X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fx86-64%2Farith.lisp;h=cc41f3daff5a7f0584a3222a7309afde592504ae;hb=2e5263a05f55e2b56a3194ad7853e9ae18ad69af;hp=cfe4ad4e5c3167716776159567cadbfa7c96de32;hpb=7deecae2d959173eda6a153d490c752c32050a9e;p=sbcl.git

diff --git a/src/compiler/x86-64/arith.lisp b/src/compiler/x86-64/arith.lisp
index cfe4ad4..cc41f3d 100644
--- a/src/compiler/x86-64/arith.lisp
+++ b/src/compiler/x86-64/arith.lisp
@@ -667,6 +667,8 @@
                                        (location= number result)))))
   (:result-types tagged-num)
   (:note "inline ASH")
+  (:variant nil)
+  (:variant-vars modularp)
   (:generator 2
     (cond ((and (= amount 1) (not (location= number result)))
            (inst lea result (make-ea :qword :base number :index number)))
@@ -685,8 +687,11 @@
                         (inst sar result (- amount))
                         (inst and result (lognot fixnum-tag-mask)))))
                  ((plusp amount)
+                  (unless modularp
+                    (aver (not "Impossible: fixnum ASH should not be called with
+constant shift greater than word length")))
                   (if (sc-is result any-reg)
-                      (inst xor result result)
+                      (zeroize result)
                       (inst mov result 0)))
                  (t (inst sar result 63)
                     (inst and result (lognot fixnum-tag-mask))))))))
@@ -1367,6 +1372,7 @@
 
 (define-vop (fast-ash-left-smod61-c/fixnum=>fixnum
              fast-ash-c/fixnum=>fixnum)
+  (:variant :modular)
   (:translate ash-left-smod61))
 (define-vop (fast-ash-left-smod61/fixnum=>fixnum
              fast-ash-left/fixnum=>fixnum))