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Assembler refactor

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This commit is contained in:
Dane Johnson 2025-06-17 15:03:10 -05:00
parent ce963c498c
commit bfe6db57b6
1 changed files with 29 additions and 27 deletions
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32
scmvm/assembler.scm
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@ -20,32 +20,30 @@
(and (not (label? x))
(not (variable? x))))
(define (find-labels inst-seq n)
(define (label-pass instructions address)
(cond
[(null? inst-seq) '()]
[(label? (car inst-seq))
(acons (car inst-seq) n (find-labels (cdr inst-seq) n))]
[(variable? (car inst-seq))
(acons (cadar inst-seq) n (find-labels (cdr inst-seq) (+ n 4)))]
[(null? instructions) '()]
[(label? (car instructions))
(acons (car instructions) address (label-pass (cdr instructions) address))]
[(variable? (car instructions))
(acons (cadar instructions) address (label-pass (cdr instructions) (+ address 4)))]
[else
(find-labels (cdr inst-seq) (if (eq? (caar inst-seq) 'push) (+ n 5) (+ n 1)))]))
(label-pass (cdr instructions) (if (eq? (caar instructions) 'push)
(+ address 5)
(+ address 1)))]))
(define (write-word word)
(define bv (make-bytevector 4))
(bytevector-s32-native-set! bv 0 word)
(write-bytevector bv))
(define (assemble inst-seq port)
(define labels (find-labels inst-seq 1))
(with-output-to-port port
(lambda ()
(let loop ([seq inst-seq])
(define (assembly-pass seq labels)
(cond
[(null? seq) '()]
[(label? (car seq)) (loop (cdr seq))]
[(label? (car seq)) (assembly-pass (cdr seq) labels)]
[(variable? (car seq))
(write-word (caddar seq))
(loop (cdr seq))]
(assembly-pass (cdr seq) labels)]
[else
(let* [(inst (car seq))
(inst-obj (lookup-instruction (car inst)))]
@ -54,5 +52,9 @@
(if (number? (cadr inst))
(write-word (cadr inst))
(write-word (assq-ref labels (cadr inst)))))
(loop (cdr seq)))]))))
(assembly-pass (cdr seq) labels))]))
(define (assemble instructions port)
(define labels (label-pass instructions 1))
(with-output-to-port port (lambda () (assembly-pass instructions labels)))
labels)