X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fgeneric%2Fvm-tran.lisp;h=0d5849eb162b3df6a35bdea8cf87121dea709dd8;hb=7c07a6f965c51828d8f452b47e0620d8e6cf2959;hp=9f0026ceed1f65670d047872d7e8696ace2fd4b0;hpb=0b3ec4b1d978b887db175b7b3bada8e727683e15;p=sbcl.git

diff --git a/src/compiler/generic/vm-tran.lisp b/src/compiler/generic/vm-tran.lisp
index 9f0026c..0d5849e 100644
--- a/src/compiler/generic/vm-tran.lisp
+++ b/src/compiler/generic/vm-tran.lisp
@@ -244,61 +244,44 @@
        (setf (%raw-bits result-bit-array index)
 	     (32bit-logical-not (%raw-bits bit-array index))))))
 
-;;;; primitive translator for BYTE-BLT
+;;;; %BYTE-BLT
 
-(def-primitive-translator byte-blt (src src-start dst dst-start dst-end)
-
-  ;; new version
-  ;;
-  ;; FIXME: CMU CL had a hairier implementation of this. 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 haven't checked how much the foreign
-  ;; function call costs us here. My guess is that if the overhead is
+;;; 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
-  (once-only ((dst-start dst-start))
-    `(flet ((sap (thing)
-	      (etypecase thing
-		(system-area-pointer thing)
-		((simple-unboxed-array (*)) (vector-sap thing)))))
-	 (declare (inline sap))
-	 (without-gcing
-	  (memmove (sap+ (sap ,dst) ,dst-start)
-		   (sap+ (sap ,src) ,src-start)
-		   (- ,dst-end ,dst-start)))))
-
-  ;; REMOVEME when new version works
-  ;;
-  ;; old version, had overflow problems because it converts byte
-  ;; indices to bit indices, which is not good when GENESIS is trying
-  ;; to read into a byte vector which represents the cold image (>16M bytes)
-  #+nil
-  `(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))))))))
+  '(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))
 
 ;;;; transforms for EQL of floating point values