09:33
So I took some ancient code and I adapted it to the future, which saved a bunch of time. Now what I have to do is delve into the actual parsing of the byte code and handling it as such.
15:02
So the basis of the JIT regardless of platform would be to transform all
stack based work into register based work. The simple caching will be how the
stack caching works (so local to stack will not waste work for the most part).
Additionally I am going to need a new way to specify types used for variable
placement. This would be where for example instead of __SMTType__ which is
internal, there would be an external one where there is no TOP or NOTHING
since those should only be artifacts of Java byte code (which I intend to
hide).
16:34
So the base JIT will treat the code as if it had 4 billion registers. The
generic JIT on the otherhand will be a bit more limited. However the generic
JIT should be configurable, perhaps based on the variant. Since every system
generally would have support for registers and such, there needs to be a way
to specify which registers and which types are supported. I suppose when it
comes to floating point simulation, that the base JIT can handle that. When a
floating point operation is requested and software mode is to be used then it
will just treat it as int/long and any operations will just call a generic
static method.
17:09
One thing my JIT will have to handle is virtual methods that use the
Assembly class in unsafe for example. One thing I can do for some operations
would be to lazily evaluate some static method calls (essentially only use
LDCed values only when actually used), so that there are no useless
operations placed in the code. So essentially loading stuff to the stack and
such would have no "real" effect at all.
17:34
Triplets need to have hardware/software floating point specified in them since the ABI is quite different.
18:01
Going to also need hardware float/double to a software variant in the event
where there is software for one type but hardware for another.
21:55
I should make a list of system specs for a bunch of limited systems and place it somewhere. One thing I could use is some kind of note system without having it part of the daily notes here.