コード例 #1
0
ファイル: value-prof.c プロジェクト: DJHartley/iphone-dev
/* Generate code for transformation 1 (with MODE and OPERATION, operands OP1
   and OP2, whose value is expected to be VALUE, result TARGET and
   probability of taking the optimal path PROB).  */
static rtx
gen_divmod_fixed_value (enum machine_mode mode, enum rtx_code operation,
			rtx target, rtx op1, rtx op2, gcov_type value,
			int prob)
{
  rtx tmp, tmp1, jump;
  rtx neq_label = gen_label_rtx ();
  rtx end_label = gen_label_rtx ();
  rtx sequence;

  start_sequence ();
  
  if (!REG_P (op2))
    {
      tmp = gen_reg_rtx (mode);
      emit_move_insn (tmp, copy_rtx (op2));
    }
  else
    tmp = op2;

  do_compare_rtx_and_jump (tmp, GEN_INT (value), NE, 0, mode, NULL_RTX,
			   NULL_RTX, neq_label);

  /* Add branch probability to jump we just created.  */
  jump = get_last_insn ();
  REG_NOTES (jump) = gen_rtx_EXPR_LIST (REG_BR_PROB,
					GEN_INT (REG_BR_PROB_BASE - prob),
					REG_NOTES (jump));

  tmp1 = simplify_gen_binary (operation, mode,
			      copy_rtx (op1), GEN_INT (value));
  tmp1 = force_operand (tmp1, target);
  if (tmp1 != target)
    emit_move_insn (copy_rtx (target), copy_rtx (tmp1));

  emit_jump_insn (gen_jump (end_label));
  emit_barrier ();

  emit_label (neq_label);
  tmp1 = simplify_gen_binary (operation, mode,
			      copy_rtx (op1), copy_rtx (tmp));
  tmp1 = force_operand (tmp1, target);
  if (tmp1 != target)
    emit_move_insn (copy_rtx (target), copy_rtx (tmp1));
  
  emit_label (end_label);

  sequence = get_insns ();
  end_sequence ();
  rebuild_jump_labels (sequence);
  return sequence;
}
コード例 #2
0
ファイル: value-prof.c プロジェクト: DJHartley/iphone-dev
static rtx
gen_speculative_prefetch (rtx address, gcov_type delta, int write)
{
  rtx tmp;
  rtx sequence;

  /* TODO: we do the prefetching for just one iteration ahead, which
     often is not enough.  */
  start_sequence ();
  if (offsettable_address_p (0, VOIDmode, address))
    tmp = plus_constant (copy_rtx (address), delta);
  else
    {
      tmp = simplify_gen_binary (PLUS, Pmode,
				 copy_rtx (address), GEN_INT (delta));
      tmp = force_operand (tmp, NULL);
    }
  if (! (*insn_data[(int)CODE_FOR_prefetch].operand[0].predicate)
      (tmp, insn_data[(int)CODE_FOR_prefetch].operand[0].mode))
    tmp = force_reg (Pmode, tmp);
  emit_insn (gen_prefetch (tmp, GEN_INT (write), GEN_INT (3)));
  sequence = get_insns ();
  end_sequence ();

  return sequence;
}
コード例 #3
0
ファイル: value-prof.c プロジェクト: DJHartley/iphone-dev
/* Generate code for transformations 3 and 4 (with MODE and OPERATION,
   operands OP1 and OP2, result TARGET, at most SUB subtractions, and
   probability of taking the optimal path(s) PROB1 and PROB2).  */
static rtx
gen_mod_subtract (enum machine_mode mode, enum rtx_code operation,
		  rtx target, rtx op1, rtx op2, int sub, int prob1, int prob2)
{
  rtx tmp, tmp1, jump;
  rtx end_label = gen_label_rtx ();
  rtx sequence;
  int i;

  start_sequence ();
  
  if (!REG_P (op2))
    {
      tmp = gen_reg_rtx (mode);
      emit_move_insn (tmp, copy_rtx (op2));
    }
  else
    tmp = op2;

  emit_move_insn (target, copy_rtx (op1));
  do_compare_rtx_and_jump (target, tmp, LTU, 0, mode, NULL_RTX,
			   NULL_RTX, end_label);

