1 ;;;; utility functions needed by the back end to generate code
3 ;;;; This software is part of the SBCL system. See the README file for
6 ;;;; This software is derived from the CMU CL system, which was
7 ;;;; written at Carnegie Mellon University and released into the
8 ;;;; public domain. The software is in the public domain and is
9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
10 ;;;; files for more information.
14 ;;; Make a fixnum out of NUM. (I.e. shift by two bits if it will fit.)
15 (defun fixnumize (num)
16 (if (<= #x-20000000 num #x1fffffff)
18 (error "~W is too big for a fixnum." num)))
20 ;;;; routines for dealing with static symbols
22 (defun static-symbol-p (symbol)
24 (and (member symbol *static-symbols*) t)))
26 ;;; the byte offset of the static symbol SYMBOL
27 (defun static-symbol-offset (symbol)
29 (let ((posn (position symbol *static-symbols*)))
30 (unless posn (error "~S is not a static symbol." symbol))
31 (+ (* posn (pad-data-block symbol-size))
32 (pad-data-block (1- symbol-size))
34 (- list-pointer-lowtag)))
37 ;;; Given a byte offset, OFFSET, return the appropriate static symbol.
38 (defun offset-static-symbol (offset)
41 (multiple-value-bind (n rem)
42 (truncate (+ offset list-pointer-lowtag (- other-pointer-lowtag)
43 (- (pad-data-block (1- symbol-size))))
44 (pad-data-block symbol-size))
45 (unless (and (zerop rem) (<= 0 n (1- (length *static-symbols*))))
46 (error "The byte offset ~W is not valid." offset))
47 (elt *static-symbols* n))))
49 ;;; Return the (byte) offset from NIL to the start of the fdefn object
50 ;;; for the static function NAME.
51 (defun static-fun-offset (name)
52 (let ((static-syms (length *static-symbols*))
53 (static-fun-index (position name *static-funs*)))
54 (unless static-fun-index
55 (error "~S isn't a static function." name))
56 (+ (* static-syms (pad-data-block symbol-size))
57 (pad-data-block (1- symbol-size))
58 (- list-pointer-lowtag)
59 (* static-fun-index (pad-data-block fdefn-size))
60 (* fdefn-raw-addr-slot n-word-bytes))))