Back end

The backend is responsible of allocating the registers, optimize the LTAC intermediate representation and generate code for the target platform.

The back end operations are described in the src/NativeBackend.cpp file.

Here is a list of all the operations performed by the backend:

• Allocate stack space for aggregates (structures and arrays)
• Generate LTAC code from MTAC. Generates code using only pseudo registers
• Perform some early optimizations to facilitate the task of the register allocation
• Allocate pseudo registers in hard registers. Use a Chaitin's style register allocator
• Generate the code for the prologue and epilogue of functions
• If the option is set remove the base pointer and use only stack pointer
• Optimize the LTAC Program
• Generate assembly code for the target platform
• Assemble and link the assembly into an executable

LTAC Optimizations

Here are all the optimizations that are performed on LTAC:

• Peephole optimizations of the instructions
• Constant propagation (local only)
• Copy propagation (local only)
• Dead Code Elimination (global)
• Replace branches by conditional moves if possible

TODO

• Add more global optimizations to the LTAC optimization engine.
• Make Constant/Propagation global