Round-14 of AUDIT-2BF (singleton-dump). Pairs with xenia-rs'
--audit-mem-read-hex to emit one comparable XELOGKERNEL line resolving
the bctrl target at sub_822F1AA8+0x90 (PC 0x822F1B4C):
[0x828E1F08] -> singleton instance ptr
[singleton+0] -> vtable
[vtable+0] -> vtable[0] (= first virtual method, bctrl tgt)
[vtable+24] -> vtable[24] (= slot 6, silph chain target)
Two complementary hooks:
1. src/xenia/cpu/backend/x64/x64_emitter.cc: extend
AuditLogJitPrologArgs. New cvar `audit_jit_prolog_mem_dump` (uint32).
When non-zero and an `audit_jit_prolog_pc` fire happens, the host
side dereferences the VA 3 levels deep and emits one
AUDIT-MEM-READ line in the same format ours emits. Defensive
per-level null + VA-range checks.
2. src/xenia/kernel/kernel_state.cc: one-shot dump in
EmulateCPInterruptDPC of the same chain (hard-coded to
0x828E1F08). Useful when audit_jit_prolog_pc isn't set; fires the
first time the CP interrupt path runs (after the singleton ctor
has had time to populate).
Read-only. Both gates default-off; no impact when cvars unset.
~65 LOC total across the two files.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Replace the round-7 hardcoded `current_guest_function_ == 0x824F7800`
gate with a runtime cvar `audit_jit_prolog_pc` (uint32, 0 = disabled).
The cvar names the guest entry PC at which the x64 emitter inserts a
CallNative to the prolog probe; the probe now dumps the active PC in
each log line so multiple instrumentation campaigns can share output.
Renames `audit_log_sub824F7800_args` (cvar) and `AuditLogSub824F7800Args`
(host function) — the round-7 sub_824F7800-specific cvar and function
are deleted, not left dormant. The `audit_handle_lifecycle` cvar and
its existing AUDIT-HLC probe sites in xboxkrnl_threading.cc /
kernel_state.cc are untouched.
Validated by audit-059 round 9: with `--audit_jit_prolog_pc=0x821B55D8`
the silph WorkerCtx-init chain entry fires 1× in canary at tid=6
lr=0x82172D8C (call site at sub_82172BA0+0x1E8 `bctrl`, the virtual
dispatch through vtable slot 6 that statically-blind xref-walkers
cannot enumerate).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds cvar audit_log_sub824F7800_args (off by default). When set, the x64
JIT emits one CallNative to AuditLogSub824F7800Args at the start of the
JIT-compiled body of guest function 0x824F7800 (silph::WorkerCtx ctor's
immediate caller per audit-058). The hook reads r3..r10, LR, and 64
bytes at host(r3) from PPCContext and writes them to XELOGKERNEL.
The hook is placed *after* the JIT prolog (stack push, GUEST_RET_ADDR /
GUEST_CALL_RET_ADDR setup, optional trace-functions block) and *before*
the first HIR body instruction, so r3..r10 and lr in PPCContext still
reflect the caller's args (no LOAD/STORE_CONTEXT has executed yet inside
the callee). The compile-time gate `current_guest_function_ == 0x824F7800`
makes this a zero-cost no-op for all other functions and a single extra
CallNative for the one target.
Audit-059 round 7 probe captures r3..r10 + LR for a-prime synthetic
replay of sub_824F7800 from a host hook in xenia-rs. Run with:
--audit_handle_lifecycle=true --audit_log_sub824F7800_args=true
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
BaseHeap::Dispose() walks the page table and calls
DeallocFixed(addr, 0, kRelease) for every allocated page region.
These addresses are within file-backed view mappings (i.e. guest memory).
On Windows, VirtualFree on file-mapped pages silently returns FALSE.
On POSIX, the code hit assert_always() and crashed. Changed to return false
to match Windows behavior.
Memory leaks from munmap(addr, 0):
Callers passed length=0 to DeallocFixed(kRelease). On Windows this works because
VirtualFree(addr, 0, MEM_RELEASE) means "release the entire region" — Windows
ignores the length parameter for MEM_RELEASE and always frees the whole
allocation. On POSIX, munmap(addr, 0) fails with EINVAL, so the memory was
silently leaked every time.
Add round-to-nearest-even to the fast float16 pack path by folding a
0xFFF rounding bias into XMMF16PackLCPI0 and extracting bit 13 of the
source as the tie-breaker, matching the software fallback behavior.
Fix PACK_SHORT_2 test to use pre-biased float input (0x40400000 = 3.0)
as the hardware expects, rather than raw 0.0f which is out of range.
Add constexpr getters to magicdiv class so it can be used from jitted x64/dxbc
Track the guest return address as well for guest/host sync, if multiple entries have the same guest stack find the first one with a matching guest retaddr. this fixes epic mickey 2 (which the previous guest-stack change had allowed to go ingame for a bit) and potentially also a crash in fable3.
Break if under debugger when stackpoints are overflowed
Add much more useful output for host exceptions, print out xenia_canary.exe relative offsets if exception is in module, formatmessage for ntstatus/win32err, strerror
Minor d3d12 microoptimization, instead of doing SetEventOnCompletion + WaitForSingleObject do SetEventOnCompletion w/ nullptr so that the wait happens in kernel mode, avoiding two extra context switches
add unimplemented kernel functions:
ExAllocatePoolWithTag
ObReferenceObject
ObDereferenceObject has no return value.
