src/compiler/generic/vm-type.lisp

   1 ;;;; This file contains implementation-dependent parts of the type
   2 ;;;; support code. This is stuff which deals with the mapping from
   3 ;;;; types defined in Common Lisp to types actually supported by an
   4 ;;;; implementation.
   5
   6 ;;;; This software is part of the SBCL system. See the README file for
   7 ;;;; more information.
   8 ;;;;
   9 ;;;; This software is derived from the CMU CL system, which was
  10 ;;;; written at Carnegie Mellon University and released into the
  11 ;;;; public domain. The software is in the public domain and is
  12 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  13 ;;;; files for more information.
  14
  15 (in-package "SB!KERNEL")
  16
  17 ;;;; FIXME: I'm not sure where to put this. -- WHN 19990817
  18
  19 (def!type sb!vm:word () `(unsigned-byte ,sb!vm:n-word-bits))
  20 \f
  21 ;;;; implementation-dependent DEFTYPEs
  22
  23 ;;; Make DOUBLE-FLOAT a synonym for LONG-FLOAT, SINGLE-FLOAT for
  24 ;;; SHORT-FLOAT. This is expanded before the translator gets a chance,
  25 ;;; so we will get precedence.
  26 #!-long-float
  27 (setf (info :type :kind 'long-float) :defined)
  28 #!-long-float
  29 (sb!xc:deftype long-float (&optional low high)
  30   `(double-float ,low ,high))
  31 (setf (info :type :kind 'short-float) :defined)
  32 (sb!xc:deftype short-float (&optional low high)
  33   `(single-float ,low ,high))
  34
  35 ;;; an index into an integer
  36 (sb!xc:deftype bit-index () `(integer 0 ,sb!xc:most-positive-fixnum))
  37
  38 ;;; worst-case values for float attributes
  39 (sb!xc:deftype float-exponent ()
  40   #!-long-float 'double-float-exponent
  41   #!+long-float 'long-float-exponent)
  42 (sb!xc:deftype float-digits ()
  43   #!-long-float `(integer 0 ,sb!vm:double-float-digits)
  44   #!+long-float `(integer 0 ,sb!vm:long-float-digits))
  45 (sb!xc:deftype float-radix () '(integer 2 2))
  46 (sb!xc:deftype float-int-exponent ()
  47   #!-long-float 'double-float-int-exponent
  48   #!+long-float 'long-float-int-exponent)
  49
  50 ;;; a code for BOOLE
  51 (sb!xc:deftype boole-code () '(unsigned-byte 4))
  52
  53 ;;; a byte specifier (as generated by BYTE)
  54 (sb!xc:deftype byte-specifier () 'cons)
  55
  56 ;;; result of CHAR-INT
  57 (sb!xc:deftype char-int () 'char-code)
  58
  59 ;;; PATHNAME pieces, as returned by the PATHNAME-xxx functions
  60 (sb!xc:deftype pathname-host () '(or sb!impl::host null))
  61 (sb!xc:deftype pathname-device ()
  62   '(or simple-string (member nil :unspecific)))
  63 (sb!xc:deftype pathname-directory () 'list)
  64 (sb!xc:deftype pathname-name ()
  65   '(or simple-string sb!impl::pattern (member nil :unspecific :wild)))
  66 (sb!xc:deftype pathname-type ()
  67   '(or simple-string sb!impl::pattern (member nil :unspecific :wild)))
  68 (sb!xc:deftype pathname-version ()
  69   '(or integer (member nil :newest :wild :unspecific)))
  70
  71 ;;; internal time format. (Note: not a FIXNUM, ouch..)
  72 (sb!xc:deftype internal-time () 'unsigned-byte)
  73
  74 (sb!xc:deftype bignum-element-type () `(unsigned-byte ,sb!vm:n-word-bits))
  75 (sb!xc:deftype bignum-type () 'bignum)
  76 ;;; FIXME: see also DEFCONSTANT MAXIMUM-BIGNUM-LENGTH in
  77 ;;; src/code/bignum.lisp.  -- CSR, 2004-07-19
  78 (sb!xc:deftype bignum-index ()
  79   '(integer 0 #.(1- (ash 1 (- 32 sb!vm:n-widetag-bits)))))
  80 \f
  81 ;;;; hooks into the type system
  82
  83 (sb!xc:deftype unboxed-array (&optional dims)
  84   (collect ((types (list 'or)))
  85     (dolist (type *specialized-array-element-types*)
  86       (when (subtypep type '(or integer character float (complex float)))
  87         (types `(array ,type ,dims))))
  88     (types)))
  89
  90 (sb!xc:deftype simple-unboxed-array (&optional dims)
  91   (collect ((types (list 'or)))
  92     (dolist (type *specialized-array-element-types*)
  93       (when (subtypep type '(or integer character float (complex float)))
  94         (types `(simple-array ,type ,dims))))
  95     (types)))
  96
  97 ;;; Return the symbol that describes the format of FLOAT.
