This is done entirely through interpreter fallbacks. It would
probably be possible to implement this using host exception
handlers instead, but I think it would be a lot of complexity
for a rarely used feature, so let's not do it for now.
For performance reasons, there are two settings for this feature:
One setting which does enables just what True Crime: New York City
needs and one setting which enables it all. The latter makes
almost all float instructions fall back to the interpreter.
There are two reasons for this.
1. Using Dolphin's logging system lets the user decide whether
the printout should go to the terminal, the GUI, or a file.
fmt::print always prints to stdout... unless you're on Android, in
which case it does nothing at all, because Android disables stdout.
2. The Windows version of Dolphin crashes when you use fmt::print.
Yes, really. The crash happens because a call to std::fprint in
fmt::v7::detail::fwrite_fully returns that less characters were
written than requested, which fmt handles by throwing an exception.
(As always, Dolphin does not use exception handling.)
I'm not sure why std::fprint is doing this, but since switching
away from using fmt::print is a good idea due to the previous point
anyway, I'd say it's best to just switch.
Makes our conversions between the different signs explicit to indicate
that they're intentional and also silences compiler warnings when
compiling with sign conversion or stricter truncation warnings enabled.
When making 92d1d60, I checked whether the ~0x1f masking in dcbx
actually was necessary. I came to the conclusion that it wasn't,
so I removed it. However, I hadn't checked the second half of
InvalidateICache closely enough - the masking is actually needed.
This commit re-adds the masking, but this time in C++ code instead
of in jitted code in order to save icache. Though I suppose the
difference doesn't matter all that much, since this is in farcode
and all...
Hopefully fixes https://bugs.dolphin-emu.org/issues/12612.
SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
Performance optimization, along with making the code a little
neater. Saves us from performing a single -> double -> single
conversion when calling UpdateFPRFSingle.
fcmpX only updates the FPCC bits, not the C bit.
This was already correctly implemented in the interpreter.
Not known to affect any games, but affects a hardware test.
Not doing this can cause desyncs when TASing. (I don't know
how common such desyncs would be, though. For games that
don't change rounding modes, they shouldn't be a problem.)
The interpreter implementation of fctiwx was treating rounding
mode 0 as "round to nearest, ties towards zero", which is not
an actual IEEE-754 rounding mode. The IBM document mentioned
in a comment at the top of the function, on the other hand,
treats rounding mode 0 as "round to nearest, ties to even",
which makes more sense.
This fixes one of JMC's console-recorded F-Zero GX replays on
JitArm64. (JitArm64 uses an interpreter fallback for fctiwx.)
This commit adds a new "discarded" state for registers.
Discarding a register is like flushing it, but without
actually writing its value back to memory. We can discard
a register only when it is guaranteed that no instruction
will read from the register before it is next written to.
Discarding reduces the register pressure a little, and can
also let us skip a few flushes on interpreter fallbacks.
The output of instructions like fabsx and ps_sel is store-safe
if and only if the relevant inputs are. The old code was always
marking the output as store-safe if the output was a single,
and never otherwise.
Also, the old code was treating the output of psq_l/psq_lu as
store-safe, which seems incorrect (if dequantization is disabled).
Converts the remaining PowerPC code over to fmt-capable logging.
Now, all that's left to convert over are the lingering remnants within
the frontend code.
