C++ scheme_sfs_expr函数代码示例

static Scheme_Object *with_immed_mark_sfs(Scheme_Object *o, SFS_Info *info)
{
  Scheme_With_Continuation_Mark *wcm = (Scheme_With_Continuation_Mark *)o;
  Scheme_Object *k, *v, *b, *vec;
  int pos, save_mnt;
  
  scheme_sfs_start_sequence(info, 3, 1);

  k = scheme_sfs_expr(wcm->key, info, -1);
  v = scheme_sfs_expr(wcm->val, info, -1);

  scheme_sfs_push(info, 1, 1);

  pos = info->stackpos;
  save_mnt = info->max_nontail;

  if (!info->pass) {
    vec = scheme_make_vector(3, NULL);
    scheme_sfs_save(info, vec);
  } else {
    vec = scheme_sfs_next_saved(info);
    if (SCHEME_VEC_SIZE(vec) != 3)
      scheme_signal_error("internal error: bad vector length");
    info->max_used[pos] = SCHEME_INT_VAL(SCHEME_VEC_ELS(vec)[0]);
    info->max_calls[pos] = SCHEME_INT_VAL(SCHEME_VEC_ELS(vec)[1]);
    info->max_nontail = SCHEME_INT_VAL(SCHEME_VEC_ELS(vec)[2]);
  }
  
  b = scheme_sfs_expr(wcm->body, info, -1);
  
  wcm->key = k;
  wcm->val = v;
  wcm->body = b;

# if MAX_SFS_CLEARING
  if (!info->pass)
    info->max_nontail = info->ip;
# endif

  if (!info->pass) {
    int n;
    info->max_calls[pos] = info->max_nontail;
    n = info->max_used[pos];
    SCHEME_VEC_ELS(vec)[0] = scheme_make_integer(n);
    n = info->max_calls[pos];
    SCHEME_VEC_ELS(vec)[1] = scheme_make_integer(n);
    SCHEME_VEC_ELS(vec)[2] = scheme_make_integer(info->max_nontail);
  } else {
    info->max_nontail = save_mnt;
  }

  return o;
}

static Scheme_Object *
ref_sfs(Scheme_Object *data, SFS_Info *info)
{
  Scheme_Object *a_naya;
  Scheme_Object *b_naya;

  scheme_sfs_start_sequence(info, 1, 0);
  a_naya = scheme_sfs_expr(SCHEME_PTR1_VAL(data), info, -1);
  b_naya = scheme_sfs_expr(SCHEME_PTR2_VAL(data), info, -1);
  SCHEME_PTR1_VAL(data) = a_naya;
  SCHEME_PTR2_VAL(data) = b_naya;

  return data;
}

Scheme_Object *scheme_sfs(Scheme_Object *o, SFS_Info *info, int max_let_depth)
{
  int init, i;

  SFS_LOG(printf("sfs %d\n", SCHEME_TYPE(o)));

  if (!info) {
    info = scheme_new_sfs_info(max_let_depth);
  }

  info->pass = 0;
  info->ip = 1;
  info->abs_ip = 1;
  info->saved = scheme_null;
  info->min_touch = -1;
  info->max_touch = -1;
  info->tail_pos = 1;
  init = info->stackpos;
  o = scheme_sfs_expr(o, info, -1);

  if (info->seqn)
    scheme_signal_error("ended in the middle of an expression?");

# if MAX_SFS_CLEARING
  info->max_nontail = info->ip;
  info->abs_max_nontail = info->abs_ip;
# endif

  for (i = info->depth; i-- > init; ) {
    info->max_calls[i] = info->max_nontail;
  }

  {
    Scheme_Object *v;
    v = scheme_reverse(info->saved);
    info->saved = v;
  }

  info->pass = 1;
  info->seqn = 0;
  info->ip = 1;
  info->abs_ip = 1;
  info->tail_pos = 1;
  info->stackpos = init;
  o = scheme_sfs_expr(o, info, -1);

  return o;
}

static Scheme_Object *sfs_wcm(Scheme_Object *o, SFS_Info *info)
{
  Scheme_With_Continuation_Mark *wcm = (Scheme_With_Continuation_Mark *)o;
  Scheme_Object *k, *v, *b;

  scheme_sfs_start_sequence(info, 3, 1);

  k = scheme_sfs_expr(wcm->key, info, -1);
  v = scheme_sfs_expr(wcm->val, info, -1);
  b = scheme_sfs_expr(wcm->body, info, -1);
  
  wcm->key = k;
  wcm->val = v;
  wcm->body = b;

  return o;
}

static Scheme_Object *
apply_values_sfs(Scheme_Object *data, SFS_Info *info)
{
  Scheme_Object *f, *e;

  f = SCHEME_PTR1_VAL(data);
  e = SCHEME_PTR2_VAL(data);

  scheme_sfs_start_sequence(info, 2, 0);

  f = scheme_sfs_expr(f, info, -1);
  e = scheme_sfs_expr(e, info, -1);

