2 ;;; An implementation of the Memory Array Redcode Simulator (MARS)
9 (chicken process-context)
16 (define (make-instr opcode modifier A-mode A-num B-mode B-num)
20 (('modifier) modifier)
25 (('make-copy) (make-instr opcode modifier A-mode A-num B-mode B-num))
26 (('set! 'opcode x) (set! opcode x))
27 (('set! 'modifier x) (set! modifier x))
28 (('set! 'A-mode x) (set! A-mode x))
29 (('set! 'A-num x) (set! A-num x))
30 (('set! 'B-mode x) (set! B-mode x))
31 (('set! 'B-num x) (set! B-num x))
33 (set! opcode (other 'opcode))
34 (set! modifier (other 'modifier))
35 (set! A-mode (other 'A-mode))
36 (set! A-num (other 'A-num))
37 (set! B-mode (other 'B-mode))
38 (set! B-num (other 'B-num)))
42 " " (mode->string A-mode) A-num
43 " " (mode->string B-mode) B-num))
45 (error "Invalid instr arguments" args)))))
47 (define (mode->string mode)
53 ((pre-indirect-A) "{")
54 ((pre-indirect-B) "<")
55 ((post-indirect-A) "}")
56 ((post-indirect-B) ">")
58 (error "Unknown mode."))))
60 (define initial-instruction
61 (make-instr 'DAT 'F 'immediate 0 'immediate 0))
64 ;;; Memory setup and addressing
67 (define (make-core core-size initial-instr)
68 (let ((core-vec (make-vector core-size '()))
69 (names-vec (make-vector core-size '())))
72 (norm-addr (+ i core-size))
73 (modulo i core-size)))
74 (define (norm-ref v i)
75 (vector-ref v (norm-addr i)))
76 (define (norm-set! v i x)
77 (vector-set! v (norm-addr i)
82 (unless (>= i core-size)
83 (vector-set! core-vec i (initial-instr 'make-copy))
88 ((norm-ref core-vec i) 'set-from! (norm-ref core-vec j))
89 (norm-set! names-vec i n))
90 ((i 'set-from-instr! instr n)
91 ((norm-ref core-vec i) 'set-from! instr)
92 (norm-set! names-vec i n))
94 ((norm-ref core-vec i) 'set! v x)
95 (norm-set! names-vec i n))
96 ((i 'name) (norm-ref names-vec i))
97 (((? integer? i) v) ((norm-ref core-vec i) v))
98 (('->addr (? integer? i)) (norm-addr i))
101 (unless (>= i core-size)
102 (print* i ":\t" ((vector-ref core-vec i) '->string))
103 (let ((n (vector-ref names-vec i)))
108 (('size) core-size)))))
111 ;;; Programmes and task queues
114 (define (make-prog name instrs offset)
115 (list name instrs offset))
117 (define (prog-name prog) (list-ref prog 0))
118 (define (prog-instrs prog) (list-ref prog 1))
119 (define (prog-offset prog) (list-ref prog 2))
121 (define (install-prog core prog addr)
122 (let loop ((ptr addr)
123 (instrs (prog-instrs prog)))
124 (unless (null? instrs)
125 (core ptr 'set-from-instr! (car instrs) (prog-name prog))
126 (loop (core '->addr (+ ptr 1)) (cdr instrs))))
127 (make-queue (prog-name prog)
128 (core '->addr (+ addr (prog-offset prog)))))
130 (define (can-install-prog? core prog-len addr)
131 (let loop ((ptr addr)
132 (remaining prog-len))
135 (if (null? (core ptr 'name))
136 (loop (core '->addr (+ ptr 1))
140 (define (install-progs core progs)
141 (let loop ((queues '())
143 (if (null? progs-left)
145 (let ((addr (pseudo-random-integer (core 'size)))
146 (prog (car progs-left)))
147 (if (can-install-prog? core (length (prog-instrs prog)) addr)
148 (loop (cons (install-prog core prog addr) queues)
150 (loop queues progs-left))))))
152 (define (make-queue name ptr)
155 (define (queue-owner queue) (car queue))
156 (define (queue-ptrs queue) (cdr queue))
158 (define (queue-set-ptrs! queue ptrs)
159 (set-cdr! queue ptrs))
162 ;;; Executive function
165 (define (run core queues steps-left)
167 ((<= steps-left 0) queues) ;Tie between remaining players
168 ;; ((<= (length queues) 1) queues) ;There's only one player left who thus wins
170 (let* ((queue (car queues))
171 (remaining-queues (cdr queues))
172 (ptrs (queue-ptrs queue))
173 (new-ptrs (execute-instr core (car ptrs) (queue-owner queue))))
175 (run remaining-queues (- steps-left 1))
177 (queue-set-ptrs! queue (append (cdr ptrs) new-ptrs))
178 (run core (append remaining-queues (list queue)) (- steps-left 1))))))))
180 (define (execute-instr core ptr name)
181 (let* ((A-ptr (eval-operand core (core ptr 'A-mode) (core ptr 'A-num) ptr name))
182 (B-ptr (eval-operand core (core ptr 'B-mode) (core ptr 'B-num) ptr name))
183 (modifier (core ptr 'modifier)))
184 (case (core ptr 'opcode)
186 '()) ;Game over, man, game over!