  /* Add branch probability to jump we just created.  */
  jump = get_last_insn ();
  REG_NOTES (jump) = gen_rtx_EXPR_LIST (REG_BR_PROB,
					GEN_INT (prob1), REG_NOTES (jump));

  for (i = 0; i < sub; i++)
    {
      tmp1 = expand_simple_binop (mode, MINUS, target, tmp, target,
	    			  0, OPTAB_WIDEN);
      if (tmp1 != target)
	emit_move_insn (target, tmp1);
      do_compare_rtx_and_jump (target, tmp, LTU, 0, mode, NULL_RTX,
    			       NULL_RTX, end_label);

      /* Add branch probability to jump we just created.  */
      jump = get_last_insn ();
      REG_NOTES (jump) = gen_rtx_EXPR_LIST (REG_BR_PROB,
					    GEN_INT (prob2), REG_NOTES (jump));
    }

  tmp1 = simplify_gen_binary (operation, mode, copy_rtx (target), copy_rtx (tmp));
  tmp1 = force_operand (tmp1, target);
  if (tmp1 != target)
    emit_move_insn (target, tmp1);
  
  emit_label (end_label);

  sequence = get_insns ();
  end_sequence ();
  rebuild_jump_labels (sequence);
  return sequence;
}
コード例 #4
0
ファイル: value-prof.c プロジェクト: DJHartley/iphone-dev
/* Generate code for transformation 2 (with MODE and OPERATION, operands OP1
   and OP2, result TARGET and probability of taking the optimal path PROB).  */
static rtx
gen_mod_pow2 (enum machine_mode mode, enum rtx_code operation, rtx target,
	      rtx op1, rtx op2, int prob)
{
  rtx tmp, tmp1, tmp2, tmp3, jump;
  rtx neq_label = gen_label_rtx ();
  rtx end_label = gen_label_rtx ();
  rtx sequence;

  start_sequence ();
  
  if (!REG_P (op2))
    {
      tmp = gen_reg_rtx (mode);
      emit_move_insn (tmp, copy_rtx (op2));
    }
  else
    tmp = op2;

  tmp1 = expand_simple_binop (mode, PLUS, tmp, constm1_rtx, NULL_RTX,
			      0, OPTAB_WIDEN);
  tmp2 = expand_simple_binop (mode, AND, tmp, tmp1, NULL_RTX,
			      0, OPTAB_WIDEN);
  do_compare_rtx_and_jump (tmp2, const0_rtx, NE, 0, mode, NULL_RTX,
			   NULL_RTX, neq_label);

  /* Add branch probability to jump we just created.  */
  jump = get_last_insn ();
  REG_NOTES (jump) = gen_rtx_EXPR_LIST (REG_BR_PROB,
					GEN_INT (REG_BR_PROB_BASE - prob),
					REG_NOTES (jump));

  tmp3 = expand_simple_binop (mode, AND, op1, tmp1, target,
			      0, OPTAB_WIDEN);
  if (tmp3 != target)
    emit_move_insn (copy_rtx (target), tmp3);
  emit_jump_insn (gen_jump (end_label));
  emit_barrier ();

  emit_label (neq_label);
  tmp1 = simplify_gen_binary (operation, mode, copy_rtx (op1), copy_rtx (tmp));
  tmp1 = force_operand (tmp1, target);
  if (tmp1 != target)
    emit_move_insn (target, tmp1);
  
  emit_label (end_label);

  sequence = get_insns ();
  end_sequence ();
  rebuild_jump_labels (sequence);
  return sequence;
}
コード例 #5
0
static void
gen_addr_rtx (enum machine_mode address_mode,
	      rtx symbol, rtx base, rtx index, rtx step, rtx offset,
	      rtx *addr, rtx **step_p, rtx **offset_p)
{
  rtx act_elem;

