X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fgeneric%2Fvm-tran.lisp;h=7c4cc00da832822b447fa959637e725d2d98e50d;hb=5930ee54090c03d242c70716683b12b95d74a089;hp=7031de38919acc1fcc89d5b09132181525f0ec7c;hpb=11b8fcf55c80cb2686fb49663fa4d96f9b152ce4;p=sbcl.git

diff --git a/src/compiler/generic/vm-tran.lisp b/src/compiler/generic/vm-tran.lisp
index 7031de3..7c4cc00 100644
--- a/src/compiler/generic/vm-tran.lisp
+++ b/src/compiler/generic/vm-tran.lisp
@@ -121,19 +121,29 @@
                               (*))
                 index)))))
 
-(deftransform %data-vector-and-index ((array index)
-                                     (simple-array t)
-                                     *
-                                     :important t)
+(deftransform %data-vector-and-index ((%array %index)
+				      (simple-array t)
+				      *
+				      :important t)
+  ;; KLUDGE: why the percent signs?  Well, ARRAY and INDEX are
+  ;; respectively exported from the CL and SB!INT packages, which
+  ;; means that they're visible to all sorts of things.  If the
+  ;; compiler can prove that the call to ARRAY-HEADER-P, below, either
+  ;; returns T or NIL, it will delete the irrelevant branch.  However,
+  ;; user code might have got here with a variable named CL:ARRAY, and
+  ;; quite often compiler code with a variable named SB!INT:INDEX, so
+  ;; this can generate code deletion notes for innocuous user code:
+  ;; (DEFUN F (ARRAY I) (DECLARE (SIMPLE-VECTOR ARRAY)) (AREF ARRAY I))
+  ;; -- CSR, 2003-04-01
 
   ;; We do this solely for the -OR-GIVE-UP side effect, since we want
   ;; to know that the type can be figured out in the end before we
   ;; proceed, but we don't care yet what the type will turn out to be.
-  (upgraded-element-type-specifier-or-give-up array)
+  (upgraded-element-type-specifier-or-give-up %array)
 
-  '(if (array-header-p array)
-       (values (%array-data-vector array) index)
-       (values array index)))
+  '(if (array-header-p %array)
+       (values (%array-data-vector %array) %index)
+       (values %array %index)))
 
 ;;; transforms for getting at simple arrays of (UNSIGNED-BYTE N) when (< N 8)
 ;;;
@@ -264,6 +274,42 @@
 		     (type index index end-1))
 	    (setf (%raw-bits result-bit-array index)
 		  (32bit-logical-not (%raw-bits bit-array index))))))))
+
+(deftransform bit-vector-= ((x y) (simple-bit-vector simple-bit-vector))
+  `(and (= (length x) (length y))
+        (let ((length (length x)))
+	  (or (= length 0)
+	      (do* ((i sb!vm:vector-data-offset (+ i 1))
+		    (end-1 (+ sb!vm:vector-data-offset
+			      (floor (1- length) sb!vm:n-word-bits))))
+		   ((= i end-1)
+		    (let* ((extra (mod length sb!vm:n-word-bits))
+			   (mask (1- (ash 1 extra)))
+			   (numx
+			    (logand
+			     (ash mask
+				  ,(ecase sb!c:*backend-byte-order*
+				     (:little-endian 0)
+				     (:big-endian
+				      '(- sb!vm:n-word-bits extra))))
+			     (%raw-bits x i)))
+			   (numy
+			    (logand
+			     (ash mask
+				  ,(ecase sb!c:*backend-byte-order*
+				     (:little-endian 0)
+				     (:big-endian
+				      '(- sb!vm:n-word-bits extra))))
+			     (%raw-bits y i))))
+		      (declare (type (integer 0 31) extra)
+			       (type (unsigned-byte 32) mask numx numy))
+		      (= numx numy)))
+		(declare (type index i end-1))
+		(let ((numx (%raw-bits x i))
+		      (numy (%raw-bits y i)))
+		  (declare (type (unsigned-byte 32) numx numy))
+		  (unless (= numx numy)
+		    (return nil))))))))
 
 ;;;; %BYTE-BLT