Similar to the previous far jmp, if the CS changes operating mode then
things will still explode with other FEX asserts. But this gets another
change out of my stashes.
These instructions go hand-in-hand obviously so they get implemented as
a pair.
Taking this very slowly because this is very fickle code. The frontend
needs to manage GDT and LDT, but before we get there, we need to
actually add support for LDT in the backend. Split the segments to two
arrays so the JIT can actually update their cached values correctly.
Still treats GDT and LDT as mirrors like how the JIT previously did (By
it ignoring the selector's TI bit).
Augment IREmitter to inline constants as we generate code, rather than
needing a later clean up pass. This replaces the last function of ConstProp.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Only the last prefix byte is retained when multiple are set. We were
accidentally generating a mask.
Additionally with 64-bit code, the legacy segment prefixes don't
overwrite if FS or GS have been set. So no weird behaviour where FS/GS
is set, a legacy prefix is used for padding, and then it "ignores" a bad
prefix by ignoring only the latest one.
This has the Frontend and OpcodeDispatcher select their operating mode
depending on the incoming code segment long-mode flag.
Adds some asserts since currently it is unexpected if the configuration
changes at runtime.
This is fairly straightforward for an initial setup but isn't fully
fleshed out.
Right now FEX's x86 tables aren't setup in a way to support choosing a
different instruction decoding depending on runtime operating mode
change, so that would break in interesting ways.
Primarily this just gets FEX setup to start piping the operating mode
through from the frontend to the backend. This is a long term task, so
it is going to take a long time to iron out all the issues.
Now that the PF flag isn't using popcount, this is a win across the
board if the hardware supports it.
Been a while since I last looked at this, added a new instcountci file
to show the improvement.
If multiblock discovers a codepath with an `int 0x80` then it would
crash the emulator even if it never gets executed. Ensure that this
ERROR_AND_DIE_FMT instead just gets handled as an UnhandledOp to ensure
the Core early terminates the block.
Found by having steamwebhelper spuriously crash when it hit this.
Adds a simple unittest to ensure discovery doesn't break again.
Part of waitpkg is the TPAUSE instruction. This instruction gives an
RDTSC deadline to go in to a low power sleep mode with the CPU.
Semantically we can't implement umonitor and umwait with ARM's exclusive
monitor implementation, but a nop implementation is sane. Just need to
make sure to clear the pre-req flags.
This lowers power consumption of UE5 games since their job handler now
goes to a tpause based implementation instead of a `pause` spinloop
implementation.
If a multiblock contains a call instruction, we know at the point
of compilation that the instruction after that call will likely be
jumped to at some point. Avoid redundant recompilation by tracking
such cases and including an entrypoint for that instruction in the
multiblock aswell.
this makes it a lot easier to turn a long division into a non-long division,
just by nulling out a source.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Ryan Houdek