Skip to content

Fix limits and printing of subnormal_min #796

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
mborland merged 18 commits into from
Jan 20, 2025
Merged

Fix limits and printing of subnormal_min #796

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
18 commits
Select commit Hold shift + click to select a range
6675c29
Add decimal32(_fast) limits printing tests
mborland Jan 18, 2025
2dc0cfc
Fix values
mborland Jan 18, 2025
74ca84d
Fix to_chars of subnormal values
mborland Jan 18, 2025
b67e034
Test and fix decimal64(_fast)
mborland Jan 18, 2025
debc4bc
Fix and test decimal128 limits
mborland Jan 18, 2025
3ed0cd7
Update clang compatibility with if consteval
mborland Jan 18, 2025
d3a54da
Add consteval testing to ensure these are properly constructed
mborland Jan 18, 2025
828e81d
Collected test fixes due to proper values of limits
mborland Jan 18, 2025
6a67771
Fix fuzzer warning
mborland Jan 18, 2025
2109023
Fix min tests and simplify consteval test
mborland Jan 18, 2025
506bd10
Add test of max + lowest
mborland Jan 18, 2025
2ce1f3b
Fix now unused variable warning
mborland Jan 18, 2025
7bad6b9
Add comment
mborland Jan 20, 2025
dd1c6e1
Add fuzzing crash reproducer
mborland Jan 20, 2025
9aa0d2d
Fix comp of zero for decimal32
mborland Jan 20, 2025
2ad7574
Fix decimal128 0 comp
mborland Jan 20, 2025
53b0c3d
Fix potential overflow in comparison
mborland Jan 20, 2025
4ae8c77
Fix decimal128 comparisons overflow
mborland Jan 20, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions fuzzing/old_crashes/fuzz_snprintf/crash-cbafdfac1d7401408ca260cef95ab6948eedc646
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Dd00000000001000000000000000000000000000000000001000000000cccccccccÿCccc0ccccccccc8888000010000)001.2
Empty file added fuzzing/old_crashes/fuzz_snprintf/crash-da39a3ee5e6b4b0d3255bfef95601890afd80709
View file
Open in desktop
Empty file.
1 change: 1 addition & 0 deletions fuzzing/old_crashes/fuzz_snprintf/crash-github-1
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
0000000000000000000000000000000000000000
8 changes: 4 additions & 4 deletions include/boost/decimal/charconv.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -353,7 +353,7 @@ BOOST_DECIMAL_CONSTEXPR auto to_chars_scientific_impl(char* first, char* last, c
}

const auto fp = fpclassify(value);
if (fp != FP_NORMAL)
if (!(fp == FP_NORMAL || fp == FP_SUBNORMAL))
{
return to_chars_nonfinite(first, last, value, fp, fmt, precision);
}
Expand Down Expand Up @@ -494,7 +494,7 @@ BOOST_DECIMAL_CONSTEXPR auto to_chars_fixed_impl(char* first, char* last, const
}

const auto fp = fpclassify(value);
if (fp != FP_NORMAL)
if (!(fp == FP_NORMAL || fp == FP_SUBNORMAL))
{
return to_chars_nonfinite(first, last, value, fp, fmt, precision);
}
Expand Down Expand Up @@ -720,7 +720,7 @@ BOOST_DECIMAL_CONSTEXPR auto to_chars_hex_impl(char* first, char* last, const Ta
}

