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4.2 Instructions ¶

Since the virtual machine is stack-based, every instruction representing an operation will pop it’s operands, and push the result to the stack.

mnemonic	description	bnf object
not	Not, invert the bits of the operand	not
lnot	Logical not, invert the boolean interpretation of the operand	lnot
neg	Negate, switch the sign of the operand	neg
and	And, performs a binary AND operation between two operands	and
or	Or, performs a binary OR operation between two operands	or
xor	Exclusive or, performs a binary XOR operation between two operands	xor
shl	Left bitshift, shifts the bits of the operand to the left, appending zeroes	shl
shr	Right bitshift, shifts the bits of the operand to the right, appending zeroes	shr
land	Logical and, boolean interpretation of the logical AND on two operands	land
lor	Logical or, boolean interpretation of the logical OR on two operands	lor
add	Addition, adds the value of two operands	add
sub	Substraction, subtract the value of two operands	sub
mult	Multiplication, multiplies the value of two operands	mult
div	Division, return the dividend of the euclidian division of operand 1 by operand 2	div
mod	Modulo, return the rest of the euclidian division of operand 1 by operand 2	mod
gt	Greater than, compares the two operands and return a result for boolean interpretation	gt
ge	Greater than or equals to, compares the two operands and return a result for boolean interpretation	ge
lt	Less than, compares the two operands and return a result for boolean interpretation	lt
le	Less than or equals to, compares the two operands and return a result for boolean interpretation	le
eq	Equals, compares the two operands and return a result for boolean interpretation	eq
neq	Different from, compares the two operands and return a result for boolean interpretation	diff
updz	Update zero flag, pops the value from the stack and set it as the new zero flag	updz
push	Push value, push a 64 bits value to the stack	push_value
push	Push relative address, push a 64 bits relative address to the stack, corresponding generally to a label	push_label
push	Push from stack pointer relative address, push to the stack the 8 bytes found at the stack pointer + the address given as operand	push_stack
pop	Pop empty, pop 8 bytes from the stack	pop
pop	Pop to stack pointer relative address, pop 8 bytes from the stack, and write them to the stack pointer + the address given as operand	pop_stack
call	Call, op 8 bytes from the stack, register the new stack pointer, push the PC and stack pointer to the callstack, and jump to the value of the 8 bytes popped from the stack	call
ret	Return, reset the stack to the stack pointer, pop the callstack and jump to the address from the callstack pop	ret
jmp	Jump, pop an address from the stack, and set the PC to it	jmp
zjmp	Zero jump, pop an address from the stack, and if the zero flag is set, set the PC to it	zjmp
aff	Show, pop 8 bytes from the stack, apply a modulo 256 to the result, and write a single ascii character corresponding to the result	aff
affs	Show string, the first operand is a 64 bits integer corresponding to the number of caracters, that we will call n. The next n bytes are the ascii values of the characters that will be wrote	affs