Log a message when ObDereferenceObject/Reference receive unregistered guest kernel objects
gave ObLookupThreadByThreadId its correct error status
hoist object_types initialization out of ObReferenceObjectByHandle
Fix out parameter values on error for a few kernel funcs
add note about msr to KeSetCurrentStackPointers
add X_STATUS_OBJECT_TYPE_MISMATCH check for xeNtSetEvent
add msr_mask field to X_KPCR
Remove dead #if 0'd code in math.h
On amd64, page_size == 4096 constant, on amd64 w/ win32, allocation_granularity == 65536. These values for x86 windows havent changed over the last 20 years so this is probably safe
and gives a modest code size reduction
Enable XE_USE_KUSER_SHARED. This sources host time from KUSER_SHARED instead of from QueryPerformanceCounter, which is far faster, but only has a granularity of 100 nanoseconds.
In some games seemingly random crashes were happening that were hard to trace because
the faulting thread was actually not the one that was misbehaving, another threads stack was underflowing into the faulting thread.
Added a bunch of code to synchronize the guest stack and host stack so that if a guest longjmps the host's stack will be adjusted.
Changes were also made to allow the guest to call into a piece of an existing x64 function.
This synchronization might have a slight performance impact on lower end cpus, to disable it set enable_host_guest_stack_synchronization to false.
It is possible it may have introduced regressions, but i dont know of any yet
So far, i know the synchronization change fixes the "hub crash" in super sonic and allows the game "london 2012" to go ingame.
Removed emit_useless_fpscr_updates, not emitting these updates breaks the raiden game
MapGuestAddressToMachineCode now returns nullptr if no address was found, instead of the start of the function
add Processor::LookupModule
Add Backend::DeinitializeBackendContext
Use WriteRegisterRangeFromRing_WithKnownBound<0, 0xFFFF> in WriteRegisterRangeFromRing for inlining (previously regressed on performance of ExecutePacketType0)
add notes about flags that trap in XamInputGetCapabilities
0 == 3 in XamInputGetCapabilities
Name arg 2 of XamInputSetState
PrefetchW in critical section kernel funcs if available & doing cmpxchg
Add terminated field to X_KTHREAD, set it on termination
Expanded the logic of NtResumeThread/NtSuspendThread to include checking the type of the handle (in release, LookupObject doesnt seem to do anything with the type)
and returning X_STATUS_OBJECT_TYPE_MISMATCH if invalid. Do termination check in NtSuspendThread.
Add basic host exception messagebox, need to flesh it out more (maybe use the new stack tracking stuff if on guest thrd?)
Add rdrand patching hack, mostly affects users with nvidia cards who have many threads on zen
Use page_size_shift in more places
Once again disable precompilation! Raiden is mostly weird ppc asm which probably breaks the precompilation. The code is still useful for running the compiler over the whole of an xex in debug to test for issues
"Fix" debug console, we were checking the cvar before any cvars were loaded, and the condition it checks in AttachConsole is somehow always false
Remove dead #if 0'd code in math.h
On amd64, page_size == 4096 constant, on amd64 w/ win32, allocation_granularity == 65536. These values for x86 windows havent changed over the last 20 years so this is probably safe
and gives a modest code size reduction
Enable XE_USE_KUSER_SHARED. This sources host time from KUSER_SHARED instead of from QueryPerformanceCounter, which is far faster, but only has a granularity of 100 nanoseconds.
In some games seemingly random crashes were happening that were hard to trace because
the faulting thread was actually not the one that was misbehaving, another threads stack was underflowing into the faulting thread.
Added a bunch of code to synchronize the guest stack and host stack so that if a guest longjmps the host's stack will be adjusted.
Changes were also made to allow the guest to call into a piece of an existing x64 function.
This synchronization might have a slight performance impact on lower end cpus, to disable it set enable_host_guest_stack_synchronization to false.
It is possible it may have introduced regressions, but i dont know of any yet
So far, i know the synchronization change fixes the "hub crash" in super sonic and allows the game "london 2012" to go ingame.
Removed emit_useless_fpscr_updates, not emitting these updates breaks the raiden game
MapGuestAddressToMachineCode now returns nullptr if no address was found, instead of the start of the function
add Processor::LookupModule
Add Backend::DeinitializeBackendContext
Use WriteRegisterRangeFromRing_WithKnownBound<0, 0xFFFF> in WriteRegisterRangeFromRing for inlining (previously regressed on performance of ExecutePacketType0)
add notes about flags that trap in XamInputGetCapabilities
0 == 3 in XamInputGetCapabilities
Name arg 2 of XamInputSetState
PrefetchW in critical section kernel funcs if available & doing cmpxchg
Add terminated field to X_KTHREAD, set it on termination
Expanded the logic of NtResumeThread/NtSuspendThread to include checking the type of the handle (in release, LookupObject doesnt seem to do anything with the type)
and returning X_STATUS_OBJECT_TYPE_MISMATCH if invalid. Do termination check in NtSuspendThread.
