full-codegen.cc
func-name-inferrer.cc
global-handles.cc
- grisu3.cc
+ fast-dtoa.cc
handles.cc
hashmap.cc
heap-profiler.cc
#include "conversions-inl.h"
#include "factory.h"
-#include "grisu3.h"
+#include "fast-dtoa.h"
#include "scanner.h"
namespace v8 {
int sign;
char* decimal_rep;
- bool used_dtoa = false;
- char grisu_buffer[kGrisu3MaximalLength + 1];
+ bool used_gay_dtoa = false;
+ char fast_dtoa_buffer[kFastDtoaMaximalLength + 1];
int length;
- if (grisu3(v, grisu_buffer, &sign, &length, &decimal_point)) {
- decimal_rep = grisu_buffer;
+ if (FastDtoa(v, fast_dtoa_buffer, &sign, &length, &decimal_point)) {
+ decimal_rep = fast_dtoa_buffer;
} else {
decimal_rep = dtoa(v, 0, 0, &decimal_point, &sign, NULL);
- used_dtoa = true;
+ used_gay_dtoa = true;
length = StrLength(decimal_rep);
}
builder.AddFormatted("%d", exponent);
}
- if (used_dtoa) freedtoa(decimal_rep);
+ if (used_gay_dtoa) freedtoa(decimal_rep);
}
}
return builder.Finalize();
--- /dev/null
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following
+// disclaimer in the documentation and/or other materials provided
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "v8.h"
+
+#include "fast-dtoa.h"
+
+#include "cached_powers.h"
+#include "diy_fp.h"
+#include "double.h"
+
+namespace v8 {
+namespace internal {
+
+// The minimal and maximal target exponent define the range of w's binary
+// exponent, where 'w' is the result of multiplying the input by a cached power
+// of ten.
+//
+// A different range might be chosen on a different platform, to optimize digit
+// generation, but a smaller range requires more powers of ten to be cached.
+static const int minimal_target_exponent = -60;
+static const int maximal_target_exponent = -32;
+
+
+// Adjusts the last digit of the generated number, and screens out generated
+// solutions that may be inaccurate. A solution may be inaccurate if it is
+// outside the safe interval, or if we ctannot prove that it is closer to the
+// input than a neighboring representation of the same length.
+//
+// Input: * buffer containing the digits of too_high / 10^kappa
+// * the buffer's length
+// * distance_too_high_w == (too_high - w).f() * unit
+// * unsafe_interval == (too_high - too_low).f() * unit
+// * rest = (too_high - buffer * 10^kappa).f() * unit
+// * ten_kappa = 10^kappa * unit
+// * unit = the common multiplier
+// Output: returns true if the buffer is guaranteed to contain the closest
+// representable number to the input.
+// Modifies the generated digits in the buffer to approach (round towards) w.
+bool RoundWeed(char* buffer,
+ int length,
+ uint64_t distance_too_high_w,
+ uint64_t unsafe_interval,
+ uint64_t rest,
+ uint64_t ten_kappa,
+ uint64_t unit) {
+ uint64_t small_distance = distance_too_high_w - unit;
+ uint64_t big_distance = distance_too_high_w + unit;
+ // Let w_low = too_high - big_distance, and
+ // w_high = too_high - small_distance.
+ // Note: w_low < w < w_high
+ //
+ // The real w (* unit) must lie somewhere inside the interval
+ // ]w_low; w_low[ (often written as "(w_low; w_low)")
+
+ // Basically the buffer currently contains a number in the unsafe interval
+ // ]too_low; too_high[ with too_low < w < too_high
+ //
+ // too_high - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ // ^v 1 unit ^ ^ ^ ^
+ // boundary_high --------------------- . . . .
+ // ^v 1 unit . . . .
+ // - - - - - - - - - - - - - - - - - - - + - - + - - - - - - . .
+ // . . ^ . .
+ // . big_distance . . .
+ // . . . . rest
+ // small_distance . . . .
+ // v . . . .
+ // w_high - - - - - - - - - - - - - - - - - - . . . .
+ // ^v 1 unit . . . .
+ // w ---------------------------------------- . . . .
+ // ^v 1 unit v . . .
+ // w_low - - - - - - - - - - - - - - - - - - - - - . . .
+ // . . v
+ // buffer --------------------------------------------------+-------+--------
+ // . .
+ // safe_interval .
+ // v .
+ // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .
+ // ^v 1 unit .
+ // boundary_low ------------------------- unsafe_interval
+ // ^v 1 unit v
+ // too_low - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ //
+ //
+ // Note that the value of buffer could lie anywhere inside the range too_low
+ // to too_high.
+ //
+ // boundary_low, boundary_high and w are approximations of the real boundaries
+ // and v (the input number). They are guaranteed to be precise up to one unit.
+ // In fact the error is guaranteed to be strictly less than one unit.
+ //
+ // Anything that lies outside the unsafe interval is guaranteed not to round
+ // to v when read again.
+ // Anything that lies inside the safe interval is guaranteed to round to v
+ // when read again.
+ // If the number inside the buffer lies inside the unsafe interval but not
+ // inside the safe interval then we simply do not know and bail out (returning
+ // false).
+ //
+ // Similarly we have to take into account the imprecision of 'w' when rounding
+ // the buffer. If we have two potential representations we need to make sure
+ // that the chosen one is closer to w_low and w_high since v can be anywhere
+ // between them.
+ //
+ // By generating the digits of too_high we got the largest (closest to
+ // too_high) buffer that is still in the unsafe interval. In the case where
+ // w_high < buffer < too_high we try to decrement the buffer.
+ // This way the buffer approaches (rounds towards) w.
+ // There are 3 conditions that stop the decrementation process:
+ // 1) the buffer is already below w_high
+ // 2) decrementing the buffer would make it leave the unsafe interval
+ // 3) decrementing the buffer would yield a number below w_high and farther
+ // away than the current number. In other words:
+ // (buffer{-1} < w_high) && w_high - buffer{-1} > buffer - w_high
+ // Instead of using the buffer directly we use its distance to too_high.
+ // Conceptually rest ~= too_high - buffer
+ while (rest < small_distance && // Negated condition 1
+ unsafe_interval - rest >= ten_kappa && // Negated condition 2
+ (rest + ten_kappa < small_distance || // buffer{-1} > w_high
+ small_distance - rest >= rest + ten_kappa - small_distance)) {
+ buffer[length - 1]--;
+ rest += ten_kappa;
+ }
+
+ // We have approached w+ as much as possible. We now test if approaching w-
+ // would require changing the buffer. If yes, then we have two possible
+ // representations close to w, but we cannot decide which one is closer.
