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Simplify constants and add more depth to a test

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This commit is contained in:
Christopher Kormanyos
2021-04-06 20:30:33 +02:00
parent 41a754c1f1
commit c46a136dc4
2 changed files with 59 additions and 36 deletions
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include/boost/multiprecision/cpp_dec_float.hpp
+26 -36
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@@ -121,22 +121,26 @@ template <unsigned Digits10, class ExponentType, class Allocator>
class cpp_dec_float
{
private:
static constexpr std::int32_t cpp_dec_float_digits10_setting = Digits10;
// We need at least 16-bits in the exponent type to do anything sensible:
static_assert(boost::multiprecision::detail::is_signed<ExponentType>::value, "ExponentType must be a signed built in integer type.");
static_assert(sizeof(ExponentType) > 1, "ExponentType is too small.");
static constexpr std::int32_t cpp_dec_float_digits10_limit_lo = INT32_C(9);
static constexpr std::int32_t cpp_dec_float_digits10_limit_hi = static_cast<std::int32_t>((std::numeric_limits<std::int32_t>::max)() - 100);
static constexpr std::int32_t cpp_dec_float_elem_digits10 = INT32_C(8);
static constexpr std::int32_t cpp_dec_float_elem_mask = INT32_C(100000000);
static constexpr std::int32_t cpp_dec_float_elems_for_kara = static_cast<std::int32_t>(64 + 1);
public:
using signed_types = std::tuple<boost::long_long_type> ;
using unsigned_types = std::tuple<boost::ulong_long_type>;
using float_types = std::tuple<double, long double>;
using exponent_type = ExponentType;
static constexpr std::int32_t cpp_dec_float_radix = 10L;
static constexpr std::int32_t cpp_dec_float_digits10_limit_lo = 9L;
static constexpr std::int32_t cpp_dec_float_digits10_limit_hi = boost::integer_traits<std::int32_t>::const_max - 100;
static constexpr std::int32_t cpp_dec_float_digits10 = ((cpp_dec_float_digits10_setting < cpp_dec_float_digits10_limit_lo) ? cpp_dec_float_digits10_limit_lo : ((cpp_dec_float_digits10_setting > cpp_dec_float_digits10_limit_hi) ? cpp_dec_float_digits10_limit_hi : cpp_dec_float_digits10_setting));
static constexpr std::int32_t cpp_dec_float_radix = INT32_C(10);
static constexpr std::int32_t cpp_dec_float_digits10 = ((static_cast<std::int32_t>(Digits10) < cpp_dec_float_digits10_limit_lo) ? cpp_dec_float_digits10_limit_lo : ((static_cast<std::int32_t>(Digits10) > cpp_dec_float_digits10_limit_hi) ? cpp_dec_float_digits10_limit_hi : static_cast<std::int32_t>(Digits10)));
static constexpr exponent_type cpp_dec_float_max_exp10 = (static_cast<exponent_type>(1) << (std::numeric_limits<exponent_type>::digits - 5));
static constexpr exponent_type cpp_dec_float_min_exp10 = -cpp_dec_float_max_exp10;
static constexpr exponent_type cpp_dec_float_max_exp = cpp_dec_float_max_exp10;
@@ -144,27 +148,17 @@ class cpp_dec_float
static_assert(cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_max_exp10 == -cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_min_exp10, "Failed exponent range check");
private:
static constexpr std::int32_t cpp_dec_float_elem_digits10 = 8L;
static constexpr std::int32_t cpp_dec_float_elem_mask = 100000000L;
static_assert(0 == cpp_dec_float_max_exp10 % cpp_dec_float_elem_digits10, "Failed digit sanity check");
private:
// There are three guard limbs.
// 1) The first limb has 'play' from 1...8 decimal digits.
// 2) The last limb also has 'play' from 1...8 decimal digits.
