Source/WTF/wtf/dtoa.cpp - Issue 14238015: Move Source/WTF/wtf to Source/wtf

Unified Diff: Source/WTF/wtf/dtoa.cpp

Issue 14238015: Move Source/WTF/wtf to Source/wtf (Closed) Base URL: svn://svn.chromium.org/blink/trunk

Patch Set: Created 7 years, 8 months ago

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Index: Source/WTF/wtf/dtoa.cpp

diff --git a/Source/WTF/wtf/dtoa.cpp b/Source/WTF/wtf/dtoa.cpp

deleted file mode 100644

index 7de4172c4bb1b9572e8916b7897e4d84f677a245..0000000000000000000000000000000000000000

--- a/Source/WTF/wtf/dtoa.cpp

+++ /dev/null

@@ -1,1313 +0,0 @@

-/****************************************************************

- *

- * The author of this software is David M. Gay.

- *

- * Permission to use, copy, modify, and distribute this software for any

- * purpose without fee is hereby granted, provided that this entire notice

- * is included in all copies of any software which is or includes a copy

- * or modification of this software and in all copies of the supporting

- * documentation for such software.

- *

- * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED

- * WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR LUCENT MAKES ANY

- * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY

- * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.

- *

- ***************************************************************/

-/* Please send bug reports to David M. Gay (dmg at acm dot org,

- * with " at " changed at "@" and " dot " changed to "."). */

-/* On a machine with IEEE extended-precision registers, it is

- * necessary to specify double-precision (53-bit) rounding precision

- * before invoking strtod or dtoa. If the machine uses (the equivalent

- * of) Intel 80x87 arithmetic, the call

- * _control87(PC_53, MCW_PC);

- * does this with many compilers. Whether this or another call is

- * appropriate depends on the compiler; for this to work, it may be

- * necessary to #include "float.h" or another system-dependent header

- * file.

- */

-#include "config.h"

-#include "dtoa.h"

-#include <stdio.h>

-#include <wtf/MathExtras.h>

-#include <wtf/Threading.h>

-#include <wtf/Vector.h>

-#if COMPILER(MSVC)

-#pragma warning(disable: 4244)

-#pragma warning(disable: 4245)

-#pragma warning(disable: 4554)

-#endif

-namespace WTF {

-Mutex* s_dtoaP5Mutex;

-typedef union {

- double d;

- uint32_t L[2];

-} U;

-#if CPU(BIG_ENDIAN) || CPU(MIDDLE_ENDIAN)

-#define word0(x) (x)->L[0]

-#define word1(x) (x)->L[1]

-#else

-#define word0(x) (x)->L[1]

-#define word1(x) (x)->L[0]

-#endif

-#define dval(x) (x)->d

-/* The following definition of Storeinc is appropriate for MIPS processors.

- * An alternative that might be better on some machines is

- * *p++ = high << 16 | low & 0xffff;

- */

-static ALWAYS_INLINE uint32_t* storeInc(uint32_t* p, uint16_t high, uint16_t low)

- uint16_t* p16 = reinterpret_cast<uint16_t*>(p);

-#if CPU(BIG_ENDIAN)

- p16[0] = high;

- p16[1] = low;

-#else

- p16[1] = high;

- p16[0] = low;

-#endif

- return p + 1;

-#define Exp_shift 20

-#define Exp_shift1 20

-#define Exp_msk1 0x100000

-#define Exp_msk11 0x100000

-#define Exp_mask 0x7ff00000

-#define P 53

-#define Bias 1023

-#define Emin (-1022)

-#define Exp_1 0x3ff00000

-#define Exp_11 0x3ff00000

-#define Ebits 11

-#define Frac_mask 0xfffff

-#define Frac_mask1 0xfffff

-#define Ten_pmax 22

-#define Bletch 0x10

-#define Bndry_mask 0xfffff

-#define Bndry_mask1 0xfffff

-#define LSB 1

-#define Sign_bit 0x80000000

-#define Log2P 1

-#define Tiny0 0

-#define Tiny1 1

-#define Quick_max 14

-#define Int_max 14

-#define rounded_product(a, b) a *= b

-#define rounded_quotient(a, b) a /= b

-#define Big0 (Frac_mask1 | Exp_msk1 * (DBL_MAX_EXP + Bias - 1))

-#define Big1 0xffffffff

-#if CPU(PPC64) || CPU(X86_64)

-// FIXME: should we enable this on all 64-bit CPUs?

-// 64-bit emulation provided by the compiler is likely to be slower than dtoa own code on 32-bit hardware.

