3c_disasm/instr/stackop.cpp

   1 #include "../Iinstr.hpp"
   2
   3 class Cstackop : public Iinstr {
   4                 char m_typ;
   5         public:
   6                 Cstackop();
   7                 void evalInstr();
   8                 void execInstr();
   9                 std::string toString();
  10                 Iinstr* getNew();
  11 };
  12
  13 /**
  14  * Name:      create_instruction
  15  * Purpose:   if compiled as shared library, this functions creates the
  16               instruction object
  17
  18  * Returns:   pointer to instruction object
  19  */
  20 extern "C" Iinstr* create_instruction() {
  21     return new Cstackop();
  22 }
  23
  24 Iinstr* Cstackop::getNew()
  25 {
  26         return new Cstackop();
  27 }
  28 /**
  29  * Name:      destroy_instruction
  30  * Purpose:   if compiled as shared library, this functions destoys the
  31               instruction object
  32
  33  * Parameter: IInstruction - the instruction object to delete
  34  */
  35 extern "C" void destroy_instruction(Iinstr* p) {
  36     delete p;
  37 }
  38
  39 Cstackop::Cstackop() : m_typ(0)
  40 {
  41         opcode = B5(01011);
  42         name = "stackop";
  43 }
  44
  45 void Cstackop::evalInstr()
  46 {
  47         argbits >>= 17;
  48
  49         dynamic_bitset<> type = argbits;
  50         type.resize(2);
  51         this->m_typ = type.to_ulong();
  52
  53         switch(this->m_typ) {
  54                 case 0:
  55                         this->name = "pop";
  56                         break;
  57                 case 1:
  58                         this->name = "disc";
  59                         break;
  60                 case 2:
  61                         this->name = "fetch";
  62                         break;
  63                 case 3:
  64                         this->name = "push";
  65                         break;
  66                 default:
  67                         cerr << "What have you done? 2 bits that have more than 4 values?!" << endl;
  68         }
  69
  70         argbits >>= 2;
  71         m_rd = this->getRegister(argbits);
  72 }
  73
  74 void Cstackop::execInstr()
  75 {
  76         CDat sp = this->m_cpu->getStack();
  77
  78         switch(this->m_typ) {
  79                 case 0:
  80                         this->m_cpu->setRegister(m_rd, this->m_cpu->getRAM(sp));
  81                         sp += 4;
  82                         break;
  83                 case 1:
  84                         sp += 4;
  85                         break;
  86                 case 2:
  87                         this->m_cpu->setRegister(m_rd, this->m_cpu->getRAM(sp));
  88                         break;
  89                 case 3:
  90                         sp -= 4;
  91                         this->m_cpu->setRAM(sp, this->m_cpu->getRegister(m_rd));
  92                         break;
  93                 default:
  94                         cerr << "What have you done? 2 bits that have more than 4 values?!" << endl;
  95         }
  96
  97         this->m_cpu->setStack(sp);
  98 }
  99
 100 std::string Cstackop::toString()
 101 {
 102         stringstream op;
 103         op << this->getName();
 104
 105         op << this->getConditionFlag();
 106         op << " r" << m_rd;
 107         return op.str();
 108 }