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