Each of the three spin-then-sleep semaphore loops watches a single
atomic word, but ShortSpin() has no way to know that: it spends its
share of SPIN_TIME_NS in batches of eight isb, and every one of those is
a pipeline flush. arm64 can watch the word itself, so ShortSpinOn()
does, and the loops that hold their whole predicate in one word take it.
Hosts that cannot watch an address keep the old spin.
Inspired by Whatcookie's work on arm64 for rpcs3.
Merges yaps2/main (github.com/yaps2/yaps2, c16b88cb7) into ARMSX2,
replacing the arm64 recompiler family with the yaps2 JITs and importing
the yaps2 testing, perf, and libretro infrastructure. Common ancestor is
upstream PCSX2 342db5152 (2026-06-19); git auto-merged all but 38 files.
Replaced (deleted in this merge, recoverable from history):
- arm64/aR5900*, aR3000A*, aVU* -> arm64/iR5900*/iR3000A*/microVU*-arm64:
EE static-pin register file with lazy dirty tracking, dual-residence
allocator, IOP block linking, native COP2 macro ops, inline unaligned
fastmem, persisted VU program cache, call-ret shadow ring, VU0 spin
fast-forward.
- MVU_DIFF shadow-run hooks in shared VU interpreter TUs (superseded by
the offline vurunner JIT-vs-interp oracle).
Imported from yaps2:
- tests/ctest/core/recompilers: ~80 gtest suites (EE/IOP/VU differential
harnesses, fuzzers, ABI digest tripwire, capture format pins) plus the
gs_vertex_tests kernel oracle.
- pcsx2-vurunner / pcsx2-eerunner headless capture-replay runners.
- tools/perf counter-based A/B rigs, perf jitdump productionization,
PmuCounters, clang-perf/clang-handheld presets.
- pcsx2-libretro core (ENABLE_LIBRETRO, default OFF; rename pending).
- GS vertex-kick fast path (GV series): TBL-based packed parse,
register-resident kick, scalar-outcode cull, fused draw-rect/FindMinMax.
- Null renderer, VK_KHR_display direct WSI, swapchain PresentStats.
- SPU2 NEON mixer vectorization, EE timer read clamp (NFL 2K5 hang),
IOP ioman signed-compare fix, assorted UB fixes.
Kept from ARMSX2 in the both-touched files:
- iOS dual-map W^X and fastmem-unavailable resilience (Memory, HostSys,
vtlb). The split data/code area model is retained; both areas now take
fixed VA hints so cached VU JIT code stays deterministic on Linux.
- Android thread-affinity model, VMState shutdown early-outs, all
platform frontends, branding, CI, RetroAchievements identity/policy.
- GSDeviceVK: ARMSX2's push-descriptor decision logic (Mali crash gate,
proprietary-vs-turnip Adreno split) merged with yaps2's descriptor-pool
exhaustion recovery (flush + render-pass restart instead of dropped
binds). Vendor feature policy is the union: Mali fbfetch policy with
MediaTek/G57/Xclipse gates from ARMSX2; Adreno stencil/ROV/
test-and-sample-depth hang avoidance and no_ps2_z_quantization from
yaps2.
Build-system notes:
- The Qt debugger is now gated behind ENABLE_QT_DEBUGGER (default off on
arm64) so handheld builds drop the KDDockWidgets dependency.
- GSDeviceNone and remaining yaps2 GS code were ported to the newer
upstream GSTexture Usage-flags API.
The replaced backend's interpreter-fallback glue (intExecuteOneInst,
AndroidEEOpHist) and the EEDiffVerify runtime differ are retained for
now; dead pieces will be removed in a follow-up commit.
Port the complete JIT and write-xor-execute infrastructure to DarwinMisc with four JitModes (Simulator, Legacy, LuckTXM, LuckNoTXM), dual-mapping via vm_remap for writable code aliases, the csops CS_DEBUGGED probe for JIT availability detection, brk assembly helpers for the TXM protocol, and the W^X toggle functions. Connect the JIT foundation to the code emitters through AsmHelpers dual-map bridge, Memory.cpp MmapCodeDualMap allocation, and the aR5900 LegacyEnsureExecutable path. Refresh the iOS SwiftUI frontend from the iOS-refresh branch, bringing in 11 missing and 20 drifted Swift files plus ios_main.mm integration. Switch the CI to a real device build using the iphoneos SDK. Fix the Achievements crash by gracefully degrading when no HTTPDownloader is available (no CURL on iOS). Fix the Metal surface to reuse the UIView's existing CAMetalLayer instead of an orphaned allocation that caused half-screen crops. Fix GS memory allocation by using mmap and vm_remap instead of shm_open which is blocked by the iOS sandbox. Suppress the false positive Graphics not Automatic OSD warning. Merge upstream master and resolve all resulting compile errors.
SharedMemoryMappingArea::Create() gains a fixed_base_hint so AllocateMemoryMap can
pin the JIT arena at a constant VA (kArenaBase=4GB, 256MB-stride fallback) on arm64;
the VTLB fastmem backpatch thunk (RecStubs), ArmAddressRecorder relocation hooks
(AsmHelpers), and the cpuTlbMiss rec-vs-interp PC split (R5900) round out the arm64
memory layer. Windows arm64 is a no-op stub.
Co-Authored-By: Ryan Walklin <ryan@testtoast.com>
Co-Authored-By: Brian Degenhardt <bmd@bmdhacks.com>
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
All games use mailbox/triple buffering. Except when you enable sync to
host refresh, in which case FIFO/double buffering is used.
This means vsync enabled will ever tear, but at the same time, never
drop to 30fps on a missed frame due to frame rate differences.
To have the "best of both worlds", you should enable vsync and sync to
host refresh. Previously, this resulted in additional input lag, since
the host vsync would drive the EE frame timing. Now, this behaviour is
disabled by default, unless you enable "Use Host VSync Timing".
pstef
Brian Degenhardt
Jeen
TellowKrinkle
SternXD
lightningterror
Ty
TheTechnician27
GovanifY
Stenzek