  98 (declaim (ftype (function (float) symbol) float-format-name))
  99 (defun float-format-name (x)
 100   (etypecase x
 101     (single-float 'single-float)
 102     (double-float 'double-float)
 103     #!+long-float (long-float 'long-float)))
 104
 105 ;;; This function is called when the type code wants to find out how
 106 ;;; an array will actually be implemented. We set the
 107 ;;; SPECIALIZED-ELEMENT-TYPE to correspond to the actual
 108 ;;; specialization used in this implementation.
 109 (declaim (ftype (function (array-type) array-type) specialize-array-type))
 110 (defun specialize-array-type (type)
 111   (let ((eltype (array-type-element-type type)))
 112     (setf (array-type-specialized-element-type type)
 113           (if (or (eq eltype *wild-type*)
 114                   ;; This is slightly dubious, but not as dubious as
 115                   ;; assuming that the upgraded-element-type should be
 116                   ;; equal to T, given the way that the AREF
 117                   ;; DERIVE-TYPE optimizer works.  -- CSR, 2002-08-19
 118                   (unknown-type-p eltype))
 119               *wild-type*
 120               (dolist (stype-name *specialized-array-element-types*
 121                                   *universal-type*)
 122                 ;; FIXME: Mightn't it be better to have
 123                 ;; *SPECIALIZED-ARRAY-ELEMENT-TYPES* be stored as precalculated
 124                 ;; SPECIFIER-TYPE results, instead of having to calculate
 125                 ;; them on the fly this way? (Call the new array
 126                 ;; *SPECIALIZED-ARRAY-ELEMENT-SPECIFIER-TYPES* or something..)
 127                 (let ((stype (specifier-type stype-name)))
 128                   (aver (not (unknown-type-p stype)))
 129                   (when (csubtypep eltype stype)
 130                     (return stype))))))
 131     type))
 132
 133 (defun sb!xc:upgraded-array-element-type (spec &optional environment)
 134   #!+sb-doc
 135   "Return the element type that will actually be used to implement an array
 136    with the specifier :ELEMENT-TYPE Spec."
 137   (declare (ignore environment))
 138   (if (unknown-type-p (specifier-type spec))
 139       (error "undefined type: ~S" spec)
 140       (type-specifier (array-type-specialized-element-type
 141                        (specifier-type `(array ,spec))))))
 142
 143 (defun sb!xc:upgraded-complex-part-type (spec &optional environment)
 144   #!+sb-doc
 145   "Return the element type of the most specialized COMPLEX number type that
 146    can hold parts of type SPEC."
 147   (declare (ignore environment))
 148   (let ((type (specifier-type spec)))
 149     (cond
 150       ((eq type *empty-type*) nil)
 151       ((unknown-type-p type) (error "undefined type: ~S" spec))
 152       (t
 153        (let ((ctype (specifier-type `(complex ,spec))))
 154          (cond
 155            ((eq ctype *empty-type*) '(eql 0))
 156            ((csubtypep ctype (specifier-type '(complex single-float)))
 157             'single-float)
 158            ((csubtypep ctype (specifier-type '(complex double-float)))
 159             'double-float)
 160            #!+long-float
 161            ((csubtypep ctype (specifier-type '(complex long-float)))
 162             'long-float)
 163            ((csubtypep ctype (specifier-type '(complex rational)))
 164             'rational)
 165            (t 'real)))))))
 166
 167 ;;; Return the most specific integer type that can be quickly checked that
 168 ;;; includes the given type.
 169 (defun containing-integer-type (subtype)
 170   (dolist (type '(fixnum
 171                   (signed-byte 32)
 172                   (unsigned-byte 32)
 173                   integer)
 174                 (error "~S isn't an integer type?" subtype))
 175     (when (csubtypep subtype (specifier-type type))
 176       (return type))))
 177
 178 ;;; If TYPE has a CHECK-xxx template, but doesn't have a corresponding
 179 ;;; PRIMITIVE-TYPE, then return the template's name. Otherwise, return NIL.
 180 (defun hairy-type-check-template-name (type)
 181   (declare (type ctype type))
 182   (typecase type
 183     (cons-type
 184      (if (type= type (specifier-type 'cons))
 185          'sb!c:check-cons
 186          nil))
 187     (built-in-classoid
 188      (if (type= type (specifier-type 'symbol))
 189          'sb!c:check-symbol
 190          nil))
 191     (numeric-type
 192      (cond ((type= type (specifier-type 'fixnum))
 193             'sb!c:check-fixnum)
 194            ((type= type (specifier-type '(signed-byte 32)))
 195             'sb!c:check-signed-byte-32)
 196            ((type= type (specifier-type '(unsigned-byte 32)))
 197             'sb!c:check-unsigned-byte-32)
 198            (t nil)))
 199     (fun-type
 200      'sb!c:check-fun)
 201     (t
 202      nil)))