-(eval-when (#-sb-xc :compile-toplevel :load-toplevel :execute)
-
- ;; information about how a slot of a given DSD-RAW-TYPE is to be accessed
- (defstruct raw-slot-data
- ;; the raw slot type, or T for a non-raw slot
- ;;
- ;; (Raw slots are allocated in the raw slots array in a vector which
- ;; the GC doesn't need to scavenge. Non-raw slots are in the
- ;; ordinary place you'd expect, directly indexed off the instance
- ;; pointer.)
- (raw-type (missing-arg) :type (or symbol cons) :read-only t)
- ;; What operator is used (on the raw data vector) to access a slot
- ;; of this type?
- (accessor-name (missing-arg) :type symbol :read-only t)
- ;; How many words are each value of this type? (This is used to
- ;; rescale the offset into the raw data vector.)
- (n-words (missing-arg) :type (and index (integer 1)) :read-only t))
-
- (defvar *raw-slot-data-list*
- (list
- ;; The compiler thinks that the raw data vector is a vector of
- ;; word-sized unsigned bytes, so if the slot we want to access
- ;; actually *is* an unsigned byte, it'll access the slot for us
- ;; even if we don't lie to it at all, just let it use normal AREF.
- (make-raw-slot-data :raw-type 'unsigned-byte
- :accessor-name 'aref
- :n-words 1)
- ;; In the other cases, we lie to the compiler, making it use
- ;; some low-level AREFish access in order to pun the hapless
- ;; bits into some other-than-unsigned-byte meaning.
- ;;
- ;; "A lie can travel halfway round the world while the truth is
- ;; putting on its shoes." -- Mark Twain
- (make-raw-slot-data :raw-type 'single-float
- :accessor-name '%raw-ref-single
- :n-words 1)
- (make-raw-slot-data :raw-type 'double-float
- :accessor-name '%raw-ref-double
- :n-words 2)
- (make-raw-slot-data :raw-type 'complex-single-float
- :accessor-name '%raw-ref-complex-single
- :n-words 2)
- (make-raw-slot-data :raw-type 'complex-double-float
- :accessor-name '%raw-ref-complex-double
- :n-words 4)
- #!+long-float
- (make-raw-slot-data :raw-type long-float
- :accessor-name '%raw-ref-long
- :n-words #!+x86 3 #!+sparc 4)
- #!+long-float
- (make-raw-slot-data :raw-type complex-long-float
- :accessor-name '%raw-ref-complex-long
- :n-words #!+x86 6 #!+sparc 8))))
+;;; Classic comment preserved for entertainment value:
+;;;
+;;; "A lie can travel halfway round the world while the truth is
+;;; putting on its shoes." -- Mark Twain
+
+;; information about how a slot of a given DSD-RAW-TYPE is to be accessed
+(defstruct (raw-slot-data
+ (:copier nil)
+ (:predicate nil))
+ ;; the raw slot type, or T for a non-raw slot
+ ;;
+ ;; (Non-raw slots are in the ordinary place you'd expect, directly
+ ;; indexed off the instance pointer. Raw slots are indexed from the end
+ ;; of the instance and skipped by GC.)
+ (raw-type (missing-arg) :type (or symbol cons) :read-only t)
+ ;; What operator is used to access a slot of this type?
+ (accessor-name (missing-arg) :type symbol :read-only t)
+ (init-vop (missing-arg) :type symbol :read-only t)
+ ;; How many words are each value of this type?
+ (n-words (missing-arg) :type (and index (integer 1)) :read-only t)
+ ;; Necessary alignment in units of words. Note that instances
+ ;; themselves are aligned by exactly two words, so specifying more
+ ;; than two words here would not work.
+ (alignment 1 :type (integer 1 2) :read-only t)
+ (comparer (missing-arg) :type function :read-only t))
+
+(defvar *raw-slot-data-list*
+ (macrolet ((make-comparer (accessor-name)
+ `(lambda (index x y)
+ (declare (optimize speed (safety 0)))
+ (= (,accessor-name x index)
+ (,accessor-name y index)))))
+ (let ((double-float-alignment
+ ;; white list of architectures that can load unaligned doubles:
+ #!+(or x86 x86-64 ppc) 1
+ ;; at least sparc, mips and alpha can't:
+ #!-(or x86 x86-64 ppc) 2))
+ (list
+ (make-raw-slot-data :raw-type 'sb!vm:word
+ :accessor-name '%raw-instance-ref/word
+ :init-vop 'sb!vm::raw-instance-init/word
+ :n-words 1
+ :comparer (make-comparer %raw-instance-ref/word))
+ (make-raw-slot-data :raw-type 'single-float
+ :accessor-name '%raw-instance-ref/single
+ :init-vop 'sb!vm::raw-instance-init/single
+ ;; KLUDGE: On 64 bit architectures, we
+ ;; could pack two SINGLE-FLOATs into the
+ ;; same word if raw slots were indexed
+ ;; using bytes instead of words. However,
+ ;; I don't personally find optimizing
+ ;; SINGLE-FLOAT memory usage worthwile
+ ;; enough. And the other datatype that
+ ;; would really benefit is (UNSIGNED-BYTE
+ ;; 32), but that is a subtype of FIXNUM, so
+ ;; we store it unraw anyway. :-( -- DFL
+ :n-words 1
+ :comparer (make-comparer %raw-instance-ref/single))
+ (make-raw-slot-data :raw-type 'double-float
+ :accessor-name '%raw-instance-ref/double
+ :init-vop 'sb!vm::raw-instance-init/double
+ :alignment double-float-alignment
+ :n-words (/ 8 sb!vm:n-word-bytes)
+ :comparer (make-comparer %raw-instance-ref/double))
+ (make-raw-slot-data :raw-type 'complex-single-float
+ :accessor-name '%raw-instance-ref/complex-single
+ :init-vop 'sb!vm::raw-instance-init/complex-single
+ :n-words (/ 8 sb!vm:n-word-bytes)
+ :comparer (make-comparer %raw-instance-ref/complex-single))
+ (make-raw-slot-data :raw-type 'complex-double-float
+ :accessor-name '%raw-instance-ref/complex-double
+ :init-vop 'sb!vm::raw-instance-init/complex-double
+ :alignment double-float-alignment
+ :n-words (/ 16 sb!vm:n-word-bytes)
+ :comparer (make-comparer %raw-instance-ref/complex-double))
+ #!+long-float
+ (make-raw-slot-data :raw-type long-float
+ :accessor-name '%raw-instance-ref/long
+ :init-vop 'sb!vm::raw-instance-init/long
+ :n-words #!+x86 3 #!+sparc 4
+ :comparer (make-comparer %raw-instance-ref/long))
+ #!+long-float
+ (make-raw-slot-data :raw-type complex-long-float
+ :accessor-name '%raw-instance-ref/complex-long
+ :init-vop 'sb!vm::raw-instance-init/complex-long
+ :n-words #!+x86 6 #!+sparc 8
+ :comparer (make-comparer %raw-instance-ref/complex-long))))))
+
+(defun raw-slot-words (type)
+ (let ((rsd (find type *raw-slot-data-list* :key #'raw-slot-data-raw-type)))
+ (if rsd
+ (raw-slot-data-n-words rsd)
+ (error "Invalid raw slot type: ~S" type))))