Simple linear scan forward of instruction decoding isn't viable to do.
We need to break up the decoding at the block boundaries.
Otherwise our decoding gets in to the weeds and decodes trash.
This changes over CondJump to have a defined True and False branch path.
Additionally needing to change over everything to handle this.
This now means that a false branch condition will no longer assume
fallthrough past this instruction.
Currently the x86-64 JIT generates an additional jmp instruction on
fallthrough that isn't optimized away.
This is working towards improvements in our IR branching model and
improving IRValidation in doing so.
This is working towards the model that IRBlocks can only have 0-2
successors.
Ret/Exit - 0 successors
Jump - 2 successors
CondJump - 2 successors
TBD:
Syscall/CPUID - Breaking block?
Useful for a quick overview of the time spent in a function. It isn't
amazing for profiling since it effects the time in the function by
itself.
Only useful as a reference.
I had to change how blocks are represented to make it easier to parse
This required a fairly substantial refactor that makes it so blocks are
represented differently and we can walk them sequentially.
This will make future analysis easier to deal with.
Had to rewrite the passes and core's parsing of the IR afterwards.
Moved RA in to a optimization pass to be shared between the JIT backends
This works because x86-64 and AArch64 RA can be identical.
Still doesn't support PHI nodes or spilling correctly, this is the first
step in the process of getting there.
Scott Mansell