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### Description
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Fix doc references for nullary expressions.
### Reference issue
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Fixes#2997.
### Additional information
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Closes#2997
See merge request libeigen/eigen!2054
(cherry picked from commit 04eb06b354)
31a2702e Fix doc references for nullary expressions.
Co-authored-by: Antonio Sánchez <cantonios@google.com>
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### Description
<!--Please explain your changes.-->
Allow user to configure if `free` is allowed at runtime.
Reverts to Eigen 3.4 behavior by default, where `free(...)` is allowed if `EIGEN_RUNTIME_NO_MALLOC` is defined but `set_is_malloc_allowed(true)`. Adds a separate `set_is_free_allowed(...)` to explicitly control use of `std::free`.
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Fixes#2983.
### Additional information
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Closes#2983
See merge request libeigen/eigen!2047
(cherry picked from commit 60122df698)
Here's the compiler error:
```
/home/tav/git/Sleipnir/build/_deps/eigen3-src/Eigen/src/Householder/Householder.h:82:16: error: call of overloaded ‘sqrt(boost::decimal::decimal64_t)’ is ambiguous
82 | beta = sqrt(numext::abs2(c0) + tailSqNorm);
| ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/tav/git/Sleipnir/build/_deps/eigen3-src/Eigen/src/Householder/Householder.h:82:16: note: there are 2 candidates
In file included from /home/tav/git/Sleipnir/build/_deps/eigen3-src/Eigen/Core:198,
from /home/tav/git/Sleipnir/test/src/optimization/cart_pole_problem_test.cpp:8:
/home/tav/git/Sleipnir/build/_deps/eigen3-src/Eigen/src/Core/MathFunctions.h:1384:75: note: candidate 1: ‘typename Eigen::internal::sqrt_retval<typename Eigen::internal::global_math_functions_filtering_base<Scalar>::type>::type Eigen::numext::sqrt(const Scalar&) [with Scalar = boost::decimal::decimal64_t; typename Eigen::internal::sqrt_retval<typename Eigen::internal::global_math_functions_filtering_base<Scalar>::type>::type = boost::decimal::decimal64_t; typename Eigen::internal::global_math_functions_filtering_base<Scalar>::type = boost::decimal::decimal64_t]’
1384 | EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE EIGEN_MATHFUNC_RETVAL(sqrt, Scalar) sqrt(const Scalar& x) {
| ^~~~
In file included from /home/tav/git/Sleipnir/build/_deps/decimal-src/include/boost/decimal/detail/cmath/ellint_1.hpp:16,
from /home/tav/git/Sleipnir/build/_deps/decimal-src/include/boost/decimal/cmath.hpp:18,
from /home/tav/git/Sleipnir/build/_deps/decimal-src/include/boost/decimal.hpp:33,
from /home/tav/git/Sleipnir/test/include/scalar_types_under_test.hpp:6,
from /home/tav/git/Sleipnir/test/src/optimization/cart_pole_problem_test.cpp:19:
/home/tav/git/Sleipnir/build/_deps/decimal-src/include/boost/decimal/detail/cmath/sqrt.hpp:167:16: note: candidate 2: ‘constexpr T boost::decimal::sqrt(T) requires is_decimal_floating_point_v<T> [with T = decimal64_t]’
167 | constexpr auto sqrt(const T val) noexcept
| ^~~~
```
Calling a function via its unqualified name invokes argument-dependent lookup. In this case, since `using numext::sqrt;` was used, both `numext::sqrt()` and `boost::decimal::sqrt()` participated in overload resolution. Since only `numext::sqrt()` was intended, the fix is to call that overload directly instead.
See merge request libeigen/eigen!2044
(cherry picked from commit be56fff1ff)
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### Description
<!--Please explain your changes.-->
Support AVX for i686.
There was an existing work-around for windows. Added the more generic
architecture comparison to also apply for linux.
### Reference issue
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Fixes#2991.
Closes#2991
See merge request libeigen/eigen!2037
(cherry picked from commit 8e60d4173c)
