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dtoa.cc
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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 
44 static BignumDtoaMode DtoaToBignumDtoaMode(DtoaMode dtoa_mode) {
45  switch (dtoa_mode) {
47  case DTOA_FIXED: return BIGNUM_DTOA_FIXED;
49  default:
50  UNREACHABLE();
51  return BIGNUM_DTOA_SHORTEST; // To silence compiler.
52  }
53 }
54 
55 
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
#define ASSERT(condition)
Definition: checks.h:270
#define UNREACHABLE()
Definition: checks.h:50
void BignumDtoa(double v, BignumDtoaMode mode, int requested_digits, Vector< char > buffer, int *length, int *decimal_point)
Definition: bignum-dtoa.cc:92
bool FastDtoa(double v, FastDtoaMode mode, int requested_digits, Vector< char > buffer, int *length, int *decimal_point)
Definition: fast-dtoa.cc:709
bool FastFixedDtoa(double v, int fractional_count, Vector< char > buffer, int *length, int *decimal_point)
Definition: fixed-dtoa.cc:312
void DoubleToAscii(double v, DtoaMode mode, int requested_digits, Vector< char > buffer, int *sign, int *length, int *point)
Definition: dtoa.cc:56