Qfalse : Qtrue;
	}
    }

    return Qundef;
}

static VALUE
vm_opt_lt(VALUE recv, VALUE obj)
{
    switch (vm_opt_binop_dispatch(recv, obj, BOP_LT)) {
      case bot_float:
	CHECK_CMP_NAN(RFLOAT_VALUE(recv), RFLOAT_VALUE(obj));
	/* FALLTHROUGH */
      case bot_flonum:
	/* flonum is not NaN */
	return RFLOAT_VALUE(recv) < RFLOAT_VALUE(obj) ? Qtrue : Qfalse;
      case bot_fixnum:
        return (SIGNED_VALUE)recv < (SIGNED_VALUE)obj ? Qtrue : Qfalse;
      default:
	return Qundef;
    }
}

static VALUE
vm_opt_le(VALUE recv, VALUE obj)
{
    switch (vm_opt_binop_dispatch(recv, obj, BOP_LT)) {
      case bot_float:
	CHECK_CMP_NAN(RFLOAT_VALUE(recv), RFLOAT_VALUE(obj));
	/* FALLTHROUGH */
      case bot_flonum:
	/* flonum is not NaN */
	return RFLOAT_VALUE(recv) <= RFLOAT_VALUE(obj) ? Qtrue : Qfalse;
      case bot_fixnum:
        return (SIGNED_VALUE)recv <= (SIGNED_VALUE)obj ? Qtrue : Qfalse;
      default:
	return Qundef;
    }
}

static VALUE
vm_opt_gt(VALUE recv, VALUE obj)
{
    switch (vm_opt_binop_dispatch(recv, obj, BOP_LT)) {
      case bot_float:
	CHECK_CMP_NAN(RFLOAT_VALUE(recv), RFLOAT_VALUE(obj));
	/* FALLTHROUGH */
      case bot_flonum:
	/* flonum is not NaN */
	return RFLOAT_VALUE(recv) > RFLOAT_VALUE(obj) ? Qtrue : Qfalse;
      case bot_fixnum:
        return (SIGNED_VALUE)recv > (SIGNED_VALUE)obj ? Qtrue : Qfalse;
      default:
	return Qundef;
    }
}

static VALUE
vm_opt_ge(VALUE recv, VALUE obj)
{
    switch (vm_opt_binop_dispatch(recv, obj, BOP_LT)) {
      case bot_float:
	CHECK_CMP_NAN(RFLOAT_VALUE(recv), RFLOAT_VALUE(obj));
	/* FALLTHROUGH */
      case bot_flonum:
	/* flonum is not NaN */
	return RFLOAT_VALUE(recv) >= RFLOAT_VALUE(obj) ? Qtrue : Qfalse;
      case bot_fixnum:
        return (SIGNED_VALUE)recv >= (SIGNED_VALUE)obj ? Qtrue : Qfalse;
      default:
	return Qundef;
    }
}


static VALUE
vm_opt_ltlt(VALUE recv, VALUE obj)
{
    if (SPECIAL_CONST_P(recv)) {
	return Qundef;
    }
    else if (RBASIC_CLASS(recv) == rb_cString &&
	     BASIC_OP_UNREDEFINED_P(BOP_LTLT, STRING_REDEFINED_OP_FLAG)) {
	return rb_str_concat(recv, obj);
    }
    else if (RBASIC_CLASS(recv) == rb_cArray &&
	     BASIC_OP_UNREDEFINED_P(BOP_LTLT, ARRAY_REDEFINED_OP_FLAG)) {
	return rb_ary_push(recv, obj);
    }
    else {
	return Qundef;
    }
}

static VALUE
vm_opt_aref(VALUE recv, VALUE obj)
{
    if (SPECIAL_CONST_P(recv)) {
	return Qundef;
    }
    else if (RBASIC_CLASS(recv) == rb_cArray &&
	     BASIC_OP_UNREDEFINED_P(BOP_AREF, ARRAY_REDEFINED_OP_FLAG)) {
	return rb_ary_aref1(recv, obj);
    }
    else if (RBASIC_CLASS(recv) == rb_cHash &&
	     BASIC_OP_UNREDEFINED_P(BOP_AREF, HASH_REDEFINED_OP_FLAG)) {
	return rb_hash_aref(recv, obj);
    }
    else {
	return Qundef;
    }
}

