I have written a few zero-overhead (fully inlining) D wrappers
around certain new x64 instructions as an exercise to help me
learn D and get used to GDC asm. I've also written D replacements
for older processors. They are templated functions with
customised variants supporting a variety of different word-widths.
1. Would anyone find these useful? Bet I'm inventing the wheel?
(But still a good learning task for me.)
2. How best to get them reviewed for correct D-style and
3. how to package them up, expose them? They need to be usable by
the caller in such a was as they get fully directly inlined with
no subroutine calls or arg passing adaptation overhead so as to
get the desired full 100% performance. For example a call with a
literal constant argument should continue to mean an immediate
operand in the generated code, which happens nicely currently in
my testbeds. So I don't know, the user needs to see the lib fn
_source_ or some equivalent GDC cleverness. (Like entire thing in
a .h file. Yes, I know, I know. :-) )
4. I would like to do the same for LDC, unfortunately the asm
system is rather different from GDC. I don't know if there is
anything clever I can do to try to avoid duplication of effort /
totally split sources and double maintenance? (Desperation?
Preprocess the D sources with an external tool if all else fails!
Yuck. Don't have one at hand right now anyway.)
Is there any way I could get D to actually generate some D code
to help with that?
I have seen some pretty mind-blowing stuff in D using mixin or
something - looks fantastic, just like the power of our old
friends the evil unconstrained C macros that can generate random
garbage C source text without limit, but in D it's done right so
the D source can actually be parsed properly, no two languages
fighting. I recall using this kind of source generation for
dealing with lots of different operator-overloading routines that
all follow a similar pattern. Can't think where else. I don't
know what is available and what the limits of various techniques
are. I'm wondering if I could get D to internally generate
GDC-specific or LDC-specific source code strings - the two asm
frameworks are syntactically different iirc - starting from a
friendly generic neutral format, transforming it somehow. (If
memory serves, I think GDC uses a non-D extended syntax, very
close to asm seen in GCC for C, for easier partial re-use of
snippets from C sources. On the other hand LDC looks more like
standard D with complex template expansion, but I haven't studied
it properly.)
Any general tips to point me in the right direction, much
appreciated.
