#stack #machine #vm #asm #stack-machine

yanked pure_stack_machine

Pure stack machine

1 unstable release

0.1.0 Mar 3, 2024

#47 in #asm

MIT license

1MB
447 lines

Contains (ELF exe/lib, 4MB) stack_machine

Concept

Pure stack machine. Small number of instructions. There are currently 20 instructions.

Usage

cargo build --release
cp target/release/stack_machine stack_machine
./stack_machine <path>

instructions

Code Instruction Pop Top Push Description
0 load - - value loads literal value
1 add a, b - result result = a + b
2 sub b, a - result result = a - b
3 mul a, b - result result = a * b
4 div b, a - result result = a / b
5 read mode - input reads char (mode = 0) or string (mode = 1) from stdin
6 put format value - prints value to stdout as a number (format = 0), char (format = 1) or bits (format = 2)
7 and a, b - result result = a & b
8 or a, b - result result = a | b
9 xor a, b - result result = a ^ b
10 not value - result result = !value
11 cmp b a result if a > b: result = 1 else if a < b: result = 2 else result = 0
12 jmp - - - jumps to #label
13 jeq value - - jumps to #label if value = 0
14 jne value - - jumps to #label if value != 0
15 jgr value - - jumps to #label if value = 1
16 jle value - - jumps to #label if value = 2
17 copy - value value makes copy of value
18 drop value - - just drops value
19 halt - - - stops executing

Examples

2 + 2

#start  ; '#start' label is required
load 2  ; stack = [2]
load 2  ; stack = [2, 2]
add     ; stack = [4]

2 + 2 + 2

#start
load 2  ; stack = [2]
load 2  ; stack = [2, 2]
add     ; stack = [4]
load 2  ; stack = [4, 2]
add     ; stack = [6]

infinite loop

#start
jmp #start

condition

#equal
load "e"
load 1
put
halt

#notequal
load "n"
load 1
put
halt

#start  ; program starts here!
load 2
load 1
cmp 
jeq #equal
jmp #notequal  ; jumps to '#notequal' because 2 != 1

TODO

Add more instructions.

No runtime deps