1 // Copyright 2011 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer.
8 // * Redistributions in binary form must reproduce the above
9 // copyright notice, this list of conditions and the following
10 // disclaimer in the documentation and/or other materials provided
11 // with the distribution.
12 // * Neither the name of Google Inc. nor the names of its
13 // contributors may be used to endorse or promote products derived
14 // from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
28 #include <math.h>
29
30 #include "../include/v8stdint.h"
31 #include "checks.h"
32 #include "utils.h"
33
34 #include "dtoa.h"
35
36 #include "bignum-dtoa.h"
37 #include "double.h"
38 #include "fast-dtoa.h"
39 #include "fixed-dtoa.h"
40
41 namespace v8 {
42 namespace internal {
43
DtoaToBignumDtoaMode(DtoaMode dtoa_mode)44 static BignumDtoaMode DtoaToBignumDtoaMode(DtoaMode dtoa_mode) {
45 switch (dtoa_mode) {
46 case DTOA_SHORTEST: return BIGNUM_DTOA_SHORTEST;
47 case DTOA_FIXED: return BIGNUM_DTOA_FIXED;
48 case DTOA_PRECISION: return BIGNUM_DTOA_PRECISION;
49 default:
50 UNREACHABLE();
51 return BIGNUM_DTOA_SHORTEST; // To silence compiler.
52 }
53 }
54
55
DoubleToAscii(double v,DtoaMode mode,int requested_digits,Vector<char> buffer,int * sign,int * length,int * point)56 void DoubleToAscii(double v, DtoaMode mode, int requested_digits,
57 Vector<char> buffer, int* sign, int* length, int* point) {
58 ASSERT(!Double(v).IsSpecial());
59 ASSERT(mode == DTOA_SHORTEST || requested_digits >= 0);
60
61 if (Double(v).Sign() < 0) {
62 *sign = 1;
63 v = -v;
64 } else {
65 *sign = 0;
66 }
67
68 if (v == 0) {
69 buffer[0] = '0';
70 buffer[1] = '\0';
71 *length = 1;
72 *point = 1;
73 return;
74 }
75
76 if (mode == DTOA_PRECISION && requested_digits == 0) {
77 buffer[0] = '\0';
78 *length = 0;
79 return;
80 }
81
82 bool fast_worked;
83 switch (mode) {
84 case DTOA_SHORTEST:
85 fast_worked = FastDtoa(v, FAST_DTOA_SHORTEST, 0, buffer, length, point);
86 break;
87 case DTOA_FIXED:
88 fast_worked = FastFixedDtoa(v, requested_digits, buffer, length, point);
89 break;
90 case DTOA_PRECISION:
91 fast_worked = FastDtoa(v, FAST_DTOA_PRECISION, requested_digits,
92 buffer, length, point);
93 break;
94 default:
95 UNREACHABLE();
96 fast_worked = false;
97 }
98 if (fast_worked) return;
99
100 // If the fast dtoa didn't succeed use the slower bignum version.
101 BignumDtoaMode bignum_mode = DtoaToBignumDtoaMode(mode);
102 BignumDtoa(v, bignum_mode, requested_digits, buffer, length, point);
103 buffer[*length] = '\0';
104 }
105
106 } } // namespace v8::internal
107