-#define USE_LONG_LONG

-#endif

-struct BigInt {

- BigInt() : sign(0) { }

- int sign;

- void clear()

- {

- sign = 0;

- m_words.clear();

- }

- size_t size() const

- {

- return m_words.size();

- }

- void resize(size_t s)

- {

- m_words.resize(s);

- }

- uint32_t* words()

- {

- return m_words.data();

- }

- const uint32_t* words() const

- {

- return m_words.data();

- }

- void append(uint32_t w)

- {

- m_words.append(w);

- }

- Vector<uint32_t, 16> m_words;

-};

-static void multadd(BigInt& b, int m, int a) /* multiply by m and add a */

-#ifdef USE_LONG_LONG

- unsigned long long carry;

-#else

- uint32_t carry;

-#endif

- int wds = b.size();

- uint32_t* x = b.words();

- int i = 0;

- carry = a;

- do {

-#ifdef USE_LONG_LONG

- unsigned long long y = *x * (unsigned long long)m + carry;

- carry = y >> 32;

- *x++ = (uint32_t)y & 0xffffffffUL;

-#else

- uint32_t xi = *x;

- uint32_t y = (xi & 0xffff) * m + carry;

- uint32_t z = (xi >> 16) * m + (y >> 16);

- carry = z >> 16;

- *x++ = (z << 16) + (y & 0xffff);

-#endif

- } while (++i < wds);

- if (carry)

- b.append((uint32_t)carry);

-static int hi0bits(uint32_t x)

- int k = 0;

- if (!(x & 0xffff0000)) {

- k = 16;

- x <<= 16;

- }

- if (!(x & 0xff000000)) {

- k += 8;

- x <<= 8;

- }

- if (!(x & 0xf0000000)) {

- k += 4;

- x <<= 4;

- }

- if (!(x & 0xc0000000)) {

- k += 2;

- x <<= 2;

- }

- if (!(x & 0x80000000)) {

- k++;

- if (!(x & 0x40000000))

- return 32;

- }

- return k;

-static int lo0bits(uint32_t* y)

- int k;

- uint32_t x = *y;

- if (x & 7) {

- if (x & 1)

- return 0;

- if (x & 2) {

- *y = x >> 1;

- return 1;

- }

- *y = x >> 2;

- return 2;

- }

- k = 0;

- if (!(x & 0xffff)) {

- k = 16;

- x >>= 16;

- }

- if (!(x & 0xff)) {

- k += 8;

- x >>= 8;

- }

- if (!(x & 0xf)) {

- k += 4;

- x >>= 4;

- }

- if (!(x & 0x3)) {

- k += 2;

- x >>= 2;

- }

- if (!(x & 1)) {

- k++;

- x >>= 1;

- if (!x)

- return 32;

- }

- *y = x;

- return k;

-static void i2b(BigInt& b, int i)

- b.sign = 0;

- b.resize(1);

- b.words()[0] = i;

-static void mult(BigInt& aRef, const BigInt& bRef)

- const BigInt* a = &aRef;

- const BigInt* b = &bRef;

- BigInt c;

- int wa, wb, wc;

- const uint32_t* x = 0;

- const uint32_t* xa;

- const uint32_t* xb;

- const uint32_t* xae;

- const uint32_t* xbe;

- uint32_t* xc;

- uint32_t* xc0;

- uint32_t y;

-#ifdef USE_LONG_LONG

- unsigned long long carry, z;

-#else

- uint32_t carry, z;

-#endif

- if (a->size() < b->size()) {

- const BigInt* tmp = a;

- a = b;

- b = tmp;

- }

- wa = a->size();

- wb = b->size();

- wc = wa + wb;

- c.resize(wc);

- for (xc = c.words(), xa = xc + wc; xc < xa; xc++)

- *xc = 0;

- xa = a->words();

- xae = xa + wa;

- xb = b->words();

- xbe = xb + wb;

- xc0 = c.words();

-#ifdef USE_LONG_LONG

- for (; xb < xbe; xc0++) {

- if ((y = *xb++)) {

- x = xa;

- xc = xc0;

- carry = 0;

- do {

- z = *x++ * (unsigned long long)y + *xc + carry;

- carry = z >> 32;

- *xc++ = (uint32_t)z & 0xffffffffUL;

- } while (x < xae);

- *xc = (uint32_t)carry;

- }

-#else

- for (; xb < xbe; xb++, xc0++) {

- if ((y = *xb & 0xffff)) {

- x = xa;

- xc = xc0;

- carry = 0;

- do {

- z = (*x & 0xffff) * y + (*xc & 0xffff) + carry;

- carry = z >> 16;

- uint32_t z2 = (*x++ >> 16) * y + (*xc >> 16) + carry;

- carry = z2 >> 16;

- xc = storeInc(xc, z2, z);

- } while (x < xae);

- *xc = carry;

- }

- if ((y = *xb >> 16)) {

- x = xa;

- xc = xc0;

- carry = 0;

- uint32_t z2 = *xc;

- do {

- z = (*x & 0xffff) * y + (*xc >> 16) + carry;

- carry = z >> 16;

- xc = storeInc(xc, z, z2);

- z2 = (*x++ >> 16) * y + (*xc & 0xffff) + carry;

- carry = z2 >> 16;

- } while (x < xae);

- *xc = z2;

- }

-#endif

- for (xc0 = c.words(), xc = xc0 + wc; wc > 0 && !*--xc; --wc) { }

- c.resize(wc);

- aRef = c;

-struct P5Node {

- WTF_MAKE_NONCOPYABLE(P5Node); WTF_MAKE_FAST_ALLOCATED;

-public:

- P5Node() { }

- BigInt val;

- P5Node* next;

-};

-static P5Node* p5s;

-static int p5sCount;

