From 11da511c784eca003deb90c23570f0873954e0de Mon Sep 17 00:00:00 2001
From: Duncan Wilkie <antigravityd@gmail.com>
Date: Sat, 18 Nov 2023 06:11:09 -0600
Subject: Initial commit.

---
 gmp-6.3.0/mpf/eq.c | 149 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 149 insertions(+)
 create mode 100644 gmp-6.3.0/mpf/eq.c

(limited to 'gmp-6.3.0/mpf/eq.c')

diff --git a/gmp-6.3.0/mpf/eq.c b/gmp-6.3.0/mpf/eq.c
new file mode 100644
index 0000000..cddb9d5
--- /dev/null
+++ b/gmp-6.3.0/mpf/eq.c
@@ -0,0 +1,149 @@
+/* mpf_eq -- Compare two floats up to a specified bit #.
+
+Copyright 1993, 1995, 1996, 2001, 2002, 2008, 2009, 2012 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 either:
+
+  * 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.
+
+or
+
+  * the GNU General Public License as published by the Free Software
+    Foundation; either version 2 of the License, or (at your option) any
+    later version.
+
+or both in parallel, as here.
+
+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 General Public License
+for more details.
+
+You should have received copies of the GNU General Public License and the
+GNU Lesser General Public License along with the GNU MP Library.  If not,
+see https://www.gnu.org/licenses/.  */
+
+#include "gmp-impl.h"
+#include "longlong.h"
+
+int
+mpf_eq (mpf_srcptr u, mpf_srcptr v, mp_bitcnt_t n_bits)
+{
+  mp_srcptr up, vp, p;
+  mp_size_t usize, vsize, minsize, maxsize, n_limbs, i, size;
+  mp_exp_t uexp, vexp;
+  mp_limb_t diff;
+  int cnt;
+
+  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.  */
+
+  /* 2. Are the exponents different?  */
+  if (uexp != vexp)
+    return 0;
+
+  usize = ABS (usize);
+  vsize = ABS (vsize);
+
+  up = u->_mp_d;
+  vp = v->_mp_d;
+
+  up += usize;			/* point just above most significant limb */
+  vp += vsize;			/* point just above most significant limb */
+
+  count_leading_zeros (cnt, up[-1]);
+  if ((vp[-1] >> (GMP_LIMB_BITS - 1 - cnt)) != 1)
+    return 0;			/* msb positions different */
+
+  n_bits += cnt - GMP_NAIL_BITS;
+  n_limbs = (n_bits + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS;
+
+  usize = MIN (usize, n_limbs);
+  vsize = MIN (vsize, n_limbs);
+
+#if 0
+  /* Ignore zeros at the low end of U and V.  */
+  while (up[0] == 0)
+    up++, usize--;
+  while (vp[0] == 0)
+    vp++, vsize--;
+#endif
+
+  minsize = MIN (usize, vsize);
+  maxsize = usize + vsize - minsize;
+
+  up -= minsize;		/* point at most significant common limb */
+  vp -= minsize;		/* point at most significant common limb */
+
+  /* Compare the most significant part which has explicit limbs for U and V. */
+  for (i = minsize - 1; i > 0; i--)
+    {
+      if (up[i] != vp[i])
+	return 0;
+    }
+
+  n_bits -= (maxsize - 1) * GMP_NUMB_BITS;
+
+  size = maxsize - minsize;
+  if (size != 0)
+    {
+      if (up[0] != vp[0])
+	return 0;
+
+      /* Now either U or V has its limbs consumed, i.e, continues with an
+	 infinite number of implicit zero limbs.  Check that the other operand
+	 has just zeros in the corresponding, relevant part.  */
+
+      if (usize > vsize)
+	p = up - size;
+      else
+	p = vp - size;
+
+      for (i = size - 1; i > 0; i--)
+	{
+	  if (p[i] != 0)
+	    return 0;
+	}
+
+      diff = p[0];
+    }
+  else
+    {
+      /* Both U or V has its limbs consumed.  */
+
+      diff = up[0] ^ vp[0];
+    }
+
+  if (n_bits < GMP_NUMB_BITS)
+    diff >>= GMP_NUMB_BITS - n_bits;
+
+  return diff == 0;
+}
-- 
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