Chiebot-Mirror
/
abseil-cpp
mirror of https://hub.fastgit.xyz/abseil/abseil-cpp.git
8
0
Fork 0
Code Issues Projects Releases Wiki Activity

Implement Eisel-Lemire for from_chars<float>

Browse Source 
This does for float what a recent commit did for double.

Median of 5 runs of "time atod_manual_test pnftd/data/*.txt"
user    0m0.730s  # Before
user    0m0.701s  # After (a speed-up of 1.04x)
where pnftd is https://github.com/nigeltao/parse-number-fxx-test-data

Part of the reason why this speed-up of 1.04x isn't as dramatic as for
the from_chars<double> change is that, out of the 5299993 pnftd test
cases, 76.42% produce result_out_of_range for single precision (compared
to 1.03% for double precision).

"benchy --reference=srcfs --benchmark_filter='SimpleAtof' :numbers_benchmark"
output (which uses deterministic but randomly generated input strings):
name                                    old cpu/op  new cpu/op  delta
BM_SimpleAtof<absl::string_view>/10/1   392ns ± 2%   323ns ± 3%  -17.60%  (p=0.000 n=48+48)
BM_SimpleAtof<absl::string_view>/10/2   426ns ± 3%   311ns ± 4%  -26.89%  (p=0.000 n=59+49)
BM_SimpleAtof<absl::string_view>/10/4   435ns ± 3%   341ns ± 3%  -21.68%  (p=0.000 n=58+48)
BM_SimpleAtof<absl::string_view>/10/8   501ns ± 3%   393ns ± 3%  -21.55%  (p=0.000 n=60+50)
BM_SimpleAtof<const char*>/10/1         409ns ± 6%   339ns ± 3%  -17.06%  (p=0.000 n=48+49)
BM_SimpleAtof<const char*>/10/2         412ns ± 4%   347ns ± 3%  -15.82%  (p=0.000 n=47+49)
BM_SimpleAtof<const char*>/10/4         463ns ± 6%   369ns ± 6%  -20.37%  (p=0.000 n=60+50)
BM_SimpleAtof<const char*>/10/8         548ns ± 3%   450ns ± 4%  -17.91%  (p=0.000 n=57+59)
BM_SimpleAtof<std::string>/10/1         386ns ± 2%   325ns ± 3%  -15.74%  (p=0.000 n=48+50)
BM_SimpleAtof<std::string>/10/2         425ns ± 3%   311ns ± 4%  -26.79%  (p=0.000 n=60+50)
BM_SimpleAtof<std::string>/10/4         435ns ± 4%   340ns ± 3%  -21.94%  (p=0.000 n=59+49)
BM_SimpleAtof<std::string>/10/8         503ns ± 4%   398ns ± 2%  -20.89%  (p=0.000 n=59+48)

PiperOrigin-RevId: 476880111
Change-Id: Ibc5583677ac2ed338d09d8db960ae8a513eb2ccb
pull/1283/head
Abseil Team 2 years ago committed by Copybara-Service
parent 8b951b0999
commit 7f9c536c0a
2 changed files with 256 additions and 34 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 149
      absl/strings/charconv.cc
  2. 129
      absl/strings/numbers_test.cc

