-(def-primitive-translator byte-blt (src src-start dst dst-start dst-end)
- `(let ((src ,src)
- (src-start (* ,src-start sb!vm:byte-bits))
- (dst ,dst)
- (dst-start (* ,dst-start sb!vm:byte-bits))
- (dst-end (* ,dst-end sb!vm:byte-bits)))
- (let ((length (- dst-end dst-start)))
- (etypecase src
- (system-area-pointer
- (etypecase dst
- (system-area-pointer
- (system-area-copy src src-start dst dst-start length))
- ((simple-unboxed-array (*))
- (copy-from-system-area src src-start
- dst (+ dst-start ,vector-data-bit-offset)
- length))))
- ((simple-unboxed-array (*))
- (etypecase dst
- (system-area-pointer
- (copy-to-system-area src (+ src-start ,vector-data-bit-offset)
- dst dst-start
- length))
- ((simple-unboxed-array (*))
- (bit-bash-copy src (+ src-start ,vector-data-bit-offset)
- dst (+ dst-start ,vector-data-bit-offset)
- length))))))))
+;;; FIXME: The old CMU CL code used various COPY-TO/FROM-SYSTEM-AREA
+;;; stuff (with all the associated bit-index cruft and overflow
+;;; issues) even for byte moves. In SBCL, we're converting to byte
+;;; moves as problems are discovered with the old code, and this is
+;;; currently (ca. sbcl-0.6.12.30) the main interface for code in
+;;; SB!KERNEL and SB!SYS (e.g. i/o code). It's not clear that it's the
+;;; ideal interface, though, and it probably deserves some thought.
+(deftransform %byte-blt ((src src-start dst dst-start dst-end)
+ ((or (simple-unboxed-array (*)) system-area-pointer)
+ index
+ (or (simple-unboxed-array (*)) system-area-pointer)
+ index
+ index))
+ ;; FIXME: CMU CL had a hairier implementation of this (back when it
+ ;; was still called (%PRIMITIVE BYTE-BLT). It had the small problem
+ ;; that it didn't work for large (>16M) values of SRC-START or
+ ;; DST-START. However, it might have been more efficient. In
+ ;; particular, I don't really know how much the foreign function
+ ;; call costs us here. My guess is that if the overhead is
+ ;; acceptable for SQRT and COS, it's acceptable here, but this
+ ;; should probably be checked. -- WHN
+ '(flet ((sapify (thing)
+ (etypecase thing
+ (system-area-pointer thing)
+ ;; FIXME: The code here rather relies on the simple
+ ;; unboxed array here having byte-sized entries. That
+ ;; should be asserted explicitly, I just haven't found
+ ;; a concise way of doing it. (It would be nice to
+ ;; declare it in the DEFKNOWN too.)
+ ((simple-unboxed-array (*)) (vector-sap thing)))))
+ (declare (inline sapify))
+ (without-gcing
+ (memmove (sap+ (sapify dst) dst-start)
+ (sap+ (sapify src) src-start)
+ (- dst-end dst-start)))
+ nil))