[GNATS 25579] __builtin_fmaf is not able to be used in constexpr

[jhsedg]

Customer bug ID

math/test/ccmath_fma_test.test/ccmath_fma_test.cpp

Description

​"../libs/math/test/ccmath_fma_test.cpp", line 37: error #28: expression must have a constant value
​ static_assert(boost::math::ccmath::fma(T(1), T(2), T(3)) == T(5));
​ ^
​"../boost/math/ccmath/fma.hpp", line 26: note #2703-D: cannot call non-constexpr function "__builtin_fmaf" (dec
​lared implicitly)
​ return __builtin_fmaf(x, y, z);
​ ^
​"../boost/math/ccmath/fma.hpp", line 70: note #2693-D: called from:
​ return boost::math::ccmath::detail::fma_imp(x, y, z);
​ ^
​ detected during instantiation of "void test() [with T=float]" at line 55

Notes

​2024-12-17, ellen.
​Boost 1.87.0 had a major update to the Math library and this test no longer exists.