Yet Another Virtual Machine - Integer Arithmetic Instructions

OPCODE: 01110

• If the flag has operand is set:
  • read two times X byte(s) following the instruction
  • increment the value of the IP register by 2 * X
• Else:
  • read two times X byte(s) at the address SB + SP - 2 * X
  • decrement the value of the SP register by 2 * X
• calculate value1 + value2
• copy the X bytes of the result at the address SB + SP where SB is the address of the stack base, and SP the stack pointer register
• increment the value of the SP register by X

Instruction	Value for X
ADD8	1
ADD16	2
ADD32	4
ADD64	8

ADD8 22 20

⇩

ADD8 (1 01110 00)

22

20

⇩

STACK HEAD (SP = 1)
42
STACK BASE

OPCODE: 01111

• If the flag has operand is set:
  • read two times X byte(s) following the instruction
  • increment the value of the IP register by 2 * X
• Else:
  • read two times X byte(s) at the address SB + SP - 2 * X
  • decrement the value of the SP register by 2 * X
• calculate value1 - value2
• copy the X bytes of the result at the address SB + SP where SB is the address of the stack base, and SP the stack pointer register
• increment the value of the SP register by X

Instruction	Value for X
SUB8	1
SUB16	2
SUB32	4
SUB64	8

SUB8 62 20

⇩

SUB8 (1 01111 00)

62

20

⇩

STACK HEAD (SP = 1)
42
STACK BASE

OPCODE: 10000

• If the flag has operand is set:
  • read two times X byte(s) following the instruction
  • increment the value of the IP register by 2 * X
• Else:
  • read two times X byte(s) at the address SB + SP - 2 * X
  • decrement the value of the SP register by 2 * X
• calculate value1 * value2
• copy the X bytes of the result at the address SB + SP where SB is the address of the stack base, and SP the stack pointer register
• increment the value of the SP register by X

Instruction	Value for X
MUL8	1
MUL16	2
MUL32	4
MUL64	8

MUL8 21 2

⇩

MUL8 (1 10000 00)

21

2

⇩

STACK HEAD (SP = 1)
42
STACK BASE

OPCODE: 10001

• If the flag has operand is set:
  • read two times X byte(s) following the instruction
  • increment the value of the IP register by 2 * X
• Else:
  • read two times X byte(s) at the address SB + SP - 2 * X
  • decrement the value of the SP register by 2 * X
• calculate value1 / value2
• copy the X bytes of the result at the address SB + SP where SB is the address of the stack base, and SP the stack pointer register
• increment the value of the SP register by X

Instruction	Value for X
DIV8	1
DIV16	2
DIV32	4
DIV64	8

DIV8 84 2

⇩

DIV8 (1 10001 00)

84

2

⇩

STACK HEAD (SP = 1)
42
STACK BASE

OPCODE: 10010

• If the flag has operand is set:
  • read two times X byte(s) following the instruction
  • increment the value of the IP register by 2 * X
• Else:
  • read two times X byte(s) at the address SB + SP - 2 * X
  • decrement the value of the SP register by 2 * X
• calculate value1 % value2
• copy the X bytes of the result at the address SB + SP where SB is the address of the stack base, and SP the stack pointer register
• increment the value of the SP register by X

Instruction	Value for X
MOD8	1
MOD16	2
MOD32	4
MOD64	8

MOD8 20 8

⇩

MOD8 (1 10010 00)

20

8

⇩

STACK HEAD (SP = 1)
4
STACK BASE

OPCODE: 10011

• If the flag has operand is set:
  • read two times X byte(s) following the instruction
  • increment the value of the IP register by 2 * X
• Else:
  • read two times X byte(s) at the address SB + SP - 2 * X
  • decrement the value of the SP register by 2 * X
• calculate value1 ** value2
• copy the X bytes of the result at the address SB + SP where SB is the address of the stack base, and SP the stack pointer register
• increment the value of the SP register by X

Instruction	Value for X
POW8	1
POW16	2
POW32	4
POW64	8

POW8 2 8

⇩

POW8 (1 10011 00)

2

8

⇩

STACK HEAD (SP = 1)
256
STACK BASE

OPCODE: 10100

• If the flag has operand is set:
  • read X byte(s) following the instruction
  • increment the value of the IP register by X
• Else:
  • read times X byte(s) at the address SB + SP - X
  • decrement the value of the SP register by X
• calculate value + 1
• copy the X bytes of the result at the address SB + SP where SB is the address of the stack base, and SP the stack pointer register
• increment the value of the SP register by X

Instruction	Value for X
INC8	1
INC16	2
INC32	4
INC64	8

INC8 41

⇩

INC8 (1 10100 00)

41

⇩

STACK HEAD (SP = 1)
42
STACK BASE

OPCODE: 10101

• If the flag has operand is set:
  • read X byte(s) following the instruction
  • increment the value of the IP register by X
• Else:
  • read times X byte(s) at the address SB + SP - X
  • decrement the value of the SP register by X
• calculate value - 1
• copy the X bytes of the result at the address SB + SP where SB is the address of the stack base, and SP the stack pointer register
• increment the value of the SP register by X

Instruction	Value for X
DEC8	1
DEC16	2
DEC32	4
DEC64	8

DEC8 43

⇩

DEC8 (1 10101 00)

43

⇩

STACK HEAD (SP = 1)
42
STACK BASE