src/compiler/x86-64/backend-parms.lisp

   1 ;;;; that part of the parms.lisp file from original CMU CL which is defined in
   2 ;;;; terms of the BACKEND structure
   3 ;;;;
   4 ;;;; FIXME: When we break up the BACKEND structure, this might be mergeable
   5 ;;;; back into the parms.lisp file.
   6
   7 ;;;; This software is part of the SBCL system. See the README file for
   8 ;;;; more information.
   9 ;;;;
  10 ;;;; This software is derived from the CMU CL system, which was
  11 ;;;; written at Carnegie Mellon University and released into the
  12 ;;;; public domain. The software is in the public domain and is
  13 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  14 ;;;; files for more information.
  15
  16 (in-package "SB!VM")
  17 \f
  18 ;;;; compiler constants
  19
  20 (defconstant +backend-fasl-file-implementation+ :x86-64)
  21
  22 (setf *backend-register-save-penalty* 3)
  23
  24 (setf *backend-byte-order* :little-endian)
  25
  26 ;;; KLUDGE: It would seem natural to set this by asking our C runtime
  27 ;;; code for it, but mostly we need it for GENESIS, which doesn't in
  28 ;;; general have our C runtime code running to ask, so instead we set
  29 ;;; it by hand. -- WHN 2001-04-15
  30 ;;;
  31 ;;; Actually any information that we can retrieve C-side would be
  32 ;;; useless in SBCL, since it's possible for otherwise binary
  33 ;;; compatible systems to return different values for getpagesize().
  34 ;;; -- JES, 2007-01-06
  35 (eval-when (:compile-toplevel :load-toplevel :execute)
  36   (setf *backend-page-bytes* 32768))
  37
  38 ;;; The size in bytes of GENCGC cards, i.e. the granularity at which
  39 ;;; writes to old generations are logged.  With mprotect-based write
  40 ;;; barriers, this must be a multiple of the OS page size.
  41 (defconstant gencgc-card-bytes *backend-page-bytes*)
  42 ;;; The minimum size of new allocation regions.  While it doesn't
  43 ;;; currently make a lot of sense to have a card size lower than
  44 ;;; the alloc granularity, it will, once we are smarter about finding
  45 ;;; the start of objects.
  46 (defconstant gencgc-alloc-granularity 0)
  47 ;;; The minimum size at which we release address ranges to the OS.
  48 ;;; This must be a multiple of the OS page size.
  49 (defconstant gencgc-release-granularity *backend-page-bytes*)
  50 ;;; The card size for immobile/low space
  51 #!+immobile-space (def!constant immobile-card-bytes 4096)
  52
  53 #!+sb-safepoint
  54 (defconstant thread-saved-csp-offset
  55     (- (/ *backend-page-bytes* n-word-bytes)))