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guile/module/language/assembly.scm
Andy Wingo 4b31848284 remove glil->objcode path in favor of passing through assembly; refactorings.
* module/language/assembly.scm: Refactor a bit; remove the name "code"
  from the API, as it's too generic, and replace with "assembly".

* module/language/assembly/compile-bytecode.scm: Get byte lengths via,
  well, byte-length.

* module/language/glil/Makefile.am:
* module/language/glil/spec.scm:
* module/language/glil/compile-objcode.scm: Remove compile-objcode, as we
  just go through bytecode now.

* module/language/glil/compile-assembly.scm (glil->assembly)
  (dump-object): s/object->code/object->assembly/.
2009-01-30 11:02:01 +01:00

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;;; Guile Virtual Machine Assembly
;; Copyright (C) 2001 Free Software Foundation, Inc.
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with this program; see the file COPYING. If not, write to
;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;; Code:
(define-module (language assembly)
#:use-module (system base pmatch)
#:use-module (system vm instruction)
#:export (byte-length
assembly-pack assembly-unpack
object->assembly assembly->object))
;; nargs, nrest, nlocs, nexts, len
(define *program-header-len* (+ 1 1 1 1 4))
;; lengths are encoded in 3 bytes
(define *len-len* 3)
(define (byte-length assembly)
(pmatch assembly
(,label (guard (not (pair? label)))
0)
((load-integer ,str)
(+ 1 *len-len* (string-length str)))
((load-number ,str)
(+ 1 *len-len* (string-length str)))
((load-string ,str)
(+ 1 *len-len* (string-length str)))
((load-symbol ,str)
(+ 1 *len-len* (string-length str)))
((load-keyword ,str)
(+ 1 *len-len* (string-length str)))
((define ,str)
(+ 1 *len-len* (string-length str)))
((load-program ,nargs ,nrest ,nlocs ,nexts ,labels ,len . ,code)
(+ 1 *program-header-len* len))
((,inst . _) (guard (>= (instruction-length inst) 0))
(+ 1 (instruction-length inst)))
(else (error "unknown instruction" assembly))))
;;;
;;; Code compress/decompression
;;;
(define *abbreviations*
'(((make-int8 0) . (make-int8:0))
((make-int8 1) . (make-int8:1))))
(define *expansions*
(map (lambda (x) (cons (cdr x) (car x))) *abbreviations*))
(define (assembly-pack code)
(or (assoc-ref code *abbreviations*)
code))
(define (assembly-unpack code)
(or (assoc-ref code *expansions*)
code))
;;;
;;; Encoder/decoder
;;;
(define (object->assembly x)
(cond ((eq? x #t) `(make-true))
((eq? x #f) `(make-false))
((null? x) `(make-eol))
((and (integer? x) (exact? x))
(cond ((and (<= -128 x) (< x 128))
`(make-int8 ,(modulo x 256)))
((and (<= -32768 x) (< x 32768))
(let ((n (if (< x 0) (+ x 65536) x)))
`(make-int16 ,(quotient n 256) ,(modulo n 256))))
(else #f)))
((char? x) `(make-char8 ,(char->integer x)))
(else #f)))
(define (assembly->object code)
(pmatch code
((make-true) #t)
((make-false) #f) ;; FIXME: Same as the `else' case!
((make-eol) '())
((make-int8 ,n)
(if (< n 128) n (- n 256)))
((make-int16 ,n1 ,n2)
(let ((n (+ (* n1 256) n2)))
(if (< n 32768) n (- n 65536))))
((make-char8 ,n)
(integer->char n))
((load-string ,s) s)
((load-symbol ,s) (string->symbol s))
((load-keyword ,s) (symbol->keyword (string->symbol s)))
(else #f)))