In order to implement the SSE4.2 string instructions in a reasonable
manner, we can make use of a fallback implementation for the time
being.
This implementation just returns the intermediate result and leaves it
up to the function making use of it to derive the final result from said
intermediate result. This is fine, considering we have the immediate
control byte that tells us exactly what is desired as far as output
formats go.
Given that the result of this IR op will never take up more than
16-bits, we store the flags we need to set in the upper 16 bits of the
result to avoid needing to implement multiple return values in the JIT.
Also, since the IR op just returns the intermediate result, this can be
used to implement all of the explicit string instructions with a single IR op.
The implementation is pretty heavily documented to help make heads or
tails of these monster instructions.
We still need to hook glibc for thunks to work with
`IsHostHeapAllocation`.
So now we link in two jemalloc allocators in different namespaces.
As usual we have multiple heap allocators that we need to be careful about.
1. jemalloc with `je_` namespace.
- This is FEX's regular heap allocator and what gets used for all the
fextl objects.
- This allocator is the one that the FEX mmap/munmap hooks hook in to
- This mmap hooking gives this allocator the full 48-bit VA even in
32-bit space.
2. jemalloc with `glibc_je_` namespace.
- This is the allocator that overrides the glibc allocator routines
- This is the allocator that thunks will use.
- This is what `IsHostHeapAllocation` will check for.
3. Guest glibc allocator
- We don't touch this one. But it is distinct from the host side
allocators.
- The guest side of thunks will use this heap allocator.
4. Host glibc allocator
- #2 replaces this one unless explicitly disabled.
- Always expected to override the allocator, so this configuration
isn't expected.
Already tested this with Dota Underlords to ensure this works with
thunks.
The dispatcher was saving AVX state even though FEX doesn't support it
currently. This is due to it checking for the config option rather than
the HostFeatures option.
The `EnableAVX` config option is supposed to be used to inform FEXCore
if we want AVX disabled or not when the host supports the feature. In
this case it is universally enabled because we haven't encountered any
games that have issues with AVX state being saved with signals. (We know
they exist, we just don't have configurations for them).
The HostFeatures option `SupportsAVX` is the option that is supposed to
be getting used for determining if the runtime AVX feature is enabled.
This also had an issue though that this was **also** always enabled if
running on an x86 host with AVX, or an ARM host with SVE2-256bit.
It was then disabled if the config option was disabled; But, since
FEX-Emu doesn't support AVX fully yet, we need to ensure this isn't yet
enabled.
But this only solves half the problem. In order for our CI to test AVX
features before fully supporting AVX, it needs to be able to enable AVX
so that the CPU state is correctly saved.
So we need to change the default configuration option to be false, and
have CI enable it for the tests that matter before AVX is fully
implemented.
Every time we are calling a function in `FEXCore::Allocator::` this is a
pointer indirection. Which means on x86 it is always a `call [rdi]` and
on AArch64 it is a `ldr x17, [x0]; blr x17;`.
Instead of doing this, use inline functions in the header that call the
correct allocation function directly. This function gets inlined and is
no longer an indirect call.
When compiling with jemalloc, we forward declare the jemalloc function
definitions so we don't have to pull in the entire jemalloc interface in
to the public header definitions.
`std::stoul` and `std::stroull` take a std::string which was converting
the string_view to a std::string first. Causing glibc fault testing to
catch this since not much uses this.
These will be added to the documentation.
This is done by consuming a single page at the end of the current sbrk
memory region. Then consuming any remaining bytes that could have
potentially ended up in it.
This ensures that glibc won't be able to return 64-bit pointers to
32-bit thunks once the remaining work is in place.
The LOAD_LIB and EXPORTS macros behave slightly differently in this regard:
* Use LOAD_LIB(libwayland-client) in Guest.cpp (library name with dash)
* Use EXPORTS(libwayland_client) in Host.cpp (library name with underscore)
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