const auto fp = fpclassify(value);
if (fp != FP_NORMAL)
if (!(fp == FP_NORMAL || fp == FP_SUBNORMAL))
{
return to_chars_nonfinite(first, last, value, fp, chars_format::hex, precision);
}
Expand All @@ -742,7 +742,7 @@ BOOST_DECIMAL_CONSTEXPR auto to_chars_hex_impl(char* first, char* last, const Ta
Unsigned_Integer significand = frexp10(value, &exp);
BOOST_DECIMAL_ASSERT(significand != 0);
// Strip zeros of the significand since frexp10 normalizes it
while (significand % 10U == 0)
while (significand % 10U == 0 && significand > 0)
{
significand /= 10U;
++exp;
Expand Down
10 changes: 5 additions & 5 deletions include/boost/decimal/decimal128.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2238,18 +2238,18 @@ struct numeric_limits<boost::decimal::decimal128>
static constexpr int digits10 = digits;
static constexpr int max_digits10 = digits;
static constexpr int radix = 10;
static constexpr int min_exponent = -6142;
static constexpr int min_exponent = -6143;
static constexpr int min_exponent10 = min_exponent;
static constexpr int max_exponent = 6145;
static constexpr int max_exponent = 6144;
static constexpr int max_exponent10 = max_exponent;
static constexpr bool traps = numeric_limits<std::uint64_t>::traps;
static constexpr bool tinyness_before = true;

// Member functions
static constexpr auto (min) () -> boost::decimal::decimal128 { return {1, min_exponent}; }
static constexpr auto (max) () -> boost::decimal::decimal128 { return {boost::decimal::detail::uint128{UINT64_C(999'999'999'999'999), UINT64_C(9'999'999'999'999'999'999)}, max_exponent}; }
static constexpr auto lowest () -> boost::decimal::decimal128 { return {boost::decimal::detail::uint128{UINT64_C(999'999'999'999'999), UINT64_C(9'999'999'999'999'999'999)}, max_exponent, true}; }
static constexpr auto epsilon () -> boost::decimal::decimal128 { return {1, -34}; }
static constexpr auto (max) () -> boost::decimal::decimal128 { return {boost::decimal::detail::uint128{UINT64_C(0b1111011010000100110111110101011011000011111000000), UINT64_C(0b0011011110001101100011100110001111111111111111111111111111111111)}, max_exponent - digits + 1}; }
static constexpr auto lowest () -> boost::decimal::decimal128 { return {boost::decimal::detail::uint128{UINT64_C(0b1111011010000100110111110101011011000011111000000), UINT64_C(0b0011011110001101100011100110001111111111111111111111111111111111)}, max_exponent - digits + 1, true}; }
static constexpr auto epsilon () -> boost::decimal::decimal128 { return {1, -digits + 1}; }
static constexpr auto round_error () -> boost::decimal::decimal128 { return epsilon(); }
static constexpr auto infinity () -> boost::decimal::decimal128 { return boost::decimal::from_bits(boost::decimal::detail::d128_inf_mask); }
static constexpr auto quiet_NaN () -> boost::decimal::decimal128 { return boost::decimal::from_bits(boost::decimal::detail::d128_nan_mask); }
Expand Down
14 changes: 7 additions & 7 deletions include/boost/decimal/decimal128_fast.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1484,25 +1484,25 @@ struct numeric_limits<boost::decimal::decimal128_fast>
static constexpr int digits10 = digits;
static constexpr int max_digits10 = digits;
static constexpr int radix = 10;
static constexpr int min_exponent = -6142;
static constexpr int min_exponent = -6143;
static constexpr int min_exponent10 = min_exponent;
static constexpr int max_exponent = 6145;
static constexpr int max_exponent = 6144;
static constexpr int max_exponent10 = max_exponent;
static constexpr bool traps = numeric_limits<std::uint64_t>::traps;
static constexpr bool tinyness_before = true;