static VALUE
vm_opt_aset(VALUE recv, VALUE obj, VALUE set)
{
    if (SPECIAL_CONST_P(recv)) {
	return Qundef;
    }
    else if (RBASIC_CLASS(recv) == rb_cArray &&
	     BASIC_OP_UNREDEFINED_P(BOP_ASET, ARRAY_REDEFINED_OP_FLAG) &&
	     FIXNUM_P(obj)) {
	rb_ary_store(recv, FIX2LONG(obj), set);
	return set;
    }
    else if (RBASIC_CLASS(recv) == rb_cHash &&
	     BASIC_OP_UNREDEFINED_P(BOP_ASET, HASH_REDEFINED_OP_FLAG)) {
	rb_hash_aset(recv, obj, set);
	return set;
    }
    else {
	return Qundef;
    }
}

static VALUE
vm_opt_aref_with(VALUE recv, VALUE key)
{
    if (!SPECIAL_CONST_P(recv) && RBASIC_CLASS(recv) == rb_cHash &&
	BASIC_OP_UNREDEFINED_P(BOP_AREF, HASH_REDEFINED_OP_FLAG) &&
	rb_hash_compare_by_id_p(recv) == Qfalse) {
	return rb_hash_aref(recv, key);
    }
    else {
	return Qundef;
    }
}

static VALUE
vm_opt_aset_with(VALUE recv, VALUE key, VALUE val)
{
    if (!SPECIAL_CONST_P(recv) && RBASIC_CLASS(recv) == rb_cHash &&
	BASIC_OP_UNREDEFINED_P(BOP_ASET, HASH_REDEFINED_OP_FLAG) &&
	rb_hash_compare_by_id_p(recv) == Qfalse) {
	return rb_hash_aset(recv, key, val);
    }
    else {
	return Qundef;
    }
}

static VALUE
vm_opt_length(VALUE recv, int bop)
{
    if (SPECIAL_CONST_P(recv)) {
	return Qundef;
    }
    else if (RBASIC_CLASS(recv) == rb_cString &&
	     BASIC_OP_UNREDEFINED_P(bop, STRING_REDEFINED_OP_FLAG)) {
	if (bop == BOP_EMPTY_P) {
	    return LONG2NUM(RSTRING_LEN(recv));
	}
	else {
	    return rb_str_length(recv);
	}
    }
    else if (RBASIC_CLASS(recv) == rb_cArray &&
	     BASIC_OP_UNREDEFINED_P(bop, ARRAY_REDEFINED_OP_FLAG)) {
	return LONG2NUM(RARRAY_LEN(recv));
    }
    else if (RBASIC_CLASS(recv) == rb_cHash &&
	     BASIC_OP_UNREDEFINED_P(bop, HASH_REDEFINED_OP_FLAG)) {
	return INT2FIX(RHASH_SIZE(recv));
    }
    else {
	return Qundef;
    }
}

static VALUE
vm_opt_empty_p(VALUE recv)
{
    switch (vm_opt_length(recv, BOP_EMPTY_P)) {
      case Qundef: return Qundef;
      case INT2FIX(0): return Qtrue;
      default: return Qfalse;
    }
}

static VALUE
vm_opt_succ(VALUE recv)
{
    if (FIXNUM_P(recv) &&
	BASIC_OP_UNREDEFINED_P(BOP_SUCC, INTEGER_REDEFINED_OP_FLAG)) {
	/* fixnum + INT2FIX(1) */
	if (recv == LONG2FIX(FIXNUM_MAX)) {
	    return LONG2NUM(FIXNUM_MAX + 1);
	}
	else {
	    return recv - 1 + INT2FIX(1);
	}
    }
    else if (SPECIAL_CONST_P(recv)) {
	return Qundef;
    }
    else if (RBASIC_CLASS(recv) == rb_cString &&
	     BASIC_OP_UNREDEFINED_P(BOP_SUCC, STRING_REDEFINED_OP_FLAG)) {
	return rb_str_succ(recv);
    }
    else {
	return Qundef;
    }
}

static VALUE
vm_opt_not(CALL_INFO ci, CALL_CACHE cc, VALUE recv)
{
    if (vm_method_cfunc_is(ci, cc, recv, rb_obj_not)) {
	return RTEST(recv) ? Qfalse : Qtrue;
    }
    else {
	return Qundef;
    }
}

static VALUE
vm_opt_regexpmatch1(VALUE recv, VALUE obj)
{
    if (BASIC_OP_UNREDEFINED_P(BOP_MATCH, REGEXP_REDEFINED_OP_FLAG)) {
	return rb_reg_match(recv, obj);
    }
    else {
	return rb_funcall(recv, idEqTilde, 1, obj);
    }
}

static VALUE
vm_opt_regexpmatch2(VALUE recv, VALUE obj)
{
    if (CLASS_OF(recv) == rb_cString &&
	BASIC_OP_UNREDEFINED_P(BOP_MATCH, STRING_REDEFINED_OP_FLAG)) {
	return rb_reg_match(obj, recv);
    }
    else {
	return Qundef;
    }
}