In some cases we can generate more optimal code if we have more
information about a syscall which number gets const-propagated.
In particular optimizing through syscalls, not synchronizing state, and
never returning.
- Noreturn is used by a syscall that never returns, like exit.
This means that it never needs to try and synchronize state coming back
- Not synchronizing state and optimizing through syscalls
Useful for syscalls that don't read the state past arguments and only
returns a value.
This allows x87 fallbacks to be loaded from the upcoming code cache
without relocations.
Only 40 pointers necessary to store and means x87 code won't hit
relocations heavily.
Probably improves performance slightly on the x86 host side but should
be neglible.
Needs #1574 and #1575 merged first.
Just like the previous AArch64 JIT.
These pointers are process or thread specific depending on the pointer
and should be loaded from the State object.
Performance here might slightly increase.
This is required for code cache on x86
Needs #1574 merged first.
These pointers are process or thread specific depending on which pointer
it is.
All of these pointers end up getting used inside of the JIT blocks
themselves and with code caching would result in a ton of relocations
occuring inside the code.
The pointers used within the dispatcher don't currently matter since I'm
not expecting to cache the dispatcher itself. It's only a page per
thread after all. This does move us significantly closer towards using a
single dispatcher for all threads though.
The performance impact of this change is unlikely to be felt at all,
some locations have less code generation which could improve perf
slightly. Some locations move from a 1-3 cycle constant calculation to a
4 cycle load, hard to be felt since it gets hidden by other
instructions.
x86-64 JIT will be added soon after this
The host provided siginfo_t definition can vary depending on the build
environment.
What doesn't change however is how the data is laid out.
It's always 128bytes, The first three 32-bit words are always known.
The 64-bit host side always has an additional 32-bit pad member.
Then the remaining bytes is the sifields.
This table is particularly terrible. CRC32 is the first instruction in
this table that needs either prefix `72h` OR `66h && F2h`
For 8bit CRC32, this ignores the 66h operand size override prefix.
- But our table decoding didn't handle this
For 16bit/32bit/64bit CRC32 this behaviour changes depending on 66h
prefix AND REX.W
- 66h prefix is ignored when REX.W is set, always 64bit but it falls
down the other table path
This is an absolutely weird edge case that nobody should hit, but here
we are.
Brings along a bunch of enhancements and ensures we always build against
the latest version.
Also fixes up a few issues that arose due to changes in fmt
Due to the way this syscall handles siginfo_t, we only need to shift
data through the padding.
This is due to the syscall not allowing you to send siginfo_t with
si_code being positive. Which is what the kernel uses to interpret the
data if it is reinterpreting it.
Had some idle time so I implemented this logic.
We do some tricky logic to have a big.little configuration even with
unknown CPU core types. Promoting or demoting a single MIDR depending on
if we have a mixed configuration or not.
In a non-hybrid design we only claim product names inside the CPUID
product string.
This will appear if you `/proc/cpuinfo` or read the CPUID registers
directly
eg on Snapdragon 888:
processor : 0
model name : FEX-2112-1-g13b14b85 Cortex-A55
processor : 1
model name : FEX-2112-1-g13b14b85 Cortex-A55
processor : 2
model name : FEX-2112-1-g13b14b85 Cortex-A55
processor : 3
model name : FEX-2112-1-g13b14b85 Cortex-A55
processor : 4
model name : FEX-2112-1-g13b14b85 Cortex-A78
processor : 5
model name : FEX-2112-1-g13b14b85 Cortex-A78
processor : 6
model name : FEX-2112-1-g13b14b85 Cortex-A78
processor : 7
model name : FEX-2112-1-g13b14b85 Cortex-X1
eg on Macbook Pro VM which can't see the CPU type:
processor : 0
model name : FEX-2112-1-g13b14b85 Unknown ARM CPU
processor : 1
model name : FEX-2112-1-g13b14b85 Unknown ARM CPU
processor : 2
model name : FEX-2112-1-g13b14b85 Unknown ARM CPU
processor : 3
model name : FEX-2112-1-g13b14b85 Unknown ARM CPU
processor : 4
model name : FEX-2112-1-g13b14b85 Unknown ARM CPU
processor : 5
model name : FEX-2112-1-g13b14b85 Unknown ARM CPU
processor : 6
model name : FEX-2112-1-g13b14b85 Unknown ARM CPU
processor : 7
model name : FEX-2112-1-g13b14b85 Unknown ARM CPU
Several API functions act as state querying functions. These can take
some parameters by const to communicate that we don't intend to modify
the respective passed in instance.
It doesn't make any sense anymore to have specific instruction names
set for UND versus a nullptr string anymore.
Was useful when we could use it to determine the difference between
undefined from the start versus set in the tables but with unknown
decoding. Which is an edge case.
Now instead just zero initialize the data, which means it is an unknown
type and nullptr name. Which works for use.
Improves initialization time of the InitializeInfoTables function from
423 microseconds to 37 microseconds.
Specifically this tries to avoid changing much behaviour and keeping the
code the same. So most of it is a direct transplant without any
modifications. This is step one of the process so I can start logically
separating the code and making sense of it.
This mostly moves the AOT IR handling to its own independent file for
separation. Cleaning up the Core.cpp file quite heavily.
Two minor behaviour changes that got mixed up with this change.
The first one is an ASAN fix.
This is the FEX_PACKED on the RegisterAllocationData class.
I didn't want to change too heavily how this serialization works but I
wanted to resolve the ASAN error. This may change in the coming work.
Problem was the padding betwene the uint32_t and the PhysicalRegister
wasn't initialized but was being read.
Since it is all uint8_t types afterwards there isn't a perf issue here.
Second fix was a crash that occurs if you're attempting to both capture
and load IR on the same run. This is a quirk where we mmap the original
IR file. Then on shutdown the IR file is getting saved.
At which point we open the IR file again, truncate it, and start
serializing all of the IR data.
The truncation makes it so our mmap of the file is no longer resident,
resulting in a crash when reading our IR cache from the mmap region.
Now open a temporary file and rename it after storing.
Resolves the crash but still doesn't really solve the issue of multiple
processes overwriting the same IR files.
Without this, the internal BucketList type will always be allocated with
T as a uint32_t, due to the default type for T, even if T is specified
differently in other code.
In quite a few places we have a raw primitive to represent an IR node's
ID. This can make reading some bits of the API (or the passes) a little
confusing to take in, since there's no meaningful type name for some
data structure members.
We can provide an alias that communicates this directly to the reader.
This also has the nice benefit of providing a single point of definition
for node IDs which can allow for easier changes in the future (e.g.
making Node IDs strongly-typed etc).
Allows BucketList to work with types that aren't a direct numeric
primitive, so long as the object has equality operators defined and are
default constructible
Ryan Houdek