149
absl/strings/charconv.cc
Unescape View File

@ -68,6 +68,12 @@ template <>
struct FloatTraits<double> {
using mantissa_t = uint64_t;
// The number of bits in the given float type.
static constexpr int kTargetBits = 64;
// The number of exponent bits in the given float type.
static constexpr int kTargetExponentBits = 11;
// The number of mantissa bits in the given float type. This includes the
// implied high bit.
static constexpr int kTargetMantissaBits = 53;
@ -86,6 +92,31 @@ struct FloatTraits<double> {
// m * 2**kMinNormalExponent is exactly equal to DBL_MIN.
static constexpr int kMinNormalExponent = -1074;
// The IEEE exponent bias. It equals ((1 << (kTargetExponentBits - 1)) - 1).
static constexpr int kExponentBias = 1023;
// The Eisel-Lemire "Shifting to 54/25 Bits" adjustment. It equals (63 - 1 -
// kTargetMantissaBits).
static constexpr int kEiselLemireShift = 9;
// The Eisel-Lemire high64_mask. It equals ((1 << kEiselLemireShift) - 1).
static constexpr uint64_t kEiselLemireMask = uint64_t{0x1FF};
// The smallest negative integer N (smallest negative means furthest from
// zero) such that parsing 9999999999999999999eN, with 19 nines, is still
// positive. Parsing a smaller (more negative) N will produce zero.
//
// Adjusting the decimal point and exponent, without adjusting the value,
// 9999999999999999999eN equals 9.999999999999999999eM where M = N + 18.
//
// 9999999999999999999, with 19 nines but no decimal point, is the largest
// "repeated nines" integer that fits in a uint64_t.
static constexpr int kEiselLemireMinInclExp10 = -324 - 18;
// The smallest positive integer N such that parsing 1eN produces infinity.
// Parsing a smaller N will produce something finite.
static constexpr int kEiselLemireMaxExclExp10 = 309;
static double MakeNan(const char* tagp) {
// Support nan no matter which namespace it's in. Some platforms
// incorrectly don't put it in namespace std.
@ -141,9 +172,16 @@ template <>
struct FloatTraits<float> {
using mantissa_t = uint32_t;
static constexpr int kTargetBits = 32;
static constexpr int kTargetExponentBits = 8;
static constexpr int kTargetMantissaBits = 24;
static constexpr int kMaxExponent = 104;
static constexpr int kMinNormalExponent = -149;
static constexpr int kExponentBias = 127;
static constexpr int kEiselLemireShift = 38;
static constexpr uint64_t kEiselLemireMask = uint64_t{0x3FFFFFFFFF};
static constexpr int kEiselLemireMinInclExp10 = -46 - 18;
static constexpr int kEiselLemireMaxExclExp10 = 39;
static float MakeNan(const char* tagp) {
// Support nanf no matter which namespace it's in. Some platforms
@ -615,33 +653,55 @@ CalculatedFloat CalculateFromParsedDecimal(
// this function returns false) is both fast and correct.
template <typename FloatType>
bool EiselLemire(const strings_internal::ParsedFloat& input, bool negative,
FloatType* value) {
// For now, implement Eisel-Lemire only for double, not float.
if (FloatTraits<FloatType>::kTargetMantissaBits != 53) {
return false;
}
FloatType* value, std::errc* ec) {
uint64_t man = input.mantissa;
int exp10 = input.exponent;
if (Power10Underflow(exp10) || Power10Overflow(exp10)) {
return false;
if (exp10 < FloatTraits<FloatType>::kEiselLemireMinInclExp10) {
*value = negative ? -0.0 : 0.0;
*ec = std::errc::result_out_of_range;
return true;
} else if (exp10 >= FloatTraits<FloatType>::kEiselLemireMaxExclExp10) {
// Return max (a finite value) consistent with from_chars and DR 3081. For
// SimpleAtod and SimpleAtof, post-processing will return infinity.
*value = negative ? -std::numeric_limits<FloatType>::max()
: std::numeric_limits<FloatType>::max();
*ec = std::errc::result_out_of_range;
return true;
