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[SpirvTranslator/Vk] Cheaper guest buffer loads and f16 conversion, gated on device probes (#1035)
* [SpirvTranslator] Load dword-aligned 32-bit formatted buffer components as words

A formatted untyped buffer load decodes the descriptor format at run time,
reading every component byte by byte through the generic layout select
chain. For dword-aligned 32-bit data formats (32, 32_32, 32_32_32,
32_32_32_32) with a raw-bit number format (UINT, SINT, FLOAT) a component is
one buffer word; that branch loads it directly and applies the same swizzle
and bounds rules. The descriptor is uniform, so the branch does not diverge.
UE GPU-skinning vertex shaders fetch bone data this way; Silent Hill: The
Short Message's menu goes from 1.3 to 2.0 FPS.

(cherry picked from commit 20540cd153855964d817daf065de3e243fd547bd)

* [SpirvTranslator] Convert f16 with the native pack/unpack when the host measured it exact

Every packed-f16 (VOP3P) lane widens its operands to f32 and rounds the
result back, and both conversions were the branchless integer sequences in
EmitHalfToFloat / EmitFloatToHalf: about twenty scalar ops each, because
GLSL UnpackHalf2x16 / PackHalf2x16 have no guaranteed rounding or subnormal
behaviour without float-controls execution modes. A device capability bit
does not settle it either - MoltenVK on Apple silicon reports
shaderRoundingModeRTEFloat16 and shaderSignedZeroInfNanPreserveFloat16 yet
not shaderDenormPreserveFloat16 - so only a measurement can.

ShaderCompileRequest.NativeHalfConversionExact, which the host sets only
after measuring the two ext instructions against these sequences on the
running device, swaps both helpers for the single ext instruction the
driver lowers to one hardware convert. It defaults to false, so an
unmeasured device keeps the exact emulation.

Silent Hill f2 volumetric fog dispatch: 30.7 -> 21.9 ms per dispatch in
replay, output unchanged.

(cherry picked from commit 10f76eeac0d4306172e41ecff86b737f6a3c9634)
(cherry picked from commit 7f18cc96ae58ac5fd47da6562c4ba3abe22ccb4a)
(cherry picked from commit 972f658033f8339effe42c5d305af87bcbab93f0)

* [Vk] Probe f16 conversion at device setup and report the verdict

A one-time compute pass at device setup measures the device's GLSL
UnpackHalf2x16 / PackHalf2x16 against the translator's own f16 conversion
before any guest shader is compiled, and only a clean measurement lets the
translator use them (ShaderCompileRequest.NativeHalfConversionExact). The
vectors cover all 65536 f16 bit patterns, every f16 value widened to f32,
the midpoint between adjacent f16 values and that midpoint one f32 ulp
either way, the overflow edge, signed zeroes, infinities, NaNs and f32
subnormals, and each is measured in both directions: 643200 comparisons.

Every finite value, zero and infinity must be bit-exact, sign included. A
NaN only has to stay a NaN, because neither side defines its payload: the
emulation picks sign | 0x7C00 | 0x200 narrowing and carries the f16 payload
widening, while the measured hardware convert canonicalizes to a positive
quiet NaN. On an Apple M4 that is the only disagreement - 2314 of 643200,
every one a negative NaN whose sign the hardware cleared - and f16
subnormals convert exactly despite shaderDenormPreserveFloat16 being false.

The probe never fails device setup: any error leaves the exact emulation in
place and says so on the reported line. SHARPEMU_NATIVE_HALF=0 forces the
emulation, =1 takes native without measuring. The result is one line:
  [VK][F16] native half conversion exact=True mismatches=0 tested=643200

The flag reaches the translator through IShaderPipelineHost, so it is
process-constant and cannot mix two translations of one program; the saved
driver pipeline cache keys its entries by the module it was given, and the
Metal host does not probe and keeps the emulation. Offline replays run the
same probe, so a case translates the way the game would.

(cherry picked from commit 6a343683d890b4c6d123c84fdacb41e718ec4c19)
(cherry picked from commit 65ca663aa2bfb1fcc69709c73ab6189b07ead3c1)
(cherry picked from commit 003b1216bd311e5c5fb1d48ca01a66efa3fc51de)

* [SpirvTranslator] Read an unaligned buffer word as a funnel shift of two words

The byte-wise decode of a formatted buffer load read each byte of a component
from its own bounds-checked word load: four loads, four range tests and a byte
assembly for a value that spans at most two words. One funnel shift of those
two words is the same value, including out of range, where a word reads zero on
both paths and so contributes zero bytes. Every sub-dword buffer load goes
through the same helper.

