bcx implementation

    #define inst_BO_0 (inst.BO & (1 << 4)) //if set, ignore BO_TRUE
    #define inst_BO_1 (inst.BO & (1 << 3)) //if set, check if condition is TRUE
    #define inst_BO_2 (inst.BO & (1 << 2)) //if set, ignore CTR
    #define inst_BO_3 (inst.BO & (1 << 1)) //if set, branch if CTR is 0 (else != 0)
    #define inst_BO_4 (inst.BO & (1 << 0)) //branch predictor hint ("+")
    bool CR::getbit(u8 index) {
        return (this->hex >> (31 - index)) & 1;
    }
    void bcx(gekko::instruction& inst, std::unique_ptr<gekko::cpu>& cpu) { //opcode 16
        if (!inst_BO_2) cpu->ctr--; //not ignoring ctr, decrement
        ctr_ok = inst_BO_2 || ((cpu->ctr != 0) ^ inst_BO_3);
        cond_ok = inst_BO_0 || (cpu->CR.getbit(inst.BI) ^ !inst_BO_1);
        if (ctr_ok && cond_ok) {
            if (inst.LK) //linking, update link register
                cpu->lr = cpu->pc + 4;

            if (inst.AA) //absolute address
                cpu->pc = EXTS(inst.BD << 2);
            else //relative, add (will go backwards if negative)
                cpu->pc += EXTS(inst.BD << 2);
        }
        else {
            cpu->pc += 4;
        }
    }