luaur-code-gen 0.1.0

use crate::enums::ir_cmd::IrCmd;
use crate::enums::ir_op_kind::IrOpKind;
use crate::functions::remove_use::remove_use;
use crate::macros::codegen_assert::CODEGEN_ASSERT;
use crate::records::ir_function::IrFunction;
use crate::records::ir_inst::IrInst;
use crate::records::ir_op::IrOp;

pub fn apply_substitutions_ir_function_ir_op(function: &mut IrFunction, op: &mut IrOp) {
    if op.kind() == IrOpKind::Inst {
        let src: *mut IrInst = &mut function.instructions[op.index() as usize];

        if unsafe { (*src).cmd } == IrCmd::SUBSTITUTE {
            let src_a: IrOp = unsafe { (*src).ops.as_slice()[0] };
            *op = src_a;

            // If we substitute with the result of a different instruction, update the use count
            if op.kind() == IrOpKind::Inst {
                let dst = &mut function.instructions[op.index() as usize];
                CODEGEN_ASSERT!(dst.cmd != IrCmd::SUBSTITUTE);
                dst.use_count += 1;
            }

            CODEGEN_ASSERT!(unsafe { (*src).use_count } > 0);
            unsafe {
                (*src).use_count -= 1;
            }

            if unsafe { (*src).use_count } == 0 {
                unsafe {
                    (*src).cmd = IrCmd::NOP;
                }
                let src_a2: IrOp = unsafe { (*src).ops.as_slice()[0] };
                remove_use(function, src_a2);
                unsafe {
                    (*src).ops.clear();
                }
            }
        }
    }
}