retroforth/vm/nga-js/nga.js
crc 9ffc6f277f END -> HALT in Nga instruction naming
FossilOrigin-Name: e3a4cbb9ac94f83d9e256cdaca70addde60626771ccb68b9f784ca4b355ee2ea
2019-12-10 18:51:56 +00:00

513 lines
10 KiB
JavaScript

/* Nga ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Copyright (c) 2008 - 2019, Charles Childers
Copyright (c) 2009 - 2010, Luke Parrish
Copyright (c) 2010, Marc Simpson
Copyright (c) 2010, Jay Skeer
Copyright (c) 2011, Kenneth Keating
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
var IMAGE_SIZE = 524288; /* Amount of simulated RAM */
var DATA_DEPTH = 8192; /* Depth of data stack */
var ADDRESS_DEPTH = 32768; /* Depth of the stacks */
var framebuffer = 0;
function Stack(size) {
this.sp = 0;
this.data = new Array(size);
this.push = function(n) {
this.sp++;
this.data[this.sp] = n;
}
this.pop = function() {
return this.data[this.sp--];
}
this.depth = function() {
return this.sp;
}
this.tos = function() {
return this.data[this.sp];
}
this.nos = function() {
return this.data[this.sp - 1];
}
this.dup = function() {
this.push(this.tos());
}
this.drop = function() {
this.sp--;
}
this.swap = function() {
var a = this.nos();
this.data[this.sp - 1] = this.tos();
this.data[this.sp] = a;
}
this.inc = function() {
this.data[this.sp]++;
}
this.dec = function() {
this.data[this.sp]--;
}
this.reset = function() {
this.sp = 0;
}
}
function Opcodes() {
this.NOP = 0;
this.LIT = 1;
this.DUP = 2;
this.DROP = 3;
this.SWAP = 4;
this.PUSH = 5;
this.POP = 6;
this.JUMP = 7;
this.CALL = 8;
this.CCALL = 9;
this.RETURN = 10;
this.EQ = 11;
this.NEQ = 12;
this.LT = 13;
this.GT = 14;
this.FETCH = 15;
this.STORE = 16;
this.ADD = 17;
this.SUB = 18;
this.MUL = 19;
this.DIVMOD = 20;
this.AND = 21;
this.OR = 22;
this.XOR = 23;
this.SHIFT = 24;
this.ZERO_EXIT = 25;
this.HALT = 26;
this.IE = 27;
this.IQ = 28;
this.II = 29;
}
var ip = 0;
var data = new Stack(DATA_DEPTH);
var address = new Stack(ADDRESS_DEPTH);
var image = new Array(IMAGE_SIZE);
var vm = new Opcodes();
var instructions = new Array(vm.II + 1);
var notfound = 0;
var interpret = 0;
function rxPrepareVM() {
ip = 0;
data.reset();
address.reset();
framebuffer = 0;
}
instructions[vm.NOP] = function() {}
instructions[vm.LIT] = function() {
ip++;
data.push(image[ip]);
}
instructions[vm.DUP] = function() {
data.dup();
}
instructions[vm.DROP] = function() {
data.drop();
}
instructions[vm.SWAP] = function() {
data.swap();
}
instructions[vm.PUSH] = function() {
address.push(data.pop());
}
instructions[vm.POP] = function() {
data.push(address.pop())
}
instructions[vm.JUMP] = function() {
ip = data.pop() - 1;
}
instructions[vm.CALL] = function() {
address.push(ip);
ip = data.pop() - 1;
}
instructions[vm.CCALL] = function() {
var a, b;
a = data.pop();
b = data.pop();
if (b != 0) {
address.push(ip);
ip = a - 1;
}
}
instructions[vm.RETURN] = function() {
ip = address.pop();
}
instructions[vm.EQ] = function() {
var a, b;
a = data.pop();
b = data.pop();
if (b == a)
data.push(-1);
else
data.push(0);
}
instructions[vm.NEQ] = function() {
var a, b;
a = data.pop();
b = data.pop();
if (b != a)
data.push(-1);
else
data.push(0);
}
instructions[vm.LT] = function() {
var a, b;
