Add processing of parsing and emiting lrw/jsri/jmpi instruction, including related fixup and relocation.
Add relax support about pseudo instructions such as jbr/jbsr.
Add objdump format support like arm in llvm-objdump.
Add support of parsing .csky_attribute directive and emit related target attributes in .csky.attribute section.
It does not emit attribute directive in assembly code, so only emit target attributes in ELF streamer.
In ELF streamer, it handles the header EFlag and the csky_attribute section which contains some attribute items.
The EFlag and attribute items are calculated from feature bits based on Subtarget.
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.
This allows us to ensure that Support doesn't have includes from MC/*.
Differential Revision: https://reviews.llvm.org/D111454
This basic parser will handle basic instructions with register or immediate operands.
With the addition of CSKYInstPrinter, we can now make use of lit tests.
Differential Revision: https://reviews.llvm.org/D93798
Add basis of CSKY MCTargetDesc and it's enough to compile and link but doesn't yet do anything particularly useful.
Once an ASM parser and printer are added in the next two patches, the whole thing can be usefully tested.
Differential Revision: https://reviews.llvm.org/D93372
