X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/8646ee380d050f1e1deef1f241da272d7f227348..3485fc41bcb8b082815b7d5e48a080c1fcfbab38:/mpint.h

diff --git a/mpint.h b/mpint.h
index ed614a8..e44c39e 100644
--- a/mpint.h
+++ b/mpint.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: mpint.h,v 1.5 2002/01/13 19:23:16 mdw Exp $
+ * $Id$
  *
  * Conversion between MPs and standard C integers
  *
@@ -27,28 +27,6 @@
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: mpint.h,v $
- * Revision 1.5  2002/01/13 19:23:16  mdw
- * Fix division-by-zero bug translating @MPW_MAX@ to an @mp@.
- *
- * Revision 1.4  2000/10/08 12:04:01  mdw
- * Remove spurious semicolon.
- *
- * Revision 1.3  2000/06/17 11:45:09  mdw
- * Major memory management overhaul.  Added arena support.  Use the secure
- * arena for secret integers.  Replace and improve the MP management macros
- * (e.g., replace MP_MODIFY by MP_DEST).
- *
- * Revision 1.2  1999/12/10 23:22:53  mdw
- * Support for uint32.
- *
- * Revision 1.1  1999/11/25 11:38:31  mdw
- * Support for conversions between MPs and C integers.
- *
- */
-
 #ifndef CATACOMB_MPINT_H
 #define CATACOMB_MPINT_H
 
@@ -85,42 +63,33 @@
   MP_DEST(_d, _sz, 0);							\
   _d->f &= ~(MP_NEG | MP_UNDEF);					\
 									\
-  /* --- Set the sign on the MP --- *					\
-   *									\
-   * If the input integer is *not* negative, then negate it.  This	\
-   * fixes a problem with two's complement machines where the most	\
-   * negative value actually has larger magnitude than the most		\
-   * positive, and hence -TYPE_MIN == TYPE_MIN but TYPE_MIN != 0.  If	\
-   * all the work is carried out on negative numbers there isn't a	\
-   * problem.								\
-   */									\
-									\
-  if (_i >= 0)								\
-    _i = -_i;								\
-  else									\
+  if (_i >= 0) {							\
+    while (_i) {							\
+      if (_o == _sz) {							\
+	_sz <<= 1;							\
+	MP_ENSURE(_d, _sz);						\
+      }									\
+      _d->v[_o++] = MPW(_i);						\
+      if (_i < MPW_MAX)							\
+	break;								\
+      else								\
+	_i /= (type)MPW_MAX + 1;					\
+    }									\
+  } else {								\
     _d->f |= MP_NEG;							\
-									\
-  while (_i) {								\
-    if (_o == _sz) {							\
-      _sz <<= 1;							\
-      MP_ENSURE(_d, _sz);						\
+    while (_i) {							\
+      if (_o == _sz) {							\
+	_sz <<= 1;							\
+	MP_ENSURE(_d, _sz);						\
+      }									\
+      _d->v[_o++] = MPW(-_i);						\
+      if (_i > -MPW_MAX)						\
+	break;								\
+      else								\
+	_i /= (type)MPW_MAX + 1;					\
     }									\
-    _d->v[_o++] = MPW(-_i);						\
-									\
-    /* --- More subtlety --- *						\
-     *									\
-     * Ideally, I'd like to just shift @i@ right by @MPW_BITS@.  But I	\
-     * can't, because that might be more than I'm allowed.  I can't	\
-     * divide by @MPW_MAX + 1@ because that might turn out to be zero	\
-     * in my current type, and besides which it's unsigned which messes	\
-     * up all of my negative arithmetic.  So do an explicit test here.	\
-     */									\
-									\
-    if (_i >= -MPW_MAX)							\
-      break;								\
-    else								\
-      _i /= (type)MPW_MAX + 1;						\
   }									\
+									\
   _d->vl = _d->v + _o;							\
   (d) = _d;								\
 } while (0)
@@ -158,7 +127,7 @@
     _v++;								\
     _max /= (mpd)MPW_MAX + 1;						\
   }									\
-  if (!(_m->f & MP_NEG))						\
+  if (!MP_NEGP(_m))							\
     _i = -_i;								\
   (i) = _i;								\
 } while (0)