This is the same extension that we all know and love but under a different name with some different requirements.
In regular OpenGL fashion, you can't just move a desktop OpenGL extension to OpenGL ES without ratifying a new extension, which is why this falls
under a EXT extension, which in turn causes it to have suffixes attached to their function names.
This is the first step in our way towards conquering all mobile GPUs that don't support desktop OpenGL, hopefully we also can add support for
buffer_storage to OpenGL ES as well so we can make full use of this extension.
This is a fairly lengthy change that can't be separated out to multiple commits well due to the nature of fastmem being a bit of an intertangled mess.
This makes my life easier for maintaining fastmem on ARMv7 because I now don't have to do any terrible instruction counting and NOP padding. Really
makes my brain stop hurting when working with it.
This enables fastmem for a whole bunch of new instructions, which basically means that all instructions now have fastmem working for them. This also
rewrites the floating point loadstores again because the last implementation was pretty crap when it comes to performance, even if they were the
cleanest implementation from my point of view.
This initially started with me rewriting the fastmem routines to work just like the previous/current implementation of floating loadstores. That was
when I noticed that the performance tanked and decided to rewrite all of it.
This also happens to implement gatherpipe optimizations alongside constant address optimization.
Overall this comment brings a fairly large speedboost when using fastmem.
Fifo overflow fix
The idea behind separating the CPU and GPU thread path is to prevent two threads executing the same function (SetCPStatusFromCPU) at the same time. The CPU thread gets to that function via GetherPipeBursted and the GPU thread gets there via SetCPStatusFromGPU. I wrote the original (factored) version as I like to keep code duplication to a minimum. This worked most of the time but not all of the time. It was a good move to separate it to a GPU version and a CPU version, but then the GPU version called the CPU version at the tail end. Removing the call (as in this PR) prevents the FIFO overflow in Starfox Adventures.
The "Updating the CPStatus before FIFO events" change is simply there to keep the DC code path and the SC code path consistent in the !GPLinked scenario. The SC code path does the same thing when !GPLinked via RunGPU. Putting the SetCPStatus call before the !GPLinked state changes the DC code path to do the same thing. The more we keep the DC and SC code paths consistent, the better.
Forcing the exception check on interrupts is the change for The Last Story. It makes the emulator process interrupts more responsively on CP interrupts.
The HiWatermark check is something that old (pre-2010) versions of Dolphin used to do. Games like Battalion Wars 2 do not expect the GPU to run so slowly and do not have the code to react to that situation, so this change makes the emulator extra careful in those situations.
Jules Blok