User:Cantonios/3.4

• New support for bfloat16

The 16-bit Brain floating point format[1] is now available as Eigen::bfloat16. The constructor must be called explicitly, but it can otherwise be used as any other scalar type. To convert back-and-forth between uint16_t to extract the bit representation, use Eigen::numext::bit_cast.

 bfloat16 s(0.25);                                 // explicit construction
 uint16_t s_bits = numext::bit_cast<uint16_t>(s);  // bit representation
 
 using MatrixBf16 = Matrix<bfloat16, Dynamic, Dynamic>;
 MatrixBf16 X = s * MatrixBf16::Random(3, 3);

• Improved support for half
  • Native support for ARM __fp16, CUDA/HIP __half, Clang F16C
  • Better vectorization support, various bug fixes.

• Improved support for custom types
  • More custom types work out-of-the-box (see #2201[2])

• Improved Geometry Module
  • Transform::computeRotationScaling() and Transform::computeScalingRotation() are now more continuous across degeneracies (!349[3]).
  • New minimal vectorization support.

• Backend-specific improvements
  • SSE/AVX/AVX512
    • Enable AVX512 instructions by default if available