diff options
Diffstat (limited to 'test/cctest/test-strtod.cc')
| -rw-r--r-- | test/cctest/test-strtod.cc | 164 |
1 files changed, 163 insertions, 1 deletions
diff --git a/test/cctest/test-strtod.cc b/test/cctest/test-strtod.cc index 56b26ea1..d71d126b 100644 --- a/test/cctest/test-strtod.cc +++ b/test/cctest/test-strtod.cc @@ -4,7 +4,10 @@ #include "v8.h" +#include "bignum.h" #include "cctest.h" +#include "diy-fp.h" +#include "double.h" #include "strtod.h" using namespace v8::internal; @@ -202,11 +205,14 @@ TEST(Strtod) { CHECK_EQ(1.7976931348623158E+308, StrtodChar("17976931348623158", 292)); CHECK_EQ(V8_INFINITY, StrtodChar("17976931348623159", 292)); - // The following number is the result of 89255.0/1e-22. Both floating-point + // The following number is the result of 89255.0/1e22. Both floating-point // numbers can be accurately represented with doubles. However on Linux,x86 // the floating-point stack is set to 80bits and the double-rounding // introduces an error. CHECK_EQ(89255e-22, StrtodChar("89255", -22)); + + // Some random values. + CHECK_EQ(358416272e-33, StrtodChar("358416272", -33)); CHECK_EQ(104110013277974872254e-225, StrtodChar("104110013277974872254", -225)); @@ -252,4 +258,160 @@ TEST(Strtod) { StrtodChar("1234567890123456789052345", 114)); CHECK_EQ(1234567890123456789052345e115, StrtodChar("1234567890123456789052345", 115)); + + // Boundary cases. Boundaries themselves should round to even. + // + // 0x1FFFFFFFFFFFF * 2^3 = 72057594037927928 + // next: 72057594037927936 + // boundary: 72057594037927932 should round up. + CHECK_EQ(72057594037927928.0, StrtodChar("72057594037927928", 0)); + CHECK_EQ(72057594037927936.0, StrtodChar("72057594037927936", 0)); + CHECK_EQ(72057594037927936.0, StrtodChar("72057594037927932", 0)); + CHECK_EQ(72057594037927928.0, StrtodChar("7205759403792793199999", -5)); + CHECK_EQ(72057594037927936.0, StrtodChar("7205759403792793200001", -5)); + + // 0x1FFFFFFFFFFFF * 2^10 = 9223372036854774784 + // next: 9223372036854775808 + // boundary: 9223372036854775296 should round up. + CHECK_EQ(9223372036854774784.0, StrtodChar("9223372036854774784", 0)); + CHECK_EQ(9223372036854775808.0, StrtodChar("9223372036854775808", 0)); + CHECK_EQ(9223372036854775808.0, StrtodChar("9223372036854775296", 0)); + CHECK_EQ(9223372036854774784.0, StrtodChar("922337203685477529599999", -5)); + CHECK_EQ(9223372036854775808.0, StrtodChar("922337203685477529600001", -5)); + + // 0x1FFFFFFFFFFFF * 2^50 = 10141204801825834086073718800384 + // next: 10141204801825835211973625643008 + // boundary: 10141204801825834649023672221696 should round up. + CHECK_EQ(10141204801825834086073718800384.0, + StrtodChar("10141204801825834086073718800384", 0)); + CHECK_EQ(10141204801825835211973625643008.0, + StrtodChar("10141204801825835211973625643008", 0)); + CHECK_EQ(10141204801825835211973625643008.0, + StrtodChar("10141204801825834649023672221696", 0)); + CHECK_EQ(10141204801825834086073718800384.0, + StrtodChar("1014120480182583464902367222169599999", -5)); + CHECK_EQ(10141204801825835211973625643008.0, + StrtodChar("1014120480182583464902367222169600001", -5)); + + // 0x1FFFFFFFFFFFF * 2^99 = 5708990770823838890407843763683279797179383808 + // next: 5708990770823839524233143877797980545530986496 + // boundary: 5708990770823839207320493820740630171355185152 + // The boundary should round up. + CHECK_EQ(5708990770823838890407843763683279797179383808.0, + StrtodChar("5708990770823838890407843763683279797179383808", 0)); + CHECK_EQ(5708990770823839524233143877797980545530986496.0, + StrtodChar("5708990770823839524233143877797980545530986496", 0)); + CHECK_EQ(5708990770823839524233143877797980545530986496.0, + StrtodChar("5708990770823839207320493820740630171355185152", 