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2cf1705c72
* module/language/assembly.scm (addr+): New helper. (align-program): New function, aligns a (load-program) form, currently to 8-byte boundaries. * module/language/glil/compile-assembly.scm (<subprogram>): Record the object table and the program code separately, so that we can align the program after the object table has been written. (glil->assembly): Use addr+. (dump-object): Rework to fold `addr' through dumping of compound objects, so that procedures can be aligned properly.
127 lines
3.7 KiB
Scheme
127 lines
3.7 KiB
Scheme
;;; Guile Virtual Machine Assembly
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;; Copyright (C) 2001 Free Software Foundation, Inc.
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;; This program is free software; you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation; either version 2, or (at your option)
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;; any later version.
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;;
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;; This program is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;;
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;; You should have received a copy of the GNU General Public License
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;; along with this program; see the file COPYING. If not, write to
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;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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;; Boston, MA 02111-1307, USA.
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;;; Code:
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(define-module (language assembly)
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#:use-module (system base pmatch)
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#:use-module (system vm instruction)
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#:use-module ((srfi srfi-1) #:select (fold))
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#:export (byte-length
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addr+ align-program
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assembly-pack assembly-unpack
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object->assembly assembly->object))
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;; nargs, nrest, nlocs, nexts, len, metalen
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(define *program-header-len* (+ 1 1 1 1 4 4))
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;; lengths are encoded in 3 bytes
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(define *len-len* 3)
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(define (byte-length assembly)
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(pmatch assembly
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(,label (guard (not (pair? label)))
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0)
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((load-integer ,str)
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(+ 1 *len-len* (string-length str)))
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((load-number ,str)
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(+ 1 *len-len* (string-length str)))
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((load-string ,str)
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(+ 1 *len-len* (string-length str)))
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((load-symbol ,str)
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(+ 1 *len-len* (string-length str)))
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((load-keyword ,str)
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(+ 1 *len-len* (string-length str)))
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((define ,str)
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(+ 1 *len-len* (string-length str)))
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((load-program ,nargs ,nrest ,nlocs ,nexts ,labels ,len ,meta . ,code)
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(+ 1 *program-header-len* len (if meta (1- (byte-length meta)) 0)))
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((,inst . _) (guard (>= (instruction-length inst) 0))
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(+ 1 (instruction-length inst)))
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(else (error "unknown instruction" assembly))))
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(define *program-alignment* 8)
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(define (addr+ addr code)
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(fold (lambda (x len) (+ (byte-length x) len))
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addr
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code))
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(define (align-program prog addr)
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`(,@(make-list (modulo (- *program-alignment*
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(modulo addr *program-alignment*))
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*program-alignment*)
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'(nop))
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,prog))
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;;;
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;;; Code compress/decompression
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;;;
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(define *abbreviations*
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'(((make-int8 0) . (make-int8:0))
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((make-int8 1) . (make-int8:1))))
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(define *expansions*
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(map (lambda (x) (cons (cdr x) (car x))) *abbreviations*))
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(define (assembly-pack code)
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(or (assoc-ref *abbreviations* code)
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code))
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(define (assembly-unpack code)
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(or (assoc-ref *expansions* code)
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code))
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;;;
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;;; Encoder/decoder
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;;;
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(define (object->assembly x)
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(cond ((eq? x #t) `(make-true))
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((eq? x #f) `(make-false))
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((null? x) `(make-eol))
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((and (integer? x) (exact? x))
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(cond ((and (<= -128 x) (< x 128))
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`(make-int8 ,(modulo x 256)))
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((and (<= -32768 x) (< x 32768))
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(let ((n (if (< x 0) (+ x 65536) x)))
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`(make-int16 ,(quotient n 256) ,(modulo n 256))))
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(else #f)))
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((char? x) `(make-char8 ,(char->integer x)))
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(else #f)))
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(define (assembly->object code)
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(pmatch code
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((make-true) #t)
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((make-false) #f) ;; FIXME: Same as the `else' case!
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((make-eol) '())
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((make-int8 ,n)
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(if (< n 128) n (- n 256)))
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((make-int16 ,n1 ,n2)
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(let ((n (+ (* n1 256) n2)))
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(if (< n 32768) n (- n 65536))))
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((make-char8 ,n)
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(integer->char n))
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((load-string ,s) s)
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((load-symbol ,s) (string->symbol s))
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((load-keyword ,s) (symbol->keyword (string->symbol s)))
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(else #f)))
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