The current separated adr and adrp handlers are difficult to use if you
don't know if the resulting address is going to be within 1MB or 4GB.
Adds a `LongAddressGen` helper that will generate the various pieces of
code that will need to be emitted.
Backward labels:
- Can generate three different code segments depending on distance to
label
- adr if label is within 1MB
- adrp if label is 4K page aligned and within 4GB
- adrp+add if label is within 4GB
Forward labels:
- Can generate three different code segments depending on distance to
label
- nop+adr if label is within 1MB
- nop+adrp if label is 4K page aligned and within 4GB
- adrp+add if label is within 4GB
There is still the limitation that this can't generate addresses to
labels that are >4GB away. Which is fine.
We can do a single LDP upfront when loading from the code cache, which
saves an instruction and one LDP costs the same as a single LDR.
Itty bitty optimization in the hot dispatcher.
Pulled from #2176.
On x86-64 the SA_SIGINFO sa_flag is actually a no-op. It is always used
even if not set.
Ensure that we setup siginfo_t regardless of flag being set.
On 32-bit x86 this still needs to be adhered to.
Little side bits that don't change anything
- EFLAGS is passed in signfo correctly.
- User provided restorer usage locations is documented but not
implemented.
We shouldn't use O_EXCL, since we need to overwrite previous entry PIDs
if they happen to exist. The kernel ensures that PIDs don't overlap, but
in some kernel configurations PIDs are aggressively reused, resulting
in O_EXCL quickly hitting an issue when writing stale files.
Additionally O_DIRECT, this doesn't allow us to write to files, so all
write functions were failing.
Additionally use O_APPEND, we are only ever appending, so let the kernel
know.
Additionally use O_TRUNC, in the case that a stale perf file exists,
this will immediately truncate the file to zero.
Optimize `FileLoad` by not using fstream.
For some reason fstream is just really bad.
Switching over to raw pread cuts the amount of time it takes to read
files by a quarter of CPU time.
Map lookup was quite expensive, switched over to three small vectors
that are constexpr instead.
Some file querying and parsing was fairly slow as well. Optimized to
make that CPU time to go away.
This improves initialization time of CPUIDEmu by 33%
If we have a fixed file to read, we can read it in three syscalls.
fstream is...weirdly slow in the other implementation.
Theoretically in the future this can be improved to a single syscall if
the `readfile` syscall ends up in upstream Linux.
Pulled from #2176.
Ensures that when we are handling signals we are actually restoring a
stack state that is what we expect..
While this could randomly intersect with other stack data, it is highly
unlikely and will still capture incorrect stack frames otherwise.
Keeps it out of release build to ensure we aren't sticking random data
in the stack when it wouldn't have even been checked.
When a process is in the process of forking and getting ready for
execve, it is common practice to do a `close_range` or close loop to
close all file descriptors before the execve.
This is a security/sanitization feature to ensure that FDs aren't leaked
to the child process. While it is more reliable to have these FDs opened
with O_CLOEXEC, people get it wrong all the time so this feature has
been put in place. Both python and glibc wrappers for launching
applications do this.
The problem with this for FEX is that we were using a FILE handle for
emitting JIT symbols to the perf file. When the underlying FD is ripped
out from under the FILE handle, it throws an assert that we can't
recover from.
Switching to a raw FD and checking to ensure the FD is still open on
writes means that we can safely stop JIT symbol logging when a process
is closing FDs under us.
Fixes a crash in Steam early startup where a python script is run for
checking if packages are installed.
Adds three classes:
- Advanced SIMD three same (FP16)
- Advanced SIMD two-register miscellaneous (FP16)
- Advanced SIMD three-register extension
A handful of the three-register extension unit tests are disabled
because the vixl disassembler doesn't support them.
Only six more classes of ASIMD operations remaining once this is merged.
CIVAU does Clean+Invalidate to `Point Of Unification`
CIVAC does Clean+Invalidate to `Point of Coherency`
`Point of Unification` means to L2/L3, so unification of core
visibility.
`Point of Coherency` means SLC/RAM, All cores, DNA engines, etc must be
coherent.
Found an application today (hashtree tests) that causes us to spill a
large amount of values on to the stack.
We were encoding larger offsets than what unsigned offset load and store
can handle.
If the offset is too large for the loadstore, use a temporary to put the
offset in to first.
Removes some startup time where we are copying nearly a page worth of
16byte vtable pointers at startup.
Also allows the compiler to choose to inline functions if it wants to.
Mai