JIT: use fastmem loads in MMU mode.

[magumagu]

Even in games that require MMU mode, loads outside the area specified by the BAT are rare, so fastmem is a substantial improvement.

All of the interesting changes are in the backpatch handler, to make it generate DSI exceptions correctly.

[PatrickFerry]

This fixes a lot of the crashes in True Crime: New York City when interacting with objects.

@JMC47 Can you test medabots if it behaves differently.

Edit: Tested with MMU on And BAT enabled.

[JMC47]

No, it behaves exactly the same as before. You can tell in the tutorial.

[skidau]

Have tested this out with RS2, RS3, TimeSplitters 3, GUN, Ultimate Spider-man, Spider-man 2, F-ZERO GX in MMU mode and MGS:TS in MMU mode. All games run fine.

[PatrickFerry]

@JMC47 Had you meant the tutorial when testing Medabots, to be sure?

[JMC47]

I was talking about True Crime. I will check medabots. Thanks.

Yeah, no Medabots is a GPU crash; it works fine on Software renderer.

[PatrickFerry]

@JMC47 It does behave differently if you don't believe me try enter the kitchen like I reported on Issue 7230
I will never work prior to this I've tested a lot. You may have to enable full MMU and Bat though.
It's pretty quick to test as well if you use the debug menu like I said.
Edit: Also many of the levels in debug menu now load. So to make the game work properly It;s evident that there are some other areas that DSI exemptions are not occurring where they should.

[JMC47]

The kitchen crash and the one in that report are different. If one of them are fixed, that's great, but this one in the issue as a CPU/GPU timing issue, and has nothing to do with MMU.

@skidau dug into the game and determined that it shouldn't ever need full MMU at all; and any fixes by this are likely due to fallbacks used in MMU mode.

[PatrickFerry]

@JMC47 Forget the kitchen or tutorial or anything they are the same issue really. There a bunch more areas where it will crash with the same error addresses.
This fixes a ton of crashing in that game but not all. It's nothing to do with timing but DSI exemptions

[JMC47]

I've spent more time than I'd care to admit researching the problems that True Crime: New York City has. Way too much time. While I can't say with certainty I'm correct; only Fiora's dual-issue hack and the vbeam speedhack affect the behavior of the crashes that I'm able to reproduce 100% of the time.

[PatrickFerry]

@JMC47 Load some of the debug levels prior to this change some of them will crash 100% of the time after this change the great majority of them work now.
This affects behavior I am sure of it. Yes I know hitting things in the tutorial and in some buildings crashes because like I said it doesn't fix everything.