Add bignum fall-back when the fast dtoa doesn't succeed. This removes Gay's d...

test/cctest/test-bignum-dtoa.cc

+// 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 <stdlib.h>
+
+#include "v8.h"
+
+#include "bignum-dtoa.h"
+
+#include "cctest.h"
+#include "double.h"
+#include "gay-fixed.h"
+#include "gay-precision.h"
+#include "gay-shortest.h"
+#include "platform.h"
+
+using namespace v8::internal;
+
+
+// Removes trailing '0' digits.

[William Hesse, 2010/11/15 15:48:30]

// Can return the empty string if all digits are 0.

[Florian Loitsch, 2010/11/16 14:32:06]

Done.

+static void TrimRepresentation(Vector<char> representation) {
+  int len = strlen(representation.start());
+  int i;
+  for (i = len - 1; i >= 0; --i) {
+    if (representation[i] != '0') break;
+  }
+  representation[i + 1] = '\0';
+}
+
+
+static const int kBufferSize = 100;
+
+
+TEST(BignumDtoaVariousDoubles) {
+  char buffer_container[kBufferSize];
+  Vector<char> buffer(buffer_container, kBufferSize);
+  int length;
+  int point;
+
+  BignumDtoa(1.0, BIGNUM_DTOA_SHORTEST, 0, buffer, &length, &point);
+  CHECK_EQ("1", buffer.start());
+  CHECK_EQ(1, point);
+
+  BignumDtoa(1.0, BIGNUM_DTOA_FIXED, 3, buffer, &length, &point);
+  CHECK_GE(3, length - point);
+  TrimRepresentation(buffer);
+  CHECK_EQ("1", buffer.start());
+  CHECK_EQ(1, point);
+
+  BignumDtoa(1.0, BIGNUM_DTOA_PRECISION, 3, buffer, &length, &point);
+  CHECK_GE(3, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("1", buffer.start());
+  CHECK_EQ(1, point);
+
+  BignumDtoa(1.5, BIGNUM_DTOA_SHORTEST, 0, buffer, &length, &point);
+  CHECK_EQ("15", buffer.start());
+  CHECK_EQ(1, point);
+
+  BignumDtoa(1.5, BIGNUM_DTOA_FIXED, 10, buffer, &length, &point);
+  CHECK_GE(10, length - point);
+  TrimRepresentation(buffer);
+  CHECK_EQ("15", buffer.start());
+  CHECK_EQ(1, point);
+
+  BignumDtoa(1.5, BIGNUM_DTOA_PRECISION, 10, buffer, &length, &point);
+  CHECK_GE(10, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("15", buffer.start());
+  CHECK_EQ(1, point);
+
+  double min_double = 5e-324;
+  BignumDtoa(min_double, BIGNUM_DTOA_SHORTEST, 0, buffer, &length, &point);
+  CHECK_EQ("5", buffer.start());
+  CHECK_EQ(-323, point);
+
+  BignumDtoa(min_double, BIGNUM_DTOA_FIXED, 5, buffer, &length, &point);
+  CHECK_GE(5, length - point);
+  TrimRepresentation(buffer);
+  CHECK_EQ("", buffer.start());
+
+  BignumDtoa(min_double, BIGNUM_DTOA_PRECISION, 5, buffer, &length, &point);
+  CHECK_GE(5, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("49407", buffer.start());
+  CHECK_EQ(-323, point);
+
+  double max_double = 1.7976931348623157e308;
+  BignumDtoa(max_double, BIGNUM_DTOA_SHORTEST, 0, buffer, &length, &point);
+  CHECK_EQ("17976931348623157", buffer.start());
+  CHECK_EQ(309, point);
+
+  BignumDtoa(max_double, BIGNUM_DTOA_PRECISION, 7, buffer, &length, &point);
+  CHECK_GE(7, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("1797693", buffer.start());
+  CHECK_EQ(309, point);
+
+  BignumDtoa(4294967272.0, BIGNUM_DTOA_SHORTEST, 0, buffer, &length, &point);
+  CHECK_EQ("4294967272", buffer.start());
+  CHECK_EQ(10, point);
+
+  BignumDtoa(4294967272.0, BIGNUM_DTOA_FIXED, 5, buffer, &length, &point);
+  CHECK_EQ("429496727200000", buffer.start());
+  CHECK_EQ(10, point);
+
+
+  BignumDtoa(4294967272.0, BIGNUM_DTOA_PRECISION, 14, buffer, &length, &point);
+  CHECK_GE(14, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("4294967272", buffer.start());
+  CHECK_EQ(10, point);
+
+  BignumDtoa(4.1855804968213567e298, BIGNUM_DTOA_SHORTEST, 0,
+             buffer, &length, &point);
+  CHECK_EQ("4185580496821357", buffer.start());
+  CHECK_EQ(299, point);
+
+  BignumDtoa(4.1855804968213567e298, BIGNUM_DTOA_PRECISION, 20,
+             buffer, &length, &point);