  *addr = NULL_RTX;
  if (step_p)
    *step_p = NULL;
  if (offset_p)
    *offset_p = NULL;

  if (index)
    {
      act_elem = index;
      if (step)
	{
	  act_elem = gen_rtx_MULT (address_mode, act_elem, step);

	  if (step_p)
	    *step_p = &XEXP (act_elem, 1);
	}

      *addr = act_elem;
    }

  if (base && base != const0_rtx)
    {
      if (*addr)
	*addr = simplify_gen_binary (PLUS, address_mode, base, *addr);
      else
	*addr = base;
    }

  if (symbol)
    {
      act_elem = symbol;
      if (offset)
	{
	  act_elem = gen_rtx_PLUS (address_mode, act_elem, offset);

	  if (offset_p)
	    *offset_p = &XEXP (act_elem, 1);

	  if (GET_CODE (symbol) == SYMBOL_REF
	      || GET_CODE (symbol) == LABEL_REF
	      || GET_CODE (symbol) == CONST)
	    act_elem = gen_rtx_CONST (address_mode, act_elem);
	}

      if (*addr)
	*addr = gen_rtx_PLUS (address_mode, *addr, act_elem);
      else
	*addr = act_elem;
    }
  else if (offset)
    {
      if (*addr)
	{
	  *addr = gen_rtx_PLUS (address_mode, *addr, offset);
	  if (offset_p)
	    *offset_p = &XEXP (*addr, 1);
	}
      else
	{
	  *addr = offset;
	  if (offset_p)
	    *offset_p = addr;
	}
    }

  if (!*addr)
    *addr = const0_rtx;
}
コード例 #6
0
ファイル: fwprop.c プロジェクト: ollie314/gcc
static bool
propagate_rtx_1 (rtx *px, rtx old_rtx, rtx new_rtx, int flags)
{
  rtx x = *px, tem = NULL_RTX, op0, op1, op2;
  enum rtx_code code = GET_CODE (x);
  machine_mode mode = GET_MODE (x);
  machine_mode op_mode;
  bool can_appear = (flags & PR_CAN_APPEAR) != 0;
  bool valid_ops = true;

  if (!(flags & PR_HANDLE_MEM) && MEM_P (x) && !MEM_READONLY_P (x))
    {
      /* If unsafe, change MEMs to CLOBBERs or SCRATCHes (to preserve whether
	 they have side effects or not).  */
      *px = (side_effects_p (x)
	     ? gen_rtx_CLOBBER (GET_MODE (x), const0_rtx)
	     : gen_rtx_SCRATCH (GET_MODE (x)));
      return false;
    }

  /* If X is OLD_RTX, return NEW_RTX.  But not if replacing only within an
     address, and we are *not* inside one.  */
  if (x == old_rtx)
    {
      *px = new_rtx;
      return can_appear;
    }

  /* If this is an expression, try recursive substitution.  */
  switch (GET_RTX_CLASS (code))
    {
    case RTX_UNARY:
      op0 = XEXP (x, 0);
      op_mode = GET_MODE (op0);
      valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
      if (op0 == XEXP (x, 0))
	return true;
      tem = simplify_gen_unary (code, mode, op0, op_mode);
      break;

    case RTX_BIN_ARITH:
    case RTX_COMM_ARITH:
      op0 = XEXP (x, 0);
      op1 = XEXP (x, 1);
      valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
      valid_ops &= propagate_rtx_1 (&op1, old_rtx, new_rtx, flags);
      if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
	return true;
      tem = simplify_gen_binary (code, mode, op0, op1);
      break;

    case RTX_COMPARE:
    case RTX_COMM_COMPARE:
      op0 = XEXP (x, 0);
      op1 = XEXP (x, 1);
      op_mode = GET_MODE (op0) != VOIDmode ? GET_MODE (op0) : GET_MODE (op1);
      valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
      valid_ops &= propagate_rtx_1 (&op1, old_rtx, new_rtx, flags);
      if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
	return true;
      tem = simplify_gen_relational (code, mode, op_mode, op0, op1);
      break;

    case RTX_TERNARY:
    case RTX_BITFIELD_OPS:
      op0 = XEXP (x, 0);
      op1 = XEXP (x, 1);
      op2 = XEXP (x, 2);
      op_mode = GET_MODE (op0);
      valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
      valid_ops &= propagate_rtx_1 (&op1, old_rtx, new_rtx, flags);
      valid_ops &= propagate_rtx_1 (&op2, old_rtx, new_rtx, flags);
      if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1) && op2 == XEXP (x, 2))
	return true;
      if (op_mode == VOIDmode)
	op_mode = GET_MODE (op0);
      tem = simplify_gen_ternary (code, mode, op_mode, op0, op1, op2);
      break;