// Member functions
static constexpr auto (min) () -> boost::decimal::decimal128_fast { return {1, min_exponent}; }
static constexpr auto (max) () -> boost::decimal::decimal128_fast { return {boost::decimal::detail::uint128{UINT64_C(999'999'999'999'999), UINT64_C(9'999'999'999'999'999'999)}, max_exponent}; }
static constexpr auto lowest () -> boost::decimal::decimal128_fast { return {boost::decimal::detail::uint128{UINT64_C(999'999'999'999'999), UINT64_C(9'999'999'999'999'999'999)}, max_exponent, true}; }
static constexpr auto epsilon () -> boost::decimal::decimal128_fast { return {1, -34}; }
static constexpr auto (max) () -> boost::decimal::decimal128_fast { return {boost::decimal::detail::uint128{UINT64_C(0b1111011010000100110111110101011011000011111000000), UINT64_C(0b0011011110001101100011100110001111111111111111111111111111111111)}, max_exponent - digits + 1}; }
static constexpr auto lowest () -> boost::decimal::decimal128_fast { return {boost::decimal::detail::uint128{UINT64_C(0b1111011010000100110111110101011011000011111000000), UINT64_C(0b0011011110001101100011100110001111111111111111111111111111111111)}, max_exponent - digits + 1, true}; }
static constexpr auto epsilon () -> boost::decimal::decimal128_fast { return {1, -digits + 1}; }
static constexpr auto round_error () -> boost::decimal::decimal128_fast { return epsilon(); }
static constexpr auto infinity () -> boost::decimal::decimal128_fast { return boost::decimal::direct_init_d128(boost::decimal::detail::d128_fast_inf, 0, false); }
static constexpr auto quiet_NaN () -> boost::decimal::decimal128_fast { return boost::decimal::direct_init_d128(boost::decimal::detail::d128_fast_qnan, 0, false); }
static constexpr auto signaling_NaN() -> boost::decimal::decimal128_fast { return boost::decimal::direct_init_d128(boost::decimal::detail::d128_fast_snan, 0, false); }
static constexpr auto denorm_min () -> boost::decimal::decimal128_fast { return {1, boost::decimal::detail::etiny_v<boost::decimal::decimal128>}; }
static constexpr auto denorm_min () -> boost::decimal::decimal128_fast { return min(); }
};

}
} // namspace std

#endif //BOOST_DECIMAL_DECIMAL128_FAST_HPP
6 changes: 3 additions & 3 deletions include/boost/decimal/decimal32.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2248,9 +2248,9 @@ struct numeric_limits<boost::decimal::decimal32>

// Member functions
static constexpr auto (min) () -> boost::decimal::decimal32 { return {1, min_exponent}; }
static constexpr auto (max) () -> boost::decimal::decimal32 { return {9'999'999, max_exponent}; }
static constexpr auto lowest () -> boost::decimal::decimal32 { return {-9'999'999, max_exponent}; }
static constexpr auto epsilon () -> boost::decimal::decimal32 { return {1, -7}; }
static constexpr auto (max) () -> boost::decimal::decimal32 { return {9'999'999, max_exponent - digits + 1}; }
static constexpr auto lowest () -> boost::decimal::decimal32 { return {9'999'999, max_exponent - digits + 1, true}; }
static constexpr auto epsilon () -> boost::decimal::decimal32 { return {1, -digits + 1}; }
static constexpr auto round_error () -> boost::decimal::decimal32 { return epsilon(); }
static constexpr auto infinity () -> boost::decimal::decimal32 { return boost::decimal::from_bits(boost::decimal::detail::d32_inf_mask); }
static constexpr auto quiet_NaN () -> boost::decimal::decimal32 { return boost::decimal::from_bits(boost::decimal::detail::d32_nan_mask); }
Expand Down
8 changes: 4 additions & 4 deletions include/boost/decimal/decimal32_fast.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1481,16 +1481,16 @@ struct numeric_limits<boost::decimal::decimal32_fast>