The decode is the branch a formatted load takes when its address is not dword
aligned, so its size also sets the register pressure of the aligned branch next
to it. Silent Hill: The Short Message's volumetric fog dispatch
(0xD5DF9DC46C4E35EA, 8 formatted loads in its light loop) goes from 8.68 to
7.28 ms in offline replay, and the module from 394 to 360 KiB. An experiment
that dropped the byte-wise branch entirely measured 7.35 ms, so the funnel
shift is worth all of what the branch cost.

(cherry picked from commit 0c996ffab38144d795517e68cb2ca9d8d48e8988)

* [SpirvTranslator] Load a guest buffer word unchecked where the device zeroes out-of-range reads

Every guest buffer word is read through a range test, an address clamp and a
zero select: three operations whose only purpose is to produce the zero the
hardware returns past the end of a V#. A device with robustBufferAccess2 that
honours it returns that zero itself, so the three are pure overhead there -
dropping them measured about 12% of Silent Hill's volumetric fog dispatch, 482
checked words in one program.

ShaderCompileRequest.ZeroOutOfBoundsBufferReads turns them off and defaults to
false: an out-of-range read is undefined without the promise, so only a host
that measured the device may set it. It is set from a device probe, never from
a capability bit, because MoltenVK runs on Metal, which has no hardware bounds
checking.

(cherry picked from commit 2ba626a0ac7157f93f348cfe7573ff1092762d8c)

* [Vk] Probe out-of-range buffer reads at device setup and report the verdict

A one-time compute pass binds 1 KiB of a 4 KiB allocation that carries a
sentinel everywhere and reads all 4 KiB back through the descriptor: the words
inside the range must still read their sentinel and the words past it must read
zero. Only a clean measurement lets the translator drop the range test, address
clamp and zero select it puts around every guest buffer word
(ShaderCompileRequest.ZeroOutOfBoundsBufferReads).

The probe only runs where the device enabled robustBufferAccess2, because an
out-of-range read is undefined without it and can fault the device; everywhere
else it reports the reason and the checks stay. On this Apple M4 through
MoltenVK the feature is not supported at all, so nothing changes:
  [VK][OOB] out-of-range buffer reads zero=False mismatches=unprobed tested=0
      note=robustBufferAccess2 is not enabled on this device

SHARPEMU_ZERO_OOB_READS=0 keeps the checks, =1 drops them without measuring.
The flag reaches the translator through IShaderPipelineHost, so it is
process-constant and cannot mix two translations of one program.

(cherry picked from commit e81d924349042acc1122a66d4c767268bd6ef2a4)
2026-10-07 10:51:57 +02:00
.github [readme] New screenshots 2026-10-06 19:07:06 +03:00
LICENSES [GUI] Redesign options page (#699) 2026-07-30 12:58:22 +03:00
assets/images [asset] upload transparent logo image 2026-08-03 10:43:43 +03:00
docs [SRT] Compile shader resource plans in the background (#1028) 2026-10-05 01:19:33 +03:00
scripts Alpha Rebuild Progress (#887) 2026-09-20 04:09:27 +03:00
src [SpirvTranslator/Vk] Cheaper guest buffer loads and f16 conversion, gated on device probes (#1035) 2026-10-07 10:51:57 +02:00
tests [SpirvTranslator/Vk] Cheaper guest buffer loads and f16 conversion, gated on device probes (#1035) 2026-10-07 10:51:57 +02:00
tools Alpha Rebuild Progress (#887) 2026-09-20 04:09:27 +03:00
.editorconfig [dotnet] configure local nuget package cache 2026-07-04 19:12:18 +03:00
.gitignore [AGC] Fix arena/fence tracking stalls and recover lost GPU progress (#770) 2026-08-07 14:37:09 +03:00
CONTRIBUTING.md Enhance contribution guidelines with PR expectations 2026-07-23 01:40:00 +03:00
Directory.Build.props chore: bump version to 0.0.5-nexus (#1018) 2026-10-03 05:15:35 +03:00
Directory.Packages.props [Font] Fix font face creation (#1010) 2026-10-03 05:04:56 +03:00
LICENSE.txt initial commit 2026-03-11 15:48:28 +03:00
README.md [readme] New screenshots v2 2026-10-06 19:07:24 +03:00
REUSE.toml [GUI] Redesign options page (#699) 2026-07-30 12:58:22 +03:00
SharpEmu.slnx Sdl backend (#670) 2026-07-28 03:33:26 +03:00
global.json [dotnet] remove lock files (#419) 2026-07-19 01:26:01 +03:00
nuget.config [dotnet] configure local nuget package cache 2026-07-04 19:12:18 +03:00

README.md

SharpEmu

An experimental PlayStation 5 emulator for Windows, Linux and macOS.


