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Added bitwise-bit-set?

This commit is contained in:
Abdulaziz Ghuloum 2007-11-22 17:42:37 -05:00
parent 42daf68195
commit 57171a243a
4 changed files with 57 additions and 16 deletions
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51
scheme/ikarus.numerics.ss
View File

@ -2402,8 +2402,8 @@
(define (shift-right-arithmetic n m who)
(unless (fixnum? m)
(error who "shift amount is not a fixnum"))
(cond
[(fixnum? m)
(cond
[(fixnum? n)
(cond
@ -2415,7 +2415,13 @@
(foreign-call "ikrt_bignum_shift_right" n m)]
[($fx= m 0) n]
[else (error who "offset must be non-negative" m)])]
[else (error who "not an exact integer" n)]))
[else (error who "not an exact integer" n)])]
[(bignum? m)
(cond
[(fixnum? n) (if ($fx>= n 0) 0 -1)]
[(bignum? n) (if ($bignum-positive? n) 0 -1)]
[else (error who "not an exact integer" n)])]
[else (error who "not an exact integer offset" m)]))
(define (sra n m)
(shift-right-arithmetic n m 'sra))
@ -2890,7 +2896,7 @@
(error 'fldiv0-and-mod0 "not a flonum" n))))
(library (ikarus bitwise misc)
(export fxfirst-bit-set bitwise-first-bit-set
(export fxfirst-bit-set bitwise-bit-set? bitwise-first-bit-set
fxbit-count bitwise-bit-count
fxlength
fxbit-set?
@ -2902,7 +2908,7 @@
(ikarus system $bignums)
(ikarus system $flonums)
(except (ikarus)
fxfirst-bit-set bitwise-first-bit-set
fxfirst-bit-set bitwise-bit-set? bitwise-first-bit-set
fxbit-count bitwise-bit-count
fxlength
fxbit-set?
@ -3022,6 +3028,41 @@
(error who "index is not a fixnum" i))
(error who "not a fixnum" x)))
(define (bitwise-bit-set? x i)
(define who 'bitwise-bit-set?)
(cond
[(fixnum? i)
(when ($fx< i 0)
(error who "index must be non-negative" i))
(cond
[(fixnum? x)
(if ($fx< i (fixnum-width))
($fx= ($fxlogand ($fxsra x i) 1) 1)
($fx< x 0))]
[(bignum? x)
(let ([n ($bignum-size x)])
(let ([m ($fx* n 8)])
(if ($fx< m i)
(not ($bignum-positive? x))
(if ($bignum-positive? x)
(let ([b ($bignum-byte-ref x ($fxsra i 3))])
($fx= ($fxlogand ($fxsra b ($fxlogand i 7)) 1) 1))
(= 1 (bitwise-and
(bitwise-arithmetic-shift-right x i)
1))))))]
[else (error who "not an exact integer" x)])]
[(bignum? i)
(unless ($bignum-positive? i)
(error who "index must be non-negative"))
(cond
[(fixnum? x) ($fx< x 0)]
[(bignum? x)
(= 1 (bitwise-and (bitwise-arithmetic-shift-right x i) 1))]
[else (error who "not an exact integer" x)])]
[else
(error who "index is not an exact integer" i)]))
(define (fxcopy-bit x i b)
(define who 'fxcopy-bit)
(if (fixnum? x)

2
scheme/last-revision
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@ -1 +1 @@
1116
1117

2
scheme/makefile.ss
View File

@ -768,7 +768,7 @@
[bitwise-xor r bw]
[bitwise-bit-count i r bw]
[bitwise-bit-field r bw]
[bitwise-bit-set? r bw]
[bitwise-bit-set? i r bw]
[bitwise-copy-bit r bw]
[bitwise-copy-bit-field r bw]
[bitwise-first-bit-set i r bw]

2
scheme/todo-r6rs.ss
View File

@ -260,7 +260,7 @@
[bitwise-xor S bw]
[bitwise-bit-count C bw]
[bitwise-bit-field S bw]
[bitwise-bit-set? S bw]
[bitwise-bit-set? C bw]
[bitwise-copy-bit S bw]
[bitwise-copy-bit-field S bw]
[bitwise-first-bit-set C bw]