Emulator

Hi, thank you for replying. I've launched Dolphin in debug mode, however I can't seem to find anything relating to Floating Point instructions. Could you tell me where in the menus that option is located?

Go into Options/Configuration/Interface and turn on the debug GUI.

Then pause the game and click the JIT dropdown on the menu bar. I turned off Jit Loadstore floating and FloatingPoint.

If we figure out which instruction is the problem we could probably fix this in the JIT as well without needing this.

Thanks, the correct one is JT Loadstore floating. On a semi-unreleated note, is there anyway to speed up dolphin faster than 200%? It would make TASing this a lot easier.

the correct one is JT Loadstore floating

This one was highly unlikely. Maybe the quantizied load/store operations?

is there anyway to speed up dolphin faster than 200%?

There is an unlimited option at the top. Else, you need a faster CPU...

Well, it started rising when I selected JT Loadstore floating, so I was just saying which one I thought it was. And thank you for pointing the unlimited setting out.

I just wanted to highlight that this was unexpected and that it reduced the amound of possible issues a lot. As our JIT does some optimization based on loaded registers, may you try to test the opposite as well: Does it start to raise as well if you only select the FloatingPoint fallbacks?

Sure, I will test that tomorrow as I am going to go to bed now.

Okay, so I restarted Dolphin and tried to get the platform to raise and for some odd reason, now I can't get it to raise with any setting!

I can still get it to rise by pausing the game and disabling JIT FFloatingPoint or FloatingPoint Loadstore, so, not sure what changed for you.

I've spent the last ~2 hours trying to raise the platform again. I've uninstalled and reinstalled dolphin multiple times, installed several different versions of Dolphin and with no luck! I can't for the life of me figure out why it won't work again. Any help you could give would be very much appreciated.

Are you activating the Debug Menu in Configuration/Interface, booting the game, pausing, and disabling JIT Floating Point or JIT FloatingPoint Loadstore?

Yep, thats what I've been doing.

I'll double check to make sure it's still happening for me in latest master.

The GUI is broken - none of the fallbacks are activating for some reason.

I'm glad it's not just me!

Try starting the game, Disabling JIT FloatingPoint and then closing the game and restarting it. That seems to have fixed it.

Still doesn't work for me

Is it hurting your performance at least? Your performance should go down if the option is working.

Nope, doesn't seem to make a difference. If it makes a difference I am running the game at 200% speed and loading a save sate, but that shouldn't really affect anything.

Can you try running it unlimited and seeing what happens? On my i7-6700K, I go from 90 fps to ~83 fps when using JIT FloatingPoint. FloatingPoint Loadstore knocks me down even further.

I tried running it unlimited and I still couldn't see any difference and my FPS sits at around the same point.

That means it's probably not activating.

Been testing more - I think it's Loadstore Floating that actually fixes it. Can you try running the game, activating the disable on that, closing the game, and reopening it and seeing if it starts rising?

I'll do that in the morning, but for now I have to go as it's 11:35pm for me and I have to wake up early tomorrow.

Alright, I'll try to sort this out. Sorry for the inconvenience :(

Likely the ConvertDoubleToSingle function here: https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/Core/PowerPC/Jit64/Jit_LoadStoreFloating.cpp#L115

This may be the cause of the problem.

The modification in that build if you want to do it yourself is to add the following at line 104 of JITLoadstoreFloating.cpp

FALLBACK_IF(single);

The chunk looks like this after the modification.

int accessSize = single ? 32 : 64;

FALLBACK_IF(single);
FALLBACK_IF(update && jo.memcheck && a == b);

if (single)

Unbelievably this still doesn't work for me! At this point I feel like it's something on my computer because I've done seemingly everything to get it working.

Are you testing in the right area? I know this glitch doesn't occur in Lethal Lava Land, for instance. I can try making a more aggressive hack if you want.

Have you tried not using a savestate? The area is so close by I've been just running there myself. It's possible the bug got embedded into the savestate.

I can confirm that I am testing in the right area and I didn't use a savestate this time but that platforms still wouldn't raise.

The platforms definitely rise using that build
https://youtu.be/lfNfR9ktlEc (didn't process correctly?)
I don't know if it matches console exactly though.

Can you explain what you mean by it not matching console exactly?

I don't know if it rises faster or slower than console
I also don't know if it is at all likely for dolphin to still be slightly wrong though.

Dolphin is very, very unlikely to be wrong on the timing of it. The formula I changed it to was hardware verified by phire. The old formula just didn't handle it because we thought no game would ever rely on the behavior.

If there are more bugs regarding this behavior, we'll happily look into it though, as edge-cases like these often expose unknown behaviors.