Augment NumTraits with min/max_exponent() again.

Replace usage of `std::numeric_limits<...>::min/max_exponent` in
codebase where possible.  Also replaced some other `numeric_limits`
usages in affected tests with the `NumTraits` equivalent.

The previous MR !443 failed for c++03 due to lack of `constexpr`.
Because of this, we need to keep around the `std::numeric_limits`
version in enum expressions until the switch to c++11.

Fixes #2148
This commit is contained in:
Antonio Sanchez
2021-03-16 20:12:46 -07:00
parent eb71e5db98
commit 8dfe1029a5
6 changed files with 70 additions and 50 deletions

View File

@@ -135,9 +135,18 @@ EIGEN_STRONG_INLINE EIGEN_DEVICE_FUNC Tgt bit_cast(const Src& src) {
* \li A dummy_precision() function returning a weak epsilon value. It is mainly used as a default
* value by the fuzzy comparison operators.
* \li highest() and lowest() functions returning the highest and lowest possible values respectively.
* \li digits() function returning the number of radix digits (non-sign digits for integers, mantissa for floating-point). This is
* the analogue of <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/digits">std::numeric_limits<T>::digits</a>
* which is used as the default implementation if specialized.
* \li digits10() function returning the number of decimal digits that can be represented without change. This is
* the analogue of <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/digits10">std::numeric_limits<T>::digits10</a>
* which is used as the default implementation if specialized.
* \li min_exponent() and max_exponent() functions returning the highest and lowest possible values, respectively,
* such that the radix raised to the power exponent-1 is a normalized floating-point number. These are equivalent to
* <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/min_exponent">std::numeric_limits<T>::min_exponent</a>/
* <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/max_exponent">std::numeric_limits<T>::max_exponent</a>.
* \li infinity() function returning a representation of positive infinity, if available.
* \li quiet_NaN function returning a non-signaling "not-a-number", if available.
*/
template<typename T> struct GenericNumTraits
@@ -179,6 +188,18 @@ template<typename T> struct GenericNumTraits
return internal::default_digits_impl<T>::run();
}
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR
static inline int min_exponent()
{
return numext::numeric_limits<T>::min_exponent;
}
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR
static inline int max_exponent()
{
return numext::numeric_limits<T>::max_exponent;
}
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR
static inline Real dummy_precision()
{
@@ -186,7 +207,6 @@ template<typename T> struct GenericNumTraits
return Real(0);
}
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR
static inline T highest() {
return (numext::numeric_limits<T>::max)();