}
// Assert that (kPower10TableMin <= exp10) and (exp10 <= kPower10TableMax).
// Equivalently, !Power10Underflow(exp10) and !Power10Overflow(exp10).
//
// The +1 is because kEiselLemireMaxExclExp10 is an exclusive bound but
// kPower10TableMax is inclusive.
static_assert(
FloatTraits<FloatType>::kEiselLemireMinInclExp10 >= kPower10TableMin,
"(exp10 - kPower10TableMin) within kPower10MantissaHighTable bounds");
static_assert(
FloatTraits<FloatType>::kEiselLemireMaxExclExp10 <= kPower10TableMax + 1,
"(exp10 - kPower10TableMin) within kPower10MantissaHighTable bounds");
// The terse (+) comments in this function body refer to sections of the
// https://nigeltao.github.io/blog/2020/eisel-lemire.html blog post.
//
// That blog post discusses double precision (11 exponent bits with a -1023
// bias, 52 mantissa bits), but the same approach applies to single precision
// (8 exponent bits with a -127 bias, 23 mantissa bits). Either way, the
// computation here happens with 64-bit values (e.g. man) or 128-bit values
// (e.g. x) before finally converting to 64- or 32-bit floating point.
//
// See also "Number Parsing at a Gigabyte per Second, Software: Practice and
// Experience 51 (8), 2021" (https://arxiv.org/abs/2101.11408) for detail.
// (+) Normalization.
int clz = countl_zero(man);
man <<= static_cast<unsigned int>(clz);
static constexpr int exp2_bias = 1023;
// The 217706 etc magic numbers encode the kPower10ExponentTable as a formula
// instead of a table. Their equivalence is confirmed by
// https://github.com/google/wuffs/blob/315b2e52625ebd7b02d8fac13e3cd85ea374fb80/script/print-mpb-powers-of-10.go
uint64_t ret_exp2 =
static_cast<uint64_t>((217706 * exp10 >> 16) + 64 + exp2_bias - clz);
static_cast<uint64_t>((217706 * exp10 >> 16) + 64 +
FloatTraits<FloatType>::kExponentBias - clz);
// (+) Multiplication.
uint128 x =
@ -649,47 +709,62 @@ bool EiselLemire(const strings_internal::ParsedFloat& input, bool negative,
static_cast<uint128>(kPower10MantissaHighTable[exp10 - kPower10TableMin]);
// (+) Wider Approximation.
if (((Uint128High64(x) & 0x1FF) == 0x1FF) &&
static constexpr uint64_t high64_mask =
FloatTraits<FloatType>::kEiselLemireMask;
if (((Uint128High64(x) & high64_mask) == high64_mask) &&
(man > (std::numeric_limits<uint64_t>::max() - Uint128Low64(x)))) {
uint128 y = static_cast<uint128>(man) *
static_cast<uint128>(
kPower10MantissaLowTable[exp10 - kPower10TableMin]);
x += Uint128High64(y);
// For example, parsing "4503599627370497.5" will take the if-true
// branch here, since:
// branch here (for double precision), since:
// - x = 0x8000000000000BFF_FFFFFFFFFFFFFFFF
// - y = 0x8000000000000BFF_7FFFFFFFFFFFF400
// - man = 0xA000000000000F00
if (((Uint128High64(x) & 0x1FF) == 0x1FF) && ((Uint128Low64(x) + 1) == 0) &&
// Likewise, when parsing "0.0625" for single precision:
// - x = 0x7FFFFFFFFFFFFFFF_FFFFFFFFFFFFFFFF
// - y = 0x813FFFFFFFFFFFFF_8A00000000000000
// - man = 0x9C40000000000000
if (((Uint128High64(x) & high64_mask) == high64_mask) &&
((Uint128Low64(x) + 1) == 0) &&
(man > (std::numeric_limits<uint64_t>::max() - Uint128Low64(y)))) {
return false;
}
}
// (+) Shifting to 54 Bits.
// (+) Shifting to 54 Bits (or for single precision, to 25 bits).
uint64_t msb = Uint128High64(x) >> 63;
uint64_t ret_man = Uint128High64(x) >> (msb + 9);
uint64_t ret_man =
Uint128High64(x) >> (msb + FloatTraits<FloatType>::kEiselLemireShift);
ret_exp2 -= 1 ^ msb;
// (+) Half-way Ambiguity.
//
// For example, parsing "1e+23" will take the if-true branch here, since:
// For example, parsing "1e+23" will take the if-true branch here (for double
// precision), since:
// - x = 0x54B40B1F852BDA00_0000000000000000