// 3) One limb can get lost when justifying after multiply,
// as only half of the triangle is multiplied and a carry
// from below is missing.
static constexpr std::int32_t cpp_dec_float_elem_number_request = static_cast<std::int32_t>((cpp_dec_float_digits10 / cpp_dec_float_elem_digits10) + (((cpp_dec_float_digits10 % cpp_dec_float_elem_digits10) != 0) ? 1 : 0));
// The number of elements needed (with a minimum of two) plus three added guard limbs.
static constexpr std::int32_t cpp_dec_float_elem_number = static_cast<std::int32_t>(((cpp_dec_float_elem_number_request < 2L) ? 2L : cpp_dec_float_elem_number_request) + 3L);
static constexpr std::int32_t cpp_dec_float_elems_for_kara = static_cast<std::int32_t>(64 + 1);
// 3) One limb can get lost when justifying after multiply.
static constexpr std::int32_t cpp_dec_float_elem_number = static_cast<std::int32_t>(((Digits10 / cpp_dec_float_elem_digits10) + (((Digits10 % cpp_dec_float_elem_digits10) != 0) ? 1 : 0)) + 3);
public:
static constexpr std::int32_t cpp_dec_float_total_digits10 = static_cast<std::int32_t>(cpp_dec_float_elem_number * cpp_dec_float_elem_digits10);
static constexpr std::int32_t cpp_dec_float_max_digits10 = static_cast<std::int32_t>(cpp_dec_float_elem_number * cpp_dec_float_elem_digits10);
private:
using array_type =
@@ -605,12 +599,12 @@ class cpp_dec_float
const std::uint32_t n,
std::uint32_t* t);
template<unsigned OtherDigits10>
template<unsigned D>
void eval_mul_dispatch_multiplication_method(
const cpp_dec_float<OtherDigits10, ExponentType, Allocator>& v,
const cpp_dec_float<D, ExponentType, Allocator>& v,
const std::int32_t prec_elems_for_multiply,
const typename std::enable_if< (OtherDigits10 == Digits10)
&& (cpp_dec_float<OtherDigits10, ExponentType, Allocator>::cpp_dec_float_elem_number < cpp_dec_float_elems_for_kara)>::type* = nullptr)
const typename std::enable_if< (D == Digits10)
&& (cpp_dec_float<D, ExponentType, Allocator>::cpp_dec_float_elem_number < cpp_dec_float_elems_for_kara)>::type* = nullptr)
{
// Use school multiplication.
@@ -641,12 +635,12 @@ class cpp_dec_float
}
}
template<unsigned OtherDigits10>
template<unsigned D>
void eval_mul_dispatch_multiplication_method(
const cpp_dec_float<OtherDigits10, ExponentType, Allocator>& v,
const cpp_dec_float<D, ExponentType, Allocator>& v,
const std::int32_t prec_elems_for_multiply,
const typename std::enable_if< (OtherDigits10 == Digits10)
&& !(cpp_dec_float<OtherDigits10, ExponentType, Allocator>::cpp_dec_float_elem_number < cpp_dec_float_elems_for_kara)>::type* = nullptr)
const typename std::enable_if< (D == Digits10)
&& !(cpp_dec_float<D, ExponentType, Allocator>::cpp_dec_float_elem_number < cpp_dec_float_elems_for_kara)>::type* = nullptr)
{
if(prec_elems_for_multiply < cpp_dec_float_elems_for_kara)
{
@@ -735,8 +729,6 @@ class cpp_dec_float
template <unsigned Digits10, class ExponentType, class Allocator>
const std::int32_t cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_radix;
template <unsigned Digits10, class ExponentType, class Allocator>
const std::int32_t cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_digits10_setting;
template <unsigned Digits10, class ExponentType, class Allocator>
const std::int32_t cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_digits10_limit_lo;
template <unsigned Digits10, class ExponentType, class Allocator>
const std::int32_t cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_digits10_limit_hi;
@@ -753,8 +745,6 @@ const ExponentType cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_flo
template <unsigned Digits10, class ExponentType, class Allocator>
const std::int32_t cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_elem_digits10;
template <unsigned Digits10, class ExponentType, class Allocator>
const std::int32_t cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_elem_number_request;
template <unsigned Digits10, class ExponentType, class Allocator>
const std::int32_t cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_elem_number;
template <unsigned Digits10, class ExponentType, class Allocator>
const std::int32_t cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_elem_mask;
@@ -1275,7 +1265,7 @@ cpp_dec_float<Digits10, ExponentType, Allocator>& cpp_dec_float<Digits10, Expone
constexpr std::int32_t double_digits10_minus_a_few = std::numeric_limits<double>::digits10 - 3;
for (std::int32_t digits = double_digits10_minus_a_few; digits <= cpp_dec_float_total_digits10; digits *= static_cast<std::int32_t>(2))
for (std::int32_t digits = double_digits10_minus_a_few; digits <= cpp_dec_float_max_digits10; digits *= static_cast<std::int32_t>(2))
{
// Adjust precision of the terms.
