byuu says:
Changelog:
- reverted nall/inline-if.hpp usage for now, since the
nall/primitives.hpp math operators still cast to (u)int64_t
- improved nall/primitives.hpp more; integer8 x = -128; print(-x) will
now print 128 (unary operator+ and - cast to (u)int64_t)
- renamed processor/lr35902 to processor/sm83; after the Sharp SM83
CPU core [gekkio discovered the name]
- a few bugfixes to the TLCS900H CPU core
- completed the disassembler for the TLCS900H core
As a result of reverting most of the inline if stuff, I guess the
testing priority has been reduced. Which is probably a good thing,
considering I seem to have a smaller pool of testers these days.
Indeed, the TLCS900H core has ended up at 131KiB compared to the M68000
core at 128KiB. So it's now the largest CPU core in all of higan. It's
even more ridiculous because the M68000 core would ordinarily be quite a
bit smaller, had I not gone overboard with the extreme templating to
reduce instruction decoding overhead (you kind of have to do this for
RISC CPUs, and the inverted design of the TLCS900H kind of makes it
infeasible to do the same there.)
This CPU core is bound to have dozens of extremely difficult CPU bugs,
and there's no easy way for me to test them. I would greatly appreciate
any help in looking over the core for bugs. A fresh pair of eyes to spot
a mistake could save me up to several days of tedious debugging work.
The core still isn't ready to actually be tested: I have to hook up
cartridge loading, a memory bus, interrupts, timers, and the micro DMA
controller before it's likely that anything happens at all.
byuu says:
Any usage of natural and integer cast to 64-bit math operations now.
Hopefully this will be the last of the major changes for a bit on
nall/primitives, at least until serious work begins on removing implicit
conversion to primitive types.
I also completed the initial TLCS900H core, sans SWI (kind of a ways off
from support interrupts.) I really shouldn't say completed, though. The
micro DMA unit is missing, interrupt priority handling is missing,
there's no debugger, and, of course, there's surely dozens of absolutely
critical CPU bugs that are going to be an absolute hellscape nightmare
to track down.
It was a damn shame, right up until the very last eight instructions,
[CP|LD][I|D](R), the instruction encoding was consistent. Of course,
there could be other inconsistencies that I missed. In fact, that's
somewhat likely ... sigh.
byuu says:
This WIP is just work on nall/primitives ...
Basically, I'm coming to the conclusion that it's just not practical to
try and make Natural/Integer implicitly castable to primitive signed and
unsigned integers. C++ just has too many edge cases there.
I also want to get away from the problem of C++ deciding that all math
operations return 32-bit values, unless one of the parameters is 64-bit,
in which case you get a 64-bit value. You know, so things like
array[-1] won't end up accessing the 4 billionth element of the array.
It's nice to be fancy and minimally size operations (eg 32-bit+32-bit =
33-bit), but it's just too unintuitive. I think all
Natural<X>+Natural<Y> expessions should result in a Natural<64> (eg
natural) type.
nall/primitives/operators.hpp has been removed, and new
Natural<>Natural / Integer<>Integer casts exist. My feeling is that
signed and unsigned types should not be implicitly convertible where
data loss can occur. In the future, I think an integer8*natural8 is
fine to return an integer64, and the bitwise operators are probably all
fine between the two types. I could probably add
(Integer,Natural)+Boolean conversions as well.
To simplify expressions, there are new user-defined literals for _b
(boolean), _n (natural), _i (integer), _r (real), _n# (eg _n8),
_i# (eg _i8), _r# (eg _r32), and _s (nall::string).
In the long-term, my intention is to make the conversion and cast
constructors explicit for primitive types, but obviously that'll shatter
most of higan, so for now that won't be the case.
Something I can do in the future is allow implicit conversion and
casting to (u)int64_t. That may be a nice balance.
byuu says:
I've implemented a lot more TLCS900H instructions. There are currently
20 missing spots, all of which are unique instructions (well, MINC and
MDEC could be considered pairs of 3 each), from a map of 1024 slots.
After that, I have to write the disassembler. Then the memory bus. Then
I get to start the fun process of debugging this monstrosity.
Also new is nall/inline-if.hpp. Note that this file is technically a war
crime, so be careful when opening it. This replaces ternary() from the
previous WIP.
byuu says:
So this turned out to be a rather unproductive ten-hour rabbit hole, but
...
I reworked nall/primitives.hpp a lot. And because the changes are
massive, testing of this WIP for regressions is critically important. I
really can't stress that enough, we're almost certainly going to have
some hidden regressions here ...
We now have a nall/primitives/ subfolder that splits up the classes into
manageable components. The bit-field support is now shared between both
Natural and Integer. All of the assignment operator overloads are now
templated and take references instead of values. Things like the
GSU::Register class are non-copyable on account of the function<>
object inside of it, and previously only operator= would work with
classes like that.
The big change is nall/primitives/operators.hpp, which is a really
elaborate system to compute the minimum number of bits needed for any
operation, and to return a Natural<T> or Integer<T> when one or both of
the arguments are such a type.
Unfortunately, it doesn't really work yet ... Kirby's Dream Land 3
breaks if we include operators.hpp. Zelda 3 runs fine with this, but I
had to make a huge amount of core changes, including introducing a new
ternary(bool, lhs, rhs) function to nall/algorithm to get past
Natural<X> and Natural<Y> not being equivalent (is_integral types get a
special exemption to ternary ?: type equivalence, yet it's impossible to
simulate with our own classes, which is bullshit.) The horrifying part
is that ternary() will evaluate both lhs and rhs, unlike ?:
I converted some of the functions to test ? uint(x) : uint(y), and
others to ternary(test, x, y) ... I don't have a strong preference
either way yet.
But the part where things may have gotten broken is in the changes to
where ternary() was placed. Some cases like in the GBA PPU renderer, it
was rather unclear the order of evaluations, so I may have made a
mistake somewhere.
So again, please please test this if you can. Or even better, look over
the diff.
Longer-term, I'd really like the enable nall/primitives/operators.hpp,
but right now I'm not sure why Kirby's Dream Land 3 is breaking. Help
would be appreciated, but ... it's gonna be really complex and difficult
to debug, so I'm probably gonna be on my own here ... sigh.
Tim Allen