    case RTX_EXTRA:
      /* The only case we try to handle is a SUBREG.  */
      if (code == SUBREG)
	{
          op0 = XEXP (x, 0);
	  valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
          if (op0 == XEXP (x, 0))
	    return true;
	  tem = simplify_gen_subreg (mode, op0, GET_MODE (SUBREG_REG (x)),
				     SUBREG_BYTE (x));
	}
      break;

    case RTX_OBJ:
      if (code == MEM && x != new_rtx)
	{
	  rtx new_op0;
	  op0 = XEXP (x, 0);

	  /* There are some addresses that we cannot work on.  */
	  if (!can_simplify_addr (op0))
	    return true;

	  op0 = new_op0 = targetm.delegitimize_address (op0);
	  valid_ops &= propagate_rtx_1 (&new_op0, old_rtx, new_rtx,
					flags | PR_CAN_APPEAR);

	  /* Dismiss transformation that we do not want to carry on.  */
	  if (!valid_ops
	      || new_op0 == op0
	      || !(GET_MODE (new_op0) == GET_MODE (op0)
		   || GET_MODE (new_op0) == VOIDmode))
	    return true;

	  canonicalize_address (new_op0);

	  /* Copy propagations are always ok.  Otherwise check the costs.  */
	  if (!(REG_P (old_rtx) && REG_P (new_rtx))
	      && !should_replace_address (op0, new_op0, GET_MODE (x),
					  MEM_ADDR_SPACE (x),
	      			 	  flags & PR_OPTIMIZE_FOR_SPEED))
	    return true;

	  tem = replace_equiv_address_nv (x, new_op0);
	}

      else if (code == LO_SUM)
	{
          op0 = XEXP (x, 0);
          op1 = XEXP (x, 1);

	  /* The only simplification we do attempts to remove references to op0
	     or make it constant -- in both cases, op0's invalidity will not
	     make the result invalid.  */
	  propagate_rtx_1 (&op0, old_rtx, new_rtx, flags | PR_CAN_APPEAR);
	  valid_ops &= propagate_rtx_1 (&op1, old_rtx, new_rtx, flags);
          if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
	    return true;

	  /* (lo_sum (high x) x) -> x  */
	  if (GET_CODE (op0) == HIGH && rtx_equal_p (XEXP (op0, 0), op1))
	    tem = op1;
	  else
	    tem = gen_rtx_LO_SUM (mode, op0, op1);

	  /* OP1 is likely not a legitimate address, otherwise there would have
	     been no LO_SUM.  We want it to disappear if it is invalid, return
	     false in that case.  */
	  return memory_address_p (mode, tem);
	}

      else if (code == REG)
	{
	  if (rtx_equal_p (x, old_rtx))
	    {
              *px = new_rtx;
              return can_appear;
	    }
	}
      break;

    default:
      break;
    }

  /* No change, no trouble.  */
  if (tem == NULL_RTX)
    return true;

  *px = tem;

  /* Allow replacements that simplify operations on a vector or complex
     value to a component.  The most prominent case is
     (subreg ([vec_]concat ...)).   */
  if (REG_P (tem) && !HARD_REGISTER_P (tem)
      && (VECTOR_MODE_P (GET_MODE (new_rtx))
	  || COMPLEX_MODE_P (GET_MODE (new_rtx)))
      && GET_MODE (tem) == GET_MODE_INNER (GET_MODE (new_rtx)))
    return true;

  /* The replacement we made so far is valid, if all of the recursive
     replacements were valid, or we could simplify everything to
     a constant.  */
  return valid_ops || can_appear || CONSTANT_P (tem);
}
コード例 #7
0
ファイル: loop-doloop.c プロジェクト: minji-um/iphone-dev
static void
doloop_modify (struct loop *loop, struct niter_desc *desc,
               rtx doloop_seq, rtx condition, rtx count)
{
    rtx counter_reg;
    rtx tmp, noloop = NULL_RTX;
    rtx sequence;
    rtx jump_insn;
    rtx jump_label;
    int nonneg = 0, irr;
    bool increment_count;
    basic_block loop_end = desc->out_edge->src;
    enum machine_mode mode;

    jump_insn = BB_END (loop_end);

    if (dump_file)
    {
        fprintf (dump_file, "Doloop: Inserting doloop pattern (");
        if (desc->const_iter)
            fprintf (dump_file, HOST_WIDEST_INT_PRINT_DEC, desc->niter);
        else
            fputs ("runtime", dump_file);
        fputs (" iterations).\n", dump_file);
    }