Add basic host exception messagebox, need to flesh it out more (maybe use the new stack tracking stuff if on guest thrd?)
Add rdrand patching hack, mostly affects users with nvidia cards who have many threads on zen
Use page_size_shift in more places
Once again disable precompilation! Raiden is mostly weird ppc asm which probably breaks the precompilation. The code is still useful for running the compiler over the whole of an xex in debug to test for issues
properly byteswap r13 for spinlock
Add PPCOpcodeBits
stub out broken fpscr updating in ppc_hir_builder. it's just code that repeatedly does nothing right now.
add note about 0 opcode bytes being executed to ppc_frontend
Add assert to check that function end is greater than function start, can happen with malformed functions
Disable prefetch and cachecontrol by default, automatic hardware prefetchers already do the job for the most part
minor cleanup in simplification_pass, dont loop optimizations, let the pass manager do it for us
Add experimental "delay_via_maybeyield" cvar, which uses MaybeYield to "emulate" the db16cyc instruction
Add much faster/simpler way of directly calling guest functions, no longer have to do a byte by byte search through the generated code
Generate label string ids on the fly
Fix unused function warnings for prefetch on clang, fix many other clang warnings
Eliminated majority of CallNativeSafes by replacing them with naive generic code paths.
^ Vector rotate left, vector shift left, vector shift right, vector shift arithmetic right, and vector average are included
These naive paths are implemented small loops that stash the two inputs to the stack and load them in gprs from there, they are not particularly fast but should be an order of magnitude faster than callnativesafe
to a host function, which would involve a call, stashing all volatile registers, an indirect call, potentially setting up a stack frame for the arrays that the inputs get stashed to, the actual operations, a return, loading all volatile registers, a return, etc
Added the fast SHR_V128 path back in
Implement signed vector average byte, signed vector average word. previously we were emitting no code for them. signed vector average byte appears in many games
Fix bug with signed vector average 32, we were doing unsigned shift, turning negative values into big positive ones potentially
Fix guest code profiler, it previously only worked with function precomp + all code you were about to execute already discovered
Allow AndNot if type is V128
remove useless memorybarrier
remove double membarrier in wait pm4 cmd
add int64 cvar
use int64 cvar for x64 feature mask
Rework some functions that were frontend bound according to vtune placing some of their code in different noinline functions, profiling after indicating l1 cache misses decreased and perf of func increased
remove long vpinsrd dep chain code for conversion.h, instead do normal load+bswap or movbe if avail
Much faster entry table via split_map, code size could be improved though
GetResolveInfo was very large and had impact on icache, mark callees as noinline + msvc pragma optimize small
use log2 shifts instead of integer divides in memory
minor optimizations in PhysicalHeap::EnableAccessCallbacks, the majority of time in the function is spent looping, NOT calling Protect! Someone should optimize this function and rework the algo completely
remove wonky scheduling log message, it was spammy and unhelpful
lock count was unnecessary for criticalsection mutex, criticalsection is already a recursive mutex
brief notes i gotta run
PM4 buffer handling made a virtual member of commandprocessor, place the implementation/declaration into reusable macro files. this is probably the biggest boost here.
Optimized SET_CONSTANT/ LOAD_CONSTANT pm4 ops based on the register range they start writing at, this was also a nice boost
Expose X64 extension flags to code outside of x64 backend, so we can detect and use things like avx512, xop, avx2, etc in normal code
Add freelists for HIR structures to try to reduce the number of last level cache misses during optimization (currently disabled... fixme later)
Analyzed PGO feedback and reordered branches, uninlined functions, moved code out into different functions based on info from it in the PM4 functions, this gave like a 2% boost at best.
Added support for the db16cyc opcode, which is used often in xb360 spinlocks. before it was just being translated to nop, now on x64 we translate it to _mm_pause but may change that in the future to reduce cpu time wasted
texture util - all our divisors were powers of 2, instead we look up a shift. this made texture scaling slightly faster, more so on intel processors which seem to be worse at int divs. GetGuestTextureLayout is now a little faster, although it is still one of the heaviest functions in the emulator when scaling is on.
xe_unlikely_mutex was not a good choice for the guest clock lock, (running theory) on intel processors another thread may take a significant time to update the clock? maybe because of the uint64 division? really not sure, but switched it to xe_mutex. This fixed audio stutter that i had introduced to 1 or 2 games, fixed performance on that n64 rare game with the monkeys.
Took another crack at DMA implementation, another failure.
Instead of passing as a parameter, keep the ringbuffer reader as the first member of commandprocessor so it can be accessed through this
Added macro for noalias
Applied noalias to Memory::LookupHeap. This reduced the size of the executable by 7 kb.
Reworked kernel shim template, this shaved like 100kb off the exe and eliminated the indirect calls from the shim to the actual implementation. We still unconditionally generate string representations of kernel calls though :(, unless it is kHighFrequency
Add nvapi extensions support, currently unused. Will use CPUVISIBLE memory at some point
Inserted prefetches in a few places based on feedback from vtune.