-static ALWAYS_INLINE void pow5mult(BigInt& b, int k)

- static int p05[3] = { 5, 25, 125 };

- if (int i = k & 3)

- multadd(b, p05[i - 1], 0);

- if (!(k >>= 2))

- return;

- s_dtoaP5Mutex->lock();

- P5Node* p5 = p5s;

- if (!p5) {

- /* first time */

- p5 = new P5Node;

- i2b(p5->val, 625);

- p5->next = 0;

- p5s = p5;

- p5sCount = 1;

- }

- int p5sCountLocal = p5sCount;

- s_dtoaP5Mutex->unlock();

- int p5sUsed = 0;

- for (;;) {

- if (k & 1)

- mult(b, p5->val);

- if (!(k >>= 1))

- break;

- if (++p5sUsed == p5sCountLocal) {

- s_dtoaP5Mutex->lock();

- if (p5sUsed == p5sCount) {

- ASSERT(!p5->next);

- p5->next = new P5Node;

- p5->next->next = 0;

- p5->next->val = p5->val;

- mult(p5->next->val, p5->next->val);

- ++p5sCount;

- }

- p5sCountLocal = p5sCount;

- s_dtoaP5Mutex->unlock();

- }

- p5 = p5->next;

- }

-static ALWAYS_INLINE void lshift(BigInt& b, int k)

- int n = k >> 5;

- int origSize = b.size();

- int n1 = n + origSize + 1;

- if (k &= 0x1f)

- b.resize(b.size() + n + 1);

- else

- b.resize(b.size() + n);

- const uint32_t* srcStart = b.words();

- uint32_t* dstStart = b.words();

- const uint32_t* src = srcStart + origSize - 1;

- uint32_t* dst = dstStart + n1 - 1;

- if (k) {

- uint32_t hiSubword = 0;

- int s = 32 - k;

- for (; src >= srcStart; --src) {

- *dst-- = hiSubword | *src >> s;

- hiSubword = *src << k;

- }

- *dst = hiSubword;

- ASSERT(dst == dstStart + n);

- b.resize(origSize + n + !!b.words()[n1 - 1]);

- }

- else {

- do {

- *--dst = *src--;

- } while (src >= srcStart);

- }

- for (dst = dstStart + n; dst != dstStart; )

- *--dst = 0;

- ASSERT(b.size() <= 1 || b.words()[b.size() - 1]);

-static int cmp(const BigInt& a, const BigInt& b)

- const uint32_t *xa, *xa0, *xb, *xb0;

- int i, j;

- i = a.size();

- j = b.size();

- ASSERT(i <= 1 || a.words()[i - 1]);

- ASSERT(j <= 1 || b.words()[j - 1]);

- if (i -= j)

- return i;

- xa0 = a.words();

- xa = xa0 + j;

- xb0 = b.words();

- xb = xb0 + j;

- for (;;) {

- if (*--xa != *--xb)

- return *xa < *xb ? -1 : 1;

- if (xa <= xa0)

- break;

- }

- return 0;

-static ALWAYS_INLINE void diff(BigInt& c, const BigInt& aRef, const BigInt& bRef)

- const BigInt* a = &aRef;

- const BigInt* b = &bRef;

- int i, wa, wb;

- uint32_t* xc;

- i = cmp(*a, *b);

- if (!i) {

- c.sign = 0;

- c.resize(1);

- c.words()[0] = 0;

- return;

- }

- if (i < 0) {

- const BigInt* tmp = a;

- a = b;

- b = tmp;

- i = 1;

- } else

- i = 0;

- wa = a->size();

- const uint32_t* xa = a->words();

- const uint32_t* xae = xa + wa;

- wb = b->size();

- const uint32_t* xb = b->words();

- const uint32_t* xbe = xb + wb;

- c.resize(wa);

- c.sign = i;

- xc = c.words();

-#ifdef USE_LONG_LONG

- unsigned long long borrow = 0;

- do {

- unsigned long long y = (unsigned long long)*xa++ - *xb++ - borrow;

- borrow = y >> 32 & (uint32_t)1;

- *xc++ = (uint32_t)y & 0xffffffffUL;

- } while (xb < xbe);

- while (xa < xae) {

- unsigned long long y = *xa++ - borrow;

- borrow = y >> 32 & (uint32_t)1;

- *xc++ = (uint32_t)y & 0xffffffffUL;

- }

-#else

- uint32_t borrow = 0;

- do {

- uint32_t y = (*xa & 0xffff) - (*xb & 0xffff) - borrow;

- borrow = (y & 0x10000) >> 16;

- uint32_t z = (*xa++ >> 16) - (*xb++ >> 16) - borrow;

- borrow = (z & 0x10000) >> 16;

- xc = storeInc(xc, z, y);

- } while (xb < xbe);

- while (xa < xae) {

- uint32_t y = (*xa & 0xffff) - borrow;

- borrow = (y & 0x10000) >> 16;

- uint32_t z = (*xa++ >> 16) - borrow;

- borrow = (z & 0x10000) >> 16;

- xc = storeInc(xc, z, y);

- }

-#endif

- while (!*--xc)

- wa--;

- c.resize(wa);

