[llvm] [Xtensa] Initial support of the ALU operations and ConstantPool (PR #78548)

[Sergei Barannikov via llvm-commits]

https://github.com/s-barannikov commented:

Calling convention implementation needs to be in separate PR. It should support passing arguments on the stack, which requires implementing some methods in *FrameLowering, *InstrInfo and *RegisterInfo, as well as supporting load/store/call/return in ISel.

I would also suggest a separate PR for boilerplate classes, i.e. *RegisterInfo, *InstrInfo, *Subtarget, *FrameLowering, *TargetMachine, *AsmPrinter and *DAGToDAGISel. You can check that everything works by launching llc on an empty *.ll file (it should produce a template assembly file without crashing).

Supporting ALU operations should then touch only files related to instruction selection. (There may be other _minor_ changes in other files.)

Changes in MCTargetDesc/ look completely unrelated.


https://github.com/llvm/llvm-project/pull/78548