1 files changed, 98 insertions, 0 deletions
diff --git a/module/language/bytecode.scm b/module/language/bytecode.scm
new file mode 100644
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+++ b/module/language/bytecode.scm
@@ -0,0 +1,98 @@
+;;; Bytecode
+
+;; Copyright (C) 2013 Free Software Foundation, Inc.
+
+;;;; This library is free software; you can redistribute it and/or
+;;;; modify it under the terms of the GNU Lesser General Public
+;;;; License as published by the Free Software Foundation; either
+;;;; version 3 of the License, or (at your option) any later version.
+;;;; 
+;;;; This library 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
+;;;; Lesser General Public License for more details.
+;;;; 
+;;;; You should have received a copy of the GNU Lesser General Public
+;;;; License along with this library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+;;; Code:
+
+(define-module (language bytecode)
+  #:use-module (ice-9 match)
+  #:use-module ((srfi srfi-1) #:select (fold))
+  #:export (instruction-list
+            instruction-arity
+            builtin-name->index
+            builtin-index->name))
+
+(load-extension (string-append "libguile-" (effective-version))
+                "scm_init_instructions")
+(load-extension (string-append "libguile-" (effective-version))
+                "scm_init_vm_builtins")
+
+(define (compute-instruction-arity name args)
+  (define (first-word-arity word)
+    (case word
+      ((U8_X24) 0)
+      ((U8_U24) 1)
+      ((U8_L24) 1)
+      ((U8_U8_I16) 2)
+      ((U8_U12_U12) 2)
+      ((U8_U8_U8_U8) 3)))
+  (define (tail-word-arity word)
+    (case word
+      ((U8_U24) 2)
+      ((U8_L24) 2)
+      ((U8_U8_I16) 3)
+      ((U8_U12_U12) 3)
+      ((U8_U8_U8_U8) 4)
+      ((U32) 1)
+      ((I32) 1)
+      ((A32) 1)
+      ((B32) 0)
+      ((N32) 1)
+      ((S32) 1)
+      ((L32) 1)
+      ((LO32) 1)
+      ((X8_U24) 1)
+      ((X8_U12_U12) 2)
+      ((X8_L24) 1)
+      ((B1_X7_L24) 2)
+      ((B1_U7_L24) 3)
+      ((B1_X31) 1)
+      ((B1_X7_U24) 2)))
+  (match args
+    ((arg0 . args)
+     (fold (lambda (arg arity)
+             (+ (tail-word-arity arg) arity))
+           (first-word-arity arg0)
+           args))))
+
+(define *macro-instruction-arities*
+  '((cache-current-module! . (0 . 2))
+    (cached-toplevel-box . (1 . 3))
+    (cached-module-box . (1 . 4))))
+
+(define (compute-instruction-arities)
+  (let ((table (make-hash-table)))
+    (for-each
+     (match-lambda
+      ;; Put special cases here.
+      ((name op '! . args)
+       (hashq-set! table name
+                   (cons 0 (compute-instruction-arity name args))))
+      ((name op '<- . args)
+       (hashq-set! table name
+                   (cons 1 (1- (compute-instruction-arity name args))))))
+     (instruction-list))
+    (for-each (match-lambda
+               ((name . arity)
+                (hashq-set! table name arity)))
+              *macro-instruction-arities*)
+    table))
+
+(define *instruction-arities* (delay (compute-instruction-arities)))
+
+(define (instruction-arity name)
+  (hashq-ref (force *instruction-arities*) name))