  SCHEME_PTR1_VAL(data) = f;
  SCHEME_PTR2_VAL(data) = e;

  return data;
}

static Scheme_Object *
define_values_sfs(Scheme_Object *data, SFS_Info *info)
{
  Scheme_Object *e;
  scheme_sfs_start_sequence(info, 1, 0);
  e = scheme_sfs_expr(SCHEME_VEC_ELS(data)[0], info, -1);
  SCHEME_VEC_ELS(data)[0] = e;
  return data;
}

static Scheme_Object *
inline_variant_sfs(Scheme_Object *data, SFS_Info *info)
{
  Scheme_Object *e;
  scheme_sfs_start_sequence(info, 1, 0);
  e = scheme_sfs_expr(SCHEME_VEC_ELS(data)[0], info, -1);
  SCHEME_VEC_ELS(data)[0] = e;
  /* we don't bother with inlinable variant, since it isn't called directly */
  return data;
}

static Scheme_Object *
set_sfs(Scheme_Object *data, SFS_Info *info)
{
  Scheme_Set_Bang *sb = (Scheme_Set_Bang *)data;
  Scheme_Object *var, *val;

  var = sb->var;
  val = sb->val;
  
  scheme_sfs_start_sequence(info, 2, 0);

  val = scheme_sfs_expr(val, info, -1);
  var = scheme_sfs_expr(var, info, -1);

  sb->var = var;
  sb->val = val;

  return (Scheme_Object *)sb;
}

static Scheme_Object *sfs_expr_k(void)
{
  Scheme_Thread *p = scheme_current_thread;
  Scheme_Object *e = (Scheme_Object *)p->ku.k.p1;
  SFS_Info *info = (SFS_Info *)p->ku.k.p2;

  p->ku.k.p1 = NULL;
  p->ku.k.p2 = NULL;

  return scheme_sfs_expr(e, info, p->ku.k.i1);
}

static Scheme_Object *sfs_let_void(Scheme_Object *o, SFS_Info *info)
{
  Scheme_Let_Void *lv = (Scheme_Let_Void *)o;
  Scheme_Object *body;
  int i, pos, save_mnt;
  Scheme_Object *vec;
    
  scheme_sfs_push(info, lv->count, 1);
  pos = info->stackpos;
  save_mnt = info->max_nontail;

  if (!info->pass) {
    vec = scheme_make_vector(lv->count + 1, NULL);
    scheme_sfs_save(info, vec);
  } else {
    vec = scheme_sfs_next_saved(info);
    if (!SCHEME_VECTORP(vec))
      scheme_signal_error("internal error: not a vector");
    for (i = 0; i < lv->count; i++) {
      info->max_used[pos + i] = SCHEME_INT_VAL(SCHEME_VEC_ELS(vec)[i]);
      info->max_calls[pos + i] = SCHEME_INT_VAL(SCHEME_VEC_ELS(vec)[lv->count]);
    }
    info->max_nontail = SCHEME_INT_VAL(SCHEME_VEC_ELS(vec)[lv->count]);
  }

  body = scheme_sfs_expr(lv->body, info, -1);

# if MAX_SFS_CLEARING
  if (!info->pass)
    info->max_nontail = info->ip;
# endif

  if (!info->pass) {
    int n;
    SCHEME_VEC_ELS(vec)[lv->count] = scheme_make_integer(info->max_nontail);
    for (i = 0; i < lv->count; i++) {
      n = info->max_used[pos + i];
      SCHEME_VEC_ELS(vec)[i] = scheme_make_integer(n);
    }
  } else {
    info->max_nontail = save_mnt;
  }

  lv->body = body;

  return o;
}

static Scheme_Object *
module_sfs(Scheme_Object *data, SFS_Info *old_info)
{
  Scheme_Module *m = (Scheme_Module *)data;
  Scheme_Object *e, *ex;
  SFS_Info *info;
  int i, j, cnt, let_depth;

