luaur-code-gen 0.1.0

use crate::enums::ir_block_kind::IrBlockKind;
use crate::enums::ir_cmd::IrCmd;
use crate::enums::ir_op_kind::IrOpKind;
use crate::functions::get_live_in_out_value_count::get_live_in_out_value_count;
use crate::functions::get_live_out_value_count::get_live_out_value_count;
use crate::functions::try_get_next_block_in_chain::try_get_next_block_in_chain;
use crate::macros::codegen_assert::CODEGEN_ASSERT;
use crate::macros::op_a::op_a;
use crate::records::ir_block::IrBlock;
use crate::records::ir_function::IrFunction;
use alloc::vec::Vec;

pub fn collect_direct_block_jump_path(
    function: &mut IrFunction,
    visited: &mut Vec<u8>,
    mut block: *mut IrBlock,
) -> Vec<u32> {
    CODEGEN_ASSERT!(get_live_out_value_count(function, unsafe { &mut *block }) == 0);

    let mut path = Vec::new();

    while !block.is_null() {
        let mut next_block: *mut IrBlock = core::ptr::null_mut();

        let (is_jump, target_op) = {
            let term_inst = &mut function.instructions[unsafe { (*block).finish } as usize];
            (term_inst.cmd == IrCmd::JUMP, op_a(term_inst))
        };

        if is_jump && target_op.kind() == IrOpKind::Block {
            let target_block = function.block_op(target_op) as *mut IrBlock;
            let target_idx = function.get_block_index(unsafe { &*target_block });

            if visited[target_idx as usize] == 0
                && unsafe { (*target_block).kind } == IrBlockKind::Internal
            {
                let (live_ins, live_outs) =
                    get_live_in_out_value_count(function, unsafe { &mut *target_block }, true);

                if live_ins == 0 && live_outs == 0 {
                    visited[target_idx as usize] = 1;
                    path.push(target_idx);

                    next_block = target_block;

                    loop {
                        let next_in_chain =
                            try_get_next_block_in_chain(function, unsafe { &mut *next_block });
                        if !next_in_chain.is_null() {
                            let next_in_chain_idx =
                                function.get_block_index(unsafe { &*next_in_chain });
                            visited[next_in_chain_idx as usize] = 1;
                            path.push(next_in_chain_idx);
                            next_block = next_in_chain;
                        } else {
                            break;
                        }
                    }
                }
            }
        }

        block = next_block;
    }

    path
}