Add native implementation of SHA int8 if all elements are the same
Vectorized comparisons for SetViewport, SetScissorRect
Vectorized ranged comparisons for WriteRegister
Add XE_MSVC_ASSUME
Move FormatInfo::name out of the structure, instead look up the name in a different table. Debug related data and critical runtime data are best kept apart
Templated UpdateSystemConstantValues based on ROV/RTV and primitive_polygonal
Add ArchFloatMask functions, these are for storing the results of floating point comparisons without doing costly float->int pipeline transfers (vucomiss/setb)
Use floatmasks in UpdateSystemConstantValues for checking if dirty, only transfer to int at end of function.
Instead of dirty |= (x == y) in UpdateSystemConstantValues, now we do dirty_u32 |= (x^y). if any of them are not equal, dirty_u32 will be nz, else if theyre all equal it will be zero. This is more friendly to register renaming and the lack of dependencies on EFLAGS lets the compiler reorder better
Add PrefetchSamplerParameters to D3D12TextureCache
use PrefetchSamplerParameters in UpdateBindings to eliminate cache misses that vtune detected
Add PrefetchTextureBinding to D3D12TextureCache
Prefetch texture bindings to get rid of more misses vtune detected (more accesses out of order with random strides)
Rewrote DMAC, still terrible though and have disabled it for now.
Replace tiny memcmp of 6 U64 in render_target_cache with inline loop, msvc fails to make it a loop and instead does a thunk to their memcmp function, which is optimized for larger sizes
PrefetchTextureBinding in AreActiveTextureSRVKeysUpToDate
Replace memcmp calls for pipelinedescription with handwritten cmp
Directly write some registers that dont have special handling in PM4 functions
Changed EstimateMaxY to try to eliminate mispredictions that vtune was reporting, msvc ended up turning the changed code into a series of blends
in ExecutePacketType3_EVENT_WRITE_EXT, instead of writing extents to an array on the stack and then doing xe_copy_and_swap_16 of the data to its dest, pre-swap each constant and then store those. msvc manages to unroll that into wider stores
stop logging XE_SWAP every time we receive XE_SWAP, stop logging the start and end of each viz query
Prefetch watch nodes in FireWatches based on feedback from vtune
Removed dead code from texture_info.cc
NOINLINE on GpuSwap, PGO builds did it so we should too.
Remove the logger_ != nullptr check from shouldlog, it will nearly always be true except on initialization and gets checked later anyway, this shrinks the size of the generated code for some
Select specialized vastcpy for current cpu, for now only have paths for MOVDIR64B and generic avx1
Add XE_UNLIKELY/LIKELY if, they map better to the c++ unlikely/likely attributes which we will need to use soon
Finished reimplementing STVL/STVR/LVL/LVR as their own opcodes. we now generate far less code for these instructions. this also means optimization passes can be written to simplify/remove/replace these instructions in some cases. Found that a good deal of the X86 we were emitting for these instructions was dead code or redundant.
the reduction in generated HIR/x86 should help a lot with compilation times and make function precompilation more feasible as a default
Don't static assert in default prefetch impl, in c++20 the assertion will be triggered even without an instantiation
Reorder some if/else to prod msvc into ordering the branches optimally. it somewhat worked...
Added some notes about which opcodes should be removed/refactored
Dispatch in WriteRegister via vector compares for the bounds. still not very optimal, we ought to be checking whether any register in a range may be special
A lot of work on trying to optimize writeregister, moved wraparound path into a noinline function based on profiling info
Hoist the IsUcodeAnalyzed check out of AnalyzeShader, instead check it before each call. Profiler recorded many hits in the stack frame setup of the function, but none in the actual body of it, so the check is often true but the stack frame setup is run unconditionally
Pre-check whether we're about to write a single register from a ring
Replace more jump tables from draw_util/texture_info with popcnt based sparse indexing/bit tables/shuffle lookups
Place the GPU register file on its own VAD/virtual allocation, it is no longer a member of graphics system
add split_map class for mapping keys to values in a way that optimizes for frequent searches and infrequent insertions/removals
remove jump table implementation of GetColorRenderTargetFormatComponentCount, it was appearing relatively high in profiles. instead pack the component counts into a single 32 bit word, which is indexed by shifting
Add cvar to align all basic blocks to a boundary
Add mmio aware load paths
liberally apply XE_RESTRICT in ringbuffer related code
Removed the IS_TRUE and IS_FALSE opcodes, they were pointless duplicates of COMPARE_EQ/COMPARE_NE and i want to simplify our set of opcodes for future backends
More work on LVSR/LVSL/STVR/STVL opcodes
Optimized X64 translated code emission, now only compute instrkey once
Add code for pre-computing integer division magic numbers
Optimized GetHostViewportInfo a little
Move args for GetHostViewportInfo into a class, cache the result and compare for future queries. moved GetHostViewportInfo far lower on the profile
Add (currently not functional, and very racy) asynchronous memcpy code. will improve it and actually use it in future commits.
Add non-temporal memcpy function for huge page-aligned allocations. Used for copying to shared memory/readback
hoist are_accumulated_render_targets_valid_ check out of loop in render_target_cache already bound check.
