At the firmware / driver level, fully open specifications for high performance hardware is an impossible dream.

At best, detailed documentation is a lower priority item below "make it work" and "increase performance".

At worst, it requires exposing trade secrets.

Edit: It'd probably be more productive for everyone if we set incentives and work such that the goal we want (compilers that produce code that runs optimally on Intel, AMD, and other architectures) isn't contingent on Intel writing them for non-Intel architectures. (Said somewhat curmudgeonly, because everyone complains about things like this, but also doesn't really how insanely hard and frustratingly edge-case-ridden compiler work is)

If Intel did that there probably wouldn't be a software suite at all for their processors.

Compare to vTune just about all open source profilers are either a bad joke or like programming in Basic in a C++ age.

No, just don't falsely market your product as fair or neutral.

It’s the Intel MKL, I don’t think Intel has ever even endorsed using it on other vendors CPUs, much less claimed that it is “fair” or “neutral”.

Well:

    On November 12, 2009 AMD and Intel Corporation announced a comprehensive settlement agreement to end all outstanding legal disputes between the companies, including antitrust and patent cross license disputes. In addition to a payment of $1.25B that Intel made to AMD, Intel agreed to abide by an important set of ground rules that continue in effect until November 11, 2019. 

    Customers and Partners

    With respect to customers and partners, Intel must not:*
    [...]
    Intentionally include design/engineering elements in its products that artificially impair the performance of any AMD microprocessor.

https://www.amd.com/en/corporate/antitrust-ruling

I like that 'in effect until November 11, 2019.' part :D