    /* Discard original jump to continue loop.  The original compare
       result may still be live, so it cannot be discarded explicitly.  */
    delete_insn (jump_insn);

    counter_reg = XEXP (condition, 0);
    if (GET_CODE (counter_reg) == PLUS)
        counter_reg = XEXP (counter_reg, 0);
    mode = GET_MODE (counter_reg);

    increment_count = false;
    switch (GET_CODE (condition))
    {
    case NE:
        /* Currently only NE tests against zero and one are supported.  */
        if (XEXP (condition, 1) == const1_rtx)
        {
            increment_count = true;
            noloop = const1_rtx;
        }
        else if (XEXP (condition, 1) == const0_rtx)
            noloop = const0_rtx;
        else
            abort ();
        break;

    case GE:
        /* Currently only GE tests against zero are supported.  */
        if (XEXP (condition, 1) != const0_rtx)
            abort ();

        noloop = constm1_rtx;

        /* The iteration count does not need incrementing for a GE test.  */
        increment_count = false;

        /* Determine if the iteration counter will be non-negative.
        Note that the maximum value loaded is iterations_max - 1.  */
        if (desc->niter_max
                <= ((unsigned HOST_WIDEST_INT) 1
                    << (GET_MODE_BITSIZE (mode) - 1)))
            nonneg = 1;
        break;

    /* Abort if an invalid doloop pattern has been generated.  */
    default:
        abort ();
    }

    if (increment_count)
        count = simplify_gen_binary (PLUS, mode, count, const1_rtx);

    /* Insert initialization of the count register into the loop header.  */
    start_sequence ();
    tmp = force_operand (count, counter_reg);
    convert_move (counter_reg, tmp, 1);
    sequence = get_insns ();
    end_sequence ();
    emit_insn_after (sequence, BB_END (loop_preheader_edge (loop)->src));

    if (desc->noloop_assumptions)
    {
        rtx ass = copy_rtx (desc->noloop_assumptions);
        basic_block preheader = loop_preheader_edge (loop)->src;
        basic_block set_zero
            = loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);
        basic_block new_preheader
            = loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);
        basic_block bb;
        edge te;
        gcov_type cnt;

        /* Expand the condition testing the assumptions and if it does not pass,
        reset the count register to 0.  */
        add_test (XEXP (ass, 0), preheader, set_zero);
        EDGE_SUCC (preheader, 0)->flags &= ~EDGE_FALLTHRU;
        cnt = EDGE_SUCC (preheader, 0)->count;
        EDGE_SUCC (preheader, 0)->probability = 0;
        EDGE_SUCC (preheader, 0)->count = 0;
        irr = EDGE_SUCC (preheader, 0)->flags & EDGE_IRREDUCIBLE_LOOP;
        te = make_edge (preheader, new_preheader, EDGE_FALLTHRU | irr);
        te->probability = REG_BR_PROB_BASE;
        te->count = cnt;
        set_immediate_dominator (CDI_DOMINATORS, new_preheader, preheader);

        set_zero->count = 0;
        set_zero->frequency = 0;

        for (ass = XEXP (ass, 1); ass; ass = XEXP (ass, 1))
        {
            bb = loop_split_edge_with (te, NULL_RTX);
            te = EDGE_SUCC (bb, 0);
            add_test (XEXP (ass, 0), bb, set_zero);
            make_edge (bb, set_zero, irr);
        }

        start_sequence ();
        convert_move (counter_reg, noloop, 0);
        sequence = get_insns ();
        end_sequence ();
        emit_insn_after (sequence, BB_END (set_zero));
    }

