--- /dev/null
+#| -*-Scheme-*-
+
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/rtlbase/regset.scm,v 1.1 1987/06/26 02:21:45 cph Exp $
+
+Copyright (c) 1987 Massachusetts Institute of Technology
+
+This material was developed by the Scheme project at the Massachusetts
+Institute of Technology, Department of Electrical Engineering and
+Computer Science. Permission to copy this software, to redistribute
+it, and to use it for any purpose is granted, subject to the following
+restrictions and understandings.
+
+1. Any copy made of this software must include this copyright notice
+in full.
+
+2. Users of this software agree to make their best efforts (a) to
+return to the MIT Scheme project any improvements or extensions that
+they make, so that these may be included in future releases; and (b)
+to inform MIT of noteworthy uses of this software.
+
+3. All materials developed as a consequence of the use of this
+software shall duly acknowledge such use, in accordance with the usual
+standards of acknowledging credit in academic research.
+
+4. MIT has made no warrantee or representation that the operation of
+this software will be error-free, and MIT is under no obligation to
+provide any services, by way of maintenance, update, or otherwise.
+
+5. In conjunction with products arising from the use of this material,
+there shall be no use of the name of the Massachusetts Institute of
+Technology nor of any adaptation thereof in any advertising,
+promotional, or sales literature without prior written consent from
+MIT in each case. |#
+
+;;;; RTL Register Sets
+
+(declare (usual-integrations))
+\f
+(define-integrable (make-regset n-registers)
+ (list 'REGSET))
+
+(define-integrable (regset-allocate n-registers)
+ (list 'REGSET))
+
+(define-integrable (for-each-regset-member regset procedure)
+ (for-each procedure (cdr regset)))
+
+(define-integrable (regset->list regset)
+ (list-copy (cdr regset)))
+
+(define-integrable regset-copy list-copy)
+
+(define-integrable (regset-clear! regset)
+ (set-cdr! regset '()))
+
+(define-integrable (regset-disjoint? x y)
+ (eq-set-disjoint? (cdr x) (cdr y)))
+
+(define (regset-adjoin! regset register)
+ (if (not (memq register (cdr regset)))
+ (set-cdr! regset (cons register (cdr regset)))))
+
+(define (regset-delete! regset register)
+ (set-cdr! regset (delq register (cdr regset))))
+
+(define-integrable (regset-member? regset register)
+ (memq register (cdr regset)))
+
+(define-integrable (regset=? x y)
+ (eq-set-same-set? (cdr x) (cdr y)))
+
+(define-integrable (regset-null? regset)
+ (null? (cdr regset)))
+
+(define-integrable (regset-copy! destination source)
+ (set-cdr! destination (cdr source)))
+
+(define (regset-union! destination source)
+ (set-cdr! destination (eq-set-union (cdr source) (cdr destination))))
+
+(define (regset-difference! destination source)
+ (set-cdr! destination (eq-set-difference (cdr destination) (cdr source))))
+
+(define (regset-intersection! destination source)
+ (set-cdr! destination (eq-set-intersection (cdr source) (cdr destination))))
+
+(define-integrable (regset-union x y)
+ (cons 'REGSET (eq-set-union (cdr x) (cdr y))))
+
+(define-integrable (regset-difference x y)
+ (cons 'REGSET (eq-set-difference (cdr x) (cdr y))))
+
+(define-integrable (regset-intersection x y)
+ (cons 'REGSET (eq-set-intersection (cdr x) (cdr y))))
+\f
+#| Alternate representation.
+
+(define-integrable (make-regset n-registers)
+ (make-bit-string n-registers false))
+
+(define (for-each-regset-member regset procedure)
+ (let ((end (bit-string-length regset)))
+ (define (loop register)
+ (if register
+ (begin (procedure register)
+ (loop (bit-substring-find-next-set-bit regset
+ (1+ register)
+ end)))))
+ (loop (bit-substring-find-next-set-bit regset 0 end))))
+
+(define (regset->list regset)
+ (let ((end (bit-string-length regset)))
+ (define (loop register)
+ (if register
+ (cons register
+ (loop (bit-substring-find-next-set-bit regset
+ (1+ register)
+ end)))
+ '()))
+ (loop (bit-substring-find-next-set-bit regset 0 end))))
+
+(define (regset-copy regset)
+ (let ((result (bit-string-allocate (bit-string-length regset))))
+ (regset-copy! result regset)
+ result))
+
+(define-integrable (regset-clear! regset)
+ (bit-string-fill! regset false))
+
+(define-integrable (regset-disjoint? x y)
+ (regset-null? (regset-intersection x y)))
+
+(define-integrable regset-allocate bit-string-allocate)
+(define-integrable regset-adjoin! bit-string-set!)
+(define-integrable regset-delete! bit-string-clear!)
+(define-integrable regset-member? bit-string-ref)
+(define-integrable regset=? bit-string=?)
+(define-integrable regset-null? bit-string-zero?)
+(define-integrable regset-copy! bit-string-move!)
+(define-integrable regset-union! bit-string-or!)
+(define-integrable regset-difference! bit-string-andc!)
+(define-integrable regset-intersection! bit-string-and!)
+
+(package (regset-union regset-difference regset-intersection)
+ (let ((wrap-operator
+ (lambda (operator)
+ (lambda (x y)
+ (let ((result (regset-copy x)))
+ (operator result y)
+ result)))))
+ (define-export regset-union (wrap-operator regset-union!))
+ (define-export regset-difference (wrap-operator regset-difference!))
+ (define-export regset-intersection (wrap-operator regset-intersection!))))
+
+|#
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