Re: amd64 missing addressing modes

[Anton Ertl]

On Thu, Aug 27, 2020 at 04:49:38PM +0100, anthony wrote:
> Dear Berndt,
> 
> thanks for this document. It is very useful and I was not aware of its
> existence.
> If all current linux distributions are following this document (2014)

Every OS but Windows uses the System V ABI on AMD64.

> 9
> registers are available for scratch i.e. AX CX DX SI DI R8 R9 R10 R11
> where CX is used as return stack in gforth.

Don't rely on the return stack pointer being in RCX.  E.g., it's not
the case in my development build.  The only thing you can count on is
that the data stack pointer is passed in in RDI, the address of a cell
containing the FP stack pointer is passed in RSI, and you return the
data stack pointer in RAX.

- anton