No need to extract the subregisters out before operating on them since
the long division and long remainder IR operations correctly zero/sign
extend the incoming sources as necessary. Saves a couple of
instructions.
guest instruction
Single instruction blocks need to be treated specially when inline SMC
is detected, the frontend only needs to reprotect RWX and invalidate
caches then continue execution as side effects from the SMC shouldn't be
seen until the instruction executes.
Frontends need to detect this in order to handle SMC within the current
block (inline SMC) differently to regular SMC which can just reprotect
and continue.
When set - either via POPF or a thread context operation - the trap flag
raises a single step exception after the execution of each instruction.
As e.g. a JUMP instruction with TF set will raise an exception at the
jump target. Handle this on the FEX side by storing both the flag itself
(in bit 0) and a 'block exceptions' flag (in bit 1, inverted). Each
generated block when TF is set is then forced to a single instruction
with logic to raise the exception at the start. Initially after setting
TF exceptions are blocked, then at the start of the block they are
unblocked so that after the instruction executes an exception is raised
at the start of the next block.
Seems the unused mutex locking is able to cause some hangs according to #4198
Hard to tell why, but might as well as get rid of that potential
pitfall.
According to the documentation for x87 FCW precision control, this only
affects fadd*, fsub*, fmul*, fdiv*, and fsqrt. FEX was incorrectly
reducing precision for all x87 operations.
Precision is ignored for the following x87 ALU operations:
- fabs
- fscale
- fprem{1,}
- fcos
- fsin
- ftan
- fyl2x
- fyl2xp1
- fpatan
- fsincos
- Plus any operations just doing data movement and conversions
Next commit adds unittests to ensure this is correct for each
instruction.
Now that all the threading behaviour has been correctly separated/moved
to the frontend, these functions serve no purpose.
- Instead of using RunUntilExit, all threads can use `ExecuteThread`
directly, since there's nothing special about the primary thread now.
- This also removes the public function definition of `ExecutionThread` since that was only used for threading logic.
- Instead of using an exit handler, just do the same cleanup after
`ExecuteThread` has returned.
- Just make gdbserver is cleaned up early if it exists since it may
want to send some things to the connected gdb instance before
threads are exited.
These are all frontend constructs with mostly deprecated constraints.
WaitingToStart isn't used anymore, Running is effectively always true
(and behaviour has changed that if a thread is alive, it's running).
The only one that remains is `ThreadSleeping` which is only handled in
the frontend, and there was some conflation between ThreadSleeping and
Running which was hard to gauge. So delete `Running` and
`WaitingToStart`, but move `ThreadSleeping` to the frontend.
We were using this variable for two things, letting the frontend signal
to the backend that it wants to start executing once the thread is
created, and also for handling thread pausing. These two features are
conflated with one another and actually makes things more confusing.
- Move StartRunning/StartPaused to the frontend, because its a construct
that only needs to exist in the frontend
- Adds a FEX::HLE::ThreadStateObject CV for handling pausing, which only
needs to exist for gdbserver
FEXCore hasn't been returning anything other than EXIT_SHUTDOWN for a
long time, so this ended up just moving data around for no reason.
This isn't going to be used for further GdbServer work anyway, so just
completely remove it.
Alloc::OSAllocator uses a TLS variable of the thread object so it can
use a forkable mutex plus a deferring signal section. This was setup
when the FEXCore "ExecutionThread" function is called, which is a bit
awkward and is an artifact from when the thread creation was mixed
between the frontend and the backend.
Instead let the frontend inform the backend when to install the TLS
variable.
This is one step required to make GdbServer work correctly again since
the thread initialization and pausing is awkward today.
This was working around an edge case in the GdbServer where a thread was
getting created while the process was shutting down. This edge case is
getting removed so get rid of it.
this is a pain to track and, it turns out, buys us virtually nothing on flagm
systems. rip it out.
this fixes a bug with failing to set in all the right places.
on non-flagm systems there's a slight instcountci impact, but that is mostly
mitigated by the earlier patches in the series. so overall a wash there but
worth it for making the codebase easier
to reason about.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Ensures reads don't go past the end of the page boundary.
SVE masked loads can make this more effective but `VLoadVectorMasked`
isn't setup to be efficient for this case yet.
NFC
Finally converts the IR operations themselves to store the OpSize for
the IR operation size and element sizes.
This also finally, FINALLY, converts that remaining `_Constant` helper
to stop using a size field that is specified in bits rather than bytes
like all the other IR op handlers. That thing was so confusing and now
it's gone.
Ryan Houdek