-static ALWAYS_INLINE void d2b(BigInt& b, U* d, int* e, int* bits)

- int de, k;

- uint32_t* x;

- uint32_t y, z;

- int i;

-#define d0 word0(d)

-#define d1 word1(d)

- b.sign = 0;

- b.resize(1);

- x = b.words();

- z = d0 & Frac_mask;

- d0 &= 0x7fffffff; /* clear sign bit, which we ignore */

- if ((de = (int)(d0 >> Exp_shift)))

- z |= Exp_msk1;

- if ((y = d1)) {

- if ((k = lo0bits(&y))) {

- x[0] = y | (z << (32 - k));

- z >>= k;

- } else

- x[0] = y;

- if (z) {

- b.resize(2);

- x[1] = z;

- }

- i = b.size();

- } else {

- k = lo0bits(&z);

- x[0] = z;

- i = 1;

- b.resize(1);

- k += 32;

- }

- if (de) {

- *e = de - Bias - (P - 1) + k;

- *bits = P - k;

- } else {

- *e = 0 - Bias - (P - 1) + 1 + k;

- *bits = (32 * i) - hi0bits(x[i - 1]);

- }

-#undef d0

-#undef d1

-static const double tens[] = {

- 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,

- 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,

- 1e20, 1e21, 1e22

-};

-static const double bigtens[] = { 1e16, 1e32, 1e64, 1e128, 1e256 };

-static const double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128,

- 9007199254740992. * 9007199254740992.e-256

- /* = 2^106 * 1e-256 */

-};

-/* The factor of 2^53 in tinytens[4] helps us avoid setting the underflow */

-/* flag unnecessarily. It leads to a song and dance at the end of strtod. */

-#define Scale_Bit 0x10

-#define n_bigtens 5

-static ALWAYS_INLINE int quorem(BigInt& b, BigInt& S)

- size_t n;

- uint32_t* bx;

- uint32_t* bxe;

- uint32_t q;

- uint32_t* sx;

- uint32_t* sxe;

-#ifdef USE_LONG_LONG

- unsigned long long borrow, carry, y, ys;

-#else

- uint32_t borrow, carry, y, ys;

- uint32_t si, z, zs;

-#endif

- ASSERT(b.size() <= 1 || b.words()[b.size() - 1]);

- ASSERT(S.size() <= 1 || S.words()[S.size() - 1]);

- n = S.size();

- ASSERT_WITH_MESSAGE(b.size() <= n, "oversize b in quorem");

- if (b.size() < n)

- return 0;

- sx = S.words();

- sxe = sx + --n;

- bx = b.words();

- bxe = bx + n;

- q = *bxe / (*sxe + 1); /* ensure q <= true quotient */

- ASSERT_WITH_MESSAGE(q <= 9, "oversized quotient in quorem");

- if (q) {

- borrow = 0;

- carry = 0;

- do {

-#ifdef USE_LONG_LONG

- ys = *sx++ * (unsigned long long)q + carry;

- carry = ys >> 32;

- y = *bx - (ys & 0xffffffffUL) - borrow;

- borrow = y >> 32 & (uint32_t)1;

- *bx++ = (uint32_t)y & 0xffffffffUL;

-#else

- si = *sx++;

- ys = (si & 0xffff) * q + carry;

- zs = (si >> 16) * q + (ys >> 16);

- carry = zs >> 16;

- y = (*bx & 0xffff) - (ys & 0xffff) - borrow;

- borrow = (y & 0x10000) >> 16;

- z = (*bx >> 16) - (zs & 0xffff) - borrow;

- borrow = (z & 0x10000) >> 16;

- bx = storeInc(bx, z, y);

-#endif

- } while (sx <= sxe);

- if (!*bxe) {

- bx = b.words();

- while (--bxe > bx && !*bxe)

- --n;

- b.resize(n);

- }

- if (cmp(b, S) >= 0) {

- q++;

- borrow = 0;

- carry = 0;

- bx = b.words();

- sx = S.words();

- do {

-#ifdef USE_LONG_LONG

- ys = *sx++ + carry;

- carry = ys >> 32;

- y = *bx - (ys & 0xffffffffUL) - borrow;

- borrow = y >> 32 & (uint32_t)1;

- *bx++ = (uint32_t)y & 0xffffffffUL;

-#else

- si = *sx++;

- ys = (si & 0xffff) + carry;

- zs = (si >> 16) + (ys >> 16);

- carry = zs >> 16;

- y = (*bx & 0xffff) - (ys & 0xffff) - borrow;

- borrow = (y & 0x10000) >> 16;

- z = (*bx >> 16) - (zs & 0xffff) - borrow;

- borrow = (z & 0x10000) >> 16;

- bx = storeInc(bx, z, y);

-#endif

- } while (sx <= sxe);

- bx = b.words();

- bxe = bx + n;

- if (!*bxe) {

- while (--bxe > bx && !*bxe)

- --n;

- b.resize(n);

- }

- return q;

-/* dtoa for IEEE arithmetic (dmg): convert double to ASCII string.

- *

- * Inspired by "How to Print Floating-Point Numbers Accurately" by

- * Guy L. Steele, Jr. and Jon L. White [Proc. ACM SIGPLAN '90, pp. 112-126].

