Add `load-unsigned-integer' instruction.

* libguile/vm-i-loader.c (load_unsigned_integer): New loader.

* module/language/assembly.scm (byte-length): Handle
  `load-unsigned-integer'.

* module/language/assembly/compile-bytecode.scm (write-bytecode):
  Likewise.

* module/language/glil/compile-assembly.scm (dump-object): Emit a
  `load-unsigned-integer' instruction for positive integers.  This fixes
  loading of integers greater than 2^31 - 1.

* testsuite/Makefile.am (vm_test_files): Add `t-literal-integers.scm'.

* doc/ref/vm.texi (Loading Instructions): Add `load-unsigned-integer'.

doc/ref/vm.texi

@@ -549,7 +549,9 @@ indicating the size of the embedded data, in bytes. The length itself
 may be encoded in 1, 2, or 4 bytes.
 
 @deffn Instruction load-integer length
-Load a 32-bit integer from the instruction stream.
+@deffnx Instruction load-unsigned-integer length
+Load a 32-bit integer (respectively unsigned integer) from the
+instruction stream.
 @end deffn
 @deffn Instruction load-number length
 Load an arbitrary number from the instruction stream. The number is

libguile/vm-i-loader.c

@@ -18,12 +18,30 @@
 
 /* This file is included in vm_engine.c */
 
+VM_DEFINE_LOADER (59, load_unsigned_integer, "load-unsigned-integer")
+{
+  size_t len;
+
+  FETCH_LENGTH (len);
+  if (SCM_LIKELY (len <= 4))
+    {
+      unsigned int val = 0;
+      while (len-- > 0)
+	val = (val << 8U) + FETCH ();
+      SYNC_REGISTER ();
+      PUSH (scm_from_uint (val));
+      NEXT;
+    }
+  else
+    SCM_MISC_ERROR ("load-unsigned-integer: not implemented yet", SCM_EOL);
+}
+
 VM_DEFINE_LOADER (60, load_integer, "load-integer")
 {
   size_t len;
 
   FETCH_LENGTH (len);
-  if (len <= 4)
+  if (SCM_LIKELY (len <= 4))
     {
       int val = 0;
       while (len-- > 0)

module/language/assembly.scm

@@ -1,6 +1,6 @@
 ;;; Guile Virtual Machine Assembly
 
-;; Copyright (C) 2001 Free Software Foundation, Inc.
+;; Copyright (C) 2001, 2009 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
@@ -38,6 +38,8 @@
   (pmatch assembly
     (,label (guard (not (pair? label)))
      0)
+    ((load-unsigned-integer ,str)
+     (+ 1 *len-len* (string-length str)))
     ((load-integer ,str)
      (+ 1 *len-len* (string-length str)))
     ((load-number ,str)

module/language/assembly/compile-bytecode.scm

@@ -1,6 +1,6 @@
 ;;; Guile VM assembler
 
-;; Copyright (C) 2001 Free Software Foundation, Inc.
+;; Copyright (C) 2001, 2009 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
@@ -107,6 +107,7 @@
                                (if (> i 0) (write-byte x))))
                       (get-addr (lambda () i)))
                (write-bytecode meta write get-addr '()))))
+        ((load-unsigned-integer ,str) (write-loader str))
         ((load-integer ,str) (write-loader str))
         ((load-number ,str) (write-loader str))
         ((load-string ,str) (write-loader str))

module/language/glil/compile-assembly.scm

@@ -1,6 +1,6 @@
 ;;; Guile VM assembler
 
-;; Copyright (C) 2001 Free Software Foundation, Inc.
+;; Copyright (C) 2001, 2009 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
@@ -343,7 +343,9 @@
                     (l '() (cons (modulo n 256) l)))
                    ((= n 0)
                     (list->string (map integer->char l))))))
-      `((load-integer ,str))))
+      (if (< x 0)
+	  `((load-integer ,str))
+	  `((load-unsigned-integer ,str)))))
    ((number? x)
     `((load-number ,(number->string x))))
    ((string? x)

testsuite/Makefile.am

@@ -13,6 +13,7 @@ vm_test_files =					\
       t-closure3.scm				\
       t-closure4.scm				\
       t-do-loop.scm				\
+      t-literal-integers.scm			\
       t-macros.scm				\
       t-macros2.scm				\
       t-map.scm					\

testsuite/t-literal-integers.scm

@@ -0,0 +1,5 @@
+;; Check whether literal integers are correctly signed.
+
+(and (=  4294967295 (- (expt 2 32) 1))      ;; unsigned
+     (= -2147483648 (- (expt 2 31)))        ;; signed
+     (=  2147483648 (expt 2 31)))           ;; unsigned