+  CHECK_GE(20, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("41855804968213567225", buffer.start());
+  CHECK_EQ(299, point);
+
+  BignumDtoa(5.5626846462680035e-309, BIGNUM_DTOA_SHORTEST, 0,
+             buffer, &length, &point);
+  CHECK_EQ("5562684646268003", buffer.start());
+  CHECK_EQ(-308, point);
+
+  BignumDtoa(5.5626846462680035e-309, BIGNUM_DTOA_PRECISION, 1,
+             buffer, &length, &point);
+  CHECK_GE(1, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("6", buffer.start());
+  CHECK_EQ(-308, point);
+
+  BignumDtoa(2147483648.0, BIGNUM_DTOA_SHORTEST, 0,
+             buffer, &length, &point);
+  CHECK_EQ("2147483648", buffer.start());
+  CHECK_EQ(10, point);
+
+
+  BignumDtoa(2147483648.0, BIGNUM_DTOA_FIXED, 2,
+             buffer, &length, &point);
+  CHECK_GE(2, length - point);
+  TrimRepresentation(buffer);
+  CHECK_EQ("2147483648", buffer.start());
+  CHECK_EQ(10, point);
+
+  BignumDtoa(2147483648.0, BIGNUM_DTOA_PRECISION, 5,
+             buffer, &length, &point);
+  CHECK_GE(5, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("21475", buffer.start());
+  CHECK_EQ(10, point);
+
+  BignumDtoa(3.5844466002796428e+298, BIGNUM_DTOA_SHORTEST, 0,
+             buffer, &length, &point);
+  CHECK_EQ("35844466002796428", buffer.start());
+  CHECK_EQ(299, point);
+
+  BignumDtoa(3.5844466002796428e+298, BIGNUM_DTOA_PRECISION, 10,
+             buffer, &length, &point);
+  CHECK_GE(10, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("35844466", buffer.start());
+  CHECK_EQ(299, point);
+
+  uint64_t smallest_normal64 = V8_2PART_UINT64_C(0x00100000, 00000000);
+  double v = Double(smallest_normal64).value();
+  BignumDtoa(v, BIGNUM_DTOA_SHORTEST, 0, buffer, &length, &point);
+  CHECK_EQ("22250738585072014", buffer.start());
+  CHECK_EQ(-307, point);
+
+  BignumDtoa(v, BIGNUM_DTOA_PRECISION, 20, buffer, &length, &point);
+  CHECK_GE(20, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("22250738585072013831", buffer.start());
+  CHECK_EQ(-307, point);
+
+  uint64_t largest_denormal64 = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF);
+  v = Double(largest_denormal64).value();
+  BignumDtoa(v, BIGNUM_DTOA_SHORTEST, 0, buffer, &length, &point);
+  CHECK_EQ("2225073858507201", buffer.start());
+  CHECK_EQ(-307, point);
+
+  BignumDtoa(v, BIGNUM_DTOA_PRECISION, 20, buffer, &length, &point);
+  CHECK_GE(20, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("2225073858507200889", buffer.start());
+  CHECK_EQ(-307, point);
+
+  BignumDtoa(4128420500802942e-24, BIGNUM_DTOA_SHORTEST, 0,
+             buffer, &length, &point);
+  CHECK_EQ("4128420500802942", buffer.start());
+  CHECK_EQ(-8, point);
+
+  v = 3.9292015898194142585311918e-10;
+  BignumDtoa(v, BIGNUM_DTOA_SHORTEST, 0, buffer, &length, &point);
+  CHECK_EQ("39292015898194143", buffer.start());
+
+  v = 4194304.0;
+  BignumDtoa(v, BIGNUM_DTOA_FIXED, 5, buffer, &length, &point);
+  CHECK_GE(5, length - point);
+  TrimRepresentation(buffer);
+  CHECK_EQ("4194304", buffer.start());
+
+  v = 3.3161339052167390562200598e-237;
+  BignumDtoa(v, BIGNUM_DTOA_PRECISION, 19, buffer, &length, &point);
+  CHECK_GE(19, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("3316133905216739056", buffer.start());
+  CHECK_EQ(-236, point);
+
+  v = 7.9885183916008099497815232e+191;
+  BignumDtoa(v, BIGNUM_DTOA_PRECISION, 4, buffer, &length, &point);
+  CHECK_GE(4, length);
+  TrimRepresentation(buffer);
+  CHECK_EQ("7989", buffer.start());
+  CHECK_EQ(192, point);
+
+  v = 1.0000000000000012800000000e+17;
+  BignumDtoa(v, BIGNUM_DTOA_FIXED, 1, buffer, &length, &point);
+  CHECK_GE(1, length - point);
+  TrimRepresentation(buffer);
+  CHECK_EQ("100000000000000128", buffer.start());
+  CHECK_EQ(18, point);
+}
+
+