a = data.pop();
b = data.pop();
if (b < a)
data.push(-1);
else
data.push(0);
}
instructions[vm.GT] = function() {
var a, b;
a = data.pop();
b = data.pop();
if (b > a)
data.push(-1);
else
data.push(0);
}
instructions[vm.FETCH] = function() {
x = data.pop();
if (x == -1)
data.push(data.sp);
else if (x == -2)
data.push(address.sp);
else if (x == -3)
data.push(IMAGE_SIZE);
else if (x == -4)
data.push(-2147483648);
else if (x == -5)
data.push(2147483647);
else
data.push(image[x]);
}
instructions[vm.STORE] = function() {
image[data.tos()] = data.nos();
data.drop();
data.drop();
}
instructions[vm.ADD] = function() {
var x = data.pop();
var y = data.pop();
data.push(x + y);
}
instructions[vm.SUB] = function() {
var x = data.pop();
var y = data.pop();
data.push(y - x);
}
instructions[vm.MUL] = function() {
var x = data.pop();
var y = data.pop();
data.push(y * x);
}
instructions[vm.DIVMOD] = function() {
var b = data.pop();
var a = data.pop();
if (b == 0) {
ip = 0;
data.sp = 0;
address.sp = 0;
} else {
var x = Math.abs(b);
var y = Math.abs(a);
var q = Math.floor(y / x);
var r = y % x;
if (a < 0 && b < 0)
r = r * -1;
if (a > 0 && b < 0)
q = q * -1;
if (a < 0 && b > 0) {
r = r * -1;
q = q * -1;
}
data.push(r);
data.push(q);
}
}
instructions[vm.AND] = function() {
var x = data.pop();
var y = data.pop();
data.push(x & y);
}
instructions[vm.OR] = function() {
var x = data.pop();
var y = data.pop();
data.push(x | y);
}
instructions[vm.XOR] = function() {
var x = data.pop();
var y = data.pop();
data.push(x ^ y);
}
instructions[vm.SHIFT] = function() {
var x = data.pop();
var y = data.pop();
if (x < 0)
data.push(y << (x * -1));
else
data.push(y >>= x);
}
instructions[vm.ZERO_EXIT] = function() {
if (data.tos() == 0) {
data.drop();
ip = address.pop();
}
}
instructions[vm.HALT] = function() {
ip = IMAGE_SIZE;
}
instructions[vm.IE] = function() {
data.push(2);
}
instructions[vm.IQ] = function() {
var chosen = data.pop();
if (chosen == 0) {
data.push(0);
data.push(0);
} else if (chosen == 1) {
data.push(20);
data.push(0);
}
}
instructions[vm.II] = function() {
var chosen = data.pop();
if (chosen == 0) {
var s = String.fromCharCode(data.pop());
document.getElementById('console').innerHTML += s;
} else if (chosen == 1) {
draw(data.pop())
}
}
window.addEventListener('load', function(e) {
rxPrepareVM();
}, false);
function processOpcode(opcode) {
if (opcode != 0) {
instructions[opcode]();
checkStack();
}
}
function validatePackedOpcodes(opcode) {
var raw = opcode;
var current;
var valid = -1;
var i = 0;
while (i < 4) {
current = raw & 0xFF;
if (!current >= 0 && current <= 29)
valid = 0;
raw = raw >> 8;
i++;
}
}
function ngaProcessPackedOpcodes(opcode) {
var raw = opcode;
ops = new Array(3);
ops[0] = raw & (255);
raw = raw >> 8;
ops[1] = raw & (255);
raw = raw >> 8;
ops[2] = raw & (255);
raw = raw >> 8;
ops[3] = raw & (255);
processOpcode(ops[0]);
processOpcode(ops[1]);
processOpcode(ops[2]);
processOpcode(ops[3]);
}
function loadInitialImage() {
image = ngaImage.slice();
}
function execute(offset) {
var opcode;
address.sp = 1;
ip = offset;
while (ip < IMAGE_SIZE) {
opcode = image[ip];
if (ip == notfound) {
document.getElementById('console').value +=