Join our Discord

Join our official Discord server for development updates, compatibility discussions, support, and community chat.


Support SharpEmu


[!IMPORTANT] Official channels: Only sharpemu.app and the links listed in this GitHub repository are affiliated with SharpEmu. Any other websites, accounts, or donation pages are unofficial and unauthorized.

[!NOTE]
SharpEmu supports Windows x64, Linux x64, and macOS x64. Apple Silicon Macs can run the macOS x64 build through Rosetta 2, and Windows on ARM devices (e.g. Snapdragon) can run the Windows x64 build through Windows' built-in x64 emulation.

[!WARNING]
SharpEmu is an experimental PS5 emulator developed from scratch in C#. The current focus is on accuracy and infrastructure setup rather than game-specific compatibility.

Info

SharpEmu is an emulator project currently in its early stages of development.

This project is developed purely for research and educational purposes. There are no commercial goals associated with it. We enjoy learning about system architecture and reverse engineering.

SharpEmu focuses exclusively on the PlayStation 5.
Our goal is not to emulate PS4 games, as there is already an excellent emulator dedicated to that platform: ShadPS4.

Games Tested

Demon's Souls Remake ASTRO BOT
DeS screenshot Astro Bot
ASTRO's PLAYROOM Dead Cells
Astro's Playroom Dead Cells
God of War: Sons of Sparta Tomb Raider V Remastered
GoW SOS Tomb Raider V

Status

The emulator can currently load the eboot.bin of real games, execute native CPU instructions, and partially handle gpu-related functionality. Included 3D games.

SharpEmu supports Windows, Linux, and macOS hosts. Video output uses Vulkan on Windows and Linux, and MoltenVK on macOS. Platform support is still experimental, so compatibility and performance vary by game, operating system, and GPU driver.

Using

Download the release archive for your operating system, extract it, and launch SharpEmu with the path to a legally obtained game's eboot.bin.

Or command line;

Windows PowerShell:

.\SharpEmu.exe "C:\path\to\game\eboot.bin" --log-to-file

Linux and macOS:

chmod +x ./SharpEmu

./SharpEmu "/path/to/game/eboot.bin" --log-to-file

SharpEmu supports environment variables that can be configured from the GUI. Undocumented variables are listed here: docs/sharpemu-gui-undocumented-env-vars.md

You can set them per game or globally in the GUI, or pass them directly through the CLI.

A Vulkan-capable GPU and current graphics driver are required. The macOS release includes the MoltenVK Vulkan implementation.

[!IMPORTANT]
This project does not support or condone piracy.
All games used during development and testing are dumped from consoles that we personally own.
Users are expected to use legally obtained copies of their games.

Build

  1. Install the .NET SDK version specified in global.json.
  2. Clone the repository: git clone https://github.com/sharpemu/sharpemu.git
  3. Open the solution file (SharpEmu.slnx) in VSCode.
  4. Build the project: dotnet build or dotnet publish
  5. Build artifacts will be located in the artifacts directory.

Disclaimer

SharpEmu is an experimental emulator intended for research and educational purposes.

This project does not contain any copyrighted system firmware, game data, or proprietary PlayStation assets.

Special Thanks

The following projects were extremely helpful during development:

  • ShadPS4
    Helped with understanding the basic architecture of the PlayStation 4.

  • Kyty
    One of the few PS5 emulator projects available and very useful for studying native code execution.

  • Ryujinx
    Provided valuable references for filesystem handling and low-level C# implementation patterns.

License

Support

Support SharpEmu via GitHub Sponsors or cryptocurrency. Every contribution helps fund ongoing development and long-term maintenance. GitHub Sponsors is the preferred way to support the project, but cryptocurrency donations are also appreciated.

ETH/USDT

0xF315F5d986c790bB3A58DbE60F1B2760997dEd82

BTC

bc1qmr9k8899njys5ny63xsues4jgmkk96erslrkmv

Contributing

Before opening an issue or pull request, please read our contribution guidelines:

CONTRIBUTING.md

The guide covers:

  • Coding style and formatting
  • AI-assisted contributions
  • Pull request expectations
  • Testing guidelines
  • Legal and reverse engineering policy