188 (if (eq? modifier 'I)
189 (core B-ptr 'set-from! A-ptr name)
190 (combine-and-store core A-ptr B-ptr modifier name (lambda (x y) y)))
191 (list (core '->addr (+ ptr 1))))
193 (combine-and-store core A-ptr B-ptr modifier name +)
194 (list (core '->addr (+ ptr 1))))
196 (combine-and-store core A-ptr B-ptr modifier name -)
197 (list (core '->addr (+ ptr 1))))
199 (combine-and-store core A-ptr B-ptr modifier name *)
200 (list (core '->addr (+ ptr 1))))
204 (combine-and-store core A-ptr B-ptr modifier name quotient)
206 (list (core '->addr (+ ptr 1))))
207 ((exn arithmetic) '())))
211 (combine-and-store core A-ptr B-ptr modifier name modulo)
212 (list (core '->addr (+ ptr 1))))
213 ((exn arithmetic) '())))
215 (list (core '->addr (+ ptr (core A-ptr 'A-num)))))
217 (list (core '->addr (+ ptr (if (instr-zero? B-ptr modifier #f name)
221 (list (core '->addr (+ ptr (if (not (instr-zero? B-ptr modifier #f name))
225 (list (core '->addr (+ ptr (if (not (instr-zero? B-ptr modifier #t name))
229 (list (core '->addr (+ ptr (if (compare-instrs core A-ptr B-ptr modifier =) 2 1)))))
231 (list (core '->addr (+ ptr (if (compare-instrs core A-ptr B-ptr modifier =) 1 2)))))
233 (list (core '->addr (+ ptr (if (compare-instrs core A-ptr B-ptr modifier <) 2 1)))))
235 (list (core '->addr (+ ptr 1) (core '->addr (+ ptr (core A-ptr 'A-num))))))
237 (list (core '->addr (+ ptr 1))))
239 (error "Unrecognised opcode" (instr 'opcode))))))
241 (define (compare-instrs core A-ptr B-ptr modifier test)
243 ((A) (test (core A-ptr 'A-num) (core B-ptr 'A-num)))
244 ((B) (test (core A-ptr 'B-num) (core B-ptr 'B-num)))
245 ((AB) (test (core A-ptr 'A-num) (core B-ptr 'B-num)))
246 ((BA) (test (core A-ptr 'B-num) (core B-ptr 'A-num)))
248 (test (core A-ptr 'A-num) (core B-ptr 'A-num))
249 (test (core A-ptr 'B-num) (core B-ptr 'B-num))))
251 (test (core A-ptr 'A-num) (core B-ptr 'B-num))
252 (test (core A-ptr 'B-num) (core B-ptr 'A-num))))
256 (eq? (core A-ptr 'opcode) (core B-ptr 'opcode))
257 (eq? (core A-ptr 'modifier) (core B-ptr 'modifier))
258 (eq? (core A-ptr 'A-mode) (core B-ptr 'B-mode))
259 (eq? (core A-ptr 'B-mode) (core B-ptr 'A-mode)))
261 (test (core A-ptr 'A-num) (core B-ptr 'B-num))
262 (test (core A-ptr 'B-num) (core B-ptr 'A-num))))))
264 (define (instr-zero? core ptr modifier decrement name)
267 (if decrement (core ptr 'set! 'A-num (- (core ptr 'A-num) 1) name))
268 (= 0 (core ptr 'A-num)))
270 (if decrement (core ptr 'set! 'B-num (- (core ptr 'B-num) 1) name))
271 (= 0 (core ptr 'B-num)))
