- The current limits are being hit in yuzu with some games (e.g. newer updates of BotW and SSBU).
- Increasing this fixes slow-downs in these games due to code being recompiled.
BMI2 instructions such as `pdep` and `pext` have been
known to be incredibly slow on AMD. But on Zen3
and newer, the performance of these instructions
are now much greater, but previous versions of AMD
architectures should still avoid BMI2.
On Zen 2, pdep/pext were 300 cycles. Now on Zen 3 it is 3 cycles.
This is a big enough improvement to allow BMI2 code to
be dispatched if available. The Zen 3 architecture is checked for
by detecting the family of the processor.
Add config entry to mask out the lower bits in page table pointers.
This is intended to allow users of Dynarmic to pack small integers
inside pointers and update the pair atomically without locks.
These lower bits can be masked out due to the expected alignment in
pointers inside the page table.
For the given usage, using AND on the pointer acts the same way as a
TEST instruction. That said when the mask value is zero, TEST is still
emitted to keep the same behavior.
The bit-matrix is generated up-front and added to the constant-pool.
I'm using an embedded 64-bit broadcast here(m64bcst) which is the particular
EVEX encoded version of the instruction with AVX512VL+GNFI.
If it ever really matters, then we would ideally detect specific host
features like bare-GFNI and specific subsets of AVX512 and emit
the assembly based on that rather than by the entire Icelake uarch.
Bitshifts of the GFNI identity matrix generates a new matrix that
applies lane-wise bitshifts as well. This allows for a fast
single-instruction implementation of a byte-lane bitshift.
Performs a full 128-bit bit-reversal using only two instructions.
First by reversing all the bits of each byte using a galois matrix
multiplication(vgf2p8affineqb, Icelake), and then by reversing the bytes
themselves(pshufb, ssse3).
std::malloc was being called inside SigHandler's constructor without a
std::free. This doesn't really matter as SigHandler is used as a
singleton and the OS will reclaim that memory. That said, properly
freeing memory keeps -fsanitize=address quiet.