+ if (rest < big_distance &&
+ unsafe_interval - rest >= ten_kappa &&
+ (rest + ten_kappa < big_distance ||
+ big_distance - rest > rest + ten_kappa - big_distance)) {
+ return false;
+ }
+
+ // Weeding test.
+ // The safe interval is [too_low + 2 ulp; too_high - 2 ulp]
+ // Since too_low = too_high - unsafe_interval this is equivalent to
+ // [too_high - unsafe_interval + 4 ulp; too_high - 2 ulp]
+ // Conceptually we have: rest ~= too_high - buffer
+ return (2 * unit <= rest) && (rest <= unsafe_interval - 4 * unit);
+}
+
+
+
+static const uint32_t kTen4 = 10000;
+static const uint32_t kTen5 = 100000;
+static const uint32_t kTen6 = 1000000;
+static const uint32_t kTen7 = 10000000;
+static const uint32_t kTen8 = 100000000;
+static const uint32_t kTen9 = 1000000000;
+
+// Returns the biggest power of ten that is less than or equal than the given
+// number. We furthermore receive the maximum number of bits 'number' has.
+// If number_bits == 0 then 0^-1 is returned
+// The number of bits must be <= 32.
+// Precondition: (1 << number_bits) <= number < (1 << (number_bits + 1)).
+static void BiggestPowerTen(uint32_t number,
+ int number_bits,
+ uint32_t* power,
+ int* exponent) {
+ switch (number_bits) {
+ case 32:
+ case 31:
+ case 30:
+ if (kTen9 <= number) {
+ *power = kTen9;
+ *exponent = 9;
+ break;
+ } // else fallthrough
+ case 29:
+ case 28:
+ case 27:
+ if (kTen8 <= number) {
+ *power = kTen8;
+ *exponent = 8;
+ break;
+ } // else fallthrough
+ case 26:
+ case 25:
+ case 24:
+ if (kTen7 <= number) {
+ *power = kTen7;
+ *exponent = 7;
+ break;
+ } // else fallthrough
+ case 23:
+ case 22:
+ case 21:
+ case 20:
+ if (kTen6 <= number) {
+ *power = kTen6;
+ *exponent = 6;
+ break;
+ } // else fallthrough
+ case 19:
+ case 18:
+ case 17:
+ if (kTen5 <= number) {
+ *power = kTen5;
+ *exponent = 5;
+ break;
+ } // else fallthrough
+ case 16:
+ case 15:
+ case 14:
+ if (kTen4 <= number) {
+ *power = kTen4;
+ *exponent = 4;
+ break;
+ } // else fallthrough
+ case 13:
+ case 12:
+ case 11:
+ case 10:
+ if (1000 <= number) {
+ *power = 1000;
+ *exponent = 3;
+ break;
+ } // else fallthrough
+ case 9:
+ case 8:
+ case 7:
+ if (100 <= number) {
+ *power = 100;
+ *exponent = 2;
+ break;
+ } // else fallthrough
+ case 6:
+ case 5:
+ case 4:
+ if (10 <= number) {
+ *power = 10;
+ *exponent = 1;
+ break;
+ } // else fallthrough
+ case 3:
+ case 2:
+ case 1:
+ if (1 <= number) {
+ *power = 1;
+ *exponent = 0;
+ break;
+ } // else fallthrough
+ case 0:
+ *power = 0;
+ *exponent = -1;
+ break;
+ default:
+ // Following assignments are here to silence compiler warnings.
+ *power = 0;
+ *exponent = 0;
+ UNREACHABLE();
+ }
+}
+
+
+// Generates the digits of input number w.
+// w is a floating-point number (DiyFp), consisting of a significand and an
+// exponent. Its exponent is bounded by minimal_target_exponent and
+// maximal_target_exponent.
+// Hence -60 <= w.e() <= -32.
+//
+// Returns false if it fails, in which case the generated digits in the buffer
+// should not be used.
+// Preconditions:
+// * low, w and high are correct up to 1 ulp (unit in the last place). That
+// is, their error must be less that a unit of their last digits.
+// * low.e() == w.e() == high.e()
+// * low < w < high, and taking into account their error: low~ <= high~
+// * minimal_target_exponent <= w.e() <= maximal_target_exponent
+// Postconditions: returns false if procedure fails.
+// otherwise:
+// * buffer is not null-terminated, but len contains the number of digits.
+// * buffer contains the shortest possible decimal digit-sequence
+// such that LOW < buffer * 10^kappa < HIGH, where LOW and HIGH are the
+// correct values of low and high (without their error).
+// * if more than one decimal representation gives the minimal number of
+// decimal digits then the one closest to W (where W is the correct value
+// of w) is chosen.
+// Remark: this procedure takes into account the imprecision of its input
+// numbers. If the precision is not enough to guarantee all the postconditions
+// then false is returned. This usually happens rarely (~0.5%).
+//
+// Say, for the sake of example, that
+// w.e() == -48, and w.f() == 0x1234567890abcdef
+// w's value can be computed by w.f() * 2^w.e()
+// We can obtain w's integral digits by simply shifting w.f() by -w.e().
+// -> w's integral part is 0x1234
+// w's fractional part is therefore 0x567890abcdef.
+// Printing w's integral part is easy (simply print 0x1234 in decimal).
+// In order to print its fraction we repeatedly multiply the fraction by 10 and
+// get each digit. Example the first digit after the comma would be computed by
+// (0x567890abcdef * 10) >> 48. -> 3
+// The whole thing becomes slightly more complicated because we want to stop
+// once we have enough digits. That is, once the digits inside the buffer
+// represent 'w' we can stop. Everything inside the interval low - high
+// represents w. However we have to pay attention to low, high and w's
+// imprecision.
+bool DigitGen(DiyFp low,
+ DiyFp w,
+ DiyFp high,
+ char* buffer,
+ int* length,
+ int* kappa) {
+ ASSERT(low.e() == w.e() && w.e() == high.e());
+ ASSERT(low.f() + 1 <= high.f() - 1);
+ ASSERT(minimal_target_exponent <= w.e() && w.e() <= maximal_target_exponent);
+ // low, w and high are imprecise, but by less than one ulp (unit in the last
+ // place).
+ // If we remove (resp. add) 1 ulp from low (resp. high) we are certain that
+ // the new numbers are outside of the interval we want the final
+ // representation to lie in.
+ // Inversely adding (resp. removing) 1 ulp from low (resp. high) would yield
+ // numbers that are certain to lie in the interval. We will use this fact
+ // later on.
