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#include <iostream> #include <stdio.h> #include <string> #include <cstdlib> #include "VirtualMachine.h" using namespace std; int VirtualMachine::get_clock() { return clock; } void VirtualMachine::run(fstream& objectCode, fstream& in, fstream& out) { const int debug = false; int opcode, rd, i, rs, constant, addr, j; base = 0; for (limit = 0; objectCode >> mem[limit]; limit++); sr = 2; sp = msize; pc = 0; while (pc < limit) { ir = mem[pc]; pc++; opcode = (ir&0xf800)>>11; rd = (ir&0x600)>>9; i = (ir&0x100)>>8; rs = (ir&0xc0)>>6; addr = ir&0xff; constant = addr; if (ir&0x80) constant |= 0xffffff00; // if neg sign extend clock++; if (opcode == 0) { /* load loadi */ if (i) r[rd] = constant; else { r[rd] = mem[addr]; clock += 3; } } else if (opcode == 1) { /* store */ mem[addr] = r[rd]; clock += 3; } else if (opcode == 2) { /* add addi */ int sign1 = (r[rd]&0x8000)>>15; int sign2; if (i) { sign2 = (constant&0x8000)>>15; r[rd] = r[rd] + constant; } else { sign2 = (r[rs]&0x8000)>>15; r[rd] = r[rd] + r[rs]; } // set CARRY if (r[rd]&0x10000) sr |= 01; else sr &= 0x1e; // set OVERFLOW if (sign1 == sign2 and sign1 != (r[rd]&0x8000)>>15) sr |= 0x10; else sr &= 0xf; // sign extend if (r[rd]&0x8000) r[rd] |= 0xffff0000; else r[rd] &= 0xffff; } else if (opcode == 3) { /* addc addci */ if (i) r[rd] = r[rd] + constant + sr&01; else r[rd] = r[rd] + r[rs] + sr&01; if (r[rd]&0x10000) sr |= 01; else sr &= 0x1e; if (r[rd]&0x8000) r[rd] |= 0xffff0000; else r[rd] &= 0xffff; } else if (opcode == 4) { /* sub subi */ int sign1 = (r[rd]&0x8000)>>15; int sign2; if (i) { sign2 = (constant&0x8000)>>15; r[rd] = r[rd] - constant; } else { sign2 = (r[rs]&0x8000)>>15; r[rd] = r[rd] - r[rs]; } // set CARRY if (r[rd]&0x10000) sr |= 01; else sr &= 0x1e; // set OVERFLOW if (sign1 != sign2 and sign2 == (r[rd]&0x8000)>>15) sr |= 0x10; else sr &= 0xf; // sign extend if (r[rd]&0x8000) r[rd] |= 0xffff0000; else r[rd] &= 0xffff; } else if (opcode == 5) { /* subc subci */ if (i) r[rd] = r[rd] - constant - sr&01; else r[rd] = r[rd] - r[rs] - sr&01; if (r[rd]&0x10000) sr |= 01; else sr &= 0x1e; if (r[rd]&0x8000) r[rd] |= 0xffff0000; else r[rd] &= 0xffff; } else if (opcode == 6) { /* and andi */ if (i) r[rd] = r[rd] & constant; else r[rd] = r[rd] & r[rs]; // sign extend if (r[rd]&0x8000) r[rd] |= 0xffff0000; else r[rd] &= 0xffff; } else if (opcode == 7) { /* xor xori */ if (i) r[rd] = r[rd] ^ constant; else r[rd] = r[rd] ^ r[rs]; if (r[rd]&0x8000) r[rd] |= 0xffff0000; else r[rd] &= 0xffff; } else if (opcode == 8) { /* compl */ r[rd] = ~r[rd]; if (r[rd]&0x8000) r[rd] |= 0xffff0000; else r[rd] &= 0xffff; } else if (opcode == 9) { /* shl */ r[rd] <<= 1; if (r[rd]&0x10000) sr |= 01; else sr &= 0x1e; if (r[rd]&0x8000) r[rd] |= 0xffff0000; else r[rd] &= 0xffff; } else if (opcode == 10) { /* shla */ r[rd] <<= 1; if (r[rd]&0x10000) { sr |= 01; r[rd] |= 0x8000; } else { sr &= 0x1e; r[rd] &= 0x7fff; } if (r[rd]&0x8000) r[rd] |= 0xffff0000; else r[rd] &= 0xffff; } else if (opcode == 11) { /* shr */ r[rd] &= 0xffff; if (r[rd]&01) sr |= 01; else sr &= 0x1e; r[rd] >>= 1; } else if (opcode == 12) { /* shra */ if (r[rd]&01) sr |= 01; else sr &= 0x1e; r[rd] >>= 1; } else if (opcode == 13) { /* compr compri */ sr &= 021; if (i) { if (r[rd]<constant) sr |= 010; if (r[rd]==constant) sr |= 04; if (r[rd]>constant) sr |= 02; } else { if (r[rd]<r[rs]) sr |= 010; if (r[rd]==r[rs]) sr |= 04; if (r[rd]>r[rs]) sr |= 02; } } else if (opcode == 14) { /* getstat */ r[rd] = sr; } else if (opcode == 15) { /* putstat */ sr = r[rd]; } else if (opcode == 16) { /* jump */ pc = addr; } else if (opcode == 17) { /* jumpl */ if (sr & 010) pc = addr; } else if (opcode == 18) { /* jumpe */ if (sr & 04) pc = addr; } else if (opcode == 19) { /* jumpg */ if (sr & 02) pc = addr; } else if (opcode == 20) { /* call */ if (sp < limit+6) { cout << "Stack Overflow\n"; exit(1); // stack overflow } mem[--sp] = pc; for (j=0; j<4; j++) mem[--sp] = r[j]; mem[--sp] = sr; pc = addr; clock += 3; } else if (opcode == 21) { /* return */ if (sp > 256-6) { cout << "Stack Underflow\n"; exit(2); // stack underflow } sr = mem[sp++]; for (j=3; j>=0; j--) r[j] = mem[sp++]; pc = mem[sp++]; clock += 3; } else if (opcode == 22) { /* read */ in >> r[rd]; // assert r[rd] is in the allowed range clock += 27; } else if (opcode == 23) { /* write */ out << r[rd]; clock += 27; } else if (opcode == 24) { /* halt */ break; } else if (opcode == 25) { /* noop */ /* do nothing */ } else { cout << "Bad opcode = " << opcode << endl; exit(3); } if (debug) { printf("ir=%d op=%d rd=%d i=%d rs=%d const=%d addr=%d\n", ir, opcode, rd, i, rs, constant, addr); printf("r[0]=%d r[1]=%d r[2]=%d r[3]=%d pc=%d sr=%d sp=%d clock=%d\n\n", r[0], r[1], r[2], r[3], pc, sr, sp, clock); //char c; //cin>>c; } } if (debug) { for (j=0; j<limit; j++) { printf("%8d", mem[j]); if ((j%8)==7) printf("\n"); } cout << endl; } } /* main */