1.0.6.8: improve (SUBSEQ FOO 0 ...) on arrays with elements >= word-size

	* check for a constant-valued start parameter and pass its value
	  through to the loop-generating machinery.  Before we would have
	  compared 'START to 0, which always fails; now we can recognize
	  that case and generate better code.

diff --git a/src/compiler/seqtran.lisp b/src/compiler/seqtran.lisp
index 2699964..c956a07 100644 (file)
--- a/src/compiler/seqtran.lisp
+++ b/src/compiler/seqtran.lisp
@@ -916,7 +916,10 @@
                       (sb!impl::signal-bounding-indices-bad-error seq start end))))
          (let* ((size (- end start))
                 (result (make-array size :element-type ',element-type)))
-           ,(maybe-expand-copy-loop-inline 'seq 'start 'result 0 'size element-type)
+           ,(maybe-expand-copy-loop-inline 'seq (if (constant-lvar-p start)
+                                                    (lvar-value start)
+                                                    'start)
+                                           'result 0 'size element-type)
            result)))))
 
 (deftransform copy-seq ((seq) ((or (simple-unboxed-array (*)) simple-vector)) *)

diff --git a/version.lisp-expr b/version.lisp-expr
index 7355f83..9947068 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".)
-"1.0.6.7"
+"1.0.6.8"