new change

examples/BV6.s

+MOV R31 3
+MOV R1 1
+SUB R31 R31 R1
+RET R31
\ No newline at end of file

examples/BV7.s

+MOV R1 1
+MOV R2 1
+MUL R-1 R1 R2
\ No newline at end of file

examples/BV8.s

+MOV R1 1
+MOV R2 1
+DIV R32 R1 R2
\ No newline at end of file

examples/BV9.s

+MOV R0 65535
+MOV R1 -32768
+MUL R0 R0 R1
+ADD R0 R0 R1
+RET R0
\ No newline at end of file

examples/EC1.s

+MOV R0 5
+
+MOV R1 10
+SUB R0 R0 R1
+STR R0 5 R1
+LDR R0 R0 5
+JMP 2
+MOV R1 20
+RET R0
\ No newline at end of file

examples/EC10.s

+MOV R0 -65536
\ No newline at end of file

examples/EC11.s

+MOV R0 2
+MOV R1 -40000
+MUL R0 R0 R1
+STR R0 100 R1
+RET R0
\ No newline at end of file

examples/EC12.s

+MOV R0 2
+MOV R1 40000
+MUL R0 R0 R1
+LDR R1 R0 100
+RET R0
\ No newline at end of file

examples/EC13-1.s

+MOVV R0 5
\ No newline at end of file

examples/EC13-2.s

+PUSH R0
\ No newline at end of file

examples/EC14.s

+MOV R0 1
+MOV R1 0
+DIV R0 R0 R1
+RET R0
\ No newline at end of file

examples/EC2.s

+MOV R0 1
+MOV R1 5
+DIV R0 R1 R0
\ No newline at end of file

examples/EC3.s

+MOV R0 1
+JMP -2
+RET R0
\ No newline at end of file

examples/EC4.S

+MOV R0 5
+MOV R1 3
+MOV R2 2
+MOV R3 1
+JZ R1 5
+MUL R0 R0 R2
+SUB R1 R1 R3
+JMP -3
+RET R0
\ No newline at end of file

examples/EC5.s

+MOV R0 1
+STR R-1 10000 R0
\ No newline at end of file

examples/EC6.s

+MOV R0 1
+LDR R0 R32 10000
\ No newline at end of file

examples/EC7.s

+MOV R0 65535
+MOV R1 -32768
+MOV R2 -1
+MUL R0 R0 R1
+ADD R0 R0 R1
+ADD R0 R0 R2
+RET R0
\ No newline at end of file

examples/EC8.s

+MOV R0 65535
+MOV R1 32768
+MUL R0 R0 R1
+ADD R0 R0 R1
+RET R0
\ No newline at end of file

examples/EC9.s

+MOV R0 65536
\ No newline at end of file

mutants/mutant-1/swen90006/machine/Machine.java

@@ -2,6 +2,7 @@ package swen90006.machine;
 
 import java.util.Arrays;
 import java.util.List;
+import java.Math;
 
 public class Machine 
 {
@@ -237,7 +238,7 @@ public class Machine
       } else if (toks[0].equals(INSTRUCTION_RETURN)){
 	int rs = parseReg(toks[1]);
 	count++;
-	return regs[rs];
+	return Math.abs(regs[rs]);
       } else if (toks[0].equals(INSTRUCTION_LOAD)){
 	if (toks.length != 4){
 	  throw new InvalidInstructionException();