Swift has its own ABI and calling convention, so that makes sense that Apple adapted to it.
The system v abi doesn't say anything about syscall.
Windows x86_64 abi is the same abi for x86, for this reason, you can only pass arguments in 4 registers ( while unix uses 6 ) because x86 only had 8 registers.
I think people have expectations that are misaligned with history and reality about this, to be honest. We can't expect all OS to do things in the same way.
C was created to rewrite the UNIX system, and POSIX compliance is followed by all successors, with minimal differences.
When it became clear that "Itanium" was a failure, Microsoft couldn't just pull an ABI out of the box and break all applications, so they just reused the same x86 ABI.
Comments
Swift has its own ABI and calling convention, so that makes sense that Apple adapted to it.
The system v abi doesn't say anything about syscall.
Windows x86_64 abi is the same abi for x86, for this reason, you can only pass arguments in 4 registers ( while unix uses 6 ) because x86 only had 8 registers.
I think people have expectations that are misaligned with history and reality about this, to be honest. We can't expect all OS to do things in the same way.
C was created to rewrite the UNIX system, and POSIX compliance is followed by all successors, with minimal differences.
When it became clear that "Itanium" was a failure, Microsoft couldn't just pull an ABI out of the box and break all applications, so they just reused the same x86 ABI.