Emulator Issues #12446
Savestating with JIT causes MMU games to desync
Spider-Man 2 (GC), Ultimate Spider-Man (GC), other titles with an MMU requirement
Game ID? (right click the game in the game list, Properties, Info tab)
GK2E52 (spider-man 2), GUTD52 (ultimate spider-man)
MD5 Hash? (right click the game in the game list, Properties, Verify tab, Verify Integrity button)
a2762a6acc32d4e523ac6848589cc147 (spider-man 2)
What's the problem? Describe what went wrong.
Saving and loading savestates while recording input will cause the input recording to desync on the JIT engine. I think it has to do with the savestates not saving properly, since I've even had Spider-Man 2 suffer an in-game crash after saving and loading states too many times. Plus, input recording without using savestates will work fine.
On the cached interpreter, the TAS will (mostly) sync fine and won't have savestate issues, although it will be playing at ~15% with no way to speed it up. Additionally, the TAS may desync 10-15 minutes into actual gameplay (which may take hours of real-time to get to, since the game runs so slow in the cached interpreter). The slow speed and late desync together make for an agonizing experience when trying to TAS these games.
What steps will reproduce the problem?
Is the issue present in the latest development version? For future reference, please also write down the version number of the latest development version.
This issue is present in 5.0-13595.
Is the issue present in the latest stable version?
This issue is present in 5.0.
If the issue isn't present in the latest stable version, which is the first broken version? (You can find the first broken version by bisecting. Windows users can use the tool https://forums.dolphin-emu.org/Thread-green-notice-development-thread-unofficial-dolphin-bisection-tool-for-finding-broken-builds and anyone who is building Dolphin on their own can use git bisect.)
[First broken version number here (if applicable)]
If your issue is a graphical issue, please attach screenshots and record a three frame fifolog of the issue if possible. Screenshots showing what it is supposed to look like from either console or older builds of Dolphin will help too. For more information on how to use the fifoplayer, please check here: https://wiki.dolphin-emu.org/index.php?title=FifoPlayer
[Attach any fifologs if possible, write a description of fifologs and screenshots here to assist people unfamiliar with the game.]
What are your PC specifications? (CPU, GPU, Operating System, more)
Windows 10, Vega 8 graphics, Nvidia GeForce GTX 1050, 16gb ram
Is there anything else that can help developers narrow down the issue? (e.g. logs, screenshots,
configuration files, savefiles, savestates)
[Anything else here]