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 '())))
71 (unless (>= i core-size)
72 (vector-set! core-vec i (initial-instr 'make-copy))
77 ((vector-ref core-vec i) 'set-from! (vector-ref core-vec j))
78 (vector-set! names-vec i n))
79 ((i 'set-from-instr! instr n)
80 ((vector-ref core-vec i) 'set-from! instr)
81 (vector-set! names-vec i n))
83 ((vector-ref core-vec i) 'set! v x)
84 (vector-set! names-vec i n))
85 ((i 'name) (vector-ref names-vec i))
86 ((i v) ((vector-ref core-vec i) v))
89 (unless (>= i core-size)
90 (print* i ":\t" ((vector-ref core-vec i) '->string))
91 (let ((n (vector-ref names-vec i)))
97 (define (addr+ . args)
99 (modulo (+ a b core-size) core-size))
102 ;;; Programmes and task queues
105 (define (make-prog name instrs offset)
106 (list name instrs offset))
108 (define (prog-name prog) (list-ref prog 0))
109 (define (prog-instrs prog) (list-ref prog 1))
110 (define (prog-offset prog) (list-ref prog 2))
112 (define (install-prog core prog addr)
113 (let loop ((ptr addr)
114 (instrs (prog-instrs prog)))
115 (unless (null? instrs)
116 (core ptr 'set-from-instr! (car instrs) (prog-name prog))
117 (loop (addr+ ptr 1) (cdr instrs))))
118 (make-queue (prog-name prog)
119 (addr+ addr (prog-offset prog))))
121 (define (can-install-prog? core prog-len addr)
122 (let loop ((ptr addr)
123 (remaining prog-len))
126 (if (null? (core ptr 'name))
131 (define (install-progs core progs)
132 (let loop ((queues '())
134 (if (null? progs-left)
136 (let ((addr (pseudo-random-integer core-size))
137 (prog (car progs-left)))
138 (if (can-install-prog? core (length (prog-instrs prog)) addr)
139 (loop (cons (install-prog core prog addr) queues)
141 (loop queues progs-left))))))
143 (define (make-queue name ptr)
146 (define (queue-owner queue) (car queue))
147 (define (queue-ptrs queue) (cdr queue))
149 (define (queue-set-ptrs! queue ptrs)
150 (set-cdr! queue ptrs))
153 ;;; Executive function
156 (define (run core queues steps-left)
158 ((<= steps-left 0) queues) ;Tie between remaining players
159 ;; ((<= (length queues) 1) queues) ;There's only one player left who thus wins
161 (let* ((queue (car queues))
162 (remaining-queues (cdr queues))
163 (ptrs (queue-ptrs queue))
164 (new-ptrs (execute-instr core (car ptrs) (queue-owner queue))))
166 (run remaining-queues (- steps-left 1))
168 (queue-set-ptrs! queue (append (cdr ptrs) new-ptrs))
169 (run core (append remaining-queues (list queue)) (- steps-left 1))))))))
171 (define (execute-instr core ptr name)
172 (let* ((A-ptr (eval-operand core (core ptr 'A-mode) (core ptr 'A-num) ptr name))
173 (B-ptr (eval-operand core (core ptr 'B-mode) (core ptr 'B-num) ptr name))
174 (modifier (core ptr 'modifier)))
175 (case (core ptr 'opcode)
177 '()) ;Game over, man, game over!
179 (if (eq? modifier 'I)
180 (core B-ptr 'set-from! A-ptr name)
181 (combine-and-store core A-ptr B-ptr modifier name (lambda (x y) y)))
182 (list (addr+ ptr 1)))
184 (combine-and-store core A-ptr B-ptr modifier name addr+)
185 (list (addr+ ptr 1)))
187 (combine-and-store core A-ptr B-ptr modifier name
188 (lambda (x y) (addr+ x (- y))))
189 (list (addr+ ptr 1)))
191 (combine-and-store core A-ptr B-ptr modifier name
192 (lambda (x y) (modulo (* (addr+ x core-size)
195 (list (addr+ ptr 1)))
199 (combine-and-store core A-ptr B-ptr modifier name
200 (lambda (x y) (quotient (addr x core-size)
201 (addr y core-size))))
202 (list (addr+ ptr 1)))
203 ((exn arithmetic) '())))
207 (combine-and-store core A-ptr B-ptr modifier name
208 (lambda (x y) (remainder (addr x core-size)
209 (addr y core-size))))
210 (list (addr+ ptr 1)))
211 ((exn arithmetic) '())))
213 (list (addr+ ptr (core A-ptr 'A-num))))
215 (list (addr+ ptr (if (instr-zero? B-ptr modifier #f name)
219 (list (addr+ ptr (if (not (instr-zero? B-ptr modifier #f name))
223 (list (addr+ ptr (if (not (instr-zero? B-ptr modifier #t name))
227 (list (addr+ ptr (if (compare-instrs core A-ptr B-ptr modifier =) 2 1))))
229 (list (addr+ ptr (if (compare-instrs core A-ptr B-ptr modifier =) 1 2))))
