| 1 | ;;; Guile Virtual Machine Assembly |
| 2 | |
| 3 | ;; Copyright (C) 2001, 2009 Free Software Foundation, Inc. |
| 4 | |
| 5 | ;;;; This library is free software; you can redistribute it and/or |
| 6 | ;;;; modify it under the terms of the GNU Lesser General Public |
| 7 | ;;;; License as published by the Free Software Foundation; either |
| 8 | ;;;; version 3 of the License, or (at your option) any later version. |
| 9 | ;;;; |
| 10 | ;;;; This library is distributed in the hope that it will be useful, |
| 11 | ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | ;;;; Lesser General Public License for more details. |
| 14 | ;;;; |
| 15 | ;;;; You should have received a copy of the GNU Lesser General Public |
| 16 | ;;;; License along with this library; if not, write to the Free Software |
| 17 | ;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | |
| 19 | ;;; Code: |
| 20 | |
| 21 | (define-module (language assembly) |
| 22 | #:use-module (rnrs bytevector) |
| 23 | #:use-module (system base pmatch) |
| 24 | #:use-module (system vm instruction) |
| 25 | #:use-module ((srfi srfi-1) #:select (fold)) |
| 26 | #:export (byte-length |
| 27 | addr+ align-program align-code align-block |
| 28 | assembly-pack assembly-unpack |
| 29 | object->assembly assembly->object)) |
| 30 | |
| 31 | ;; len, metalen |
| 32 | (define *program-header-len* (+ 4 4)) |
| 33 | |
| 34 | ;; lengths are encoded in 3 bytes |
| 35 | (define *len-len* 3) |
| 36 | |
| 37 | |
| 38 | (define (byte-length assembly) |
| 39 | (pmatch assembly |
| 40 | (,label (guard (not (pair? label))) |
| 41 | 0) |
| 42 | ((load-number ,str) |
| 43 | (+ 1 *len-len* (string-length str))) |
| 44 | ((load-string ,str) |
| 45 | (+ 1 *len-len* (string-length str))) |
| 46 | ((load-wide-string ,str) |
| 47 | (+ 1 *len-len* (* 4 (string-length str)))) |
| 48 | ((load-symbol ,str) |
| 49 | (+ 1 *len-len* (string-length str))) |
| 50 | ((load-array ,bv) |
| 51 | (+ 1 *len-len* (bytevector-length bv))) |
| 52 | ((load-program ,labels ,len ,meta . ,code) |
| 53 | (+ 1 *program-header-len* len (if meta (1- (byte-length meta)) 0))) |
| 54 | ((,inst . _) (guard (>= (instruction-length inst) 0)) |
| 55 | (+ 1 (instruction-length inst))) |
| 56 | (else (error "unknown instruction" assembly)))) |
| 57 | |
| 58 | |
| 59 | (define *program-alignment* 8) |
| 60 | |
| 61 | (define *block-alignment* 8) |
| 62 | |
| 63 | (define (addr+ addr code) |
| 64 | (fold (lambda (x len) (+ (byte-length x) len)) |
| 65 | addr |
| 66 | code)) |
| 67 | |
| 68 | (define (code-alignment addr alignment header-len) |
| 69 | (make-list (modulo (- alignment |
| 70 | (modulo (+ addr header-len) alignment)) |
| 71 | alignment) |
| 72 | '(nop))) |
| 73 | |
| 74 | (define (align-block addr) |
| 75 | '()) |
| 76 | |
| 77 | (define (align-code code addr alignment header-len) |
| 78 | `(,@(code-alignment addr alignment header-len) |
