1// Copyright 2011 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include <cmath>
6
7#include "include/v8stdint.h"
8#include "src/base/logging.h"
9#include "src/utils.h"
10
11#include "src/dtoa.h"
12
13#include "src/bignum-dtoa.h"
14#include "src/double.h"
15#include "src/fast-dtoa.h"
16#include "src/fixed-dtoa.h"
17
18namespace v8 {
19namespace internal {
20
21static BignumDtoaMode DtoaToBignumDtoaMode(DtoaMode dtoa_mode) {
22  switch (dtoa_mode) {
23    case DTOA_SHORTEST:  return BIGNUM_DTOA_SHORTEST;
24    case DTOA_FIXED:     return BIGNUM_DTOA_FIXED;
25    case DTOA_PRECISION: return BIGNUM_DTOA_PRECISION;
26    default:
27      UNREACHABLE();
28      return BIGNUM_DTOA_SHORTEST;  // To silence compiler.
29  }
30}
31
32
33void DoubleToAscii(double v, DtoaMode mode, int requested_digits,
34                   Vector<char> buffer, int* sign, int* length, int* point) {
35  DCHECK(!Double(v).IsSpecial());
36  DCHECK(mode == DTOA_SHORTEST || requested_digits >= 0);
37
38  if (Double(v).Sign() < 0) {
39    *sign = 1;
40    v = -v;
41  } else {
42    *sign = 0;
43  }
44
45  if (v == 0) {
46    buffer[0] = '0';
47    buffer[1] = '\0';
48    *length = 1;
49    *point = 1;
50    return;
51  }
52
53  if (mode == DTOA_PRECISION && requested_digits == 0) {
54    buffer[0] = '\0';
55    *length = 0;
56    return;
57  }
58
59  bool fast_worked;
60  switch (mode) {
61    case DTOA_SHORTEST:
62      fast_worked = FastDtoa(v, FAST_DTOA_SHORTEST, 0, buffer, length, point);
63      break;
64    case DTOA_FIXED:
65      fast_worked = FastFixedDtoa(v, requested_digits, buffer, length, point);
66      break;
67    case DTOA_PRECISION:
68      fast_worked = FastDtoa(v, FAST_DTOA_PRECISION, requested_digits,
69                             buffer, length, point);
70      break;
71    default:
72      UNREACHABLE();
73      fast_worked = false;
74  }
75  if (fast_worked) return;
76
77  // If the fast dtoa didn't succeed use the slower bignum version.
78  BignumDtoaMode bignum_mode = DtoaToBignumDtoaMode(mode);
79  BignumDtoa(v, bignum_mode, requested_digits, buffer, length, point);
80  buffer[*length] = '\0';
81}
82
83} }  // namespace v8::internal
84