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.
byuu says:
Changelog:
- nall::lstring -> nall::string_vector
- added IntegerBitField<type, lo, hi> -- hopefully it works correctly...
- Multitap 1-4 -> Super Multitap 2-5
- fixed SFC PPU CGRAM read regression
- huge amounts of SFC PPU IO register cleanups -- .bits really is lovely
- re-added the read/write(VRAM,OAM,CGRAM) helpers for the SFC PPU
- but they're now optimized to the realities of the PPU (16-bit data
sizes / no address parameter / where appropriate)
- basically used to get the active-display overrides in a unified place;
but also reduces duplicate code in (read,write)IO
byuu says:
Changelog:
- fixed FC AxROM / VRC7 regression
- BitField split to BooleanBitField/NaturalBitField (in preparation
for IntegerBitField)
- BitFieldReference removed
- GB CPU cleaned up
- GB Cartridge + Mappers cleaned up
- SFC CGRAM is now emulated as uint15[256] instead of uint[512]
- sfc/ppu/memory.cpp no longer needed; removed
- purged SFC Debugger hooks for now (some of the operator[] calls were
bypassing them anyway)
Unfortunately, for reasons that defy all semblance of logic, the CGRAM
change caused a slight speed hit. As have the last few changes. We're
now down to around 129.5fps compared to 123.fps for v099 and 134.5fps
at our peak (v099r01-r02).
I really like the style I came up with for the Game Boy mappers to settle
the purpose(ROM,RAM) vs (rom,ram)Purpose naming convention. If I ever get
around to redoing the NES mappers, that's likely the approach I'll take.
byuu says:
Changelog:
- NES PPU core updated to use BitFields (absolutely massive improvement
in code readability)
- NES APU core updated to new coding style
- NES cartridge/board and cartridge/chip updated to new coding style
- pushed NES PPU rendering one dot forward (doesn't fix King's Quest V
yet, sadly)
- fixed SNES PPU BG tilemask for 128KiB VRAM mode (doesn't fix Yoshi's
Island, though)
So ... I kind of went overboard with the fc/cartridge changes. This WIP
diff is 185KiB >_>
I didn't realize it was going to be as big a task as it was, but once
I started everything broke in a chain reaction, so I had to do it all
at once.
There's a massive chance we've broken a bunch of NES things. Any typos
in this WIP are going to be absolutely insidious to track down =(
But ... supposing I pulled it off, this means the Famicom core is now
fully converted to the new coding style as well. That leaves only the
GB and GBA cores. Once those are finished, then we'll finally be free
of these gigantic hellspawn diffs.
byuu says:
Changelog:
- finished cleaning up the SFC core to my new coding conventions
- removed sfc/controller/usart (superseded by 21fx)
- hid Synchronize Video option from the menu (still in the configuration
file)
Pretty much the only minor detail left is some variable names in the
SA-1 core that really won't look good at all if I move to camelCase,
so I'll have to rethink how I handle those. It's probably a good area
to attempt using BitFields, to see how it impacts performance. But I'll
do that in a test branch first.
But for the most part, this should be the end of the gigantic diffs (this
one was 174KiB), at least for the SFC/WS cores. Still have the FC/GB/GBA
cores to clean up more fully. Assuming we don't spot any new regressions,
we should be ~95% out of the woods on code cleanups breaking things.
byuu says:
Changelog:
- added nall/bit-field.hpp
- updated all CPU cores (sans LR35902 due to some complexities) to use
BitFields instead of bools
- updated as many CPU cores as I could to use BitFields instead of union {
struct { uint8_t ... }; }; pairs
The speed changes are mostly a wash for this. In some instances,
I noticed a ~2-3% speedup (eg SNES emulation), and in others a 2-3%
slowdown (eg Famicom emulation.) It's within the margin of error, so
it's safe to say it has no impact.
This does give us a lot of new useful things, however:
- no more manual reconstruction of flag values from lots of left shifts
and ORs
- no more manual deconstruction of flag values from lots of ANDs
- ability to get completely free aliases to flag groups (eg GSU can
provide alt2, alt1 and also alt (which is alt2,alt1 combined)
- removes the need for the nasty order_lsbN macro hack (eventually will
make higan 100% endian independent)
- saves us from insane compilers that try and do nasty things with
alignment on union-structs
- saves us from insane compilers that try to store bit-field bits in
reverse order
- will allow some really novel new use cases (I'm planning an
instant-decode ARM opcode function, for instance.)
- reduces code size (we can serialize flag registers in one line instead
of one for each flag)
However, I probably won't use it for super critical code that's constantly
reading out register values (eg PPU MMIO registers.) I think there we
would end up with a performance penalty.
Tim Allen