Here is the patch with the doxygen comments for the intrinsincs in the header file __wmmintrin_pclmul.h.
The doxygen comments are automatically generated based on our internal intrinsics document.
I will submit more doxygen comments for the other intrinsic header files as soon as this patch is approved.
Here is the link to the general discussion about adding comments to x86 intrinsics headers.
Here is the link to the similar code review for the doxygen comments for the header file ammintrin.h "Adding doxygen comments to the LLVM intrinsics (part 1, ammintrin.h)"