From d6e89d16d332954dde3fc4c5ee7549af7c8bb556 Mon Sep 17 00:00:00 2001
From: sanine-a <sanine.not@pm.me>
Date: Mon, 22 May 2023 17:24:43 -0500
Subject: begin writing vm

---
 src/vm/instruction.js | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 src/vm/instruction.js

(limited to 'src/vm/instruction.js')

diff --git a/src/vm/instruction.js b/src/vm/instruction.js
new file mode 100644
index 0000000..0fe922d
--- /dev/null
+++ b/src/vm/instruction.js
@@ -0,0 +1,116 @@
+'use strict';
+
+const { AddrMode } = require('./enum.js');
+
+
+function DoDat(core, pc, ins) {
+	// do nothing
+	return [];
+}
+
+
+function DoMov(core, pc, ins) {
+	if (ins.a.mode === AddrMode.Immediate) {
+		let mem = core.getValue(pc, ins.b);
+		mem.b.value = ins.a.value;
+	} else {
+		const src = core.getValue(pc, ins.a);
+		const dstLoc = core.getLocation(pc, ins.b);
+
+		// hacky deep copy
+		core.data[dstLoc] = JSON.parse(JSON.stringify(src));
+	}
+	return [pc + 1];
+}
+
+
+function DoAdd(core, pc, ins) {
+	if (ins.a.mode === AddrMode.Immediate) {
+		let dst = core.getValue(pc, ins.b);
+		dst.b += ins.a.value;
+	} else {
+		let src = core.getValue(pc, ins.a);
+		let dst = core.getValue(pc, ins.b);
+		dst.a.value += src.a.value;
+		dst.b.value += src.b.value;
+	}
+	return [pc + 1];
+}
+
+
+function DoSub(core, pc, ins) {
+	if (ins.a.mode === AddrMode.Immediate) {
+		let dst = core.getValue(pc, ins.b);
+		dst.b -= ins.a.value;
+	} else {
+		let src = core.getValue(pc, ins.a);
+		let dst = core.getValue(pc, ins.b);
+		dst.a.value -= src.a.value;
+		dst.b.value -= src.b.value;
+	}
+	return [pc + 1];
+}
+
+
+function DoJmp(core, pc, ins) {
+	return [core.getLocation(pc, ins.a)];
+}
+
+
+function DoJmz(core, pc, ins) {
+	let test
+	if (ins.b.mode === AddrMode.Immediate) {
+		test = ins;
+	} else {
+		test = core.getValue(pc, ins.b);
+	}
+
+	if (test.b.value === 0) {
+		return [core.getLocation(pc, ins.a)];
+	} else {
+		return [pc + 1];
+	}
+}
+
+
+function DoJmn(core, pc, ins) {
+	let test
+	if (ins.b.mode === AddrMode.Immediate) {
+		test = ins;
+	} else {
+		test = core.getValue(pc, ins.b);
+	}
+
+	if (test.b.value !== 0) {
+		return [core.getLocation(pc, ins.a)];
+	} else {
+		return [pc + 1];
+	}
+}
+
+
+function DoCmp(core, pc, ins) {
+	if (ins.a.mode === AddrMode.Immediate) {
+		const test = core.getValue(pc, ins.b);
+		if (ins.a.value === test.b.value) {
+			return [pc + 2];
+		} else {
+			return [pc + 1];
+		}
+	} else {
+		const a = core.getValue(pc, ins.a);
+		const b = core.getValue(pc, ins.b);
+
+		if (
+			a.opcode === b.opcode &&
+			a.a.value === b.a.value &&
+			a.b.value === b.b.value)
+		) {
+			return [pc + 2];
+		} else {
+			return [pc + 1];
+		}
+	}
+}
+
+
-- 
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