  if (!old_info->for_mod) {
    if (old_info->pass)
      return data;

    info = scheme_new_sfs_info(m->max_let_depth);
    info->for_mod = 1;
    scheme_sfs(data, info, m->max_let_depth);
    return data;
  }

  info = old_info;

  cnt = SCHEME_VEC_SIZE(m->bodies[0]);
  scheme_sfs_start_sequence(info, cnt, 0);

  for (i = 0; i < cnt; i++) {
    e = scheme_sfs_expr(SCHEME_VEC_ELS(m->bodies[0])[i], info, -1);
    SCHEME_VEC_ELS(m->bodies[0])[i] = e;
  }

  if (!info->pass) {
    for (j = m->num_phases; j-- > 1; ) {
      cnt = SCHEME_VEC_SIZE(m->bodies[j]);
      for (i = 0; i < cnt; i++) {
        e = SCHEME_VEC_ELS(m->bodies[j])[i];
        
        let_depth = SCHEME_INT_VAL(SCHEME_VEC_ELS(e)[2]);
        ex = SCHEME_VEC_ELS(e)[1];
        
        info = scheme_new_sfs_info(let_depth);
        ex = scheme_sfs(ex, info, let_depth);
        SCHEME_VEC_ELS(e)[1] = ex;
      }
    }
  }

  return data;
}

static Scheme_Object *
begin0_sfs(Scheme_Object *obj, SFS_Info *info)
{
  int i, cnt;
  
  cnt = ((Scheme_Sequence *)obj)->count;

  scheme_sfs_start_sequence(info, cnt, 0);

  for (i = 0; i < cnt; i++) {
    Scheme_Object *le;
    le = scheme_sfs_expr(((Scheme_Sequence *)obj)->array[i], info, -1);
    ((Scheme_Sequence *)obj)->array[i] = le;
  }

  return obj;
}

static Scheme_Object *
case_lambda_sfs(Scheme_Object *expr, SFS_Info *info)
{
  Scheme_Case_Lambda *seq = (Scheme_Case_Lambda *)expr;
  Scheme_Object *le, *clears = scheme_null;
  int i;

  scheme_sfs_start_sequence(info, seq->count, 0);

  for (i = 0; i < seq->count; i++) {
    le = seq->array[i];
    le = scheme_sfs_expr(le, info, -1);
    if (SAME_TYPE(SCHEME_TYPE(le), scheme_begin0_sequence_type)) {
      /* Some clearing actions were added to the closure.
         Lift them out. */
      int j;
      Scheme_Sequence *cseq = (Scheme_Sequence *)le;
      if (!cseq->count)
        scheme_signal_error("internal error: empty sequence");
      for (j = 1; j < cseq->count; j++) {
        int pos;
        pos = SCHEME_LOCAL_POS(cseq->array[j]);
        clears = scheme_make_pair(scheme_make_integer(pos), clears);
      }
      le = cseq->array[0];
    }
    if (!SAME_TYPE(SCHEME_TYPE(le), scheme_unclosed_procedure_type)
        && !SAME_TYPE(SCHEME_TYPE(le), scheme_closure_type)) {
      scheme_signal_error("internal error: not a lambda for case-lambda: %d",
                          SCHEME_TYPE(le));
    }
    seq->array[i] = le;
  }

  if (!SCHEME_NULLP(clears)) {
    return scheme_sfs_add_clears(expr, clears, 0);
  } else
    return expr;
}

static Scheme_Object *bangboxenv_sfs(Scheme_Object *data, SFS_Info *info)
{
  Scheme_Object *e;
  int spos, drop;

  spos = SCHEME_INT_VAL(SCHEME_PTR1_VAL(data)) + info->stackpos;
  if (info->pass 
      && (info->max_used[spos] < info->ip))
    /* Not used, so don't bother boxing. In fact, the original value
       might be cleared already, so we wan't legally box anymore. */
    drop = 1;
  else
    drop = 0;

  e = scheme_sfs_expr(SCHEME_PTR2_VAL(data), info, -1);

  if (drop)
    return e;
  else {
    SCHEME_PTR2_VAL(data) = e;
    return data;
  }
}

static Scheme_Object *sfs_one_branch(SFS_Info *info, int ip, 
                                     Scheme_Object *vec, int delta,
                                     Scheme_Object *tbranch)
{
  int t_min_t, t_max_t, t_cnt, n, stackpos, i, save_nt, b_end, nt;
  Scheme_Object *t_vec, *o;
  Scheme_Object *clears = scheme_null;

  info->min_touch = -1;
  info->max_touch = -1;
  save_nt = info->max_nontail;

