0.8.2.41:

	Slightly alleviate the bit-vector user's surprise ("mummy, why
	does initializing a bit-vector's elements to 1 take so long?")
	... DEFTRANSFORM FILL for the easy case.

diff --git a/src/compiler/generic/vm-tran.lisp b/src/compiler/generic/vm-tran.lisp
index bc21fbe..3f17ce6 100644 (file)
--- a/src/compiler/generic/vm-tran.lisp
+++ b/src/compiler/generic/vm-tran.lisp
@@ -340,6 +340,38 @@
                  (declare (type (unsigned-byte 32) numx numy))
                  (unless (= numx numy)
                    (return nil))))))))
+
+;;; FIXME: it is probably worth doing something like this for
+;;; SIMPLE-BASE-STRINGs too, if only so that (MAKE-STRING 100000
+;;; :INITIAL-ELEMENT #\Space) doesn't surprise the user with its
+;;; performance characteristics.  Getting it right is harder than with
+;;; bit-vectors, though, as one needs to be more careful with the loop
+;;; epilogue so as not to overwrite the convenient extra null byte
+;;; (for SB-ALIEN/C termination convention convenience).
+(deftransform fill ((sequence item) (simple-bit-vector bit) *
+                   :policy (>= speed space))
+  (let ((value (if (constant-continuation-p item)
+                  (if (= (continuation-value item) 0)
+                      0
+                      #.(1- (ash 1 32)))
+                  `(if (= item 0) 0 #.(1- (ash 1 32))))))
+    `(let ((length (length sequence))
+          (value ,value))
+       (if (= length 0)
+          sequence
+          (do ((index sb!vm:vector-data-offset (1+ index))
+               (end-1 (+ sb!vm:vector-data-offset
+                         ;; bit-vectors of length 1-32 need precisely
+                         ;; one (SETF %RAW-BITS), done here in the
+                         ;; epilogue. - CSR, 2002-04-24
+                         (truncate (truly-the index (1- length))
+                                   sb!vm:n-word-bits))))
+              ((= index end-1)
+               (setf (%raw-bits sequence index) value)
+               sequence)
+            (declare (optimize (speed 3) (safety 0))
+                     (type index index end-1))
+            (setf (%raw-bits sequence index) value))))))
 \f
 ;;;; %BYTE-BLT
 

diff --git a/version.lisp-expr b/version.lisp-expr
index a8a0220..6ebf795 100644 (file)
--- a/version.lisp-expr
+++ b/version.lisp-expr
@@ -17,4 +17,4 @@
 ;;; checkins which aren't released. (And occasionally for internal
 ;;; versions, especially for internal versions off the main CVS
 ;;; branch, it gets hairier, e.g. "0.pre7.14.flaky4.13".)
-"0.8.2.40"
+"0.8.2.41"