231 (list (addr+ ptr (if (compare-instrs core A-ptr B-ptr modifier <) 2 1))))
233 (list (addr+ ptr 1) (addr+ ptr (core A-ptr 'A-num))))
235 (list (addr+ ptr 1)))
237 (error "Unrecognised opcode" (instr 'opcode))))))
239 (define (compare-instrs core A-ptr B-ptr modifier test)
241 ((A) (test (core A-ptr 'A-num) (core B-ptr 'A-num)))
242 ((B) (test (core A-ptr 'B-num) (core B-ptr 'B-num)))
243 ((AB) (test (core A-ptr 'A-num) (core B-ptr 'B-num)))
244 ((BA) (test (core A-ptr 'B-num) (core B-ptr 'A-num)))
246 (test (core A-ptr 'A-num) (core B-ptr 'A-num))
247 (test (core A-ptr 'B-num) (core B-ptr 'B-num))))
249 (test (core A-ptr 'A-num) (core B-ptr 'B-num))
250 (test (core A-ptr 'B-num) (core B-ptr 'A-num))))
254 (eq? (core A-ptr 'opcode) (core B-ptr 'opcode))
255 (eq? (core A-ptr 'modifier) (core B-ptr 'modifier))
256 (eq? (core A-ptr 'A-mode) (core B-ptr 'B-mode))
257 (eq? (core A-ptr 'B-mode) (core B-ptr 'A-mode)))
259 (test (core A-ptr 'A-num) (core B-ptr 'B-num))
260 (test (core A-ptr 'B-num) (core B-ptr 'A-num))))))
262 (define (instr-zero? core ptr modifier decrement name)
265 (if decrement (core ptr 'set! 'A-num (addr+ (core ptr 'A-num) -1) name))
266 (= 0 (core ptr 'A-num)))
268 (if decrement (core ptr 'set! 'B-num (addr+ (core ptr 'B-num) -1) name))
269 (= 0 (core ptr 'B-num)))
273 (core ptr 'set! 'A-num (addr+ (core ptr 'A-num) -1) name)
274 (core ptr 'set! 'B-num (addr+ (core ptr 'B-num) -1) name)))
275 (and (= 0 (core ptr 'A-num))
276 (= 0 (core ptr 'B-num))))))
278 (define (combine-and-store core A-ptr B-ptr modifier name f)
280 ((A) (core B-ptr 'set! 'A-num
281 (f (core B-ptr 'A-num) (core A-ptr 'A-num)) name))
282 ((B) (core B-ptr 'set! 'B-num
283 (f (core B-ptr 'B-num) (core A-ptr 'B-num)) name))
284 ((AB) (core B-ptr 'set! 'B-num
285 (f (core B-ptr 'B-num) (core A-ptr 'A-num)) name))
286 ((BA) (core B-ptr 'set! 'A-num
287 (f (core B-ptr 'A-num) (core A-ptr 'B-num)) name))
288 ((F I) (core B-ptr 'set! 'A-num
289 (f (core B-ptr 'A-num) (core A-ptr 'A-num)) name)
290 (core B-ptr 'set! 'B-num
291 (f (core B-ptr 'B-num) (core A-ptr 'B-num)) name))
292 ((X) (core B-ptr 'set! 'A-num
293 (f (core B-ptr 'A-num) (core A-ptr 'B-num)) name)
294 (core B-ptr 'set! 'B-num
295 (f (core B-ptr 'B-num) (core A-ptr 'A-num)) name))))
297 (define (eval-operand core mode num ptr name)
302 ((indirect-A) (addr+ num (core (addr+ ptr num) 'A-num)))
303 ((indirect-B) (addr+ num (core (addr+ ptr num) 'B-num)))
305 (let ((aux-ptr (addr+ ptr num)))
306 (core aux-ptr 'set! 'A-num (addr+ -1 (core aux-ptr 'A-num)) name)
307 (addr+ num (core aux-ptr 'A-num))))
309 (let ((aux-ptr (addr+ ptr num)))
310 (core aux-ptr 'set! 'B-num (addr+ -1 (core aux-ptr 'B-num)) name)
311 (addr+ num (core aux-ptr 'B-num))))
313 (let* ((aux-ptr (addr+ ptr num))
314 (old-A-num (core aux-ptr 'A-num)))
315 (core aux-ptr 'set! 'A-num (addr+ 1 (core aux-ptr 'A-num)) name)
316 (addr+ num old-A-num)))
318 (let* ((aux-ptr (addr+ ptr num))
319 (old-B-num (core aux-ptr 'B-num)))
320 (core aux-ptr 'set! 'B-num (addr+ 1 (core aux-ptr 'B-num)) name)
321 (addr+ num old-B-num)))
323 (error "Unrecognized mode" mode)))))
330 (define addressing-test
332 (make-instr 'DAT 'F 'immediate 42 'immediate 53)
333 (make-instr 'DAT 'F 'immediate 123 'immediate 256)
334 (make-instr 'MOV 'A 'indirect-B 4 'direct 7)
335 (make-instr 'NOP 'I 'immediate 0 'immediate 0)
336 (make-instr 'NOP 'I 'immediate 0 'immediate 0)
337 (make-instr 'NOP 'I 'immediate 0 'immediate 0)
338 (make-instr 'DAT 'F 'immediate -5 'immediate -6)) 2))
341 (make-prog 'imp (list (make-instr 'MOV 'I 'direct 0 'direct 1)) 0))
344 (make-prog 'dwarf (list
345 (make-instr 'DAT 'F 'immediate 0 'immediate -1)
346 (make-instr 'ADD 'AB 'immediate 5 'direct -1)
347 (make-instr 'MOV 'I 'direct -2 'indirect-B -2)
348 (make-instr 'JMP 'I 'immediate -2 'immediate 0)) 1))
350 (define core (make-core 20 (make-instr 'DAT 'F 'immediate 0 'immediate 0)))
351 (define queues (install-progs core (list dwarf imp)))