precision(static_cast<std::int32_t>((digits + 10) * static_cast<std::int32_t>(2)));
@@ -1356,7 +1346,7 @@ cpp_dec_float<Digits10, ExponentType, Allocator>& cpp_dec_float<Digits10, Expone
constexpr std::uint32_t double_digits10_minus_a_few = std::numeric_limits<double>::digits10 - 3;
for (std::int32_t digits = double_digits10_minus_a_few; digits <= cpp_dec_float_total_digits10; digits *= 2u)
for (std::int32_t digits = double_digits10_minus_a_few; digits <= cpp_dec_float_max_digits10; digits *= 2u)
{
// Adjust precision of the terms.
precision((digits + 10) * 2);
@@ -1823,7 +1813,7 @@ std::string cpp_dec_float<Digits10, ExponentType, Allocator>::str(std::intmax_t
exponent_type my_exp = order();
if (number_of_digits == 0)
number_of_digits = cpp_dec_float_total_digits10;
number_of_digits = cpp_dec_float_max_digits10;
if (f & std::ios_base::fixed)
{
@@ -3406,7 +3396,7 @@ class numeric_limits<boost::multiprecision::number<boost::multiprecision::cpp_de
static constexpr bool is_iec559 = false;
static constexpr int digits = boost::multiprecision::cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_digits10;
static constexpr int digits10 = boost::multiprecision::cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_digits10;
static constexpr int max_digits10 = boost::multiprecision::cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_total_digits10;
static constexpr int max_digits10 = boost::multiprecision::cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_max_digits10;
static constexpr typename boost::multiprecision::cpp_dec_float<Digits10, ExponentType, Allocator>::exponent_type min_exponent = boost::multiprecision::cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_min_exp; // Type differs from int.
static constexpr typename boost::multiprecision::cpp_dec_float<Digits10, ExponentType, Allocator>::exponent_type min_exponent10 = boost::multiprecision::cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_min_exp10; // Type differs from int.
static constexpr typename boost::multiprecision::cpp_dec_float<Digits10, ExponentType, Allocator>::exponent_type max_exponent = boost::multiprecision::cpp_dec_float<Digits10, ExponentType, Allocator>::cpp_dec_float_max_exp; // Type differs from int.
test/test_roots_10k_digits.cpp
+33
View File
@@ -153,6 +153,34 @@ bool test_pisot(const T tol = std::numeric_limits<T>::epsilon() * 1000000U)
return result_is_ok;
}
template <class T>
bool test_sqrt_pi_modify_one_digit_to_fail(const T tol = std::numeric_limits<T>::epsilon() * 1000000U)
{
using std::fabs;
using std::sqrt;
const T sqrt_pi = sqrt(boost::math::constants::pi<T>());
std::string str_wrong(str_control_sqrt_pi);
// We will now purposefully modify the string at position 9502.
// This is the character '8' at the beginning of the final complete
// line of the initialization of the string str_control_sqrt_pi.
if(str_wrong[9502U] == (char) '8')
{
str_wrong[9502U] = (char) '9';
}
const T control(str_wrong);
const T closeness = fabs(1 - fabs(sqrt_pi / control));
// Ensure that the answer is wrong (which is the correct behavior).
const bool wrong_result_is_ok = (closeness > tol);
return wrong_result_is_ok;
}
int main()
{
#if defined(TEST_CPP_DEC_FLOAT)
@@ -171,5 +199,10 @@ int main()
BOOST_CHECK_EQUAL(result_pisot_is_ok, true);
}
{
const bool result_sqrt_pi_modify_one_digit_to_fail_is_ok = test_sqrt_pi_modify_one_digit_to_fail<big_float_type>(local_tol);
BOOST_CHECK_EQUAL(result_sqrt_pi_modify_one_digit_to_fail_is_ok, true);
}
return boost::report_errors();
}