| 79 | ,code)) |
| 80 | |
| 81 | (define (align-program prog addr) |
| 82 | (align-code prog addr *program-alignment* 1)) |
| 83 | |
| 84 | ;;; |
| 85 | ;;; Code compress/decompression |
| 86 | ;;; |
| 87 | |
| 88 | (define *abbreviations* |
| 89 | '(((make-int8 0) . (make-int8:0)) |
| 90 | ((make-int8 1) . (make-int8:1)))) |
| 91 | |
| 92 | (define *expansions* |
| 93 | (map (lambda (x) (cons (cdr x) (car x))) *abbreviations*)) |
| 94 | |
| 95 | (define (assembly-pack code) |
| 96 | (or (assoc-ref *abbreviations* code) |
| 97 | code)) |
| 98 | |
| 99 | (define (assembly-unpack code) |
| 100 | (or (assoc-ref *expansions* code) |
| 101 | code)) |
| 102 | |
| 103 | \f |
| 104 | ;;; |
| 105 | ;;; Encoder/decoder |
| 106 | ;;; |
| 107 | |
| 108 | (define (object->assembly x) |
| 109 | (cond ((eq? x #t) `(make-true)) |
| 110 | ((eq? x #f) `(make-false)) |
| 111 | ((null? x) `(make-eol)) |
| 112 | ((and (integer? x) (exact? x)) |
| 113 | (cond ((and (<= -128 x) (< x 128)) |
| 114 | (assembly-pack `(make-int8 ,(modulo x 256)))) |
| 115 | ((and (<= -32768 x) (< x 32768)) |
| 116 | (let ((n (if (< x 0) (+ x 65536) x))) |
| 117 | `(make-int16 ,(quotient n 256) ,(modulo n 256)))) |
| 118 | ((and (<= 0 x #xffffffffffffffff)) |
| 119 | `(make-uint64 ,@(bytevector->u8-list |
| 120 | (let ((bv (make-bytevector 8))) |
| 121 | (bytevector-u64-set! bv 0 x (endianness big)) |
| 122 | bv)))) |
| 123 | ((and (<= 0 (+ x #x8000000000000000) #x7fffffffffffffff)) |
| 124 | `(make-int64 ,@(bytevector->u8-list |
| 125 | (let ((bv (make-bytevector 8))) |
| 126 | (bytevector-s64-set! bv 0 x (endianness big)) |
| 127 | bv)))) |
| 128 | (else #f))) |
| 129 | ((char? x) |
| 130 | (cond ((<= (char->integer x) #xff) |
| 131 | `(make-char8 ,(char->integer x))) |
| 132 | (else |
| 133 | `(make-char32 ,(char->integer x))))) |
| 134 | (else #f))) |
| 135 | |
| 136 | (define (assembly->object code) |
| 137 | (pmatch code |
| 138 | ((make-true) #t) |
| 139 | ((make-false) #f) ;; FIXME: Same as the `else' case! |
| 140 | ((make-eol) '()) |
| 141 | ((make-int8 ,n) |
| 142 | (if (< n 128) n (- n 256))) |
| 143 | ((make-int16 ,n1 ,n2) |
| 144 | (let ((n (+ (* n1 256) n2))) |
| 145 | (if (< n 32768) n (- n 65536)))) |
| 146 | ((make-uint64 ,n1 ,n2 ,n3 ,n4 ,n5 ,n6 ,n7 ,n8) |
| 147 | (bytevector-u64-ref |
| 148 | (u8-list->bytevector (list n1 n2 n3 n4 n5 n6 n7 n8)) |
| 149 | 0 |
| 150 | (endianness big))) |
| 151 | ((make-int64 ,n1 ,n2 ,n3 ,n4 ,n5 ,n6 ,n7 ,n8) |
| 152 | (bytevector-s64-ref |
| 153 | (u8-list->bytevector (list n1 n2 n3 n4 n5 n6 n7 n8)) |
| 154 | 0 |
| 155 | (endianness big))) |
| 156 | ((make-char8 ,n) |
| 157 | (integer->char n)) |
| 158 | ((make-char32 ,n1 ,n2 ,n3 ,n4) |
| 159 | (integer->char (+ (* n1 #x1000000) |
| 160 | (* n2 #x10000) |
| 161 | (* n3 #x100) |
| 162 | n4))) |
| 163 | ((load-string ,s) s) |
| 164 | ((load-symbol ,s) (string->symbol s)) |
| 165 | (else #f))) |