+ // We will now start by generating the digits within the uncertain
+ // interval. Later we will weed out representations that lie outside the safe
+ // interval and thus _might_ lie outside the correct interval.
+ uint64_t unit = 1;
+ DiyFp too_low = DiyFp(low.f() - unit, low.e());
+ DiyFp too_high = DiyFp(high.f() + unit, high.e());
+ // too_low and too_high are guaranteed to lie outside the interval we want the
+ // generated number in.
+ DiyFp unsafe_interval = DiyFp::Minus(too_high, too_low);
+ // We now cut the input number into two parts: the integral digits and the
+ // fractionals. We will not write any decimal separator though, but adapt
+ // kappa instead.
+ // Reminder: we are currently computing the digits (stored inside the buffer)
+ // such that: too_low < buffer * 10^kappa < too_high
+ // We use too_high for the digit_generation and stop as soon as possible.
+ // If we stop early we effectively round down.
+ DiyFp one = DiyFp(static_cast<uint64_t>(1) << -w.e(), w.e());
+ // Division by one is a shift.
+ uint32_t integrals = static_cast<uint32_t>(too_high.f() >> -one.e());
+ // Modulo by one is an and.
+ uint64_t fractionals = too_high.f() & (one.f() - 1);
+ uint32_t divider;
+ int divider_exponent;
+ BiggestPowerTen(integrals, DiyFp::kSignificandSize - (-one.e()),
+ ÷r, ÷r_exponent);
+ *kappa = divider_exponent + 1;
+ *length = 0;
+ // Loop invariant: buffer = too_high / 10^kappa (integer division)
+ // The invariant holds for the first iteration: kappa has been initialized
+ // with the divider exponent + 1. And the divider is the biggest power of ten
+ // that is smaller than integrals.
+ while (*kappa > 0) {
+ int digit = integrals / divider;
+ buffer[*length] = '0' + digit;
+ (*length)++;
+ integrals %= divider;
+ (*kappa)--;
+ // Note that kappa now equals the exponent of the divider and that the
+ // invariant thus holds again.
+ uint64_t rest =
+ (static_cast<uint64_t>(integrals) << -one.e()) + fractionals;
+ // Invariant: too_high = buffer * 10^kappa + DiyFp(rest, one.e())
+ // Reminder: unsafe_interval.e() == one.e()
+ if (rest < unsafe_interval.f()) {
+ // Rounding down (by not emitting the remaining digits) yields a number
+ // that lies within the unsafe interval.
+ return RoundWeed(buffer, *length, DiyFp::Minus(too_high, w).f(),
+ unsafe_interval.f(), rest,
+ static_cast<uint64_t>(divider) << -one.e(), unit);
+ }
+ divider /= 10;
+ }
+
+ // The integrals have been generated. We are at the point of the decimal
+ // separator. In the following loop we simply multiply the remaining digits by
+ // 10 and divide by one. We just need to pay attention to multiply associated
+ // data (like the interval or 'unit'), too.
+ // Instead of multiplying by 10 we multiply by 5 (cheaper operation) and
+ // increase its (imaginary) exponent. At the same time we decrease the
+ // divider's (one's) exponent and shift its significand.
+ // Basically, if fractionals was a DiyFp (with fractionals.e == one.e):
+ // fractionals.f *= 10;
+ // fractionals.f >>= 1; fractionals.e++; // value remains unchanged.
+ // one.f >>= 1; one.e++; // value remains unchanged.
+ // and we have again fractionals.e == one.e which allows us to divide
+ // fractionals.f() by one.f()
+ // We simply combine the *= 10 and the >>= 1.
+ while (true) {
+ fractionals *= 5;
+ unit *= 5;
+ unsafe_interval.set_f(unsafe_interval.f() * 5);
+ unsafe_interval.set_e(unsafe_interval.e() + 1); // Will be optimized out.
+ one.set_f(one.f() >> 1);
+ one.set_e(one.e() + 1);
+ // Integer division by one.
+ int digit = static_cast<int>(fractionals >> -one.e());
+ buffer[*length] = '0' + digit;
+ (*length)++;
+ fractionals &= one.f() - 1; // Modulo by one.
+ (*kappa)--;
+ if (fractionals < unsafe_interval.f()) {
+ return RoundWeed(buffer, *length, DiyFp::Minus(too_high, w).f() * unit,
+ unsafe_interval.f(), fractionals, one.f(), unit);
+ }
+ }
+}
+
+
+// Provides a decimal representation of v.
+// Returns true if it succeeds, otherwise the result cannot be trusted.
+// There will be *length digits inside the buffer (not null-terminated).
+// If the function returns true then
+// v == (double) (buffer * 10^decimal_exponent).
+// The digits in the buffer are the shortest representation possible: no
+// 0.09999999999999999 instead of 0.1. The shorter representation will even be
+// chosen even if the longer one would be closer to v.
+// The last digit will be closest to the actual v. That is, even if several
+// digits might correctly yield 'v' when read again, the closest will be
+// computed.
+bool grisu3(double v, char* buffer, int* length, int* decimal_exponent) {
+ DiyFp w = Double(v).AsNormalizedDiyFp();
+ // boundary_minus and boundary_plus are the boundaries between v and its
+ // closest floating-point neighbors. Any number strictly between
+ // boundary_minus and boundary_plus will round to v when convert to a double.
+ // Grisu3 will never output representations that lie exactly on a boundary.
+ DiyFp boundary_minus, boundary_plus;
+ Double(v).NormalizedBoundaries(&boundary_minus, &boundary_plus);
+ ASSERT(boundary_plus.e() == w.e());
+ DiyFp ten_mk; // Cached power of ten: 10^-k
+ int mk; // -k
+ GetCachedPower(w.e() + DiyFp::kSignificandSize, minimal_target_exponent,
+ maximal_target_exponent, &mk, &ten_mk);
+ ASSERT(minimal_target_exponent <= w.e() + ten_mk.e() +
+ DiyFp::kSignificandSize &&
+ maximal_target_exponent >= w.e() + ten_mk.e() +
+ DiyFp::kSignificandSize);
+ // Note that ten_mk is only an approximation of 10^-k. A DiyFp only contains a
+ // 64 bit significand and ten_mk is thus only precise up to 64 bits.
+
+ // The DiyFp::Times procedure rounds its result, and ten_mk is approximated
+ // too. The variable scaled_w (as well as scaled_boundary_minus/plus) are now
+ // off by a small amount.
+ // In fact: scaled_w - w*10^k < 1ulp (unit in the last place) of scaled_w.