Add stosb/movsb code for small constant memcpys/memsets that arent worth the overhead of memcpy/memset
Proper handling of nans for VMX max/min on x64 (minps/maxps has special behavior depending on the operand order that vmx does not have for vminfp/vmaxfp)
Add extremely unintrusive guest code profiler utilizing KUSER_SHARED systemtime. This profiler is disabled on platforms other than windows, and on windows is disabled by default by a cvar
Repurpose GUEST_SCRATCH64 stack offset to instead be for storing guest function profile times, define GUEST_SCRATCH as 0 instead, since thats already meant to be a scratch area
Fix xenia silently closing on config errors/other fatal errors by setting has_console_attached_'s default to false
Add alternative code path for guest clock that uses kusershared systemtime instead of QueryPerformanceCounter. This is way faster and I have tested it and found it to be working, but i have disabled it because i do not know how well it works on wine or on processors other than mine
Significantly reduce log spam by setting XELOGAPU and XELOGGPU to be LogLevel::Debug
Changed some LOGI to LOGD in places to reduce log spam
Mark VdSwap as kHighFrequency, it was spamming up logs
Make logging calls less intrusive for the caller by forcing the test of log level inline and moving the format/AppendLogLine stuff to an outlined cold function
Add swcache namespace for software cache operations like prefetches, streaming stores and streaming loads.
Add XE_MSVC_REORDER_BARRIER for preventing msvc from propagating a value too close to its store or from its load
Add xe_unlikely_mutex for locks we know have very little contention
add XE_HOST_CACHE_LINE_SIZE and XE_RESTRICT to platform.h
Microoptimization: Changed most uses of size_t to ring_size_t in RingBuffer, this reduces the size of the inlined ringbuffer operations slightly by eliminating rex prefixes, depending on register allocation
Add BeginPrefetchedRead to ringbuffer, which prefetches the second range if there is one according to the provided PrefetchTag
added inline_loadclock cvar, which will directly use the value of the guest clock from clock.cc in jitted guest code. off by default
change uses of GUEST_SCRATCH64 to GUEST_SCRATCH
Add fast vectorized xenos_half_to_float/xenos_float_to_half (currently resides in x64_seq_vector, move to gpu code maybe at some point)
Add fast x64 codegen for PackFloat16_4/UnpackFloat16_4. Same code can be used for Float16_2 in future commit. This should speed up some games that use these functions heavily
Remove cvar for toggling old float16 behavior
Add VRSAVE register, support mfspr/mtspr vrsave
Add cvar for toggling off codegen for trap instructions and set it to true by default.
Add specialized methods to CommandProcessor: WriteRegistersFromMem, WriteRegisterRangeFromRing, and WriteOneRegisterFromRing. These reduce the overall cost of WriteRegister
Use a fixed size vmem vector for upload ranges, realloc/memsetting on resize in the inner loop of requestranges was showing up on the profiler (the search in requestranges itself needs work)
Rename fixed_vmem_vector to better fit xenia's naming convention
Only log unknown register writes in WriteRegister if DEBUG :/. We're stuck on MSVC with c++17 so we have no way of influencing the branch ordering for that function without profile guided optimization
Remove binding stride assert in shader_translator.cc, triangle told me its leftover ogl stuff
Mark xe::FatalError as noreturn
If a controller is not connected, delay by 1.1 seconds before checking if it has been reconnected. Asking Xinput about a controller slot that is unused is extremely slow, and XinputGetState/SetState were taking up
an enormous amount of time in profiles. this may have caused a bit of input lag
Protect accesses to input_system with a lock
Add proper handling for user_index>= 4 in XamInputGetState/SetState, properly return zeroed state in GetState
Add missing argument to NtQueryVirtualMemory_entry
Fixed RtlCompareMemoryUlong_entry, it actually does not care if the source is misaligned, and for length it aligns down
Fixed RtlUpperChar and RtlLowerChar, added a table that has their correct return values precomputed
But for normal msvc builds i would put it at around 30-50%
Added per-xexmodule caching of information per instruction, can be used to remember what code needs compiling at start up
Record what guest addresses wrote mmio and backpropagate that to future runs, eliminating dependence on exception trapping. this makes many games like h3 actually tolerable to run under a debugger
fixed a number of errors where temporaries were being passed by reference/pointer
Can now be compiled with clang-cl 14.0.1, requires -Werror off though and some other solution/project changes.
Added macros wrapping compiler extensions like noinline, forceinline, __expect, and cold.
Removed the "global lock" in guest code completely. It does not properly emulate the behavior of mfmsrd/mtmsr and it seriously cripples amd cpus. Removing this yielded around a 3x speedup in Halo Reach for me.