// Member functions
static constexpr auto (min) () -> boost::decimal::decimal32_fast { return {1, min_exponent}; }
static constexpr auto (max) () -> boost::decimal::decimal32_fast { return {9'999'999, max_exponent}; }
static constexpr auto lowest () -> boost::decimal::decimal32_fast { return {-9'999'999, max_exponent}; }
static constexpr auto epsilon () -> boost::decimal::decimal32_fast { return {1, -7}; }
static constexpr auto (max) () -> boost::decimal::decimal32_fast { return {9'999'999, max_exponent - digits + 1}; }
static constexpr auto lowest () -> boost::decimal::decimal32_fast { return {9'999'999, max_exponent - digits + 1, true}; }
static constexpr auto epsilon () -> boost::decimal::decimal32_fast { return {1, -digits + 1}; }
static constexpr auto round_error () -> boost::decimal::decimal32_fast { return epsilon(); }
static constexpr auto infinity () -> boost::decimal::decimal32_fast { return boost::decimal::direct_init(boost::decimal::detail::d32_fast_inf, UINT8_C((0))); }
static constexpr auto quiet_NaN () -> boost::decimal::decimal32_fast { return boost::decimal::direct_init(boost::decimal::detail::d32_fast_qnan, UINT8_C((0))); }
static constexpr auto signaling_NaN() -> boost::decimal::decimal32_fast { return boost::decimal::direct_init(boost::decimal::detail::d32_fast_snan, UINT8_C((0))); }

// With denorm absent returns the same value as min
static constexpr auto denorm_min () -> boost::decimal::decimal32_fast { return {1, min_exponent}; }
static constexpr auto denorm_min () -> boost::decimal::decimal32_fast { return min(); }
};

} // Namespace std
Expand Down
10 changes: 5 additions & 5 deletions include/boost/decimal/decimal64.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2149,18 +2149,18 @@ struct numeric_limits<boost::decimal::decimal64>
static constexpr int digits10 = digits;
static constexpr int max_digits10 = digits;
static constexpr int radix = 10;
static constexpr int min_exponent = -382;
static constexpr int min_exponent = -383;
static constexpr int min_exponent10 = min_exponent;
static constexpr int max_exponent = 385;
static constexpr int max_exponent = 384;
static constexpr int max_exponent10 = max_exponent;
static constexpr bool traps = numeric_limits<std::uint64_t>::traps;
static constexpr bool tinyness_before = true;

// Member functions
static constexpr auto (min) () -> boost::decimal::decimal64 { return {1, min_exponent}; }
static constexpr auto (max) () -> boost::decimal::decimal64 { return {9'999'999'999'999'999, max_exponent}; }
static constexpr auto lowest () -> boost::decimal::decimal64 { return {-9'999'999'999'999'999, max_exponent}; }
static constexpr auto epsilon () -> boost::decimal::decimal64 { return {1, -16}; }
static constexpr auto (max) () -> boost::decimal::decimal64 { return {9'999'999'999'999'999, max_exponent - digits + 1}; }
static constexpr auto lowest () -> boost::decimal::decimal64 { return {9'999'999'999'999'999, max_exponent - digits + 1, true}; }
static constexpr auto epsilon () -> boost::decimal::decimal64 { return {1, -digits + 1}; }
static constexpr auto round_error () -> boost::decimal::decimal64 { return epsilon(); }
static constexpr auto infinity () -> boost::decimal::decimal64 { return boost::decimal::from_bits(boost::decimal::detail::d64_inf_mask); }
static constexpr auto quiet_NaN () -> boost::decimal::decimal64 { return boost::decimal::from_bits(boost::decimal::detail::d64_nan_mask); }
Expand Down
12 changes: 6 additions & 6 deletions include/boost/decimal/decimal64_fast.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1427,26 +1427,26 @@ struct numeric_limits<boost::decimal::decimal64_fast>
static constexpr int digits10 = digits;
static constexpr int max_digits10 = digits;
static constexpr int radix = 10;
static constexpr int min_exponent = -382;
static constexpr int min_exponent = -383;
static constexpr int min_exponent10 = min_exponent;
static constexpr int max_exponent = 385;
static constexpr int max_exponent = 384;
static constexpr int max_exponent10 = max_exponent;
static constexpr bool traps = numeric_limits<std::uint_fast64_t>::traps;
static constexpr bool tinyness_before = true;