+ // In other words: let f = scaled_w.f() and e = scaled_w.e(), then
+ // (f-1) * 2^e < w*10^k < (f+1) * 2^e
+ DiyFp scaled_w = DiyFp::Times(w, ten_mk);
+ ASSERT(scaled_w.e() ==
+ boundary_plus.e() + ten_mk.e() + DiyFp::kSignificandSize);
+ // In theory it would be possible to avoid some recomputations by computing
+ // the difference between w and boundary_minus/plus (a power of 2) and to
+ // compute scaled_boundary_minus/plus by subtracting/adding from
+ // scaled_w. However the code becomes much less readable and the speed
+ // enhancements are not terriffic.
+ DiyFp scaled_boundary_minus = DiyFp::Times(boundary_minus, ten_mk);
+ DiyFp scaled_boundary_plus = DiyFp::Times(boundary_plus, ten_mk);
+
+ // DigitGen will generate the digits of scaled_w. Therefore we have
+ // v == (double) (scaled_w * 10^-mk).
+ // Set decimal_exponent == -mk and pass it to DigitGen. If scaled_w is not an
+ // integer than it will be updated. For instance if scaled_w == 1.23 then
+ // the buffer will be filled with "123" und the decimal_exponent will be
+ // decreased by 2.
+ int kappa;
+ bool result = DigitGen(scaled_boundary_minus, scaled_w, scaled_boundary_plus,
+ buffer, length, &kappa);
+ *decimal_exponent = -mk + kappa;
+ return result;
+}
+
+
+bool FastDtoa(double v, char* buffer, int* sign, int* length, int* point) {
+ ASSERT(v != 0);
+ ASSERT(!Double(v).IsSpecial());
+
+ if (v < 0) {
+ v = -v;
+ *sign = 1;
+ } else {
+ *sign = 0;
+ }
+ int decimal_exponent;
+ bool result = grisu3(v, buffer, length, &decimal_exponent);
+ *point = *length + decimal_exponent;
+ buffer[*length] = '\0';
+ return result;
+}
+
+} } // namespace v8::internal
--- /dev/null
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following
+// disclaimer in the documentation and/or other materials provided
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_FAST_DTOA_H_
+#define V8_FAST_DTOA_H_
+
+namespace v8 {
+namespace internal {
+
+// FastDtoa will produce at most kFastDtoaMaximalLength digits. This does not
+// include the terminating '\0' character.
+static const int kFastDtoaMaximalLength = 17;
+
+// Provides a decimal representation of v.
+// v must not be (positive or negative) zero and it must not be Infinity or NaN.
+// Returns true if it succeeds, otherwise the result can not be trusted.
+// There will be *length digits inside the buffer followed by a null terminator.
+// If the function returns true then
+// v == (double) (buffer * 10^(point - length)).
+// The digits in the buffer are the shortest representation possible: no
+// 0.099999999999 instead of 0.1.
+// The last digit will be closest to the actual v. That is, even if several
+// digits might correctly yield 'v' when read again, the buffer will contain the
+// one closest to v.
+// The variable 'sign' will be '0' if the given number is positive, and '1'
+// otherwise.
+bool FastDtoa(double d, char* buffer, int* sign, int* length, int* point);
+
+} } // namespace v8::internal
+
+#endif // V8_FAST_DTOA_H_
+++ /dev/null
-// Copyright 2010 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-// * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-// * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following
-// disclaimer in the documentation and/or other materials provided
-// with the distribution.
-// * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived
-// from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-#include "v8.h"
-
-#include "grisu3.h"
-
-#include "cached_powers.h"
-#include "diy_fp.h"
-#include "double.h"
-
-namespace v8 {
-namespace internal {
-
-template <int alpha = -60, int gamma = -32>
-class Grisu3 {
- public:
- // Provides a decimal representation of v.
- // Returns true if it succeeds, otherwise the result can not be trusted.
- // There will be *length digits inside the buffer (not null-terminated).
- // If the function returns true then
- // v == (double) (buffer * 10^decimal_exponent).
- // The digits in the buffer are the shortest representation possible: no
- // 0.099999999999 instead of 0.1.
- // The last digit will be closest to the actual v. That is, even if several
- // digits might correctly yield 'v' when read again, the closest will be
- // computed.
- static bool grisu3(double v,
- char* buffer, int* length, int* decimal_exponent);
-
- private:
- // Rounds the buffer according to the rest.
- // If there is too much imprecision to round then false is returned.
- // Similarily false is returned when the buffer is not within Delta.
- static bool RoundWeed(char* buffer, int len, uint64_t wp_W, uint64_t Delta,
- uint64_t rest, uint64_t ten_kappa, uint64_t ulp);
- // Dispatches to the a specialized digit-generation routine. The chosen
- // routine depends on w.e (which in turn depends on alpha and gamma).
- // Currently there is only one digit-generation routine, but it would be easy
- // to add others.
- static bool DigitGen(DiyFp low, DiyFp w, DiyFp high,
- char* buffer, int* len, int* kappa);
- // Generates w's digits. The result is the shortest in the interval low-high.
- // All DiyFp are assumed to be imprecise and this function takes this
- // imprecision into account. If the function cannot compute the best
- // representation (due to the imprecision) then false is returned.
- static bool DigitGen_m60_m32(DiyFp low, DiyFp w, DiyFp high,
- char* buffer, int* length, int* kappa);
-};
-
-
-template<int alpha, int gamma>
-bool Grisu3<alpha, gamma>::grisu3(double v,
- char* buffer,
- int* length,
- int* decimal_exponent) {
- DiyFp w = Double(v).AsNormalizedDiyFp();
- // boundary_minus and boundary_plus are the boundaries between v and its
- // neighbors. Any number strictly between boundary_minus and boundary_plus
- // will round to v when read as double.
- // Grisu3 will never output representations that lie exactly on a boundary.
- DiyFp boundary_minus, boundary_plus;
- Double(v).NormalizedBoundaries(&boundary_minus, &boundary_plus);
- ASSERT(boundary_plus.e() == w.e());
- DiyFp ten_mk; // Cached power of ten: 10^-k
- int mk; // -k
- GetCachedPower(w.e() + DiyFp::kSignificandSize, alpha, gamma, &mk, &ten_mk);
- ASSERT(alpha <= w.e() + ten_mk.e() + DiyFp::kSignificandSize &&
- gamma >= w.e() + ten_mk.e() + DiyFp::kSignificandSize);
- // Note that ten_mk is only an approximation of 10^-k. A DiyFp only contains a
- // 64 bit significand and ten_mk is thus only precise up to 64 bits.
-
- // The DiyFp::Times procedure rounds its result, and ten_mk is approximated
- // too. The variable scaled_w (as well as scaled_boundary_minus/plus) are now
- // off by a small amount.