// - ret_man = 0x002A5A058FC295ED
if ((Uint128Low64(x) == 0) && ((Uint128High64(x) & 0x1FF) == 0) &&
// Likewise, when parsing "20040229.0" for single precision:
// - x = 0x4C72894000000000_0000000000000000
// - ret_man = 0x000000000131CA25
if ((Uint128Low64(x) == 0) && ((Uint128High64(x) & high64_mask) == 0) &&
((ret_man & 3) == 1)) {
return false;
}
// (+) From 54 to 53 Bits.
// (+) From 54 to 53 Bits (or for single precision, from 25 to 24 bits).
ret_man += ret_man & 1; // Line From54a.
ret_man >>= 1; // Line From54b.
// Incrementing ret_man (at line From54a) may have overflowed 54 bits (53
// bits after the right shift by 1 at line From54b), so adjust for that.
//
// For example, parsing "9223372036854775807" will take the if-true branch
// here, since ret_man = 0x0020000000000000 = (1 << 53).
if ((ret_man >> 53) > 0) {
// here (for double precision), since:
// - ret_man = 0x0020000000000000 = (1 << 53)
// Likewise, when parsing "2147483647.0" for single precision:
// - ret_man = 0x0000000001000000 = (1 << 24)
if ((ret_man >> FloatTraits<FloatType>::kTargetMantissaBits) > 0) {
ret_exp2 += 1;
// Conceptually, we need a "ret_man >>= 1" in this if-block to balance
// incrementing ret_exp2 in the line immediately above. However, we only
@ -705,29 +780,51 @@ bool EiselLemire(const strings_internal::ParsedFloat& input, bool negative,
}
// ret_exp2 is a uint64_t. Zero or underflow means that we're in subnormal
// space. 0x7FF or above means that we're in Inf/NaN space.
// space. max_exp2 (0x7FF for double precision, 0xFF for single precision) or
// above means that we're in Inf/NaN space.
//
// The if block is equivalent to (but has fewer branches than):
// if ((ret_exp2 <= 0) || (ret_exp2 >= 0x7FF)) { etc }
// if ((ret_exp2 <= 0) || (ret_exp2 >= max_exp2)) { etc }
//
// For example, parsing "4.9406564584124654e-324" will take the if-true
// branch here, since ret_exp2 = -51.
if ((ret_exp2 - 1) >= (0x7FF - 1)) {
static constexpr uint64_t max_exp2 =
(1 << FloatTraits<FloatType>::kTargetExponentBits) - 1;
if ((ret_exp2 - 1) >= (max_exp2 - 1)) {
return false;
}
#ifndef ABSL_BIT_PACK_FLOATS
if (FloatTraits<FloatType>::kTargetBits == 64) {
*value = FloatTraits<FloatType>::Make(
(ret_man & 0x000FFFFFFFFFFFFFu) | 0x0010000000000000u,
ret_exp2 - 1023 - 52, negative);
static_cast<int>(ret_exp2) - 1023 - 52, negative);
return true;
} else if (FloatTraits<FloatType>::kTargetBits == 32) {
*value = FloatTraits<FloatType>::Make(
(static_cast<uint32_t>(ret_man) & 0x007FFFFFu) | 0x00800000u,
static_cast<int>(ret_exp2) - 127 - 23, negative);
return true;
}
#else
if (FloatTraits<FloatType>::kTargetBits == 64) {
uint64_t ret_bits = (ret_exp2 << 52) | (ret_man & 0x000FFFFFFFFFFFFFu);
if (negative) {
ret_bits |= 0x8000000000000000u;
}
*value = absl::bit_cast<double>(ret_bits);
#endif // ABSL_BIT_PACK_FLOATS
return true;
} else if (FloatTraits<FloatType>::kTargetBits == 32) {
uint32_t ret_bits = (static_cast<uint32_t>(ret_exp2) << 23) |
(static_cast<uint32_t>(ret_man) & 0x007FFFFFu);
if (negative) {
ret_bits |= 0x80000000u;
}
*value = absl::bit_cast<float>(ret_bits);
return true;
}
#endif // ABSL_BIT_PACK_FLOATS
return false;
}
template <typename FloatType>
@ -806,7 +903,7 @@ from_chars_result FromCharsImpl(const char* first, const char* last,
// A nullptr subrange_begin means that the decimal_parse.mantissa is exact
// (not truncated), a precondition of the Eisel-Lemire algorithm.
if ((decimal_parse.subrange_begin == nullptr) &&
EiselLemire<FloatType>(decimal_parse, negative, &value)) {
EiselLemire<FloatType>(decimal_parse, negative, &value, &result.ec)) {
return result;
}
CalculatedFloat calculated =

