A prevalent pattern in the FEX codebase is to compute some data and store it
in a maybe_unused variable that's only ever passed to LOGMAN_THROW_A_FMT.
Besides few exceptions, we never compute expensive data in the macro
arguments themselves, so we can remove a lot of code noise by unconditionally
evaluating the condition even in assertion-disabled builds.
The host stack pointer can't be reused since explicit bounds checks
would be far too expensive, and on-stack signals prevent implicit ones
using guard pages from working.
TMP4 was used before we passed in a tmp register. Now use that temp
register.
Also return the amount of stack used on the push function. This will be
used in a bit.
In the Push/Pop CalleeSavedRegisters these vectors were getting created
on the heap, allocating memory and then just iterating them.
Just use a std::array which makes it stop allocating memory and saves
the number of instructions.
stop doing weird special cases. just dump all the regs except what aapcs64 says
we don't have to.
this fixes saving x18 across thunks and things. so probably fixes things *cry*
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
* x18 wasn't getting spilled even though it was supposed to be.
* arm64ec preserve_all definitions were all messed up, specialize these to fix.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
- IsImmLogical already existed in our CodeEmitter. We just forgot to
allow nullptr arguments and to use it.
- Adds an equivalent IsImmAddSub helper and uses it
This gets us closer to removing vixl's global initializers from FEXCore.
Some locations could end up with SRA registers that only spilled one
register.
Allow passing in temporaries from the call site.
Fixes rpid and syscalls asserting.
When AFP is supported then we can actually support DAZ. This might also
fix the audio corruption in Animal Well but I can't test it until Steam
is running on Oryon. Requires a bit of plumbing for MXCSR which we were
hacking around before but now we actually want to store the value.
Fixes#3856
We can support a few combinations of guest and host vector sizes
Host: 128-bit or 256-bit
Guest: 128-bit or 256-bit
The typical case is Host = 128-bit and Guest = 256-bit now that AVX is
implemented.
On 32-bit this changes to Host=128-bit and Guest=128-bit because we
disable AVX.
In the vixl simulator 32-bit turns in to Host=256-bit and Guest=128-bit.
And then in the vixl sim 64-bit turns in to Host=256-bit and
Guest=256-bit.
We cover all four combinations of guest and host vector register sizes!
Fixes a few assumptions that SVE256 = AVX256 basically.
In quite a few locations we are mixing the case that SVE256 == AVX or
that AVX means the guest register size is 256-bit.
While this is true today, this is entanglement is going to change very
quickly and cause confusion in follow-up PRs.
Now we have SVE128, SVE256, and SVE2 HostFeatures to disambiguate the
different features which mean different things.
This PR keeps the alias that `SupportsAVX` = `SupportsSVE256 && SupportsSVE2`
but that alias is going to very quickly change its definition.
I recommend viewing the new source file as the diff is quite messy.
---
The old RA commits every "how not to write an RA" sin in the book.
Chaitin spill-one loop? Check.
Potential spilling caused by alignment issues since there's no live range
splitting? Check.
Panic spilling? Check.
Generating an interference graph with linear live ranges, so you get the code
quality of linear scan with the cost of graph colouring? Check.
...
It is wholly unsuitable to any application, and specifically unsuitable for FEX.
---
The new RA exploits a key IR invariant unique to FEX: no values are live across
block boundaries. This is validated.
Because of this invariant, all RA is block local. This lets us use a dead simple
2 pass RA that generates ~optimal code in linear time.
The first pass walks the IR backwards, analyzing the IR. This is a souped up
analogue to liveness analysis.
The second pass walks the IR forward, blasting out registers. If necessary, it
will insert spill and/or shuffle code on the fly. Spilling uses the well-known
furthest-first heuristic, which has excellent results for straight line code.
That's it :-)
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
While the ARM64EC ABI mostly matches FEX's SRA, the stack still needs to
be switched to the emulator stack and target RIP stored into the FEX
context before jumping to the dispatcher loop.
Tony Wasserka