No, not really. Go's assembly might be considered somewhat higher level than regular assembly code, but it's certainly architecture specific. The examples highlighted use x86 SIMD instructions unavailable on other architectures.

Freedoms taken by the go assemblers also seem to be decreasing as the compiler becomes smarter. E.g. instruction reordering is no longer performed (https://github.com/golang/go/issues/15837).

You can read about the assemblers here: https://golang.org/doc/asm