I haven't observed this breaking any game, but it didn't match
the behavior of the interpreter as far as I could tell from
reading the code, in that denormals weren't being flushed.
If we can prove that FCVT will provide a correct conversion,
we can use FCVT. This makes the common case a bit faster
and the less likely cases (unfortunately including zero,
which FCVT actually can convert correctly) a bit slower.
Preparation for following commits.
This commit intentionally doesn't touch paired stores,
since paired stores are supposed to flush to zero.
(Consistent with Jit64.)
This simplifies some of the following commits. It does require
an extra register, but hey, we have 32 of them.
Something I think would be nice to add to the register cache
in the future is the ability to keep both the single and double
version of a guest register in two different host registers
when that is useful. That way, the extra register we write to
here can be read by a later instruction, saving us from
having to perform the same conversion again.
Fixes https://bugs.dolphin-emu.org/issues/12388. Might also fix
other games that have problems with float/paired instructions
in JitArm64, but I haven't tested any.
When the interpreter writes to a discarded register, its type
must be changed so that it is no longer considered discarded.
Fixes a 62ce1c7 regression.
Repeated erase() + iteration on a std::multimap is extremely slow.
Slow enough that it causes a 7 second long stutter during some
transitions in F-Zero X (a N64 VC game that triggers many, many icache
invalidations).
And slow enough that JitBaseBlockCache::DestroyBlock shows up on a
flame graph as taking >50% of total CPU time on the CPU-GPU thread:
https://i.imgur.com/vvqiFL6.png
This commit optimises those block link queries by replacing the
std::multimap (which is typically implemented with red-black trees)
with hash tables.
Master: https://i.imgur.com/vvqiFL6.png / 7s stutters
(starting from 5.0-2021 and with branch following disabled)
This commit: https://i.imgur.com/hAO74fy.png / ~0.7s stutters, which
is pretty close to 5.0 stable. (5.0-2021 introduced the performance
regression and it is especially noticeable when branch following
is disabled, which is the case for all N64 VC games since 5.0-8377.)
VideoCommon: Change the type of BPMemory.scissorOffset to 10bit signed: S32X10Y10
VideoBackends: Fix Software Clipper.PerspectiveDivide function, use BPMemory.scissorOffset instead of hard code 342
Oversight from #9545, which moved the "new game has been loaded" logic
to a separate OnNewTitleLoad function that has to be called explicitly
*after* a title has loaded.
Coupled with the commit that makes Dolphin not clobber 0x1800-0x3000
when using MIOS, this fixes Wind Waker and other MIOS-patched games
when they are launched from the System Menu.
MIOS puts patch data in low MEM1 (0x1800-0x3000) for its own use.
Overwriting data in this range can cause the IPL to crash when
launching games that get patched by MIOS.
See https://bugs.dolphin-emu.org/issues/11952 for more info.
Not applying the Gecko HLE patches means that Gecko codes will not work
under MIOS, but this is better than the alternative of having specific
games crash.
iwubcode
