A bit more efficient if we are only pushing two VFP registers.
We can probably be a bit more efficient in the future by mixing paired loadstores in to the other paths as well.
Previously on FPR pushing and popping we would do a single STR/LDR per quad FPR we wanted to push/pop.
In most of our cases when we are pushing and popping VFP registers they will be consecutive registers that will save more efficiently using the NEON
loadstores that can do up to four quad registers.
So this can potentially cutting instructions down to ~1/4th the amount of instructions if the registers are all consecutive.
On the Cortex-A57 this is basically just an icache improvement, but on the Nvidia Denver this may be optimized to be more efficient. Either way it's a
win.
Fixes issues with negative offsets in loadstore instructions.
Adds ADRP/ADR instructions.
Optimizes MOVI2R function to take advantage of ADRP on pointers, can change a 3 instruction operation down to one.
Adds GPR push/pop operations for ABI related things.
I've tested a few instruction encodings and am expecting most to work as long as one stays away from VFP/SIMD.
This implements mostly instructions to bring up an initial JIT with integer support.
This can be improved to allow ease of use functions in the future, dealing with the raw imms/immr encodings is probably the worst thing ever.