129
absl/strings/numbers_test.cc
Unescape View File

@ -19,6 +19,7 @@
#include <sys/types.h>
#include <cfenv> // NOLINT(build/c++11)
#include <cfloat>
#include <cinttypes>
#include <climits>
#include <cmath>
@ -388,7 +389,18 @@ TEST(NumbersTest, Atoi) {
}
TEST(NumbersTest, Atod) {
// DBL_TRUE_MIN and FLT_TRUE_MIN were not mandated in <cfloat> before C++17.
#if !defined(DBL_TRUE_MIN)
static constexpr double DBL_TRUE_MIN =
4.940656458412465441765687928682213723650598026143247644255856825e-324;
#endif
#if !defined(FLT_TRUE_MIN)
static constexpr float FLT_TRUE_MIN =
1.401298464324817070923729583289916131280261941876515771757068284e-45f;
#endif
double d;
float f;
// NaN can be spelled in multiple ways.
EXPECT_TRUE(absl::SimpleAtod("NaN", &d));
@ -412,12 +424,116 @@ TEST(NumbersTest, Atod) {
EXPECT_EQ(d, 1.7976931348623157e+308);
EXPECT_TRUE(absl::SimpleAtod("5e308", &d));
EXPECT_TRUE(std::isinf(d) && (d > 0));
// Parse DBL_MIN (normal) and DBL_TRUE_MIN (subnormal).
// Ditto, but for FLT_MAX.
EXPECT_TRUE(absl::SimpleAtof("3.4028234663852886e+38", &f));
EXPECT_EQ(f, 3.4028234663852886e+38f);
EXPECT_TRUE(absl::SimpleAtof("7e38", &f));
EXPECT_TRUE(std::isinf(f) && (f > 0));
// Parse the largest N such that parsing 1eN produces a finite value and the
// smallest M = N + 1 such that parsing 1eM produces infinity.
//
// The 309 exponent (and 39) confirms the "definition of
// kEiselLemireMaxExclExp10" comment in charconv.cc.
EXPECT_TRUE(absl::SimpleAtod("1e308", &d));
EXPECT_EQ(d, 1e308);
EXPECT_FALSE(std::isinf(d));
EXPECT_TRUE(absl::SimpleAtod("1e309", &d));
EXPECT_TRUE(std::isinf(d));
// Ditto, but for Atof instead of Atod.
EXPECT_TRUE(absl::SimpleAtof("1e38", &f));
EXPECT_EQ(f, 1e38f);
EXPECT_FALSE(std::isinf(f));
EXPECT_TRUE(absl::SimpleAtof("1e39", &f));
EXPECT_TRUE(std::isinf(f));
// Parse the largest N such that parsing 9.999999999999999999eN, with 19
// nines, produces a finite value.
//
// 9999999999999999999, with 19 nines but no decimal point, is the largest
// "repeated nines" integer that fits in a uint64_t.
EXPECT_TRUE(absl::SimpleAtod("9.999999999999999999e307", &d));
EXPECT_EQ(d, 9.999999999999999999e307);
EXPECT_FALSE(std::isinf(d));
EXPECT_TRUE(absl::SimpleAtod("9.999999999999999999e308", &d));
EXPECT_TRUE(std::isinf(d));
// Ditto, but for Atof instead of Atod.
EXPECT_TRUE(absl::SimpleAtof("9.999999999999999999e37", &f));
EXPECT_EQ(f, 9.999999999999999999e37f);
EXPECT_FALSE(std::isinf(f));
EXPECT_TRUE(absl::SimpleAtof("9.999999999999999999e38", &f));
EXPECT_TRUE(std::isinf(f));
// Parse DBL_MIN (normal), DBL_TRUE_MIN (subnormal) and (DBL_TRUE_MIN / 10)
// (effectively zero).
EXPECT_TRUE(absl::SimpleAtod("2.2250738585072014e-308", &d));
EXPECT_EQ(d, 2.2250738585072014e-308);
EXPECT_TRUE(absl::SimpleAtod("4.9406564584124654e-324", &d));
EXPECT_EQ(d, 4.9406564584124654e-324);
EXPECT_TRUE(absl::SimpleAtod("4.9406564584124654e-325", &d));
EXPECT_EQ(d, 0);
// Ditto, but for FLT_MIN, FLT_TRUE_MIN and (FLT_TRUE_MIN / 10).
EXPECT_TRUE(absl::SimpleAtof("1.1754943508222875e-38", &f));
EXPECT_EQ(f, 1.1754943508222875e-38f);
EXPECT_TRUE(absl::SimpleAtof("1.4012984643248171e-45", &f));
EXPECT_EQ(f, 1.4012984643248171e-45f);
