Create assembler driver script for recording word addresses

This will allow the profiler to sample the current return stack and
instruction pointer.  It can't just use the ip and rsp globals
directly, as I had initially planned, since these cannot be sent
in between threads.

README.md

@@ -2,7 +2,7 @@
 
 Wipforth is a Forth implementation that runs in the WebAssembly
 virtual machine.  The system is bootstrapped from source on page load:
-the only binary file is the favicon :)
+the only non-text file is the favicon :)
 
 I/O is done via memory-mapped peripherals, which are emulated in
 JavaScript.
@@ -17,8 +17,8 @@ JavaScript.
 
 ## Building and Running Locally
 
-There is simple [Guile](https://www.gnu.org/software/guile/) script
-you can use for this:
+There's a [Guile](https://www.gnu.org/software/guile/) script in the
+repo you can use for this:
 
 ```
 guile server.scm
@@ -27,15 +27,17 @@ guile server.scm
 You should then be able to open <http://localhost:8080> in a browser
 and use the system from there.
 
-Since everything is bootstrapped on the client, you only need an HTTP
-server, so if you don't have Guile on your system you can bring your
-own.  The only requirement is that it sets the cross-origin isolation
-headers required for `SharedMemoryBuffer` use:
+However, since everything is bootstrapped on the client, basically any
+HTTP server will do as long as it sets the appropriate response
+headers for `SharedMemoryBuffer` use:
 
 - `Cross-Origin-Opener-Policy: same-origin`
 - `Cross-Origin-Embedder-Policy: require-corp`
 
-You should **definitely not** use `server.scm` to serve the
+So, if you don't have Guile on your system you can use something else
+like Python's `http.server`.
+
+**NOTE**: You should **definitely not** use `server.scm` to serve the
 application on the open internet or anything like that; I just hacked
 it together for testing on localhost during development and it's
 probably hilariously insecure.

asm.js

@@ -187,6 +187,9 @@ const opcodes = {
     "i32.shl":          0x74,
     "i32.shr_s":        0x75,
     "i32.shr_u":        0x76,
+    "i64.or":           0x84,
+    "i64.shl":          0x86,
+    "i64.extend_i32_u": 0xad,
 
     // Threads instructions
     "memory.atomic.notify": [ 0xfe, 0x00 ],
@@ -194,6 +197,7 @@ const opcodes = {
     "i32.atomic.load":      [ 0xfe, 0x10 ],
     "i32.atomic.load8_u":   [ 0xfe, 0x12 ],
     "i32.atomic.store":     [ 0xfe, 0x17 ],
+    "i64.atomic.store":     [ 0xfe, 0x18 ],
     "i32.atomic.store8":    [ 0xfe, 0x19 ],
 };
 
@@ -888,6 +892,7 @@ const Section = Object.freeze({
 const Kind = Object.freeze({
     FUNC:   0x00,
     MEM:    0x02,
+    GLOBAL: 0x03,
 });
 
 export class Assembler {
@@ -942,8 +947,28 @@ export class Assembler {
     }
 
     action_export(action) {
-        const index = Object.keys(this.funcs).indexOf(action.name);
-        this.exports[action.name] = { kind: Kind.FUNC, index };
+        const func_index = Object.keys(this.funcs).indexOf(action.name);
+        if (func_index != -1) {
+            this.exports[action.name] = {
+                kind: Kind.FUNC,
+                index: func_index,
+            };
+            return;
+        }
+
+        const global_index = Object.keys(this.globals).indexOf(action.name);
+        if (global_index != -1) {
+            this.exports[action.name] = {
+                kind: Kind.GLOBAL,
+                index: global_index,
+            };
+            return;
+        }
+
+        console.error(
+            `ERROR: Unable to resolve export ${action.name} `
+                + "(only functions and globals currently supported)"
+        );
     }
 
     action_func(action) {

boot.js

@@ -10,10 +10,17 @@ const assemble = (async () => {
 })();
 
 self.onmessage = async (e) => {
-	const exports = { emu: { mem: e.data } };
+	switch (e.data.type) {
+	case "load":
+		const exports = { emu: { mem: e.data.mem } };
 		const wasm = await assemble;
-	const mod = await WebAssembly.instantiate(wasm, exports);
-	await self.postMessage('booting');
-	mod.instance.exports.reset();
+		self.mod = await WebAssembly.instantiate(wasm, exports);
