Windows/iOS: LRCPC2 on and AFP off for the ARM64EC module - #11
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Local Madeira change for the iOS port; not for FEX-Emu upstream (FEX's contribution policy forbids AI-generated code, see CLAUDE.md). The FEX_IOS_HOST branch of FetchHostFeatures hand-rolls the host features. For the 64-bit (ARM64EC) module, where Unity-class games spend their CPU: - FEAT_LRCPC2 lets a TSO guest access [reg+disp] be one LDAPUR/STLUR instead of an ADD plus LDAPR/STLR; in Ori and the Will of the Wisps' hot JIT code nearly every LDAPR had that ADD in front of it. A wrong `true` is SIGILL, so it is taken only from an explicit LRCPC2=1 in the app's sysctl probe (FEX_MADEIRA_HOSTPROBE, the Madeira branch of the same name adds it). The WOW64 module is left alone: its guest window folds every displacement into the address. - FEAT_AFP is off by default. With it FEX writes FPCR on every entry to and exit from JIT code, twice per x64 -> ARM64EC call, and an FPCR write is expensive on Apple cores: ~9% of Ori and the Will of the Wisps' render-thread samples sat on the instruction after the write in ExitFunctionEC. FEX_HOSTFEATURES=enableafp restores AFP (unless the probe says AFP=0) and FEX_HOSTFEATURES=disablelrcpc2 turns the offset forms off. One "FEX: ml1231 iOS ARM64EC host features" line logs the result. Once FEX emits LDAPUR/STLUR, the unix-side fault emulators must decode them; that is in the Madeira branch of the same name and must ship together. Ran on the device (Ori and the Will of the Wisps): the log shows "LRCPC2=true AFP=false" and the owner reported a large frame-rate and CPU gain; no before/after numbers were logged. Rebuild arm64ec-windows/xtajit64.dll with build/fex-arm64ec/build.sh (not committed). Signed-off-by: spitefulowl <spitefulowll@gmail.com> Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
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…ebuilt DLLs - wine (willfaust/wine#22, #23, #24): ntdll.dll (stripped, padded to SizeOfImage + 0x50000) and kernelbase.dll rebuilt; the provenance record lists the three changes. - FEX (willfaust/FEX#11, #12, and the ARM64EC module honouring the app's host feature probe): xtajit64.dll and xtajit.dll rebuilt. - DXMT (willfaust/dxmt#16, #17): the 64-bit d3d11.dll and dxgi.dll rebuilt; the unix side is rebuilt with the app. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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Wine and FEX runtime fixes, DXMT texture and memory fixes, audio, the swap tier and library launch options (#178-#187 and willfaust/wine#22-#24, willfaust/FEX#11-#12, willfaust/dxmt#16-#17). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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A local change for the iOS port, not meant for FEX-Emu upstream: FEX's contribution policy forbids AI-generated code (see CLAUDE.md).
Why
Ori and the Will of the Wisps is CPU-bound (GPU busy 12-14 ms of a ~25 ms frame), mostly in translated x64 code. For the ARM64EC module, where Unity-class games spend their CPU:
[reg+disp]be one LDAPUR/STLUR instead of an ADD plus LDAPR/STLR. In the game's hot JIT code nearly every LDAPR had that ADD in front of it.ExitFunctionEC.Change
The
FEX_IOS_HOSTbranch ofFetchHostFeatures, for the ARM64EC module only:LRCPC2=1in the app's sysctl probe (FEX_MADEIRA_HOSTPROBE), because a wrong "present" is SIGILL.FEX_HOSTFEATURES=enableafprestores AFP (unless the probe says AFP=0), andFEX_HOSTFEATURES=disablelrcpc2turns the offset forms off.FEX: ml1231 iOS ARM64EC host featuresline logs the result.The WOW64 module is left alone: its guest window folds every displacement into the address.
Safe to merge on its own
The current Madeira app does not report LRCPC2 in its probe, so with this merged alone LRCPC2 stays off and only AFP changes. Once FEX emits LDAPUR/STLUR, Wine's fault emulators must decode them. That decoding, together with the probe key, is in willfaust/Madeira#184, which pins this commit together with willfaust/wine#23. Merge this one first.
Testing
Ran on the device with Ori and the Will of the Wisps. The log shows
LRCPC2=true AFP=false, and the owner reported a large frame-rate and CPU gain. No before/after numbers were logged.Notes
No binary is included.
app/Madeira/arm64ec-windows/xtajit64.dllneeds a rebuild (build/fex-arm64ec/build.sh).🤖 Generated with Claude Code