diff options
Diffstat (limited to 'src/svm/ExecuteVM.java')
| -rwxr-xr-x | src/svm/ExecuteVM.java | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/src/svm/ExecuteVM.java b/src/svm/ExecuteVM.java new file mode 100755 index 0000000..d3dec33 --- /dev/null +++ b/src/svm/ExecuteVM.java @@ -0,0 +1,234 @@ +package svm; + +import java.util.concurrent.TimeUnit; + +public class ExecuteVM { + + public static final int CODESIZE = 1000 ; + public static final int MEMSIZE = 1000 ; //10000; + + private AssemblyClass[] code; + private int[] memory = new int[MEMSIZE]; + + private int ip = 0; // instruction pointer + private int sp = MEMSIZE-1 ; // stack pointer + private int al = MEMSIZE-2 ; // access link + private int fp = MEMSIZE-1 ; // frame pointer + private int ra; // return address + private int a0; // the register for values of expressions + private int t1; // temporary register + private int t2; // additional temporary register, just in case + + public ExecuteVM(AssemblyClass[] _code) { + code = _code ; + } + + + public void StampaMem(int _j){ + System.out.print(_j + ": " + code[ip].getCode()) ; + for (int i = MEMSIZE-1; i > sp ; i--){ + System.out.print("\t" + memory[i]) ; + } + System.out.println(" ----- " + "SP = " + sp + ", FP = " + fp + ", AL = " + al + ", RA = " + ra + ", A0 = " + a0 + ", T1 = " + t1 ) ; + } + + public int read(String _strg) { + int tmp ; + switch (_strg) { + case "IP": + tmp = ip ; + break ; + case "SP": + tmp = sp ; + break ; + case "AL": + tmp = al ; + break ; + case "FP": + tmp = fp ; + break ; + case "RA": + tmp = ra ; + break ; + case "A0": + tmp = a0 ; + break ; + case "T1": + tmp = t1 ; + break ; + case "T2": + tmp = t2 ; + break ; + default : + tmp = -99999 ; // error value + break ; + } + return tmp ; + } + + public void update(String _strg, int _val) { + switch (_strg) { + case "IP": + ip = _val ; + break ; + case "SP": + sp = _val ; + break ; + case "AL": + al = _val ; + break ; + case "FP": + fp = _val ; + break ; + case "RA": + ra = _val ; + break ; + case "A0": + a0 = _val; + break ; + case "T1": + t1 = _val ; + break ; + case "T2": + t2 = _val ; + break ; + default : + // error value + break ; + } + } + + public void cpu() { + int j = 0 ; + + while ( true ) { + // try { + // TimeUnit.SECONDS.sleep(1); + // } catch (InterruptedException e) { + // // TODO Auto-generated catch block + // e.printStackTrace(); + // } + StampaMem(j) ; j=j+1 ; + AssemblyClass bytecode = code[ip] ; // fetch + int tmp ; + int address; + switch ( bytecode.getCode() ) { + case SVMParser.PUSH: + push(Integer.parseInt(bytecode.getArg1())) ; + ip = ip+1 ; + break; + case SVMParser.PUSHR: + push(read(bytecode.getArg1())); + ip = ip+1 ; + break ; + case SVMParser.POP: + pop(); + ip = ip+1 ; + break; + case SVMParser.LOAD: + tmp = read(bytecode.getArg3()) + Integer.parseInt(bytecode.getArg2()) ; + if ((tmp < 0) || (tmp >= MEMSIZE)) { + System.out.println("\nError: Null pointer exception1"); + return; + } else { + memory[tmp] = read(bytecode.getArg1()) ; + ip = ip+1 ; + break; + } + case SVMParser.STOREI: + update(bytecode.getArg1(), Integer.parseInt(bytecode.getArg2())) ; + ip = ip+1 ; + break; + case SVMParser.STORE: + tmp = read(bytecode.getArg3()) + Integer.parseInt(bytecode.getArg2()); + if ((tmp < 0) || (tmp >= MEMSIZE)) { + System.out.println("\nError: Null pointer exception2"); + return; + } else { + update(bytecode.getArg1(), memory[tmp]); + ip = ip+1 ; + break; + } + case SVMParser.MOVE: + update(bytecode.getArg2(), read(bytecode.getArg1())) ; + ip = ip+1 ; + break; + case SVMParser.ADD: + push(read(bytecode.getArg1()) + read(bytecode.getArg2())) ; + ip = ip+1 ; + break; + case SVMParser.ADDI: + update(bytecode.getArg1(), read(bytecode.getArg1()) + Integer.parseInt(bytecode.getArg2()) ); + ip = ip+1 ; + break; + case SVMParser.SUB: + push(read(bytecode.getArg1()) - read(bytecode.getArg2())); + ip = ip+1 ; + break; + case SVMParser.SUBI: + update(bytecode.getArg1(), read(bytecode.getArg1()) - Integer.parseInt(bytecode.getArg2()) ); + ip = ip+1 ; + break; + case SVMParser.MUL: + push(read(bytecode.getArg1()) * read(bytecode.getArg2())); + ip = ip+1 ; + break; + case SVMParser.MULI: + update(bytecode.getArg1(), read(bytecode.getArg1()) * Integer.parseInt(bytecode.getArg2()) ) ; + ip = ip+1 ; + break; + case SVMParser.DIV: + push(read(bytecode.getArg1()) / read(bytecode.getArg2())); + ip = ip+1 ; + break; + case SVMParser.DIVI: + update(bytecode.getArg1(), read(bytecode.getArg1()) / Integer.parseInt(bytecode.getArg2()) ); + ip = ip+1 ; + break; + case SVMParser.POPR : // + update(bytecode.getArg1(), memory[sp+1]); + pop() ; + ip = ip+1 ; + break; + case SVMParser.BRANCH: + address = ip + 1; + ip = code[address].getCode() ; + break; + case SVMParser.BRANCHEQ : // + if (read(bytecode.getArg1()) == read(bytecode.getArg2())){ + address = ip+1; + ip = code[address].getCode() ; + } else ip = ip+2 ; + break; + case SVMParser.BRANCHLESSEQ : + if (read(bytecode.getArg1()) <= read(bytecode.getArg2())){ + address = ip+1; + ip = code[address].getCode() ; + } else ip = ip+2 ; + break; + case SVMParser.JUMPSUB : + ra = ip+1 ; + address = ip ; + ip = Integer.parseInt(code[address].getArg1()) ; + break; + case SVMParser.RETURNSUB: + ip = read(bytecode.getArg1()) ; + break; + case SVMParser.HALT : //to print the result + System.out.println("\nResult: " + a0 + "\n"); + return; + } + } + } + + private int pop() { + sp = sp+1 ; + return memory[sp] ; + } + + private void push(int v) { + memory[sp] = v; + sp = sp-1 ; + } + +}
\ No newline at end of file |