"err:notfound : " + string_extract(1024) + "\n";
}
if (validatePackedOpcodes(opcode) != 0) {
ngaProcessPackedOpcodes(opcode);
} else {
alert("Invalid instruction!");
alert("At " + ip + ", opcode " + opcode);
}
if (address.sp == 0)
ip = IMAGE_SIZE;
ip++;
}
}
function checkStack() {
var depth = data.depth();
var adepth = address.depth();
var flag = 0;
if (depth < 0 || adepth < 0) {
flag = -1;
}
if (depth > DATA_DEPTH || adepth > DATA_DEPTH) {
flag = -1;
}
if (flag == -1) {
ip = 0;
data.sp = 0;
address.sp = 0;
}
}
function string_inject(str, buffer) {
var m = str.length;
var i = 0;
while (m > 0) {
image[buffer + i] = str[i].charCodeAt(0);
image[buffer + i + 1] = 0;
m--;
i++;
}
}
function string_extract(at) {
string_data = "";
var starting = at;
var i = 0;
while (image[starting] != 0)
string_data += String.fromCharCode(image[starting++]);
return string_data;
}
function d_xt(dt) {
return dt + 1;
}
function d_name(dt) {
return dt + 3;
}
function d_lookup(name) {
var dt = 0;
var i = image[2];
var dname;
while (image[i] != 0 && i != 0) {
dname = string_extract(d_name(i));
if (dname == name) {
dt = i;
i = 0;
} else {
i = image[i];
}
}
return dt;
}
function d_xt_for(name) {
return image[d_xt(d_lookup(name))];
}
function evaluate(s) {
if (s.length == 0)
return;
string_inject(s, 1024);
data.push(1024);
execute(interpret);
}
function cls() {
document.getElementById('console').innerHTML = "";
const context = canvas.getContext('2d');
context.clearRect(0, 0, canvas.width, canvas.height);
}
function unu(src) {
raw = src.split("\n");
var i = raw.length;
var lines = new Array();
var j = 0;
var code = 0;
while (j < i) {
if (code == 1 && raw[j] == "~~~") {
code = 0;
} else if (code == 0 && raw[j] == "~~~") {
code = 1;
} else if (code == 1) {
lines.push(raw[j]);
}
j++;
}
return lines.join(" ");
}
function go() {
rxPrepareVM();
loadInitialImage();
notfound = d_xt_for("err:notfound");
interpret = d_xt_for("interpret");
document.getElementById("console").innerHTML = "";
src = document.getElementById("input").value;
tokens = unu(src).match(/\S+/g);
var i = tokens.length;
var j = 0;
while (j < i) {
evaluate(tokens[j]);
j++;
}
s = "";
i = data.depth();
j = 1;
while (j <= i) {
s = s + data.data[j] + " ";
j++;
}
document.getElementById("console").innerHTML += "\n" + s;
if (framebuffer === 0) {
var canvas = document.getElementById('canvas');
canvas.style.display = "none";
} else {
var canvas = document.getElementById('canvas');
canvas.style.display = "block";
}
}
function saveproject() {
src = document.getElementById("input").value;
localStorage.setItem("Snapshot", src);
}
function loadproject() {
src = localStorage.getItem("Snapshot");
document.getElementById("input").value = src;
}
function draw(fb_start) {
framebuffer = 1;
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
var imgData = ctx.createImageData(300, 300);
var i;
for (i = 0; i < imgData.data.length / 4; i += 1) {
imgData.data[i * 4 + 0] = ((image[i + fb_start] >> 8) >> 8) & 255;
imgData.data[i * 4 + 1] = (image[i + fb_start] >> 8) & 255;
imgData.data[i * 4 + 2] = image[i + fb_start] & 255;
imgData.data[i * 4 + 3] = 255;
}
ctx.putImageData(imgData, 0, 0);
}