- *

- * Modifications:

- * 1. Rather than iterating, we use a simple numeric overestimate

- * to determine k = floor(log10(d)). We scale relevant

- * quantities using O(log2(k)) rather than O(k) multiplications.

- * 2. For some modes > 2 (corresponding to ecvt and fcvt), we don't

- * try to generate digits strictly left to right. Instead, we

- * compute with fewer bits and propagate the carry if necessary

- * when rounding the final digit up. This is often faster.

- * 3. Under the assumption that input will be rounded nearest,

- * mode 0 renders 1e23 as 1e23 rather than 9.999999999999999e22.

- * That is, we allow equality in stopping tests when the

- * round-nearest rule will give the same floating-point value

- * as would satisfaction of the stopping test with strict

- * inequality.

- * 4. We remove common factors of powers of 2 from relevant

- * quantities.

- * 5. When converting floating-point integers less than 1e16,

- * we use floating-point arithmetic rather than resorting

- * to multiple-precision integers.

- * 6. When asked to produce fewer than 15 digits, we first try

- * to get by with floating-point arithmetic; we resort to

- * multiple-precision integer arithmetic only if we cannot

- * guarantee that the floating-point calculation has given

- * the correctly rounded result. For k requested digits and

- * "uniformly" distributed input, the probability is

- * something like 10^(k-15) that we must resort to the int32_t

- * calculation.

- *

- * Note: 'leftright' translates to 'generate shortest possible string'.

- */

-template<bool roundingNone, bool roundingSignificantFigures, bool roundingDecimalPlaces, bool leftright>

-void dtoa(DtoaBuffer result, double dd, int ndigits, bool& signOut, int& exponentOut, unsigned& precisionOut)

- // Exactly one rounding mode must be specified.

- ASSERT(roundingNone + roundingSignificantFigures + roundingDecimalPlaces == 1);

- // roundingNone only allowed (only sensible?) with leftright set.

- ASSERT(!roundingNone || leftright);

- ASSERT(std::isfinite(dd));

- int bbits, b2, b5, be, dig, i, ieps, ilim = 0, ilim0, ilim1 = 0,

- j, j1, k, k0, k_check, m2, m5, s2, s5,

- spec_case;

- int32_t L;

- int denorm;

- uint32_t x;

- BigInt b, delta, mlo, mhi, S;

- U d2, eps, u;

- double ds;

- char* s;

- char* s0;

- u.d = dd;

- /* Infinity or NaN */

- ASSERT((word0(&u) & Exp_mask) != Exp_mask);

- // JavaScript toString conversion treats -0 as 0.

- if (!dval(&u)) {

- signOut = false;

- exponentOut = 0;

- precisionOut = 1;

- result[0] = '0';

- result[1] = '\0';

- return;

- }

- if (word0(&u) & Sign_bit) {

- signOut = true;

- word0(&u) &= ~Sign_bit; // clear sign bit

- } else

- signOut = false;

- d2b(b, &u, &be, &bbits);

- if ((i = (int)(word0(&u) >> Exp_shift1 & (Exp_mask >> Exp_shift1)))) {

- dval(&d2) = dval(&u);

- word0(&d2) &= Frac_mask1;

- word0(&d2) |= Exp_11;

- /* log(x) ~=~ log(1.5) + (x-1.5)/1.5

- * log10(x) = log(x) / log(10)

- * ~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10))

- * log10(d) = (i-Bias)*log(2)/log(10) + log10(d2)

- *

- * This suggests computing an approximation k to log10(d) by

- *

- * k = (i - Bias)*0.301029995663981

- * + ( (d2-1.5)*0.289529654602168 + 0.176091259055681 );

- *

- * We want k to be too large rather than too small.

- * The error in the first-order Taylor series approximation

- * is in our favor, so we just round up the constant enough

- * to compensate for any error in the multiplication of

- * (i - Bias) by 0.301029995663981; since |i - Bias| <= 1077,

- * and 1077 * 0.30103 * 2^-52 ~=~ 7.2e-14,

- * adding 1e-13 to the constant term more than suffices.

- * Hence we adjust the constant term to 0.1760912590558.

- * (We could get a more accurate k by invoking log10,

- * but this is probably not worthwhile.)

- */

- i -= Bias;

- denorm = 0;

- } else {

- /* d is denormalized */

- i = bbits + be + (Bias + (P - 1) - 1);

- x = (i > 32) ? (word0(&u) << (64 - i)) | (word1(&u) >> (i - 32))

- : word1(&u) << (32 - i);

- dval(&d2) = x;

- word0(&d2) -= 31 * Exp_msk1; /* adjust exponent */

- i -= (Bias + (P - 1) - 1) + 1;

- denorm = 1;

- }

- ds = (dval(&d2) - 1.5) * 0.289529654602168 + 0.1760912590558 + (i * 0.301029995663981);

- k = (int)ds;

- if (ds < 0. && ds != k)

- k--; /* want k = floor(ds) */

- k_check = 1;

- if (k >= 0 && k <= Ten_pmax) {

- if (dval(&u) < tens[k])

