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; Copyright (c) 1993-2008 by Richard Kelsey. See file COPYING.
(define (test x)
(cond ((= x 1)
(goto raise-exception 2))
((= x 2)
(goto raise-exception1 2 0))
((= x 3)
(goto raise-exception 3))
((= x 4)
(goto raise-exception1 4 0))))
(define *code-pointer* 0)
(define *stack* 0)
(define (push x)
(vector-set! *stack* 0 x)
(set! *stack* (- *stack* 4)))
(define (fetch-byte address)
(byte-vector-ref address 0))
(define (current-opcode code-args)
(fetch-byte (- *code-pointer* (+ code-args 1))))
(define (start-exception args)
(push (current-opcode args)))
(define (raise-exception args)
(start-exception args)
(goto raise 0))
(define (raise-exception1 args a1)
(start-exception args)
(push a1)
(goto raise 1))
(define (raise n)
(goto test n))
(define-local-syntax (define-primitive id nargs)
(let ((args (reverse (list-tail '(z y x) (- '3 nargs)))))
`(define (,id . ,args)
(call-primitively ,id . ,args))))
(define-local-syntax (define-effect-primitive id nargs)
(let ((args (reverse (list-tail '(z y x) (- '3 nargs)))))
`(define (,id . ,args)
(call-primitively ,id . ,args)
(call-primitively undefined-value))))
(define-primitive + 2)
(define-primitive - 2)
(define-primitive * 2)
(define-primitive < 2)
(define-primitive = 2)
(define-primitive quotient 2)
(define-primitive remainder 2)
(define (unassigned) (call-primitively undefined-value))
(define (byte-vector-ref vec index)
(call-primitively byte-contents (+ vec index)))
(define (byte-vector-set! vec index value)
(call-primitively byte-set-contents! (+ vec index) value))
(define (vector-set! vec index value)
(call-primitively set-contents! (+ vec (* index 4)) value))
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