// Member functions
static constexpr auto (min) () -> boost::decimal::decimal64_fast { return {1, min_exponent}; }
static constexpr auto (max) () -> boost::decimal::decimal64_fast { return {9'999'999'999'999'999, max_exponent}; }
static constexpr auto lowest () -> boost::decimal::decimal64_fast { return {-9'999'999'999'999'999, max_exponent}; }
static constexpr auto epsilon () -> boost::decimal::decimal64_fast { return {1, -16}; }
static constexpr auto (max) () -> boost::decimal::decimal64_fast { return {9'999'999'999'999'999, max_exponent - digits + 1}; }
static constexpr auto lowest () -> boost::decimal::decimal64_fast { return {9'999'999'999'999'999, max_exponent - digits + 1, true}; }
static constexpr auto epsilon () -> boost::decimal::decimal64_fast { return {1, -digits + 1}; }
static constexpr auto round_error () -> boost::decimal::decimal64_fast { return epsilon(); }
static constexpr auto infinity () -> boost::decimal::decimal64_fast { return boost::decimal::direct_init_d64(
boost::decimal::detail::d64_fast_inf, 0, false); }
static constexpr auto quiet_NaN () -> boost::decimal::decimal64_fast { return boost::decimal::direct_init_d64(
boost::decimal::detail::d64_fast_qnan, 0, false); }
static constexpr auto signaling_NaN() -> boost::decimal::decimal64_fast { return boost::decimal::direct_init_d64(
boost::decimal::detail::d64_fast_snan, 0, false); }
static constexpr auto denorm_min () -> boost::decimal::decimal64_fast { return {1, boost::decimal::detail::etiny_v<boost::decimal::decimal64>}; }
static constexpr auto denorm_min () -> boost::decimal::decimal64_fast { return min(); }
};

} // namespace std
Expand Down
52 changes: 44 additions & 8 deletions include/boost/decimal/detail/comparison.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -57,15 +57,36 @@ BOOST_DECIMAL_FORCE_INLINE constexpr auto equality_impl(DecimalType lhs, Decimal

const auto delta_exp {lhs_exp - rhs_exp};

if (delta_exp > detail::precision_v<DecimalType> || delta_exp < -detail::precision_v<DecimalType> ||
((lhs_sig == static_cast<comp_type>(0)) ^ (rhs_sig == static_cast<comp_type>(0))))
if (lhs_sig == 0 && rhs_sig == 0)
{
// The difference in exponent is irrelevant here
return true;
}
if (delta_exp > detail::precision_v<DecimalType> || delta_exp < -detail::precision_v<DecimalType>)
{
return false;
}

// Step 5: Normalize the significand and compare
delta_exp >= 0 ? lhs_sig *= detail::pow10(static_cast<comp_type>(delta_exp)) :
rhs_sig *= detail::pow10(static_cast<comp_type>(-delta_exp));
// Instead of multiplying the larger number, divide the smaller one
if (delta_exp >= 0)
{
// Check if we can divide rhs_sig safely
if (delta_exp > 0 && rhs_sig % detail::pow10(static_cast<comp_type>(delta_exp)) != 0)
{
return false;
}
rhs_sig /= detail::pow10(static_cast<comp_type>(delta_exp));
}
else
{
// Check if we can divide lhs_sig safely
if (lhs_sig % detail::pow10(static_cast<comp_type>(-delta_exp)) != 0)
{
return false;
}
lhs_sig /= detail::pow10(static_cast<comp_type>(-delta_exp));
}

return lhs_sig == rhs_sig;
}
Expand Down Expand Up @@ -93,19 +114,34 @@ constexpr auto equal_parts_impl(T1 lhs_sig, U1 lhs_exp, bool lhs_sign,