EXPECT_TRUE(absl::SimpleAtof("1.4012984643248171e-46", &f));
EXPECT_EQ(f, 0);
// Parse the largest N (the most negative -N) such that parsing 1e-N produces
// a normal or subnormal (but still positive) or zero value.
EXPECT_TRUE(absl::SimpleAtod("1e-307", &d));
EXPECT_EQ(d, 1e-307);
EXPECT_GE(d, DBL_MIN);
EXPECT_LT(d, DBL_MIN * 10);
EXPECT_TRUE(absl::SimpleAtod("1e-323", &d));
EXPECT_EQ(d, 1e-323);
EXPECT_GE(d, DBL_TRUE_MIN);
EXPECT_LT(d, DBL_TRUE_MIN * 10);
EXPECT_TRUE(absl::SimpleAtod("1e-324", &d));
EXPECT_EQ(d, 0);
// Ditto, but for Atof instead of Atod.
EXPECT_TRUE(absl::SimpleAtof("1e-37", &f));
EXPECT_EQ(f, 1e-37f);
EXPECT_GE(f, FLT_MIN);
EXPECT_LT(f, FLT_MIN * 10);
EXPECT_TRUE(absl::SimpleAtof("1e-45", &f));
EXPECT_EQ(f, 1e-45f);
EXPECT_GE(f, FLT_TRUE_MIN);
EXPECT_LT(f, FLT_TRUE_MIN * 10);
EXPECT_TRUE(absl::SimpleAtof("1e-46", &f));
EXPECT_EQ(f, 0);
// Parse the largest N (the most negative -N) such that parsing
// 9.999999999999999999e-N, with 19 nines, produces a normal or subnormal
// (but still positive) or zero value.
//
// 9999999999999999999, with 19 nines but no decimal point, is the largest
// "repeated nines" integer that fits in a uint64_t.
//
// The -324/-325 exponents (and -46/-47) confirms the "definition of
// kEiselLemireMinInclExp10" comment in charconv.cc.
EXPECT_TRUE(absl::SimpleAtod("9.999999999999999999e-308", &d));
EXPECT_EQ(d, 9.999999999999999999e-308);
EXPECT_GE(d, DBL_MIN);
EXPECT_LT(d, DBL_MIN * 10);
EXPECT_TRUE(absl::SimpleAtod("9.999999999999999999e-324", &d));
EXPECT_EQ(d, 9.999999999999999999e-324);
EXPECT_GE(d, DBL_TRUE_MIN);
EXPECT_LT(d, DBL_TRUE_MIN * 10);
EXPECT_TRUE(absl::SimpleAtod("9.999999999999999999e-325", &d));
EXPECT_EQ(d, 0);
// Ditto, but for Atof instead of Atod.
EXPECT_TRUE(absl::SimpleAtof("9.999999999999999999e-38", &f));
EXPECT_EQ(f, 9.999999999999999999e-38f);
EXPECT_GE(f, FLT_MIN);
EXPECT_LT(f, FLT_MIN * 10);
EXPECT_TRUE(absl::SimpleAtof("9.999999999999999999e-46", &f));
EXPECT_EQ(f, 9.999999999999999999e-46f);
EXPECT_GE(f, FLT_TRUE_MIN);
EXPECT_LT(f, FLT_TRUE_MIN * 10);
EXPECT_TRUE(absl::SimpleAtof("9.999999999999999999e-47", &f));
EXPECT_EQ(f, 0);
// Leading and/or trailing whitespace is OK.
EXPECT_TRUE(absl::SimpleAtod(" \t\r\n 2.718", &d));
@ -459,6 +575,13 @@ TEST(NumbersTest, Atod) {
EXPECT_EQ(d, 1e+23);
EXPECT_TRUE(absl::SimpleAtod("9223372036854775807", &d));
EXPECT_EQ(d, 9223372036854775807);
// Ditto, but for Atof instead of Atod.
EXPECT_TRUE(absl::SimpleAtof("0.0625", &f));
EXPECT_EQ(f, 0.0625f);
EXPECT_TRUE(absl::SimpleAtof("20040229.0", &f));
EXPECT_EQ(f, 20040229.0f);
EXPECT_TRUE(absl::SimpleAtof("2147483647.0", &f));
EXPECT_EQ(f, 2147483647.0f);
// Some parsing algorithms don't always round correctly (but absl::SimpleAtod
// should). This test case comes from
@ -467,6 +590,8 @@ TEST(NumbersTest, Atod) {
// See also atod_manual_test.cc for running many more test cases.
EXPECT_TRUE(absl::SimpleAtod("122.416294033786585", &d));
EXPECT_EQ(d, 122.416294033786585);
EXPECT_TRUE(absl::SimpleAtof("122.416294033786585", &f));
EXPECT_EQ(f, 122.416294033786585f);
}
TEST(NumbersTest, Prefixes) {

Write Preview
Loading…
Cancel
Save