Bitwise arithmetic procedures

This proposal is based mainly on SRFI 33, with some changes and additions from Olin's late revisions to SRFI 33 (which were never consummated) and from SRFI 60. Until a full spec is written, see the final column of the table in BitwiseComparison.

Comparison of proposals

The following table compares the names of the bitwise (aka logical) functions of Common Lisp, SRFI 33, SRFI 60, R6RS, and BitwiseCowan. SRFI 33 was never finalized, but is a comprehensive proposal. SRFI 60 (based on SLIB) is smaller but has a few procedures of its own; some of its procedures have both native (often CL) and SRFI 33 names. R6RS is a subset of SRFI 60, but all procedure names begin with a bitwise- prefix.

Function	CL	SRFI 33	SRFI 33 late revs	SRFI 60	R6RS	Cowan
Bitwise NOT	lognot	bitwise-not	bitwise-not	lognot, bitwise-not	bitwise-not	bitwise-not
Bitwise AND (variadic)	logand	bitwise-and	bitwise-and	logand, bitwise-and	bitwise-and	bitwise-and
Bitwise IOR (variadic)	logior	bitwise-ior	bitwise-ior	logior, bitwise-ior	bitwise-ior	bitwise-ior
Bitwise XOR (variadic)	logxor	bitwise-xor	bitwise-xor	logxor, bitwise-xor	bitwise-xor	bitwise-xor
Bitwise EQV (variadic)	logeqv	bitwise-eqv	bitwise-eqv	---	---	bitwise-eqv
Bitwise NAND (variadic*)	lognand	bitwise-nand	bitwise-nand	---	---	bitwise-nand
Bitwise NOR (variadic*)	lognor	bitwise-nor	bitwise-nor	---	---	bitwise-nor
Bitwise AND with NOT of first arg	logandc1	bitwise-andc1	bitwise-andc1	---	---	bitwise-andc1
Bitwise AND with NOT of second arg	logandc2	bitwise-andc2	bitwise-andc2	---	---	bitwise-andc2
Bitwise OR with NOT of first arg	logorc1	bitwise-orc1	bitwise-orc1	---	---	bitwise-orc1
Bitwise OR with NOT of second arg	logorc2	bitwise-orc2	bitwise-orc2	---	---	bitwise-orc2
Arithmetic shift	ash	arithmetic-shift	arithmetic-shift	ash, arithmetic-shift	bitwise-arithmetic-shift	arithmetic-shift
Population count	logcount	bit-count	bit-count	logcount, bit-count	bitwise-bit-count	bit-count
Integer length	integer-length	integer-length	integer-length	integer-length	bitwise-integer-length	integer-length
Mask selects source of bits	---	bitwise-merge	bitwise-merge	bitwise-if, bitwise-merge	bitwise-if	bitwise-if
Test single bit	logbitp	bit-set?	bit-set?	logbit?, bit-set?	bitwise-bit-set?	bit-set?
See if any mask bits set	logtest	any-bits-set?	any-bit-set?	logtest, any-bit-set?	---	any-bit-set
See if all mask bits set	---	all-bits-set?	every-bit-set?	---	---	every-bit-set?
Replace single bit	---	---	copy-bit	bitwise-copy-bit	---	copy-bit
Find first bit set	---	---	first-set-bit	log2-binary-factors, first-set-bit	---	first-set-bit
Extract bit field�	ldb	extract-bit-field	extract-bit-field	bit-field	bitwise-bit-field	bit-field
Test bit field (any)�	ldb-test	test-bit-field?	bit-field-any?	---	---	bit-field-any?
Test bit field (every)�	---	---	bit-field-every?	---	---	bit-field-every?
Clear bit field�	mask-field	clear-bit-field	bit-field-clear	---	---	bit-field-clear
Replace bit field�	dpb	replace-bit-field	bit-field-replace	copy-bit-field	bitwise-copy-bit-field	copy-bit-field
Replace corresponding bit field�	deposit-field	deposit-field	copy-bit-field	---	---	bit-field-copy-same
Rotate bit field�	---	---	---	rotate-bit-field	bitwise-rotate-bit-field	bit-field-rotate
Reverse bit field�	---	---	---	reverse-bit-field	bitwise-reverse-bit-field	bit-field-reverse
Integer to boolean list	---	---	---	integer->list	---	integer->list
Boolean list to integer	---	---	---	list->integer	---	list->integer
Booleans to integer	---	---	---	booleans->integer	---	bits

*These procedures were made dyadic in late revisions to SRFI 33 that were never consummated. BitwiseCowan adopts this change.

†These procedures take a byte-spec object in Common Lisp (which encodes size and position), leading size and position arguments in SRFI-33, and trailing start and end arguments in SRFI-60, R6RS, and BitwiseCowan. Consequently, they are not quite compatible across specifications. Note that copy-bit-field corresponds to different procedures in SRFI 33 and SRFI 60.

Rationale for name changes in BitwiseCowan

BitwiseCowan retains SRFI 33 names for procedures adapted from SRFI 33, with these exceptions:

The name bitwise-merge is replaced by bitwise-if, the name used in SRFI 60 and R6RS.

The name extract-bit-field (bit-field-extract in Olin's revisions) is replaced by bit-field, the name used in SRFI 60 and R6RS.

The names any-bits-set? and all-bits-set? are replaced by any-bit-set? and every-bit-set?, in accordance with Olin's revisions.

Because copy-bit-field means different things in SRFI 33 and SRFI 60, I have replaced SRFI 33's names replace-bit-field and copy-bit-field (bit-field-replace and bit-field-copy in Olin's revisions) with bit-field-copy and bit-field-copy-same.

The procedures that do not exist in SRFI 33 have their SRFI 60 names, with these exceptions.

The procedure booleans->integer is a convenient way to specify a bitwise integer in the absence of datum syntax: it accepts an arbitrary number of boolean arguments and returns a non-negative integer. So I gave it the short name bits, roughly analogous to list, string, and vector.

The names rotate-bit-field and reverse-bit-field are replaced by bit-field-rotate and bit-field-reverse, in parallel with Olin's revisions.

Bitwise­Cowan

Bitwise arithmetic procedures

Comparison of proposals

Rationale for name changes in BitwiseCowan

BitwiseCowan