- // In fact: scaled_w - w*10^k < 1ulp (unit in the last place) of scaled_w.
- // In other words: let f = scaled_w.f() and e = scaled_w.e(), then
- // (f-1) * 2^e < w*10^k < (f+1) * 2^e
- DiyFp scaled_w = DiyFp::Times(w, ten_mk);
- ASSERT(scaled_w.e() ==
- boundary_plus.e() + ten_mk.e() + DiyFp::kSignificandSize);
- // In theory it would be possible to avoid some recomputations by computing
- // the difference between w and boundary_minus/plus (a power of 2) and to
- // compute scaled_boundary_minus/plus by subtracting/adding from
- // scaled_w. However the code becomes much less readable and the speed
- // enhancements are not terriffic.
- DiyFp scaled_boundary_minus = DiyFp::Times(boundary_minus, ten_mk);
- DiyFp scaled_boundary_plus = DiyFp::Times(boundary_plus, ten_mk);
-
- // DigitGen will generate the digits of scaled_w. Therefore we have
- // v == (double) (scaled_w * 10^-mk).
- // Set decimal_exponent == -mk and pass it to DigitGen. If scaled_w is not an
- // integer than it will be updated. For instance if scaled_w == 1.23 then
- // the buffer will be filled with "123" und the decimal_exponent will be
- // decreased by 2.
- int kappa;
- bool result = DigitGen(scaled_boundary_minus, scaled_w, scaled_boundary_plus,
- buffer, length, &kappa);
- *decimal_exponent = -mk + kappa;
- return result;
-}
-
-// Generates the digits of input number w.
-// w is a floating-point number (DiyFp), consisting of a significand and an
-// exponent. Its exponent is bounded by alpha and gamma. Typically alpha >= -63
-// and gamma <= 3.
-// Returns false if it fails, in which case the generated digits in the buffer
-// should not be used.
-// Preconditions:
-// * low, w and high are correct up to 1 ulp (unit in the last place). That
-// is, their error must be less that a unit of their last digits.
-// * low.e() == w.e() == high.e()
-// * low < w < high, and taking into account their error: low~ <= high~
-// * alpha <= w.e() <= gamma
-// Postconditions: returns false if procedure fails.
-// otherwise:
-// * buffer is not null-terminated, but len contains the number of digits.
-// * buffer contains the shortest possible decimal digit-sequence
-// such that LOW < buffer * 10^kappa < HIGH, where LOW and HIGH are the
-// correct values of low and high (without their error).
-// * if more than one decimal representation gives the minimal number of
-// decimal digits then the one closest to W (where W is the correct value
-// of w) is chosen.
-// Remark: this procedure takes into account the imprecision of its input
-// numbers. If the precision is not enough to guarantee all the postconditions
-// then false is returned. This usually happens rarely (~0.5%).
-template<int alpha, int gamma>
-bool Grisu3<alpha, gamma>::DigitGen(DiyFp low,
- DiyFp w,
- DiyFp high,
- char* buffer,
- int* len,
- int* kappa) {
- ASSERT(low.e() == w.e() && w.e() == high.e());
- ASSERT(low.f() + 1 <= high.f() - 1);
- ASSERT(alpha <= w.e() && w.e() <= gamma);
- // The following tests use alpha and gamma to avoid unnecessary dynamic tests.
- if ((alpha >= -60 && gamma <= -32) || // -60 <= w.e() <= -32
- (alpha <= -32 && gamma >= -60 && // Alpha/gamma overlaps -60/-32 region.
- -60 <= w.e() && w.e() <= -32)) {
- return DigitGen_m60_m32(low, w, high, buffer, len, kappa);
- } else {
- // A simple adaption of the special case -60/-32 would allow greater ranges
- // of alpha/gamma and thus reduce the number of precomputed cached powers of
- // ten.
- UNIMPLEMENTED();
- return false;
- }
-}
-
-static const uint32_t kTen4 = 10000;
-static const uint32_t kTen5 = 100000;
-static const uint32_t kTen6 = 1000000;
-static const uint32_t kTen7 = 10000000;
-static const uint32_t kTen8 = 100000000;
-static const uint32_t kTen9 = 1000000000;
-
-// Returns the biggest power of ten that is <= than the given number. We
-// furthermore receive the maximum number of bits 'number' has.
-// If number_bits == 0 then 0^-1 is returned
-// The number of bits must be <= 32.
-static void BiggestPowerTen(uint32_t number,
- int number_bits,
- uint32_t* power,
- int* exponent) {
- switch (number_bits) {
- case 32:
- case 31:
- case 30:
- if (kTen9 <= number) {
- *power = kTen9;
- *exponent = 9;
- break;
- } // else fallthrough
- case 29:
- case 28:
- case 27:
- if (kTen8 <= number) {
- *power = kTen8;
- *exponent = 8;
- break;
- } // else fallthrough
- case 26:
- case 25:
- case 24:
- if (kTen7 <= number) {
- *power = kTen7;
- *exponent = 7;
- break;
- } // else fallthrough
- case 23:
- case 22:
- case 21:
- case 20:
- if (kTen6 <= number) {
- *power = kTen6;
- *exponent = 6;
- break;
- } // else fallthrough
- case 19:
- case 18:
- case 17:
- if (kTen5 <= number) {
- *power = kTen5;
- *exponent = 5;
- break;
- } // else fallthrough
- case 16:
- case 15:
- case 14:
- if (kTen4 <= number) {
- *power = kTen4;
- *exponent = 4;
- break;
- } // else fallthrough
- case 13:
- case 12:
- case 11:
- case 10:
- if (1000 <= number) {
- *power = 1000;
- *exponent = 3;
- break;
- } // else fallthrough
- case 9:
- case 8:
- case 7:
- if (100 <= number) {
- *power = 100;
- *exponent = 2;
- break;
- } // else fallthrough
- case 6:
- case 5:
- case 4:
- if (10 <= number) {
- *power = 10;
- *exponent = 1;
- break;
- } // else fallthrough
- case 3:
- case 2:
- case 1:
- if (1 <= number) {
- *power = 1;
- *exponent = 0;
- break;
- } // else fallthrough
- case 0:
- *power = 0;
- *exponent = -1;
- break;
- default:
- // Following assignments are here to silence compiler warnings.
- *power = 0;
- *exponent = 0;
- UNREACHABLE();
- }
-}
-
-
-// Same comments as for DigitGen but with additional precondition:
-// -60 <= w.e() <= -32
-//
-// Say, for the sake of example, that
-// w.e() == -48, and w.f() == 0x1234567890abcdef
-// w's value can be computed by w.f() * 2^w.e()
-// We can obtain w's integral digits by simply shifting w.f() by -w.e().