[William Hesse, 2010/11/15 15:48:30]

Are these tests taken from the Gay strtod implementation?  Otherwise, the above
tests could be merged into the below ones, right?

[Florian Loitsch, 2010/11/16 14:32:06]

They could be merged, but the numbers from Gay are simply random values, whereas
most of the "Various" ones try to exercise different parts of the dtoa-routine.

+TEST(BignumDtoaGayShortest) {
+  char buffer_container[kBufferSize];
+  Vector<char> buffer(buffer_container, kBufferSize);
+  int length;
+  int point;
+
+  Vector<const PrecomputedShortest> precomputed =
+      PrecomputedShortestRepresentations();
+  for (int i = 0; i < precomputed.length(); ++i) {
+    const PrecomputedShortest current_test = precomputed[i];
+    double v = current_test.v;
+    BignumDtoa(v, BIGNUM_DTOA_SHORTEST, 0, buffer, &length, &point);
+    CHECK_EQ(current_test.decimal_point, point);
+    CHECK_EQ(current_test.representation, buffer.start());
+  }
+}
+
+
+TEST(BignumDtoaGayFixed) {
+  char buffer_container[kBufferSize];
+  Vector<char> buffer(buffer_container, kBufferSize);
+  int length;
+  int point;
+
+  Vector<const PrecomputedFixed> precomputed =
+      PrecomputedFixedRepresentations();
+  for (int i = 0; i < precomputed.length(); ++i) {
+    const PrecomputedFixed current_test = precomputed[i];
+    double v = current_test.v;
+    int number_digits = current_test.number_digits;
+    BignumDtoa(v, BIGNUM_DTOA_FIXED, number_digits, buffer, &length, &point);
+    CHECK_EQ(current_test.decimal_point, point);
+    CHECK_GE(number_digits, length - point);
+    TrimRepresentation(buffer);
+    CHECK_EQ(current_test.representation, buffer.start());
+  }
+}
+
+
+TEST(BignumDtoaGayPrecision) {
+  char buffer_container[kBufferSize];
+  Vector<char> buffer(buffer_container, kBufferSize);
+  int length;
+  int point;
+
+  Vector<const PrecomputedPrecision> precomputed =
+      PrecomputedPrecisionRepresentations();
+  for (int i = 0; i < precomputed.length(); ++i) {
+    const PrecomputedPrecision current_test = precomputed[i];
+    double v = current_test.v;
+    int number_digits = current_test.number_digits;
+    BignumDtoa(v, BIGNUM_DTOA_PRECISION, number_digits,
+               buffer, &length, &point);
+    CHECK_EQ(current_test.decimal_point, point);
+    CHECK_GE(number_digits, length);
+    TrimRepresentation(buffer);
+    CHECK_EQ(current_test.representation, buffer.start());
+  }
+}