Disabled the microprofiler for now. The microprofiler has a huge performance cost associated with it. Developers can re-enable it in the base/profiling header if they really need it
Disable the trace writer in release builds. despite just returning after checking if the file was open the trace functions were consuming about 0.60% cpu time total
Add IsValidReg, GetRegisterInfo is a huge (about 45k) branching function and using that to check if a register was valid consumed a significant chunk of time
Optimized RingBuffer::ReadAndSwap and RingBuffer::read_count. This gave us the largest overall boost in performance. The memcpies were unnecessary and one of them was always a no-op
Added simplification rules for multiplicative patterns like (x+x), (x<<1)+x
For the most frequently called win32 functions i added code to call their underlying NT implementations, which lets us skip a lot of MS code we don't care about/isnt relevant to our usecases
^this can be toggled off in the platform_win header
handle indirect call true with constant function pointer, was occurring in h3
lookup host format swizzle in denser array
by default, don't check if a gpu register is unknown, instead just check if its out of range. controlled by a cvar
^looking up whether its known or not took approx 0.3% cpu time
Changed some things in /cpu to make the project UNITYBUILD friendly
The timer thread was spinning way too much and consuming a ton of cpu, changed it to use a blocking wait instead
tagged some conditions as XE_UNLIKELY/LIKELY based on profiler feedback (will only affect clang builds)
Shifted around some code in CommandProcessor::WriteRegister based on how frequently it was executed
added support for docdecaduple precision floating point so that we can represent our performance gains numerically
tons of other stuff im probably forgetting
"turns out theres a lot of quirks with the div instructions we havent been covering
if the denom is 0, we jump to the end and mov eax/rax to dst, which is correct because ppc raises no exceptions for divide by 0 unlike x86
except we don't initialize eax before that jump, so whatever garbage from the previous sequence that has been left in eax/rax is what the result of the instruction will be
and then in our constant folding, we don't do the same zero check in Value::Div, so if we constant folded the denom to 0 we will host crash
the ppc manual says the result for a division by 0 is undefined, but in reality it seems it is always 0
there are a few posts i saw from googling about it, and tests on my rgh gave me 0, but then another issue came up
and that is that we dont check for signed overflow in our division, so we raise an exception if guest code ever does (1<<signbit_pos) / -1
signed overflow in division also produces 0 on ppc
the last thing is that if src2 is constant we skip the 0 check for division
without checking if its nonzero
all weird, likely very rare edge cases, except for maybe the signed overflow division
chrispy — Today at 9:51 AM
oh yeah, and because the int members of constantvalue are all signed ints, we were actually doing signed division always with constant folding"
fixed an earlier mistake by me with the precision of fresx
made some optimization disableable
implemented vkpkx
fixed possible bugs with vsr/vsl constant folding
disabled the nice imul code for now, there was a bug with int64 version and i dont have time to check
started on multiplication/addition/subtraction/division identities
Removed optimized VSL implementation, it's going to have to be rewritten anyway
Added ppc_ctx_t to xboxkrnl shim for direct context access
started working on KeSaveFloatingPointState, re'ed most of it
Exposed some more state/functionality to the kernel for implementing lower level routines like the save/restore ones
Add cvar to re-enable incorrect mxcsr behavior if a user doesnt care and wants better cpu performance
Stubbed out more impossible sequences, replace mul_hi_i32 with a 64 bit multiply
Add alternate path to DOT_PRODUCT_3/4 for use_fast_dot_product that skips all the status register stuff and just remaps inf to qnan
Add OPCODE_TO_SINGLE to replace the CONVERT_F32_F64 - CONVERT_F64_F32 sequence we used to emit with the idea that a backend could implement a more correct rounding behavior if possible on its arch
Remove some impossible sequences like MUL_HI_I8/I16, MUL_ADD_F32, DIV_V128. These instructions have no equivalent in PPC. Many other instructions are unused/dead code and should be removed to make the x64 backend a better reference for future ones
Add backend_flags to Instr. Basically, flags field that a backend can use for whatever it wants when generating code.
Add backend instr flag to x64 that tells it to not generate code for an instruction. this allows sequences to consume subsequent instructions
Generate actual x64 code for VSL instruction instead of using callnativesafe
Detect repeated COMPARE instructions w/ identical operands and reuse the results in FLAGS if so. this eliminates a ton of garbage compare/set instructions.
If a COMPARE instructions destination is stored to context with no intervening instruction and no additional uses besides the store, do setx [ctx address]
Detect prefetchw and use it in CACHE_CONTROL if prefetch for write is requested instead of doing prefetch to all cache levels
Fixed an accident in an earlier commit by me, VECTOR_DENORMFLUSH was not being emitted at all, so denormal inputs to MUL_ADD_V128 were not becoming zero and outputs from DOT_PRODUCT_X were not either. I believe this introduced a bug into RDR where a wagon wouldnt spawn? (https://discord.com/channels/308194948048486401/308207592482668545/1000443975817252874)
Compute fresx in double precision using RECIP_F64 and then round to single instead of doing (double)(1.0f / (float)value), matching original behavior better
Refactor some of ppc_emit_fpu, much of the InstrEmit function are identical except for whether they round to single or not
Added "tail emitters" to X64Emitter. These are callbacks that get invoked with their label and the X64Emitter after the epilog code. This allows us to move cold code out of the critical path and in the future place constant pools near functions
guest_to_host_thunk/host_to_guest_thunk now gets directly rel32 called, instead of doing a mov
Add X64BackendContext structure, represents data before the start of the PPCContext
Instead of doing branchless sequence, do a compare and jump to tail emitted code for address translation. This makes converting addresses a 3 uop affair in most cases.