+		await self.postMessage('ready');
+		break;
+
+	case "boot":
+		self.mod.instance.exports.reset();
 		console.log('System halt');
+		break;
+	}
 };

driver.js

@@ -1,9 +0,0 @@
-import { Assembler } from "./asm.js";
-import { writeAll } from "jsr:@std/io/write-all";
-
-const asm = new Assembler();
-for await (const chunk of Deno.stdin.readable) {
-	asm.push(chunk);
-}
-const wasm = asm.wasm();
-await writeAll(Deno.stdout, wasm);

emu.js

@@ -51,13 +51,28 @@ class Emulator {
 		document.addEventListener('keydown', (e) => this.handle_keydown(e));
 		window.addEventListener('resize', () => this.handle_resize());
 
+		this.prof = new Worker("prof.js");
+		this.prof.onmessage = (e) => {
+			const blob = new Blob(
+				[JSON.stringify(e.data)],
+				{ type: "application/json" });
+			const url = URL.createObjectURL(blob);
+			const a = document.createElement("a");
+			a.href = url;
+			a.download = "wipforth-profile.json";
+			a.click();
+			URL.revokeObjectURL(url);
+		};
+
 		this.print("Assembling kernel ");
 		const dots = setInterval(() => this.print("."), DOT_INTERVAL_MS);
 		this.worker = new Worker('boot.js', { type: 'module' });
-		this.worker.postMessage(this.mem);
+		this.worker.postMessage({ type: "load", mem: this.mem });
 		this.worker.onmessage = (e) => {
 			clearInterval(dots);
 			this.print(" done\n");
+			this.worker.postMessage({ type: "boot" });
+			this.prof.postMessage({ type: "start", mem: this.mem });
 		};
 
 		fetch('prelude.f')
@@ -84,6 +99,7 @@ class Emulator {
 		if (!this.input_enable) {
 			const sysready = Atomics.load(this.mem_u8, SYSREADY);
 			if (sysready != 0) {
+				this.prof.postMessage({ type: "stop" });
 				this.input_enable = true;
 				this.flush_output();
 				document.getElementById('cursor').classList.add('blinking');

prelude.f

@@ -250,7 +250,7 @@ CHAR . EMIT
 
 0 CONSTANT VERSION-MAJOR
 2 CONSTANT VERSION-MINOR
-0 CONSTANT VERSION-PATCH
+1 CONSTANT VERSION-PATCH
 
 : PRINT-VERSION
   CHAR v EMIT VERSION-MAJOR .

prof.js

@@ -0,0 +1,48 @@
+const INTERVAL_MS = 1;
+const RS_TOP_ADDR = 0x10000;
+const PROF_DATA_ADDR = 0x58;
+const PROF_DATA_IDX = PROF_DATA_ADDR / 8;
+
+let mem_8;
+let mem_64;
+let sampler;
+
+const samples = [];
+
+function sample() {
+	const data = Atomics.load(mem_64, PROF_DATA_IDX);
+	const ip = Number(data & 0xffffffffn);
+	const rsp = Number(data >> 32n);
+	samples.push({ ip, rs_bytes: mem_8.slice(rsp, RS_TOP_ADDR) });
+}
+
+function i32(bytes) {
+	return bytes[0]
+		| (bytes[1] << 8)
+		| (bytes[2] << 16)
+		| (bytes[3] << 24);
+}
+function postproc({ ip, rs_bytes }) {
+	const rs = [];
+	for (let i = 0; i < rs_bytes.length; i += 4)
+		rs.push(i32(rs_bytes.slice(i, i + 4)));
+	rs.reverse();
+	return { ip, rs };
+}
+
+self.onmessage = (e) => {
+	switch (e.data.type) {
+	case "start":
+		console.log("Starting profiler");
+		mem_8 = new Uint8Array(e.data.mem.buffer);
+		mem_64 = new BigUint64Array(e.data.mem.buffer);
+		ip = e.data.ip;
+		rsp = e.data.rsp;
+		sampler = setInterval(sample, INTERVAL_MS);
+		break;
+	case "stop":
+		clearInterval(sample);
+		console.log("Stopped profiler");
+		self.postMessage(samples.map(postproc));
+	}
+};

wipforth.ws

@@ -9,6 +9,9 @@
 .def RXHEAD 48h
 .def RXTAIL 4Ch
 
+;; Mirror of registers for profiler to sample
+.def PROF_DATA 58h
+
 .def DICT_START 0200h
 
 .def RSP_INIT 10000h
@@ -2073,6 +2076,13 @@ KERNEL_DEFS_END:
 .func trampoline
     loop iter
       global.get fn call_indirect codeword codewords
+
+	  i32.const PROF_DATA
+	  global.get ip  i64.extend_i32_u
+	  global.get rsp i64.extend_i32_u
+	  i64.const 32 i64.shl i64.or
+	  i64.atomic.store 3 0
+
       global.get run br_if iter
     end
 

words.js

@@ -0,0 +1,16 @@
+import { Assembler } from "./asm.js";
+
+const asm = new Assembler();
+for await (const chunk of Deno.stdin.readable) {
+	asm.push(chunk);
+}
+asm.wasm();
+
+const defs = Object.entries(asm.defs);
+while (defs[0][0] != '_DUP')
+	defs.shift();
+while (defs.at(-1)[0] != 'WNF_HANDLER')
+	defs.pop();
+const words = Object.fromEntries(defs.filter(([k,v]) => !k.startsWith("_")));
+
+console.log(JSON.stringify(words));