From 16501e40befcc136cd5e002878c1260ff0aa7efb Mon Sep 17 00:00:00 2001
From: Henrik Hautakoski <henrik.hautakoski@gmail.com>
Date: Sat, 24 Nov 2018 19:57:36 +0100
Subject: [PATCH] asm: adding instr_encode module

---
 src/as/instr_encode.c | 50 +++++++++++++++++++++++++++++++++++++++++++
 src/as/instr_encode.h | 27 +++++++++++++++++++++++
 2 files changed, 77 insertions(+)
 create mode 100644 src/as/instr_encode.c
 create mode 100644 src/as/instr_encode.h

diff --git a/src/as/instr_encode.c b/src/as/instr_encode.c
new file mode 100644
index 0000000..1478928
--- /dev/null
+++ b/src/as/instr_encode.c
@@ -0,0 +1,50 @@
+/* instr_encode.c
+ *
+ *   Copyright (C) 2018   Henrik Hautakoski <henrik@fiktivkod.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ *   MA 02110-1301, USA.
+ */
+#include <stdio.h>
+#include <string.h>
+#include "instr_encode.h"
+
+void instr_encode(struct instr* instr, uint16_t *out) {
+
+	uint8_t *p = (uint8_t *) out;
+
+	*out = 0;
+	*p = instr->opcode << 4;
+
+	if (instr->opcode == OP_NOOP) {
+		// Do nothing.
+	} else if (instr->opcode == OP_JMP) {
+		*p |= (instr->j.addr >> 8);
+		*(p+1) = instr->j.addr;
+	} else {
+		*p |= instr->r.rs;
+
+		// I-Type
+		if (instr->opcode == OP_MOVL || instr->opcode == OP_MOVH
+			|| instr->opcode == OP_JR || instr->opcode == OP_INT) {
+
+			*(p+1) = instr->i.imm;
+		}
+		// R/RI-Type
+		else {
+			*(p+1) = (instr->r.r0 << 4) | instr->r.r1;
+		}
+	}
+}
diff --git a/src/as/instr_encode.h b/src/as/instr_encode.h
new file mode 100644
index 0000000..0f01304
--- /dev/null
+++ b/src/as/instr_encode.h
@@ -0,0 +1,27 @@
+/* instr_encode.h
+ *
+ *   Copyright (C) 2018   Henrik Hautakoski <henrik.hautakoski@gmail.com>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ *   MA 02110-1301, USA.
+ */
+#ifndef ASM_INSTR_ENCODE_H
+#define ASM_INSTR_ENCODE_H
+
+#include <instr.h>
+
+void instr_encode(struct instr* instr, uint16_t *out);
+
+#endif /* ASM_INSTR_ENCODE_H */