X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fgeneric%2Fearly-vm.lisp;h=ae59eff109fbaf32ff62c9383043626214797519;hb=5edd74f6911093805a009a152b32216b3dba59f7;hp=10636b65e2c11f620b6cb7cd55e7f8a786da9587;hpb=cea4896b2482b7b2b429c1631d774b4cfbc0efba;p=sbcl.git

diff --git a/src/compiler/generic/early-vm.lisp b/src/compiler/generic/early-vm.lisp
index 10636b6..ae59eff 100644
--- a/src/compiler/generic/early-vm.lisp
+++ b/src/compiler/generic/early-vm.lisp
@@ -9,34 +9,30 @@
 
 (in-package "SB!VM")
 
-(eval-when (:compile-toplevel :execute :load-toplevel)
-
-(defconstant lowtag-bits 3
-  #!+sb-doc
-  "Number of bits at the low end of a pointer used for type information.")
-
-(defconstant lowtag-mask (1- (ash 1 lowtag-bits))
-  #!+sb-doc
-  "Mask to extract the low tag bits from a pointer.")
-
-(defconstant lowtag-limit (ash 1 lowtag-bits)
-  #!+sb-doc
-  "Exclusive upper bound on the value of the low tag bits from a pointer.")
-
-(defconstant type-bits 8
-  #!+sb-doc
-  "Number of bits used in the header word of a data block to store the type.")
-
-(defconstant type-mask (1- (ash 1 type-bits))
-  #!+sb-doc
-  "Mask to extract the type from a header word.")
-
-); eval-when
-
-;;; FIXME: Couldn't/shouldn't these be DEFCONSTANT instead of DEFPARAMETER?
+;;; the number of bits at the low end of a pointer used for type
+;;; information
+(defconstant n-lowtag-bits 3)
+;;; a mask to extract the low tag bits from a pointer
+(defconstant lowtag-mask (1- (ash 1 n-lowtag-bits)))
+;;; the exclusive upper bound on the value of the low tag bits from a
+;;; pointer
+(defconstant lowtag-limit (ash 1 n-lowtag-bits))
+
+;;; the number of bits used in the header word of a data block to store
+;;; the type
+(defconstant n-widetag-bits 8)
+;;; a mask to extract the type from a data block header word
+(defconstant widetag-mask (1- (ash 1 n-widetag-bits)))
+
+;;; FIXME: Couldn't/shouldn't these be DEFCONSTANT instead of
+;;; DEFPARAMETER? (It might seem even more tempting to make them
+;;; SB!XC:MOST-POSITIVE-FIXNUM and SB!XC:MOST-NEGATIVE-FIXNUM,
+;;; but that's probably not a good idea, since then we'd need
+;;; to worry about the effect of UNCROSS in expressions like
+;;; (DEFTYPE INDX3 () `(INTEGER 3 ,SB!XC:MOST-POSITIVE-FIXNUM)).)
 (defparameter *target-most-positive-fixnum* (1- (ash 1 29))
   #!+sb-doc
-  "most-positive-fixnum in the target architecture.")
+  "most-positive-fixnum in the target architecture")
 (defparameter *target-most-negative-fixnum* (ash -1 29)
   #!+sb-doc
-  "most-negative-fixnum in the target architecture.")
+  "most-negative-fixnum in the target architecture")