star.isa.txt

A minimum list of instructions of StAr:

Note: notation prefix(var1|var2)postfix will be used below to denote 2
variants of command: prefixvar1postfix/prefixvar2postfix.

(derived from task.txt)

alloc <size>		--  Stack frame allocation on the top of the stack, with
						given <size>.

ldc(i|d) <const>	--  Load a constant into stack top.

ld(i|d)	<shift>		--  Load a value from <frame-pointer> + <shift> into the
						top of the stack.

lda <shift>			--  Produce an adress of the cell <frame-pointer> +
						<shift>.

lds(i|d)			--  Read a value by the adress in the top of the stack. The
						adress was produced by the lda command.

st(i|d)				--  Write a second value from the top of the stack by an
						adress in the top. Saves the top of the stack.

scr					--  Drop the top value.

index				--  Form an array adress by begin-adress(produced by lda)
						and element index. Machine must check array borders.

add					--  stack.push (stack.pop + stack.pop)

sub					--  stack.push (stack.pop - stack.pop)

mul					--  stack.push (stack.pop * stack.pop)

div					--  stack.push (stack.pop / stack.pop)

rem					--  stack.push (stack.pop mod stack.pop)

chs					--  stack.push (- stack.pop)

fi2d				--  Change the type of the top element from float to
						integer.

fd2f				--  Change the type of the top element from integer to
						float.

ms					--  Prepare to enter to a procedure. Mark stack by pushing
						to it a special element, designating a separate area
						of arguments.

call				--  Call a user-defined or system function, such as print.