    /* Some targets (eg, C4x) need to initialize special looping
       registers.  */
#ifdef HAVE_doloop_begin
    {
        rtx init;
        unsigned level = get_loop_level (loop) + 1;
        init = gen_doloop_begin (counter_reg,
                                 desc->const_iter ? desc->niter_expr : const0_rtx,
                                 desc->niter_max,
                                 GEN_INT (level));
        if (init)
        {
            start_sequence ();
            emit_insn (init);
            sequence = get_insns ();
            end_sequence ();
            emit_insn_after (sequence, BB_END (loop_preheader_edge (loop)->src));
        }
    }
#endif

    /* Insert the new low-overhead looping insn.  */
    emit_jump_insn_after (doloop_seq, BB_END (loop_end));
    jump_insn = BB_END (loop_end);
    jump_label = block_label (desc->in_edge->dest);
    JUMP_LABEL (jump_insn) = jump_label;
    LABEL_NUSES (jump_label)++;

    /* Ensure the right fallthru edge is marked, for case we have reversed
       the condition.  */
    desc->in_edge->flags &= ~EDGE_FALLTHRU;
    desc->out_edge->flags |= EDGE_FALLTHRU;

    /* Add a REG_NONNEG note if the actual or estimated maximum number
       of iterations is non-negative.  */
    if (nonneg)
    {
        REG_NOTES (jump_insn)
            = gen_rtx_EXPR_LIST (REG_NONNEG, NULL_RTX, REG_NOTES (jump_insn));
    }
}
コード例 #8
0
ファイル: value-prof.c プロジェクト: DJHartley/iphone-dev
/* Find values inside INSN for that we want to measure histograms for
   division/modulo optimization and stores them to VALUES.  */
static void
insn_divmod_values_to_profile (rtx insn, histogram_values *values)
{
  rtx set, set_src, op1, op2;
  enum machine_mode mode;
  histogram_value hist;

  if (!INSN_P (insn))
    return;

  set = single_set (insn);
  if (!set)
    return;

  mode = GET_MODE (SET_DEST (set));
  if (!INTEGRAL_MODE_P (mode))
    return;

  set_src = SET_SRC (set);
  switch (GET_CODE (set_src))
    {
    case DIV:
    case MOD:
    case UDIV:
    case UMOD:
      op1 = XEXP (set_src, 0);
      op2 = XEXP (set_src, 1);
      if (side_effects_p (op2))
	return;

      /* Check for a special case where the divisor is power of 2.  */
      if ((GET_CODE (set_src) == UMOD) && !CONSTANT_P (op2))
	{
	  hist = ggc_alloc (sizeof (*hist));
	  hist->value = op2;
	  hist->seq = NULL_RTX;
	  hist->mode = mode;
	  hist->insn = insn;
	  hist->type = HIST_TYPE_POW2;
	  hist->hdata.pow2.may_be_other = 1;
	  VEC_safe_push (histogram_value, *values, hist);
	}

      /* Check whether the divisor is not in fact a constant.  */
      if (!CONSTANT_P (op2))
	{
	  hist = ggc_alloc (sizeof (*hist));
	  hist->value = op2;
	  hist->mode = mode;
	  hist->seq = NULL_RTX;
	  hist->insn = insn;
	  hist->type = HIST_TYPE_SINGLE_VALUE;
	  VEC_safe_push (histogram_value, *values, hist);
	}

      /* For mod, check whether it is not often a noop (or replaceable by
	 a few subtractions).  */
      if (GET_CODE (set_src) == UMOD && !side_effects_p (op1))
	{
	  rtx tmp;

	  hist = ggc_alloc (sizeof (*hist));
	  start_sequence ();
	  tmp = simplify_gen_binary (DIV, mode, copy_rtx (op1), copy_rtx (op2));
	  hist->value = force_operand (tmp, NULL_RTX);
	  hist->seq = get_insns ();
	  end_sequence ();
	  hist->mode = mode;
	  hist->insn = insn;
	  hist->type = HIST_TYPE_INTERVAL;
	  hist->hdata.intvl.int_start = 0;
	  hist->hdata.intvl.steps = 2;
	  hist->hdata.intvl.may_be_less = 1;
	  hist->hdata.intvl.may_be_more = 1;
	  VEC_safe_push (histogram_value, *values, hist);
	}
      return;

    default:
      return;
    }
}