X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/c29970a7717261e63ffaabb3c67381f13c5dbca5..3485fc41bcb8b082815b7d5e48a080c1fcfbab38:/mpint.h

diff --git a/mpint.h b/mpint.h
index 23378cd..e44c39e 100644
--- a/mpint.h
+++ b/mpint.h
@@ -63,42 +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)