- k--;

- k_check = 0;

- }

- j = bbits - i - 1;

- if (j >= 0) {

- b2 = 0;

- s2 = j;

- } else {

- b2 = -j;

- s2 = 0;

- }

- if (k >= 0) {

- b5 = 0;

- s5 = k;

- s2 += k;

- } else {

- b2 -= k;

- b5 = -k;

- s5 = 0;

- }

- if (roundingNone) {

- ilim = ilim1 = -1;

- i = 18;

- ndigits = 0;

- }

- if (roundingSignificantFigures) {

- if (ndigits <= 0)

- ndigits = 1;

- ilim = ilim1 = i = ndigits;

- }

- if (roundingDecimalPlaces) {

- i = ndigits + k + 1;

- ilim = i;

- ilim1 = i - 1;

- if (i <= 0)

- i = 1;

- }

- s = s0 = result;

- if (ilim >= 0 && ilim <= Quick_max) {

- /* Try to get by with floating-point arithmetic. */

- i = 0;

- dval(&d2) = dval(&u);

- k0 = k;

- ilim0 = ilim;

- ieps = 2; /* conservative */

- if (k > 0) {

- ds = tens[k & 0xf];

- j = k >> 4;

- if (j & Bletch) {

- /* prevent overflows */

- j &= Bletch - 1;

- dval(&u) /= bigtens[n_bigtens - 1];

- ieps++;

- }

- for (; j; j >>= 1, i++) {

- if (j & 1) {

- ieps++;

- ds *= bigtens[i];

- }

- dval(&u) /= ds;

- } else if ((j1 = -k)) {

- dval(&u) *= tens[j1 & 0xf];

- for (j = j1 >> 4; j; j >>= 1, i++) {

- if (j & 1) {

- ieps++;

- dval(&u) *= bigtens[i];

- }

- if (k_check && dval(&u) < 1. && ilim > 0) {

- if (ilim1 <= 0)

- goto fastFailed;

- ilim = ilim1;

- k--;

- dval(&u) *= 10.;

- ieps++;

- }

- dval(&eps) = (ieps * dval(&u)) + 7.;

- word0(&eps) -= (P - 1) * Exp_msk1;

- if (!ilim) {

- S.clear();

- mhi.clear();

- dval(&u) -= 5.;

- if (dval(&u) > dval(&eps))

- goto oneDigit;

- if (dval(&u) < -dval(&eps))

- goto noDigits;

- goto fastFailed;

- }

- if (leftright) {

- /* Use Steele & White method of only

- * generating digits needed.

- */

- dval(&eps) = (0.5 / tens[ilim - 1]) - dval(&eps);

- for (i = 0;;) {

- L = (long int)dval(&u);

- dval(&u) -= L;

- *s++ = '0' + (int)L;

- if (dval(&u) < dval(&eps))

- goto ret;

- if (1. - dval(&u) < dval(&eps))

- goto bumpUp;

- if (++i >= ilim)

- break;

- dval(&eps) *= 10.;

- dval(&u) *= 10.;

- }

- } else {

- /* Generate ilim digits, then fix them up. */

- dval(&eps) *= tens[ilim - 1];

- for (i = 1;; i++, dval(&u) *= 10.) {

- L = (int32_t)(dval(&u));

- if (!(dval(&u) -= L))

- ilim = i;

- *s++ = '0' + (int)L;

- if (i == ilim) {

- if (dval(&u) > 0.5 + dval(&eps))

- goto bumpUp;

- if (dval(&u) < 0.5 - dval(&eps)) {

- while (*--s == '0') { }

- s++;

- goto ret;

- }

- break;

- }

-fastFailed:

- s = s0;

- dval(&u) = dval(&d2);

- k = k0;

- ilim = ilim0;

- }

- /* Do we have a "small" integer? */

- if (be >= 0 && k <= Int_max) {

- /* Yes. */

- ds = tens[k];

- if (ndigits < 0 && ilim <= 0) {

- S.clear();

- mhi.clear();

- if (ilim < 0 || dval(&u) <= 5 * ds)

- goto noDigits;

- goto oneDigit;

- }

- for (i = 1;; i++, dval(&u) *= 10.) {

- L = (int32_t)(dval(&u) / ds);

- dval(&u) -= L * ds;

- *s++ = '0' + (int)L;

- if (!dval(&u)) {

- break;

- }

- if (i == ilim) {

- dval(&u) += dval(&u);

- if (dval(&u) > ds || (dval(&u) == ds && (L & 1))) {

-bumpUp:

- while (*--s == '9')

- if (s == s0) {

- k++;

- *s = '0';

- break;

- }

- ++*s++;

- }

- break;

- }

- goto ret;

- }

- m2 = b2;

- m5 = b5;

- mhi.clear();

- mlo.clear();

- if (leftright) {

- i = denorm ? be + (Bias + (P - 1) - 1 + 1) : 1 + P - bbits;

- b2 += i;

- s2 += i;

- i2b(mhi, 1);

- }

- if (m2 > 0 && s2 > 0) {

- i = m2 < s2 ? m2 : s2;

- b2 -= i;

- m2 -= i;

- s2 -= i;