Do qnan move for dot product in a tail emitter
Detect whether EFLAGS bits are independent variables for the current cpu (not really detecting it ehe, just checking if zen) and if so generate inc/dec for add/sub 1
Detect whether low 32 bits of membase are 0. If they are then we can use membasereg.cvt32() in place of immediate 0 in many places, particularly in stores
Detect LOAD MODIFY STORE pattern for context variables (currently only done for 64 bit ones) and turn them into modify [context ptr]. This is done for add, sub, and, or, xor, not, neg
Tail emit error handling for TRAP opcodes
Stub out unused trap opcodes like TRAP_TRUE_I32, TRAP_TRUE_I64, TRAP_TRUE_I16 (the call_true/return_true opcodes for these types are also probably unused)
Remove BackpropTruncations. It was poorly written and causes crashes on the game Viva pinata (https://discord.com/channels/308194948048486401/701111856600711208/1000249460451983420)
Use shuffle_ps instead of broadcastss, broadcastss is slower on many intel and amd processors and encodes to the same number of bytes as shuffle_ps
Detect and optimize away PERMUTE with a zero src2 and src3 in constant_propagation_pass instead of in the x64 sequence
For constant PERMUTE, do the Xor/And prior to LoadConstantXmm instead of in the generated code
Simplified code for PERMUTE
Added simplification rule that detects (lzcnt(x) >> log2(bitsizeof_x)) == ( x == 0)
Added set_srcN(value, idx) which can be used to set the nth source of an instruction, which makes more sense than having three different functions that only differ by the field they touch
Added Value::VisitValueOperands for iterating all Value operands an instruction has.
Add BackpropTruncations code to simplification_pass
Changed the (void**) dereferences of raw_context that are done to grab thread_state to instead reference PPCContext and the thread_state field. Moved the thread_state field to the tail of PPCContext.
Moved membase to the tail of PPCContext, since now it is reloaded very infrequently.
Rearranged PPCContext so that the condition registers come first (most accesses to them cant get SSA'd), moved lr and ctr to after gp regs since they are not accessed as much as the main gpregs. This way the most frequently
accessed registers will be accessible via a rel8 displacement instead of rel32 (ideally, we would have only certain CRs at the start, but xenia does pointer arithmetic on CR0's offset to get CRn)
Use alignas(64) to ensure PPCContext's padding
Map PPCContext specially so that the low 32 bits of the context register is 0xE0000000, for the 4k page offset check. Also allocate the page before, so that backends can store their own information that is not relevant to the PPCContext on that page and
reference that data in the generated asm via 8-bit signed displ or 32-bit signed displ. Currently this page is not being utilized, but I plan on stashing some data critical to the x86 backend there
Changed many wrong avx instructions, they worked but they were not intended for the data they operated on, meaning they transferred domains and caused 1-2 cycle stall each time
Added SimdDomain checking/deduction to X64Emitter.
Used SimdDomain code to fix a lot of float/int domain stalls
Use the low 32 bits of the context register instead of constant 0xE0000000 in ComputeAddress
Special path for SELECT_V128 with result of comparison that will use a blend instruction instead of and/or
Many HIR optimizations added in simp pass
A bunch of other stuff running out of time to write this msg
pack local_slot and constant in hir::Value
Instead of loading membase at the start of every function, just load it in HostToGuestThunk
vzeroupper in GuestToHostThunk before calling host function, and in HostToGuestThunk after calling function to prevent AVX dirty state slowdowns. In the future, check if CPU implements AVX as 128x2 and skip if so (https://john-h-k.github.io/VexTransitionPenalties.html)
Remove useless save/restore of ctx pointer, nothing modifies it and it prevents cpus from doing cross-function memory renaming (https://www.agner.org/forum/viewtopic.php?t=41). Could not remove the space on stack because of alignment issues, instead turned it into GUEST_SCRATCH64 which is a temporary that sequences may use
Reorder OpcodeInfo so that name is at offset 0, remove name and add GetOpcodeName function (name is only used for debug code, we are seperating frequently accessed data and rarely accessed data)
Add VECTOR_DENORMFLUSH opcode for handling output to DOT_PRODUCT and other opcodes that implicitly force denormal inputs/outputs to zero, will eventually use for implementing NJM
Rewrite sequences for LOAD_VECTOR_SHL/SHR. The mask with 0xf in it was pointless as all InstrEmit_ functions that create the load shift instructions do that in HIR. The tables are only used for nonzero constant inputs now, which are probably pretty rare. Instead of doing a shift and lookup, a base value is used for both in the constant table and adding/subtracting of the input is done
Reuse result of LoadVectorShl/Shr in InstrEmit_stvlx_, InstrEmit_stvrx_. We were previously calculating it twice which was contributing to the final sequences' fatness. Use OPCODE_SELECT instead of the sequence of or, andnot, and that it was using for merging
Add the proper unconditional denormal input flushing behavior to vfmadd, add it also to vfmsub (making the assumption it has the same behavior)
Remove constant propagation for DOT_PRODUCT_3/4
DOT_PRODUCT_3/4 now returns a vector with all four elements set to the result. (what we were doing before, truncating to float32 and then splatting didnt make any sense)
Add much more correct versions of DOT_PRODUCT_3/4, matching the Xb360's to 1 bit. Still needs work to be a perfect emulation.
