Agner's CPU blog

spudwa wrote:

Would WSL be okay?

I am not sure if the driver works under WSL.
I already have test results for Zen4

spudwa wrote Sorry I'm running Windows 11 on a 7800X3D so I can't give you a linux shell but I'd be happy to run any tests for you. If you want, you can boot Ubuntu from a USB stick and run my tests. It will be a great help if you run all my tests scripts and send the results to me. https://ubuntu.c...

Thank you.
I cannot afford to buy every new microprocessor on the market, just to test it. It would be very helpful if somebody out there can give me access to one of the new microprocessors. All I need is a remote login to a Linux installation on the computer.

Good idea. I will put testp on github when I get the time. I don't have the time and resources to test every new microprocessor family on the market, so it will be good if other people can help.

Sorry for the bug. I have removed the extra case label.

__builtin_ctz is not portable to all compilers. I don't think there is any difference in performance. Let's keep this discussion on stackoverflow. Remember to use the tag "vector-class-library" on stackoverflow.

No, there is no performance penalty.

Karalinda wrote:

In many cases, there are no good alternatives to Intel's function libraries

Apparently, it is now possible to use the Intel function libraries without the cripple feature. See my previous post "New Clang-based Intel compiler is better"

Language evolves. I am not sure this is the right forum to discuss this.

An optimizing assembler should code mov rax,123 as mov eax,123 because the result is zero-extended into rax anyway. The two instructions should give identical results. Test results may vary for random reasons. Zero extension cannot be used with negative constants. mov rax,-123 is two bytes longer th...

APX, on the other hand, does add decoder complexity. X86 until AVX512 already has 15 - 18 different prefixes, depending on how you count. APX adds just one more prefix (REX2) and extends the number of uses of an existing one (EVEX). This is just an incremental increase in complexity. It should be p...