- }

- if (b5 > 0) {

- if (leftright) {

- if (m5 > 0) {

- pow5mult(mhi, m5);

- mult(b, mhi);

- }

- if ((j = b5 - m5))

- pow5mult(b, j);

- } else

- pow5mult(b, b5);

- }

- i2b(S, 1);

- if (s5 > 0)

- pow5mult(S, s5);

- /* Check for special case that d is a normalized power of 2. */

- spec_case = 0;

- if ((roundingNone || leftright) && (!word1(&u) && !(word0(&u) & Bndry_mask) && word0(&u) & (Exp_mask & ~Exp_msk1))) {

- /* The special case */

- b2 += Log2P;

- s2 += Log2P;

- spec_case = 1;

- }

- /* Arrange for convenient computation of quotients:

- * shift left if necessary so divisor has 4 leading 0 bits.

- *

- * Perhaps we should just compute leading 28 bits of S once

- * and for all and pass them and a shift to quorem, so it

- * can do shifts and ors to compute the numerator for q.

- */

- if ((i = ((s5 ? 32 - hi0bits(S.words()[S.size() - 1]) : 1) + s2) & 0x1f))

- i = 32 - i;

- if (i > 4) {

- i -= 4;

- b2 += i;

- m2 += i;

- s2 += i;

- } else if (i < 4) {

- i += 28;

- b2 += i;

- m2 += i;

- s2 += i;

- }

- if (b2 > 0)

- lshift(b, b2);

- if (s2 > 0)

- lshift(S, s2);

- if (k_check) {

- if (cmp(b, S) < 0) {

- k--;

- multadd(b, 10, 0); /* we botched the k estimate */

- if (leftright)

- multadd(mhi, 10, 0);

- ilim = ilim1;

- }

- if (ilim <= 0 && roundingDecimalPlaces) {

- if (ilim < 0)

- goto noDigits;

- multadd(S, 5, 0);

- // For IEEE-754 unbiased rounding this check should be <=, such that 0.5 would flush to zero.

- if (cmp(b, S) < 0)

- goto noDigits;

- goto oneDigit;

- }

- if (leftright) {

- if (m2 > 0)

- lshift(mhi, m2);

- /* Compute mlo -- check for special case

- * that d is a normalized power of 2.

- */

- mlo = mhi;

- if (spec_case)

- lshift(mhi, Log2P);

- for (i = 1;;i++) {

- dig = quorem(b, S) + '0';

- /* Do we yet have the shortest decimal string

- * that will round to d?

- */

- j = cmp(b, mlo);

- diff(delta, S, mhi);

- j1 = delta.sign ? 1 : cmp(b, delta);

-#ifdef DTOA_ROUND_BIASED

- if (j < 0 || !j) {

-#else

- // FIXME: ECMA-262 specifies that equidistant results round away from

- // zero, which probably means we shouldn't be on the unbiased code path

- // (the (word1(&u) & 1) clause is looking highly suspicious). I haven't

- // yet understood this code well enough to make the call, but we should

- // probably be enabling DTOA_ROUND_BIASED. I think the interesting corner

- // case to understand is probably "Math.pow(0.5, 24).toString()".

- // I believe this value is interesting because I think it is precisely

- // representable in binary floating point, and its decimal representation

- // has a single digit that Steele & White reduction can remove, with the

- // value 5 (thus equidistant from the next numbers above and below).

- // We produce the correct answer using either codepath, and I don't as

- // yet understand why. :-)

- if (!j1 && !(word1(&u) & 1)) {

- if (dig == '9')

- goto round9up;

- if (j > 0)

- dig++;

- *s++ = dig;

- goto ret;

- }

- if (j < 0 || (!j && !(word1(&u) & 1))) {

-#endif

- if ((b.words()[0] || b.size() > 1) && (j1 > 0)) {

- lshift(b, 1);

- j1 = cmp(b, S);

- // For IEEE-754 round-to-even, this check should be (j1 > 0 || (!j1 && (dig & 1))),

- // but ECMA-262 specifies that equidistant values (e.g. (.5).toFixed()) should

- // be rounded away from zero.

- if (j1 >= 0) {

- if (dig == '9')

- goto round9up;

- dig++;

- }

- *s++ = dig;

- goto ret;

- }

- if (j1 > 0) {

- if (dig == '9') { /* possible if i == 1 */

-round9up:

- *s++ = '9';

- goto roundoff;

- }

- *s++ = dig + 1;

- goto ret;

- }

- *s++ = dig;

- if (i == ilim)

- break;

- multadd(b, 10, 0);

- multadd(mlo, 10, 0);

- multadd(mhi, 10, 0);

- }

- } else {

- for (i = 1;; i++) {

- *s++ = dig = quorem(b, S) + '0';

- if (!b.words()[0] && b.size() <= 1)

- goto ret;

- if (i >= ilim)

- break;

- multadd(b, 10, 0);

- }

- /* Round off last digit */

- lshift(b, 1);

- j = cmp(b, S);

- // For IEEE-754 round-to-even, this check should be (j > 0 || (!j && (dig & 1))),

- // but ECMA-262 specifies that equidistant values (e.g. (.5).toFixed()) should

- // be rounded away from zero.