-// -> w's integral part is 0x1234
-// w's fractional part is therefore 0x567890abcdef.
-// Printing w's integral part is easy (simply print 0x1234 in decimal).
-// In order to print its fraction we repeatedly multiply the fraction by 10 and
-// get each digit. Example the first digit after the comma would be computed by
-// (0x567890abcdef * 10) >> 48. -> 3
-// The whole thing becomes slightly more complicated because we want to stop
-// once we have enough digits. That is, once the digits inside the buffer
-// represent 'w' we can stop. Everything inside the interval low - high
-// represents w. However we have to pay attention to low, high and w's
-// imprecision.
-template<int alpha, int gamma>
-bool Grisu3<alpha, gamma>::DigitGen_m60_m32(DiyFp low,
- DiyFp w,
- DiyFp high,
- char* buffer,
- int* length,
- int* kappa) {
- // low, w and high are imprecise, but by less than one ulp (unit in the last
- // place).
- // If we remove (resp. add) 1 ulp from low (resp. high) we are certain that
- // the new numbers are outside of the interval we want the final
- // representation to lie in.
- // Inversely adding (resp. removing) 1 ulp from low (resp. high) would yield
- // numbers that are certain to lie in the interval. We will use this fact
- // later on.
- // We will now start by generating the digits within the uncertain
- // interval. Later we will weed out representations that lie outside the safe
- // interval and thus _might_ lie outside the correct interval.
- uint64_t unit = 1;
- DiyFp too_low = DiyFp(low.f() - unit, low.e());
- DiyFp too_high = DiyFp(high.f() + unit, high.e());
- // too_low and too_high are guaranteed to lie outside the interval we want the
- // generated number in.
- DiyFp unsafe_interval = DiyFp::Minus(too_high, too_low);
- // We now cut the input number into two parts: the integral digits and the
- // fractionals. We will not write any decimal separator though, but adapt
- // kappa instead.
- // Reminder: we are currently computing the digits (stored inside the buffer)
- // such that: too_low < buffer * 10^kappa < too_high
- // We use too_high for the digit_generation and stop as soon as possible.
- // If we stop early we effectively round down.
- DiyFp one = DiyFp(static_cast<uint64_t>(1) << -w.e(), w.e());
- // Division by one is a shift.
- uint32_t integrals = static_cast<uint32_t>(too_high.f() >> -one.e());
- // Modulo by one is an and.
- uint64_t fractionals = too_high.f() & (one.f() - 1);
- uint32_t divider;
- int divider_exponent;
- BiggestPowerTen(integrals, DiyFp::kSignificandSize - (-one.e()),
- ÷r, ÷r_exponent);
- *kappa = divider_exponent + 1;
- *length = 0;
- // Loop invariant: buffer = too_high / 10^kappa (integer division)
- // The invariant holds for the first iteration: kappa has been initialized
- // with the divider exponent + 1. And the divider is the biggest power of ten
- // that is smaller than integrals.
- while (*kappa > 0) {
- int digit = integrals / divider;
- buffer[*length] = '0' + digit;
- (*length)++;
- integrals %= divider;
- (*kappa)--;
- // Note that kappa now equals the exponent of the divider and that the
- // invariant thus holds again.
- uint64_t rest =
- (static_cast<uint64_t>(integrals) << -one.e()) + fractionals;
- // Invariant: too_high = buffer * 10^kappa + DiyFp(rest, one.e())
- // Reminder: unsafe_interval.e() == one.e()
- if (rest < unsafe_interval.f()) {
- // Rounding down (by not emitting the remaining digits) yields a number
- // that lies within the unsafe interval.
- return RoundWeed(buffer, *length, DiyFp::Minus(too_high, w).f(),
- unsafe_interval.f(), rest,
- static_cast<uint64_t>(divider) << -one.e(), unit);
- }
- divider /= 10;
- }
-
- // The integrals have been generated. We are at the point of the decimal
- // separator. In the following loop we simply multiply the remaining digits by
- // 10 and divide by one. We just need to pay attention to multiply associated
- // data (like the interval or 'unit'), too.
- // Instead of multiplying by 10 we multiply by 5 (cheaper operation) and
- // increase its (imaginary) exponent. At the same time we decrease the
- // divider's (one's) exponent and shift its significand.
- // Basically, if fractionals was a DiyFp (with fractionals.e == one.e):
- // fractionals.f *= 10;
- // fractionals.f >>= 1; fractionals.e++; // value remains unchanged.
- // one.f >>= 1; one.e++; // value remains unchanged.
- // and we have again fractionals.e == one.e which allows us to divide
- // fractionals.f() by one.f()
- // We simply combine the *= 10 and the >>= 1.
- while (true) {
- fractionals *= 5;
- unit *= 5;
- unsafe_interval.set_f(unsafe_interval.f() * 5);
- unsafe_interval.set_e(unsafe_interval.e() + 1); // Will be optimized out.
- one.set_f(one.f() >> 1);
- one.set_e(one.e() + 1);
- // Integer division by one.
- int digit = static_cast<int>(fractionals >> -one.e());
- buffer[*length] = '0' + digit;
- (*length)++;
- fractionals &= one.f() - 1; // Modulo by one.
- (*kappa)--;
- if (fractionals < unsafe_interval.f()) {
- return RoundWeed(buffer, *length, DiyFp::Minus(too_high, w).f() * unit,
- unsafe_interval.f(), fractionals, one.f(), unit);
- }
- }
-}
-
-
-// Rounds the given generated digits in the buffer and weeds out generated
-// digits that are not in the safe interval, or where we cannot find a rounded
-// representation.
-// Input: * buffer containing the digits of too_high / 10^kappa
-// * the buffer's length
-// * distance_too_high_w == (too_high - w).f() * unit
-// * unsafe_interval == (too_high - too_low).f() * unit
-// * rest = (too_high - buffer * 10^kappa).f() * unit
-// * ten_kappa = 10^kappa * unit
-// * unit = the common multiplier
-// Output: returns true on success.
-// Modifies the generated digits in the buffer to approach (round towards) w.
-template<int alpha, int gamma>
-bool Grisu3<alpha, gamma>::RoundWeed(char* buffer,
- int length,
- uint64_t distance_too_high_w,
- uint64_t unsafe_interval,
- uint64_t rest,
- uint64_t ten_kappa,
- uint64_t unit) {
- uint64_t small_distance = distance_too_high_w - unit;
- uint64_t big_distance = distance_too_high_w + unit;
- // Let w- = too_high - big_distance, and
- // w+ = too_high - small_distance.