275 (core ptr 'set! 'A-num (- (core ptr 'A-num) 1) name)
276 (core ptr 'set! 'B-num (- (core ptr 'B-num) 1) name)))
277 (and (= 0 (core ptr 'A-num))
278 (= 0 (core ptr 'B-num))))))
280 (define (combine-and-store core A-ptr B-ptr modifier name f)
282 ((A) (core B-ptr 'set! 'A-num
283 (f (core B-ptr 'A-num) (core A-ptr 'A-num)) name))
284 ((B) (core B-ptr 'set! 'B-num
285 (f (core B-ptr 'B-num) (core A-ptr 'B-num)) name))
286 ((AB) (core B-ptr 'set! 'B-num
287 (f (core B-ptr 'B-num) (core A-ptr 'A-num)) name))
288 ((BA) (core B-ptr 'set! 'A-num
289 (f (core B-ptr 'A-num) (core A-ptr 'B-num)) name))
290 ((F I) (core B-ptr 'set! 'A-num
291 (f (core B-ptr 'A-num) (core A-ptr 'A-num)) name)
292 (core B-ptr 'set! 'B-num
293 (f (core B-ptr 'B-num) (core A-ptr 'B-num)) name))
294 ((X) (core B-ptr 'set! 'A-num
295 (f (core B-ptr 'A-num) (core A-ptr 'B-num)) name)
296 (core B-ptr 'set! 'B-num
297 (f (core B-ptr 'B-num) (core A-ptr 'A-num)) name))))
299 (define (eval-operand core mode num ptr name)
304 ((indirect-A) (+ num (core (+ ptr num) 'A-num)))
305 ((indirect-B) (+ num (core (+ ptr num) 'B-num)))
307 (let ((aux-ptr (+ ptr num)))
308 (core aux-ptr 'set! 'A-num (- (core aux-ptr 'A-num) 1) name)
309 (+ num (core aux-ptr 'A-num))))
311 (let ((aux-ptr (+ ptr num)))
312 (core aux-ptr 'set! 'B-num (- (core aux-ptr 'B-num) 1) name)
313 (+ num (core aux-ptr 'B-num))))
315 (let* ((aux-ptr (+ ptr num))
316 (old-A-num (core aux-ptr 'A-num)))
317 (core aux-ptr 'set! 'A-num (+ (core aux-ptr 'A-num) 1) name)
320 (let* ((aux-ptr (+ ptr num))
321 (old-B-num (core aux-ptr 'B-num)))
322 (core aux-ptr 'set! 'B-num (+ (core aux-ptr 'B-num) 1) name)
325 (error "Unrecognized mode" mode))))))
332 (define addressing-test
334 (make-instr 'DAT 'F 'immediate 42 'immediate 53)
335 (make-instr 'DAT 'F 'immediate 123 'immediate 256)
336 (make-instr 'MOV 'A 'indirect-B 4 'direct 7)
337 (make-instr 'NOP 'I 'immediate 0 'immediate 0)
338 (make-instr 'NOP 'I 'immediate 0 'immediate 0)
339 (make-instr 'NOP 'I 'immediate 0 'immediate 0)
340 (make-instr 'DAT 'F 'immediate -5 'immediate -6)) 2))
343 (make-prog 'imp (list (make-instr 'MOV 'I 'direct 0 'direct 1)) 0))
346 (make-prog 'dwarf (list
347 (make-instr 'DAT 'F 'immediate 0 'immediate -1)
348 (make-instr 'ADD 'AB 'immediate 5 'direct -1)
349 (make-instr 'MOV 'I 'direct -2 'indirect-B -2)
350 (make-instr 'JMP 'I 'immediate -2 'immediate 0)) 1))
352 (define core (make-core 20 (make-instr 'DAT 'F 'immediate 0 'immediate 0)))
353 (define queues (install-progs core (list dwarf imp)))