// Check the value of delta exp to avoid to large a value for pow10
// Also if only one of the significands is 0 then we know the values have to be mismatched
if (delta_exp > detail::precision_v<DecimalType> || delta_exp < -detail::precision_v<DecimalType> ||
((new_lhs_sig == static_cast<comp_type>(0)) ^ (new_rhs_sig == static_cast<comp_type>(0))))
if (new_lhs_sig == static_cast<comp_type>(0) && new_rhs_sig == static_cast<comp_type>(0))
{
return true;
}
if (delta_exp > detail::precision_v<DecimalType> || delta_exp < -detail::precision_v<DecimalType>)
{
return false;
}

// Step 5: Normalize the significand and compare
// Instead of multiplying the larger number, divide the smaller one
if (delta_exp >= 0)
{
new_lhs_sig *= detail::pow10(static_cast<comp_type>(delta_exp));
// Check if we can divide rhs_sig safely
if (delta_exp > 0 && new_rhs_sig % detail::pow10(static_cast<comp_type>(delta_exp)) != 0)
{
return false;
}
new_rhs_sig /= detail::pow10(static_cast<comp_type>(delta_exp));
}
else
{
new_rhs_sig *= detail::pow10(static_cast<comp_type>(-delta_exp));
// Check if we can divide lhs_sig safely
if (new_lhs_sig % detail::pow10(static_cast<comp_type>(-delta_exp)) != 0)
{
return false;
}
new_lhs_sig /= detail::pow10(static_cast<comp_type>(-delta_exp));
}

#ifdef BOOST_DECIMAL_DEBUG_EQUAL
Expand Down
2 changes: 1 addition & 1 deletion include/boost/decimal/detail/config.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -244,7 +244,7 @@ typedef unsigned __int128 uint128_t;
#endif

// https://github.com/llvm/llvm-project/issues/55638
#if defined(__clang__) && __cplusplus > 202002L
#if defined(__clang__) && __cplusplus > 202002L && __clang_major__ < 17
# undef BOOST_DECIMAL_IS_CONSTANT_EVALUATED
# define BOOST_DECIMAL_IS_CONSTANT_EVALUATED(x) false
# define BOOST_DECIMAL_NO_CONSTEVAL_DETECTION
Expand Down
1 change: 1 addition & 0 deletions test/Jamfile
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -124,6 +124,7 @@ run test_implicit_integral_conversion.cpp ;
run test_laguerre.cpp ;
run test_legendre.cpp ;
run test_literals.cpp ;
run test_limits.cpp ;
run test_lgamma.cpp ;
run test_log.cpp ;
run test_log1p.cpp ;
Expand Down
23 changes: 0 additions & 23 deletions test/test_decimal32.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -261,15 +261,6 @@ void test_addition()
BOOST_TEST(isinf(one + inf_val));
BOOST_TEST(isnan(inf_val + qnan_val));
BOOST_TEST(isnan(qnan_val + inf_val));

// Overflow
constexpr decimal32 max_val((std::numeric_limits<decimal32>::max)());
if (!BOOST_TEST(isinf(max_val + one)))
{
// LCOV_EXCL_START
std::cerr << std::bitset<32>(to_bits(max_val + one)) << std::endl;
// LCOV_EXCL_STOP
}
}

void test_subtraction()
Expand Down Expand Up @@ -320,20 +311,6 @@ void test_subtraction()
BOOST_TEST(isinf(one - inf_val));
BOOST_TEST(isnan(inf_val - qnan_val));
BOOST_TEST(isnan(qnan_val - inf_val));

// Why does MSVC 14.1 warn about unary minus but nothing else does?
#ifdef _MSC_VER
# pragma warning(push)
# pragma warning(disable: 4146)
#endif

// Underflow
constexpr decimal32 lowest_val(std::numeric_limits<decimal32>::lowest());
BOOST_TEST(isinf(lowest_val - one));

#ifdef _MSC_VER
# pragma warning(pop)
#endif
}

void test_multiplicatiom()
Expand Down
Loading
Loading