- if (j >= 0) {

-roundoff:

- while (*--s == '9')

- if (s == s0) {

- k++;

- *s++ = '1';

- goto ret;

- }

- ++*s++;

- } else {

- while (*--s == '0') { }

- s++;

- }

- goto ret;

-noDigits:

- exponentOut = 0;

- precisionOut = 1;

- result[0] = '0';

- result[1] = '\0';

- return;

-oneDigit:

- *s++ = '1';

- k++;

- goto ret;

-ret:

- ASSERT(s > result);

- *s = 0;

- exponentOut = k;

- precisionOut = s - result;

-void dtoa(DtoaBuffer result, double dd, bool& sign, int& exponent, unsigned& precision)

- // flags are roundingNone, leftright.

- dtoa<true, false, false, true>(result, dd, 0, sign, exponent, precision);

-void dtoaRoundSF(DtoaBuffer result, double dd, int ndigits, bool& sign, int& exponent, unsigned& precision)

- // flag is roundingSignificantFigures.

- dtoa<false, true, false, false>(result, dd, ndigits, sign, exponent, precision);

-void dtoaRoundDP(DtoaBuffer result, double dd, int ndigits, bool& sign, int& exponent, unsigned& precision)

- // flag is roundingDecimalPlaces.

- dtoa<false, false, true, false>(result, dd, ndigits, sign, exponent, precision);

-const char* numberToString(double d, NumberToStringBuffer buffer)

- double_conversion::StringBuilder builder(buffer, NumberToStringBufferLength);

- const double_conversion::DoubleToStringConverter& converter = double_conversion::DoubleToStringConverter::EcmaScriptConverter();

- converter.ToShortest(d, &builder);

- return builder.Finalize();

-static inline const char* formatStringTruncatingTrailingZerosIfNeeded(NumberToStringBuffer buffer, double_conversion::StringBuilder& builder)

- size_t length = builder.position();

- size_t decimalPointPosition = 0;

- for (; decimalPointPosition < length; ++decimalPointPosition) {

- if (buffer[decimalPointPosition] == '.')

- break;

- }

- // No decimal seperator found, early exit.

- if (decimalPointPosition == length)

- return builder.Finalize();

- size_t truncatedLength = length - 1;

- for (; truncatedLength > decimalPointPosition; --truncatedLength) {

- if (buffer[truncatedLength] != '0')

- break;

- }

- // No trailing zeros found to strip.

- if (truncatedLength == length - 1)

- return builder.Finalize();

- // If we removed all trailing zeros, remove the decimal point as well.

- if (truncatedLength == decimalPointPosition) {

- ASSERT(truncatedLength > 0);

- --truncatedLength;

- }

- // Truncate the StringBuilder, and return the final result.

- builder.SetPosition(truncatedLength + 1);

- return builder.Finalize();

-const char* numberToFixedPrecisionString(double d, unsigned significantFigures, NumberToStringBuffer buffer, bool truncateTrailingZeros)

- // Mimic String::format("%.[precision]g", ...), but use dtoas rounding facilities.

- // "g": Signed value printed in f or e format, whichever is more compact for the given value and precision.

- // The e format is used only when the exponent of the value is less than –4 or greater than or equal to the

- // precision argument. Trailing zeros are truncated, and the decimal point appears only if one or more digits follow it.

- // "precision": The precision specifies the maximum number of significant digits printed.

- double_conversion::StringBuilder builder(buffer, NumberToStringBufferLength);

- const double_conversion::DoubleToStringConverter& converter = double_conversion::DoubleToStringConverter::EcmaScriptConverter();

- converter.ToPrecision(d, significantFigures, &builder);

- if (!truncateTrailingZeros)

- return builder.Finalize();

- return formatStringTruncatingTrailingZerosIfNeeded(buffer, builder);

-const char* numberToFixedWidthString(double d, unsigned decimalPlaces, NumberToStringBuffer buffer)

- // Mimic String::format("%.[precision]f", ...), but use dtoas rounding facilities.

- // "f": Signed value having the form [ – ]dddd.dddd, where dddd is one or more decimal digits.

- // The number of digits before the decimal point depends on the magnitude of the number, and

- // the number of digits after the decimal point depends on the requested precision.

- // "precision": The precision value specifies the number of digits after the decimal point.

- // If a decimal point appears, at least one digit appears before it.

- // The value is rounded to the appropriate number of digits.

- double_conversion::StringBuilder builder(buffer, NumberToStringBufferLength);

- const double_conversion::DoubleToStringConverter& converter = double_conversion::DoubleToStringConverter::EcmaScriptConverter();

- converter.ToFixed(d, decimalPlaces, &builder);

- return builder.Finalize();

-namespace Internal {

-double parseDoubleFromLongString(const UChar* string, size_t length, size_t& parsedLength)

- Vector<LChar> conversionBuffer(length);

- for (size_t i = 0; i < length; ++i)

- conversionBuffer[i] = isASCII(string[i]) ? string[i] : 0;

- return parseDouble(conversionBuffer.data(), length, parsedLength);

-} // namespace Internal

-} // namespace WTF

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