  SFS_LOG(printf("%d %d %s %d\n", info->pass, ip, (delta ? "else" : "then"), ip));

  if (info->pass) {
    /* Re-install max_used entries that refer to the branch */
    o = SCHEME_VEC_ELS(vec)[delta * SFS_BRANCH_W];
    t_min_t = SCHEME_INT_VAL(o);
    o = SCHEME_VEC_ELS(vec)[(delta * SFS_BRANCH_W) + 2];
    nt = SCHEME_INT_VAL(o);
    if (nt > info->max_nontail)
      info->max_nontail = nt;
    if (t_min_t > -1) {
      t_vec = SCHEME_VEC_ELS(vec)[(delta * SFS_BRANCH_W) + 1];
      t_cnt = SCHEME_VEC_SIZE(t_vec);
      for (i = 0; i < t_cnt; i++) {
        o = SCHEME_VEC_ELS(t_vec)[i];
        if (SCHEME_INTP(o)) {
          n = SCHEME_INT_VAL(o);
          SFS_LOG(printf(" @%d %d\n", i + t_min_t, n));
          if (info->max_used[i + t_min_t] < n) {
            SFS_LOG(printf(" |%d %d %d\n", i + t_min_t, n, info->max_nontail));
            info->max_used[i + t_min_t] = n;
            info->max_calls[i + t_min_t] = info->max_nontail;
          }
        }
      }
    }
    /* If the other branch has last use for something not used in this
       branch, and if there's a non-tail call in this branch
       of later, then we'll have to start with explicit clears. 
       Note that it doesn't matter whether the other branch actually
       clears them (i.e., the relevant non-tail call might be only
       in this branch). */
    o = SCHEME_VEC_ELS(vec)[(delta * SFS_BRANCH_W) + 3];
    b_end = SCHEME_INT_VAL(o);
    SFS_LOG(printf(" %d %d %d %d\n", nt, ip, b_end, save_nt));
    if (((nt > (ip + 1)) && (nt < b_end)) /* => non-tail call in branch */
        || ((ip + 1) < save_nt)) { /* => non-tail call after branches */
      SFS_LOG(printf(" other\n"));
      o = SCHEME_VEC_ELS(vec)[(1 - delta) * SFS_BRANCH_W];
      t_min_t = SCHEME_INT_VAL(o);
      if (t_min_t > -1) {
        int at_ip, pos;
        t_vec = SCHEME_VEC_ELS(vec)[((1 - delta) * SFS_BRANCH_W) + 1];
        t_cnt = SCHEME_VEC_SIZE(t_vec);
        o = SCHEME_VEC_ELS(vec)[((1 - delta) * SFS_BRANCH_W) + 2];
        nt = SCHEME_INT_VAL(o);
        o = SCHEME_VEC_ELS(vec)[((1 - delta) * SFS_BRANCH_W) + 3];
        b_end = SCHEME_INT_VAL(o);
        for (i = 0; i < t_cnt; i++) {
          o = SCHEME_VEC_ELS(t_vec)[i];
          if (SCHEME_INTP(o)) {
            n = SCHEME_INT_VAL(o);
            pos = i + t_min_t;
            at_ip = info->max_used[pos];
            SFS_LOG(printf(" ?%d %d %d\n", pos, n, at_ip));
            /* is last use in other branch? */
            if (((!delta && (at_ip == ip))
                 || (delta && (at_ip == n)))) {
              /* Yes, so add clear */
              SFS_LOG(printf(" !%d %d %d\n", pos, n, at_ip));
              pos -= info->stackpos;
              clears = scheme_make_pair(scheme_make_integer(pos), 
                                        clears);
            }
          }
        }
      }
    }
  }

  stackpos = info->stackpos;

  tbranch = scheme_sfs_expr(tbranch, info, -1);

  if (info->pass)
    info->max_nontail = save_nt;
# if MAX_SFS_CLEARING
  else
    info->max_nontail = info->ip;
# endif

  tbranch = scheme_sfs_add_clears(tbranch, clears, 1);

  if (!info->pass) {
    t_min_t = info->min_touch;
    t_max_t = info->max_touch;
    if (t_min_t < stackpos)
      t_min_t = stackpos;
//.........这里部分代码省略.........