- // Note: w- < w < w+
- //
- // The real w (* unit) must lie somewhere inside the interval
- // ]w-; w+[ (often written as "(w-; w+)")
-
- // Basically the buffer currently contains a number in the unsafe interval
- // ]too_low; too_high[ with too_low < w < too_high
- //
- // By generating the digits of too_high we got the biggest last digit.
- // In the case that w+ < buffer < too_high we try to decrement the buffer.
- // This way the buffer approaches (rounds towards) w.
- // There are 3 conditions that stop the decrementation process:
- // 1) the buffer is already below w+
- // 2) decrementing the buffer would make it leave the unsafe interval
- // 3) decrementing the buffer would yield a number below w+ and farther away
- // than the current number. In other words:
- // (buffer{-1} < w+) && w+ - buffer{-1} > buffer - w+
- // Instead of using the buffer directly we use its distance to too_high.
- // Conceptually rest ~= too_high - buffer
- while (rest < small_distance && // Negated condition 1
- unsafe_interval - rest >= ten_kappa && // Negated condition 2
- (rest + ten_kappa < small_distance || // buffer{-1} > w+
- small_distance - rest >= rest + ten_kappa - small_distance)) {
- buffer[length - 1]--;
- rest += ten_kappa;
- }
-
- // We have approached w+ as much as possible. We now test if approaching w-
- // would require changing the buffer. If yes, then we have two possible
- // representations close to w, but we cannot decide which one is closer.
- if (rest < big_distance &&
- unsafe_interval - rest >= ten_kappa &&
- (rest + ten_kappa < big_distance ||
- big_distance - rest > rest + ten_kappa - big_distance)) {
- return false;
- }
-
- // Weeding test.
- // The safe interval is [too_low + 2 ulp; too_high - 2 ulp]
- // Since too_low = too_high - unsafe_interval this is equivalent too
- // [too_high - unsafe_interval + 4 ulp; too_high - 2 ulp]
- // Conceptually we have: rest ~= too_high - buffer
- return (2 * unit <= rest) && (rest <= unsafe_interval - 4 * unit);
-}
-
-
-bool grisu3(double v, char* buffer, int* sign, int* length, int* point) {
- ASSERT(v != 0);
- ASSERT(!Double(v).IsSpecial());
-
- if (v < 0) {
- v = -v;
- *sign = 1;
- } else {
- *sign = 0;
- }
- int decimal_exponent;
- bool result = Grisu3<-60, -32>::grisu3(v, buffer, length, &decimal_exponent);
- *point = *length + decimal_exponent;
- buffer[*length] = '\0';
- return result;
-}
-
-} } // namespace v8::internal
+++ /dev/null
-// Copyright 2010 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-// * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-// * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following
-// disclaimer in the documentation and/or other materials provided
-// with the distribution.
-// * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived
-// from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-#ifndef V8_GRISU3_H_
-#define V8_GRISU3_H_
-
-namespace v8 {
-namespace internal {
-
-// Grisu3 will produce at most kGrisu3MaximalLength digits. This does not
-// include the terminating '\0' character.
-static const int kGrisu3MaximalLength = 17;
-
-// Provides a decimal representation of v.
-// v must satisfy v != 0 and it must not be Infinity or NaN.
-// Returns true if it succeeds, otherwise the result can not be trusted.
-// There will be *length digits inside the buffer followed by a null terminator.
-// If the function returns true then
-// v == (double) (buffer * 10^(decimal-point - length)).
-// The digits in the buffer are the shortest representation possible: no
-// 0.099999999999 instead of 0.1.
-// The last digit will be closest to the actual v. That is, even if several
-// digits might correctly yield 'v' when read again, the buffer will contain the
-// one closest to v.
-// The variable 'sign' will be '0' if the given number is positive, and '1'
-// otherwise.
-bool grisu3(double d, char* buffer, int* sign, int* length, int* decimal_point);
-
-} } // namespace v8::internal
-
-#endif // V8_GRISU3_H_
'test-decls.cc',
'test-diy_fp.cc',
'test-double.cc',
+ 'test-fast-dtoa.cc',
'test-flags.cc',
'test-func-name-inference.cc',
- 'test-grisu3.cc',
'test-hashmap.cc',
'test-heap.cc',
'test-heap-profiler.cc',
--- /dev/null
+// Copyright 2006-2008 the V8 project authors. All rights reserved.
+
+#include <stdlib.h>
+
+#include "v8.h"
+
+#include "platform.h"
+#include "cctest.h"
+#include "diy_fp.h"
+#include "double.h"
+#include "fast-dtoa.h"
+#include "gay_shortest.h"
+
+using namespace v8::internal;
+
+static const int kBufferSize = 100;
+
+TEST(FastDtoaVariousDoubles) {
+ char buffer[kBufferSize];
+ int sign;
+ int length;
+ int point;
+ int status;
+
+ double min_double = 5e-324;
+ status = FastDtoa(min_double, buffer, &sign, &length, &point);
+ CHECK(status);
+ CHECK_EQ(0, sign);
+ CHECK_EQ("5", buffer);
+ CHECK_EQ(-323, point);
+
+ double max_double = 1.7976931348623157e308;
+ status = FastDtoa(max_double, buffer, &sign, &length, &point);
+ CHECK(status);
+ CHECK_EQ(0, sign);
+ CHECK_EQ("17976931348623157", buffer);
+ CHECK_EQ(309, point);
+
+ status = FastDtoa(4294967272.0, buffer, &sign, &length, &point);
+ CHECK(status);
+ CHECK_EQ(0, sign);
+ CHECK_EQ("4294967272", buffer);
+ CHECK_EQ(10, point);
+
+ status = FastDtoa(4.1855804968213567e298, buffer, &sign, &length, &point);
+ CHECK(status);
+ CHECK_EQ(0, sign);
+ CHECK_EQ("4185580496821357", buffer);
+ CHECK_EQ(299, point);
+
+ status = FastDtoa(5.5626846462680035e-309, buffer, &sign, &length, &point);
+ CHECK(status);
+ CHECK_EQ(0, sign);
+ CHECK_EQ("5562684646268003", buffer);
+ CHECK_EQ(-308, point);
+
+ status = FastDtoa(2147483648.0, buffer, &sign, &length, &point);
+ CHECK(status);
+ CHECK_EQ(0, sign);
+ CHECK_EQ("2147483648", buffer);
+ CHECK_EQ(10, point);
+
+ status = FastDtoa(3.5844466002796428e+298, buffer, &sign, &length, &point);
+ if (status) { // Not all FastDtoa variants manage to compute this number.
