Re: [PATCH] cksum: Use pclmul hardware instruction for CRC32 calculation

[Kaz Kylheku (Coreutils)]

On 2021-03-14 12:55, Jeffrey Walton wrote:
> The underlying problem is GCC, Clang and friends conflate the user's
> ISA with ISA the compiler uses. They are not the same - they are
> distinct. Unfortunately, GCC and Clang never addressed the underlying
> problem.

Sorry, what does that mean?

GCC works fine as a cross-compiler. E.g. built to run on the x86_64 ISA, 
but putting out Aarch64 code.

The "Submodel" options of GCC are determined by the configuration: how 
that GCC was built.

On x86 9and maybe others), there is a "native" argument for -march and 
-mtune as in -march=native.

If GCC is configured that way, it will generate code according to the 
processor of the machine it is running on. (Unless, I'm guessing, it's 
built as a cross-compiler, so the build machine's architecture is 
irrelevant.)