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- Committer: Bazaar Package Importer
- Author(s): Daniel Schepler
- Date: 2001-01-28 18:06:24 UTC
- Revision ID: james.westby@ubuntu.com-20010128180624-hf85cm3jyb5df4cj
Tags: upstream-1.8.2
Import upstream version 1.8.2
- files added:
added
removed
interpre.c
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/*
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* interpre.c
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*
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* Main interpreter loop
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*
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*/
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#include "ztypes.h"
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static int halt = FALSE;
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/*
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* interpret
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*
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* Interpret Z code
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*
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*/
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#ifdef __STDC__
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int interpret ()
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#else
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int interpret ()
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#endif
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{
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zbyte_t opcode;
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zword_t specifier, operand[8];
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int maxoperands, count, extended, i;
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interpreter_status = 1;
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/* Loop until HALT instruction executed */
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for (interpreter_state = RUN; interpreter_state == RUN && halt == FALSE; ) {
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/* Load opcode and set operand count */
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opcode = read_code_byte ();
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if (h_type > V4 && opcode == 0xbe) {
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opcode = read_code_byte ();
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extended = TRUE;
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} else
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extended = FALSE;
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count = 0;
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/* Multiple operand instructions */
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if ((opcode < 0x80 || opcode > 0xc0) || extended == TRUE) {
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/* Two operand class, load both operands */
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if (opcode < 0x80 && extended == FALSE) {
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operand[count++] = load_operand ((opcode & 0x40) ? 2 : 1);
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operand[count++] = load_operand ((opcode & 0x20) ? 2 : 1);
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opcode &= 0x1f;
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} else {
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/* Variable operand class, load operand specifier */
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opcode &= 0x3f;
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if (opcode == 0x2c || opcode == 0x3a) { /* Extended CALL instruction */
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specifier = read_code_word ();
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maxoperands = 8;
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} else {
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specifier = read_code_byte ();
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maxoperands = 4;
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}
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/* Load operands */
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for (i = (maxoperands - 1) * 2; i >= 0; i -= 2)
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if (((specifier >> i) & 0x03) != 3)
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operand[count++] = load_operand ((specifier >> i) & 0x03);
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else
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i = 0;
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}
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if (extended == TRUE)
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switch ((char) opcode) {
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/* Extended operand instructions */
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case 0x00: save (count, operand); break;
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case 0x01: restore (count, operand); break;
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case 0x02: shift (operand[0], operand[1]); break;
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case 0x03: arith_shift (operand[0], operand[1]); break;
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case 0x04: set_font_attribute (operand[0]); break;
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case 0x09: undo_save (); break;
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case 0x0a: undo_restore (); break;
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default: fatal ("Illegal operation");
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}
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else
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switch ((char) opcode) {
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/* Two or multiple operand instructions */
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case 0x01: compare_je (count, operand); break;
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case 0x02: compare_jl (operand[0], operand[1]); break;
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case 0x03: compare_jg (operand[0], operand[1]); break;
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case 0x04: decrement_check (operand[0], operand[1]); break;
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case 0x05: increment_check (operand[0], operand[1]); break;
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case 0x06: compare_parent_object (operand[0], operand[1]); break;
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case 0x07: test (operand[0], operand[1]); break;
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case 0x08: or (operand[0], operand[1]); break;
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case 0x09: and (operand[0], operand[1]); break;
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case 0x0a: test_attr (operand[0], operand[1]); break;
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case 0x0b: set_attr (operand[0], operand[1]); break;
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case 0x0c: clear_attr (operand[0], operand[1]); break;
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case 0x0d: store_variable (operand[0], operand[1]); break;
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case 0x0e: insert_object (operand[0], operand[1]); break;
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case 0x0f: load_word (operand[0], operand[1]); break;
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case 0x10: load_byte (operand[0], operand[1]); break;
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case 0x11: load_property (operand[0], operand[1]); break;
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case 0x12: load_property_address (operand[0], operand[1]); break;
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case 0x13: load_next_property (operand[0], operand[1]); break;
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case 0x14: add (operand[0], operand[1]); break;
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case 0x15: subtract (operand[0], operand[1]); break;
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case 0x16: multiply (operand[0], operand[1]); break;
