Bernd Oppolzer wrote:
I'm about to head out, so have to be extremely brief.
Thank you very much for that, that made things much clearer for me.
So the compiler relies heavily on the external assembler and the syntax
it supports,
as long as you don't want to do changes to step 2 (that is, change the
linear assembler
representation, which IMO should not be done in the first step).
And: the assembler is not called once, but for every unit.
So here, I think, we have some problems or issues, because, as already
pointed out,
the z-Arch doesn't have PUSH and POP instructions, and I guess that the
outcome
of the linear assembler representation will not be very suitable to the
things that the
z-Arch instruction set provides, although in the meantime there are some
1500 instructions.
Understanding that, I would now like to have some description of the
linear assembler
representation that FPC generates, that is: it is of course not
target-specific, but it does of
course do some assumptions on the type of the underlying hardware.
Look at the output when using FPC's -a options, for example -aln... that
might in practice need the EXTDEBUG setting during compilation but I
can't go into more detail now.
Push will typically be used to put parameters onto the stack, otherwise
they'll be accessed by indexed operation. The stack frame is discarded
by target-specific code.
--
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk
[Opinions above are the author's, not those of his employers or colleagues]
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