0.8.3.62:

[sbcl.git] / src / code / sxhash.lisp

diff --git a/src/code/sxhash.lisp b/src/code/sxhash.lisp
index 2db5a48..8b13e79 100644 (file)
--- a/src/code/sxhash.lisp
+++ b/src/code/sxhash.lisp
@@ -38,10 +38,56 @@
 ;;; simple.
 (deftransform sxhash ((x) (fixnum))
   '(logand most-positive-fixnum
-          (logxor x
-                  (ash x -3) ; to get sign bit into hash
+          (logxor (ash (logand x (ash most-positive-fixnum -4)) 4) 
+                  (ash x -1) ; to get sign bit into hash
                   361475658)))
 
+;;; SXHASH of SIMPLE-BIT-VECTOR values is defined as a DEFTRANSFORM
+;;; because it is endian-dependent.
+(deftransform sxhash ((x) (simple-bit-vector))
+  `(let ((result 410823708))
+    (declare (type fixnum result))
+    (let ((length (length x)))
+      (cond
+       ((= length 0) (mix result (sxhash 0)))
+       (t
+        (mixf result (sxhash (length x)))
+        (do* ((i sb!vm:vector-data-offset (+ i 1))
+              ;; FIXME: should we respect DEPTHOID?  SXHASH on
+              ;; strings doesn't seem to...
+              (end-1 (+ sb!vm:vector-data-offset
+                        (floor (1- length) sb!vm:n-word-bits))))
+             ((= i end-1)
+              (let ((num
+                     (logand
+                      (ash (1- (ash 1 (mod length sb!vm:n-word-bits)))
+                           ,(ecase sb!c:*backend-byte-order*
+                              (:little-endian 0)
+                              (:big-endian
+                               '(- sb!vm:n-word-bits
+                                   (mod length sb!vm:n-word-bits)))))
+                      (%raw-bits x i))))
+                (declare (type (unsigned-byte 32) num))
+                (mix result ,(ecase sb!c:*backend-byte-order*
+                               (:little-endian
+                                '(logand num most-positive-fixnum))
+                               (:big-endian
+                                '(ash num (- sb!vm:n-lowtag-bits)))))))
+          (declare (type index i end-1))
+          (let ((num (%raw-bits x i)))
+            (declare (type (unsigned-byte 32) num))
+            (mixf result ,(ecase sb!c:*backend-byte-order*
+                            (:little-endian
+                             '(logand num most-positive-fixnum))
+                            ;; FIXME: I'm not certain that
+                            ;; N-LOWTAG-BITS is the clearest way of
+                            ;; expressing this: it's essentially the
+                            ;; difference between `(UNSIGNED-BYTE
+                            ;; ,SB!VM:N-WORD-BITS) and (AND FIXNUM
+                            ;; UNSIGNED-BYTE).
+                            (:big-endian
+                             '(ash num (- sb!vm:n-lowtag-bits))))))))))))
+
 ;;; Some other common SXHASH cases are defined as DEFTRANSFORMs in
 ;;; order to avoid having to do TYPECASE at runtime.
 ;;;
@@ -52,10 +98,12 @@
 ;;; easily do this optimization in the cross-compiler, and SBCL itself
 ;;; doesn't seem to need this optimization, so we don't try.
 (deftransform sxhash ((x) (simple-string))
-  (if #+sb-xc-host nil #-sb-xc-host (constant-continuation-p x)
-      (sxhash (continuation-value x))
+  (if #+sb-xc-host nil #-sb-xc-host (constant-lvar-p x)
+      (sxhash (lvar-value x))
       '(%sxhash-simple-string x)))
 (deftransform sxhash ((x) (symbol))
-  (if #+sb-xc-host nil #-sb-xc-host (constant-continuation-p x)
-      (sxhash (continuation-value x))
+  (if #+sb-xc-host nil #-sb-xc-host (constant-lvar-p x)
+      (sxhash (lvar-value x))
       '(%sxhash-simple-string (symbol-name x))))
+
+