+ CHECK_EQ("35844466002796428", buffer);
+ CHECK_EQ(0, sign);
+ CHECK_EQ(299, point);
+ }
+
+ uint64_t smallest_normal64 = V8_2PART_UINT64_C(0x00100000, 00000000);
+ double v = Double(smallest_normal64).value();
+ status = FastDtoa(v, buffer, &sign, &length, &point);
+ if (status) {
+ CHECK_EQ(0, sign);
+ CHECK_EQ("22250738585072014", buffer);
+ CHECK_EQ(-307, point);
+ }
+
+ uint64_t largest_denormal64 = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF);
+ v = Double(largest_denormal64).value();
+ status = FastDtoa(v, buffer, &sign, &length, &point);
+ if (status) {
+ CHECK_EQ(0, sign);
+ CHECK_EQ("2225073858507201", buffer);
+ CHECK_EQ(-307, point);
+ }
+}
+
+
+TEST(FastDtoaGayShortest) {
+ char buffer[kBufferSize];
+ bool status;
+ int sign;
+ int length;
+ int point;
+ int succeeded = 0;
+ int total = 0;
+ bool needed_max_length = false;
+
+ Vector<const GayShortest> precomputed = PrecomputedShortestRepresentations();
+ for (int i = 0; i < precomputed.length(); ++i) {
+ const GayShortest current_test = precomputed[i];
+ total++;
+ double v = current_test.v;
+ status = FastDtoa(v, buffer, &sign, &length, &point);
+ CHECK_GE(kFastDtoaMaximalLength, length);
+ if (!status) continue;
+ if (length == kFastDtoaMaximalLength) needed_max_length = true;
+ succeeded++;
+ CHECK_EQ(0, sign); // All precomputed numbers are positive.
+ CHECK_EQ(current_test.decimal_point, point);
+ CHECK_EQ(current_test.representation, buffer);
+ }
+ CHECK_GT(succeeded*1.0/total, 0.99);
+ CHECK(needed_max_length);
+}
+++ /dev/null
-// Copyright 2006-2008 the V8 project authors. All rights reserved.
-
-#include <stdlib.h>
-
-#include "v8.h"
-
-#include "platform.h"
-#include "cctest.h"
-#include "diy_fp.h"
-#include "double.h"
-#include "gay_shortest.h"
-#include "grisu3.h"
-
-using namespace v8::internal;
-
-static const int kBufferSize = 100;
-
-TEST(GrisuVariousDoubles) {
- char buffer[kBufferSize];
- int sign;
- int length;
- int point;
- int status;
-
- double min_double = 5e-324;
- status = grisu3(min_double, buffer, &sign, &length, &point);
- CHECK(status);
- CHECK_EQ(0, sign);
- CHECK_EQ("5", buffer);
- CHECK_EQ(-323, point);
-
- double max_double = 1.7976931348623157e308;
- status = grisu3(max_double, buffer, &sign, &length, &point);
- CHECK(status);
- CHECK_EQ(0, sign);
- CHECK_EQ("17976931348623157", buffer);
- CHECK_EQ(309, point);
-
- status = grisu3(4294967272.0, buffer, &sign, &length, &point);
- CHECK(status);
- CHECK_EQ(0, sign);
- CHECK_EQ("4294967272", buffer);
- CHECK_EQ(10, point);
-
- status = grisu3(4.1855804968213567e298, buffer, &sign, &length, &point);
- CHECK(status);
- CHECK_EQ(0, sign);
- CHECK_EQ("4185580496821357", buffer);
- CHECK_EQ(299, point);
-
- status = grisu3(5.5626846462680035e-309, buffer, &sign, &length, &point);
- CHECK(status);
- CHECK_EQ(0, sign);
- CHECK_EQ("5562684646268003", buffer);
- CHECK_EQ(-308, point);
-
- status = grisu3(2147483648.0, buffer, &sign, &length, &point);
- CHECK(status);
- CHECK_EQ(0, sign);
- CHECK_EQ("2147483648", buffer);
- CHECK_EQ(10, point);
-
- status = grisu3(3.5844466002796428e+298, buffer, &sign, &length, &point);
- if (status) { // Not all grisu3 variants manage to compute this number.
- CHECK_EQ("35844466002796428", buffer);
- CHECK_EQ(0, sign);
- CHECK_EQ(299, point);
- }
-
- uint64_t smallest_normal64 = V8_2PART_UINT64_C(0x00100000, 00000000);
- double v = Double(smallest_normal64).value();
- status = grisu3(v, buffer, &sign, &length, &point);
- if (status) {
- CHECK_EQ(0, sign);
- CHECK_EQ("22250738585072014", buffer);
- CHECK_EQ(-307, point);
- }
-
- uint64_t largest_denormal64 = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF);
- v = Double(largest_denormal64).value();
- status = grisu3(v, buffer, &sign, &length, &point);
- if (status) {
- CHECK_EQ(0, sign);
- CHECK_EQ("2225073858507201", buffer);
- CHECK_EQ(-307, point);
- }
-}
-
-
-TEST(GrisuGayShortest) {
- char buffer[kBufferSize];
- bool status;
- int sign;
- int length;
- int point;
- int succeeded = 0;
- int total = 0;
- bool needed_max_length = false;
-
- Vector<const GayShortest> precomputed = PrecomputedShortestRepresentations();
- for (int i = 0; i < precomputed.length(); ++i) {
- const GayShortest current_test = precomputed[i];
- total++;
- double v = current_test.v;
- status = grisu3(v, buffer, &sign, &length, &point);
- CHECK_GE(kGrisu3MaximalLength, length);
- if (!status) continue;
- if (length == kGrisu3MaximalLength) needed_max_length = true;
- succeeded++;
- CHECK_EQ(0, sign); // All precomputed numbers are positive.
- CHECK_EQ(current_test.decimal_point, point);
- CHECK_EQ(current_test.representation, buffer);
- }
- CHECK_GT(succeeded*1.0/total, 0.99);
- CHECK(needed_max_length);
-}
'../../src/factory.cc',
'../../src/factory.h',
'../../src/fast-codegen.h',
+ '../../src/fast-dtoa.cc',
+ '../../src/fast-dtoa.h',
'../../src/flag-definitions.h',
'../../src/flags.cc',
'../../src/flags.h',
'../../src/global-handles.cc',
'../../src/global-handles.h',
'../../src/globals.h',
- '../../src/grisu3.h',
- '../../src/grisu3.cc',
'../../src/handles-inl.h',
'../../src/handles.cc',
'../../src/handles.h',
projects / platform / upstream / v8.git / commitdiff