Add constant folding for OPCODE_SELECT, OPCODE_INSERT, OPCODE_PERMUTE, OPCODE_SWIZZLE
Remove constant folding for DOT_PRODUCT
Removed the multibyte nop code I committed earlier, it doesnt help us much because nops are only used for debug stuff and its ugly and wouldnt survive in a pr to main
Check for AVX512BMI, use vpermb to shuffle if supported
Added recognition of impossible comparisons via NZM and optimize them away
Recognize (x + -y) and transform to (x - y) for constants
Recognize (~x ) + 1 and transform to -x
Check and transform comparisons if theyre semantically equal to others
Detect comparisons of single-bit values with their only possible non-zero value and transform to true/false tests
Transform ==0 to IS_FALSE, !=0 to IS_TRUE
Truncate to int8 if operand for IS_TRUE/IS_FALSE has a nzm of 1
Reduced code generated for SubDidCarry slightly
Add special case for InstrEmit_srawix if mask == 1
Cut down the code generated for trap instructions, instead of naive or'ing or compare results do a switch and select the best condition
Rerun simplification pass until no changes, as some optimizations will enable others to be done
Enable rel32 call optimization by default
Add special case to TYPE_INT64's EmitAnd for UINT_MAX mask. Do mov32 to 32 if detected to take advantage of implicit zero xt/reg renaming
Add helper function for skipping assignment defs in instr.
Add helper function for checking if an opcode is binary value type
Add several new optimizations to simplificationpass, plus weak NZM calculation code (better full evaluation of Z/NZ will be done later) .
List of optimizations:
If a value is anded with a bitmask that it was already masked against, reuse the old value (this cuts out most FPSCR update garbage, although it does cause a local variable to be allocated for the masked FPSCR and it still repeatedly stores the masked value to the context)
If masking a value that was or'ed against another check whether our mask only considers bits from one value or another. if so, change the operand to the OR input that actually matters
If the only usage of a rotate left's output is an AND against a mask that discards the bits that were rotated in change the opcode to SHIFT_LEFT
If masking against all ones, become an assign.
If XOR or OR against 0, become an assign (additional FPSCR codegen cleanup)
If XOR against all ones, become a NOT
Adding a direct CPUID check to x64_emitter for lzcnt, the version of xbyak we are using is skipping checking for lzcnt on all non-intel cpus, meaning we are generating the much slower bitscan path for AMD cpus.
the emitted asm as rel32 calls. Disabled by default, enabled via
resolve_rel32_guest_calls
detect whether cpu has fast jrcxz, fast loop/loope/loopne
much more thorough LoadConstantXMM
New cvar elide_e0_check that allows the backend to assume accesses via
the SP or TLS register will not cross into 0xe0 range
Add x64 codegen for Vector shift uint8
If has fast jrcxz use for some traptrue/breaktrue instructions
Use phat nops
Add cvar use_fast_dot_product, which uses a four instruction sequence
for both dot product instructions which ought to be equivalent. disabled
by default.
Rather than having a huge list of if-statements that all do the same
thing, this preprocessor allows a more concise pattern to detecting if
the emit-flag is enabled as well as the correlated Xbyak flag that it
needs to check for to before allowing the feature-flag to be emitted.
Also moved the AVX-check to the beginning to early-out rather than do a
bunch of wasted work only to find out last that the host doesn't even
support AVX.
Rather than having a single bool to conditionally detect haswell-level
instruction features. The granularity is increased with a new
`x64_extension_mask` where individual features within the x64 backend
can be turned on or off in a bit-mask manner. Since we have an ARM
backend on the horizon, I've added this to the new `x64`
configuration-group rather than `CPU`. This new pattern will hopefully
allow for testing to be more targetted to certain processor features and
allows the user to determine if they want certain features to be enabled
or disabled(such as avoiding BMI2 on certain AMD processors due to
pdep/pext being incredibly slow). The default configuration is to detect
and utilize all available features.
The `BMI1 feature` fits into the current pattern of `use_haswell_instructions` as BMI1 was only introduced in haswell.
Also moved the aliases to the end of the enum rather than interleave it with the bit definitions.
Implements the detection of some baseline `AVX512` subsets and some common aliases into `X64EmitterFeatureFlags`.
So far, `AVX512{F,VL,BW,DQ}` are the only subsets of `AVX512` that are detected with this PR since I anticipate these are the ones that will actually be used a lot in the x64 backend. Some aliases are also implemented such as `kX64EmitAVX512Ortho` which is `AVX512F` and `AVX512VL` combined which are the two subsets of AVX512 required to allow for `AVX512` operations upon `ymm` and `xmm` registers.
These aliases can possibly be collapsed since we could just always require `AVX512VL` to be supported to allow for _any_ kind of `AVX512` to be used since we will practically always want to use `AVX512` on `xmm` registers at the very least as there is no use-case where we want to use the 512-bit `zmm` registers exclusively.
Rather than using `n * 1024 * 1024`, this adds a convenient `_MiB`/`_KiB` user-literal to the new `literals.h` header to concisely describe units of memory in a much more readable way. Any other useful literals can be added to this header. These literals exist in the `xe::literals` namespace so they are opt-in, similar to `std::chrono` literals, and require a `using namespace xe::literals` statement to utilize it within the current scope.
I've done a pass through the codebase to replace trivial instances of `1024 * 1024 * ...` expressions being used but avoided anything that added additional casting complexity from `size_t` to `uint32_t` and such to keep this commit concise.