0)); + CHECK_EQ(5708990770823838890407843763683279797179383808.0, + StrtodChar("5708990770823839207320493820740630171355185151999", -3)); + CHECK_EQ(5708990770823839524233143877797980545530986496.0, + StrtodChar("5708990770823839207320493820740630171355185152001", -3)); +} + + +static int CompareBignumToDiyFp(const Bignum& bignum_digits, + int bignum_exponent, + DiyFp diy_fp) { + Bignum bignum; + bignum.AssignBignum(bignum_digits); + Bignum other; + other.AssignUInt64(diy_fp.f()); + if (bignum_exponent >= 0) { + bignum.MultiplyByPowerOfTen(bignum_exponent); + } else { + other.MultiplyByPowerOfTen(-bignum_exponent); + } + if (diy_fp.e() >= 0) { + other.ShiftLeft(diy_fp.e()); + } else { + bignum.ShiftLeft(-diy_fp.e()); + } + return Bignum::Compare(bignum, other); +} + + +static bool CheckDouble(Vector<const char> buffer, + int exponent, + double to_check) { + DiyFp lower_boundary; + DiyFp upper_boundary; + Bignum input_digits; + input_digits.AssignDecimalString(buffer); + if (to_check == 0.0) { + const double kMinDouble = 4e-324; + // Check that the buffer*10^exponent < (0 + kMinDouble)/2. + Double d(kMinDouble); + d.NormalizedBoundaries(&lower_boundary, &upper_boundary); + return CompareBignumToDiyFp(input_digits, exponent, lower_boundary) <= 0; + } + if (to_check == V8_INFINITY) { + const double kMaxDouble = 1.7976931348623157e308; + // Check that the buffer*10^exponent >= boundary between kMaxDouble and inf. + Double d(kMaxDouble); + d.NormalizedBoundaries(&lower_boundary, &upper_boundary); + return CompareBignumToDiyFp(input_digits, exponent, upper_boundary) >= 0; + } + Double d(to_check); + d.NormalizedBoundaries(&lower_boundary, &upper_boundary); + if ((d.Significand() & 1) == 0) { + return CompareBignumToDiyFp(input_digits, exponent, lower_boundary) >= 0 && + CompareBignumToDiyFp(input_digits, exponent, upper_boundary) <= 0; + } else { + return CompareBignumToDiyFp(input_digits, exponent, lower_boundary) > 0 && + CompareBignumToDiyFp(input_digits, exponent, upper_boundary) < 0; + } +} + + +// Copied from v8.cc and adapted to make the function deterministic. +static uint32_t DeterministicRandom() { + // Random number generator using George Marsaglia's MWC algorithm. + static uint32_t hi = 0; + static uint32_t lo = 0; + + // Initialization values don't have any special meaning. (They are the result + // of two calls to random().) + if (hi == 0) hi = 0xbfe166e7; + if (lo == 0) lo = 0x64d1c3c9; + + // Mix the bits. + hi = 36969 * (hi & 0xFFFF) + (hi >> 16); + lo = 18273 * (lo & 0xFFFF) + (lo >> 16); + return (hi << 16) + (lo & 0xFFFF); +} + + +static const int kBufferSize = 1024; +static const int kShortStrtodRandomCount = 2; +static const int kLargeStrtodRandomCount = 2; + +TEST(RandomStrtod) { + char buffer[kBufferSize]; + for (int length = 1; length < 15; length++) { + for (int i = 0; i < kShortStrtodRandomCount; ++i) { + int pos = 0; + for (int j = 0; j < length; ++j) { + buffer[pos++] = random() % 10 + '0'; + } + int exponent = DeterministicRandom() % (25*2 + 1) - 25 - length; + buffer[pos] = '\0'; + Vector<const char> vector(buffer, pos); + double strtod_result = Strtod(vector, exponent); + CHECK(CheckDouble(vector, exponent, strtod_result)); + } + } + for (int length = 15; length < 800; length += 2) { + for (int i = 0; i < kLargeStrtodRandomCount; ++i) { + int pos = 0; + for (int j = 0; j < length; ++j) { + buffer[pos++] = random() % 10 + '0'; + } + int exponent = DeterministicRandom() % (308*2 + 1) - 308 - length; + buffer[pos] = '\0'; + Vector<const char> vector(buffer, pos); + double strtod_result = Strtod(vector, exponent); + CHECK(CheckDouble(vector, exponent, strtod_result)); + } + } } |