Initial revision

1 files changed, 121 insertions, 0 deletions

diff --git a/mpf/eq.c b/mpf/eq.c
new file mode 100644
index 000000000..a474a4dc0
--- /dev/null
+++ b/mpf/eq.c
@@ -0,0 +1,121 @@
+/* mpf_cmp2 -- Compare two floats up to a specified bit #.
+
+Copyright (C) 1993, 1995, 1996 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Library General Public License as published by
+the Free Software Foundation; either version 2 of the License, or (at your
+option) any later version.
+
+The GNU MP 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 Library General Public
+License for more details.
+
+You should have received a copy of the GNU Library General Public License
+along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+int
+#if __STDC__
+mpf_cmp2 (mpf_srcptr u, mpf_srcptr v, unsigned long int n_bits)
+#else
+mpf_cmp2 (u, v, n_bits)
+     mpf_srcptr u;
+     mpf_srcptr v;
+     unsigned long int n_bits;
+#endif
+{
+  mp_srcptr up, vp;
+  mp_size_t usize, vsize, size, i;
+  mp_exp_t uexp, vexp;
+  int usign;
+
+  uexp = u->_mp_exp;
+  vexp = v->_mp_exp;
+
+  usize = u->_mp_size;
+  vsize = v->_mp_size;
+
+  /* 1. Are the signs different?  */
+  if ((usize ^ vsize) >= 0)
+    {
+      /* U and V are both non-negative or both negative.  */
+      if (usize == 0)
+	return vsize == 0;
+      if (vsize == 0)
+	return 0;
+
+      /* Fall out.  */
+    }
+  else
+    {
+      /* Either U or V is negative, but not both.  */
+      return 0;
+    }
+
+  /* U and V have the same sign and are both non-zero.  */
+
+  usign = usize >= 0 ? 1 : -1;
+
+  /* 2. Are the exponents different?  */
+  if (uexp > vexp)
+    return 0;			/* ??? handle (uexp = vexp + 1)   */
+  if (vexp > uexp)
+    return 0;			/* ??? handle (vexp = uexp + 1)   */
+
+  usize = ABS (usize);
+  vsize = ABS (vsize);
+
+  up = u->_mp_d;
+  vp = v->_mp_d;
+
+  /* Ignore zeroes at the low end of U and V.  */
+  while (up[0] == 0)
+    {
+      up++;
+      usize--;
+    }
+  while (vp[0] == 0)
+    {
+      vp++;
+      vsize--;
+    }
+
+  if (usize > vsize)
+    {
+      if (vsize * BITS_PER_MP_LIMB < n_bits)
+	return 0;		/* surely too different */
+      size = vsize;
+    }
+  else if (vsize > usize)
+    {
+      if (usize * BITS_PER_MP_LIMB < n_bits)
+	return 0;		/* surely too different */
+      size = usize;
+    }
+  else
+    {
+      size = usize;
+    }
+
+  if (size > (n_bits + BITS_PER_MP_LIMB - 1) / BITS_PER_MP_LIMB)
+    size = (n_bits + BITS_PER_MP_LIMB - 1) / BITS_PER_MP_LIMB;
+
+  up += usize - size;
+  vp += vsize - size;
+
+  for (i = size - 1; i >= 0; i--)
+    {
+      if (up[i] != vp[i])
+	return 0;
+    }
+
+  return 1;
+}