X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fx86-64%2Farith.lisp;h=cfe4ad4e5c3167716776159567cadbfa7c96de32;hb=7deecae2d959173eda6a153d490c752c32050a9e;hp=4735ce3ea4aa241e8b0e0b2f92aae4f9ad7ef9f5;hpb=2230ea0c1765a95fd2aa0a8996b3555b93ba3745;p=sbcl.git

diff --git a/src/compiler/x86-64/arith.lisp b/src/compiler/x86-64/arith.lisp
index 4735ce3..cfe4ad4 100644
--- a/src/compiler/x86-64/arith.lisp
+++ b/src/compiler/x86-64/arith.lisp
@@ -509,8 +509,9 @@
     (inst cqo)
     (inst idiv eax y)
     (if (location= quo eax)
-        (inst shl eax 3)
-        (inst lea quo (make-ea :qword :index eax :scale 8)))
+        (inst shl eax n-fixnum-tag-bits)
+        (inst lea quo (make-ea :qword :index eax
+                               :scale (ash 1 n-fixnum-tag-bits))))
     (move rem edx)))
 
 (define-vop (fast-truncate-c/fixnum=>fixnum fast-safe-arith-op)
@@ -537,8 +538,9 @@
         (setf y-arg (register-inline-constant :qword (fixnumize y))))
     (inst idiv eax y-arg)
     (if (location= quo eax)
-        (inst shl eax 3)
-        (inst lea quo (make-ea :qword :index eax :scale 8)))
+        (inst shl eax n-fixnum-tag-bits)
+        (inst lea quo (make-ea :qword :index eax
+                               :scale (ash 1 n-fixnum-tag-bits))))
     (move rem edx)))
 
 (define-vop (fast-truncate/unsigned=>unsigned fast-safe-arith-op)