[Bug target/68081] Cygwin GCC cannot compile program that uses __builtin_ia32_rdseed64_step

["glisse at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68081

--- Comment #6 from Marc Glisse <glisse at gcc dot gnu.org> ---
This comment makes no sense (sorry, couldn't find a nice way to say it).

> Intel builds software

We are talking about gcc, not Intel software. Documentation is not fast or
slow.

> Microsoft has lots of footnotes

Those aren't footnotes.

> that effectively state "does not work with AMD CPUs".

And they have [1] for intrinsics that only work with AMD, not Intel.

> Does GCC arbitrarily penalize AMD?

In what way is anyone penalizing AMD here? Intrinsics are an interface to get
access to specific hardware instructions. They are mostly equivalent to a
suitable inline asm written by knowledgeable compiler writers. Like asm, they
only work on hardware that does provide said instruction. AVX2 intrinsics will
fail on older Intel CPUs. Gcc also provides intrinsics that currently only work
on some AMD CPUs.

> And using the documented GCC functions is proving to be more trouble than its worth.

I was never in favor of documenting those builtins, it makes people believe
that they can use them...