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+/* Copyright (C) 2023 Aryadev Chavali
+
+ * You may distribute and modify this code under the terms of the GPLv2
+ * license. You should have received a copy of the GPLv2 license with
+ * this file. If not, please write to: aryadev@aryadevchavali.com.
+
+ * Created: 2023-10-23
+ * Author: Aryadev Chavali
+ * Description: An example virtual machine program which computes and
+ * prints fibonacci numbers. Note that by default the virtual machine
+ * just rolls overflows over, so this program will never terminate.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "../vm/inst.h"
+#include "../vm/runtime.h"
+
+int main(void)
+{
+ inst_t instructions[] = {
+ // MOV the values 1 and 1 to REG[0] and REG[1] respectively
+ INST_PUSH(WORD, 1),
+ INST_MOV(WORD, 0),
+ INST_PUSH(WORD, 1),
+ INST_MOV(WORD, 1),
+
+ // Print value at register 0 with newline.
+ INST_PUSH_REG(WORD, 0), // <-- #
+ INST_PRINT(WORD),
+ INST_PUSH(BYTE, '\n'),
+ INST_PRINT(CHAR),
+
+ // Print value at register 1 with newline
+ INST_PUSH_REG(WORD, 1),
+ INST_PRINT(WORD),
+ INST_PUSH(BYTE, '\n'),
+ INST_PRINT(CHAR),
+
+ /* Compute the next pair of fibonacci numbers */
+ // REG[0] + REG[1]
+ INST_PUSH_REG(WORD, 0),
+ INST_PUSH_REG(WORD, 1),
+ INST_PLUS(WORD),
+
+ // Mov REG[0] + REG[1] to REG[0]
+ INST_MOV(WORD, 0),
+
+ // REG[0] + REG[1]
+ INST_PUSH_REG(WORD, 0),
+ INST_PUSH_REG(WORD, 1),
+ INST_PLUS(WORD),
+
+ // Mov REG[0] + REG[1] to REG[1]
+ INST_MOV(WORD, 1),
+
+ // Jump to the point #
+ INST_JUMP_ABS(4),
+ INST_HALT,
+ };
+
+ byte stack[256];
+ vm_t vm = {0};
+ vm_load_stack(&vm, stack, ARR_SIZE(stack));
+ vm_load_program(&vm, instructions, ARR_SIZE(instructions));
+ err_t err = vm_execute_all(&vm);
+
+ if (err)
+ {
+ const char *error_str = err_as_cstr(err);
+ fprintf(stderr, "[ERROR]: %s\n", error_str);
+ fprintf(stderr, "[ERROR]: VM Trace:\n");
+ vm_print_all(&vm, stderr);
+ return 255 - err;
+ }
+ return 0;
+}