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case 0x17: divide (operand[0], operand[1]); break;
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case 0x18: remainder (operand[0], operand[1]); break;
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case 0x19: call (count, operand, FUNCTION); break;
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case 0x1a: call (count, operand, PROCEDURE); break;
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case 0x1b: set_colour_attribute (operand[0], operand[1]); break;
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case 0x1c: unwind (operand[0], operand[1]); break;
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/* Multiple operand instructions */
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case 0x20: call (count, operand, FUNCTION); break;
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case 0x21: store_word (operand[0], operand[1], operand[2]); break;
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case 0x22: store_byte (operand[0], operand[1], operand[2]); break;
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case 0x23: store_property (operand[0], operand[1], operand[2]); break;
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case 0x24: read_line (count, operand); break;
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case 0x25: print_character (operand[0]); break;
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case 0x26: print_number (operand[0]); break;
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case 0x27: ziprandom (operand[0]); break;
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case 0x28: push_var (operand[0]); break;
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case 0x29: pop_var (operand[0]); break;
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case 0x2a: set_status_size (operand[0]); break;
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case 0x2b: select_window (operand[0]); break;
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case 0x2c: call (count, operand, FUNCTION); break;
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case 0x2d: erase_window (operand[0]); break;
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case 0x2e: erase_line (operand[0]); break;
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case 0x2f: set_cursor_position (operand[0], operand[1]); break;
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case 0x31: set_video_attribute (operand[0]); break;
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case 0x32: set_format_mode (operand[0]); break;
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case 0x33: set_print_modes (operand[0], operand[1]); break;
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case 0x34: open_playback (operand[0]); break;
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case 0x35: sound (count, operand); break;
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case 0x36: read_character (count, operand); break;
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case 0x37: scan_data (count, operand); break;
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case 0x38: not (operand[0]); break;
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case 0x39: call (count, operand, PROCEDURE); break;
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case 0x3a: call (count, operand, PROCEDURE); break;
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case 0x3b: tokenise (count, operand); break;
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case 0x3c: encode (operand[0], operand[1], operand[2], operand[3]); break;
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case 0x3d: move_data (operand[0], operand[1], operand[2]); break;
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case 0x3e: print_window (count, operand); break;
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case 0x3f: check_argument (operand[0]); break;
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default: fatal ("Illegal operation");
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}
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} else {
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/* Single operand class, load operand and execute instruction */
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if (opcode < 0xb0) {
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operand[0] = load_operand ((opcode >> 4) & 0x03);
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switch ((char) opcode & 0x0f) {
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case 0x00: compare_zero (operand[0]); break;
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case 0x01: load_next_object (operand[0]); break;
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case 0x02: load_child_object (operand[0]); break;
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case 0x03: load_parent_object (operand[0]); break;
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case 0x04: load_property_length (operand[0]); break;
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case 0x05: increment (operand[0]); break;
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case 0x06: decrement (operand[0]); break;
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case 0x07: print_offset (operand[0]); break;
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case 0x08: call (1, operand, FUNCTION); break;
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case 0x09: remove_object (operand[0]); break;
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case 0x0a: print_object (operand[0]); break;
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case 0x0b: ret (operand[0]); break;
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case 0x0c: jump (operand[0]); break;
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case 0x0d: print_address (operand[0]); break;
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case 0x0e: load (operand[0]); break;
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case 0x0f:
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if (h_type > V4)
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call (1, operand, PROCEDURE);
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else
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not (operand[0]);
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break;
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}
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} else {
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/* Zero operand class, execute instruction */
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switch ((char) opcode & 0x0f) {
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case 0x00: ret (TRUE); break;
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case 0x01: ret (FALSE); break;
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case 0x02: print_literal (); break;
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case 0x03: println_return (); break;
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case 0x05: save (count, operand); break;
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case 0x06: restore (count, operand); break;
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case 0x07: restart (); break;
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case 0x08: ret (stack[sp++]); break;
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case 0x09: get_fp (); break;
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case 0x0a: halt = TRUE; break;
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case 0x0b: new_line (); break;
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case 0x0c: display_status_line (); break;
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case 0x0d: verify (); break;
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case 0x0f: conditional_jump (TRUE); break;
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default: fatal ("Illegal operation");
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}
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}
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}
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}
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return (interpreter_status);
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}/* interpret */
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