1 files changed, 94 insertions, 0 deletions
diff --git a/src/cmp_abs.c b/src/cmp_abs.c
new file mode 100644
index 0000000..a6e6d9e
--- /dev/null
+++ b/src/cmp_abs.c
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+/* mpfr_cmpabs -- compare the absolute values of two FP numbers
+
+Copyright 1999, 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
+Contributed by the AriC and Caramel projects, INRIA.
+
+This file is part of the GNU MPFR Library.
+
+The GNU MPFR Library is free software; you can redistribute it and/or modify
+it under the terms of 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.
+
+The GNU MPFR 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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
+http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
+51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#include "mpfr-impl.h"
+
+/* Return a positive value if abs(b) > abs(c), 0 if abs(b) = abs(c), and
+   a negative value if abs(b) < abs(c). Neither b nor c may be NaN. */
+
+int
+mpfr_cmpabs (mpfr_srcptr b, mpfr_srcptr c)
+{
+  mpfr_exp_t be, ce;
+  mp_size_t bn, cn;
+  mp_limb_t *bp, *cp;
+
+  if (MPFR_ARE_SINGULAR (b, c))
+    {
+      if (MPFR_IS_NAN (b) || MPFR_IS_NAN (c))
+        {
+          MPFR_SET_ERANGE ();
+          return 0;
+        }
+      else if (MPFR_IS_INF (b))
+        return ! MPFR_IS_INF (c);
+      else if (MPFR_IS_INF (c))
+        return -1;
+      else if (MPFR_IS_ZERO (c))
+        return ! MPFR_IS_ZERO (b);
+      else /* b == 0 */
+        return -1;
+    }
+
+  MPFR_ASSERTD (MPFR_IS_PURE_FP (b));
+  MPFR_ASSERTD (MPFR_IS_PURE_FP (c));
+
+  /* Now that we know that b and c are pure FP numbers (i.e. they have
+     a meaningful exponent), we use MPFR_EXP instead of MPFR_GET_EXP to
+     allow exponents outside the current exponent range. For instance,
+     this is useful for mpfr_pow, which compares values to __gmpfr_one.
+     This is for internal use only! For compatibility with other MPFR
+     versions, the user must still provide values that are representable
+     in the current exponent range. */
+  be = MPFR_EXP (b);
+  ce = MPFR_EXP (c);
+  if (be > ce)
+    return 1;
+  if (be < ce)
+    return -1;
+
+  /* exponents are equal */
+
+  bn = MPFR_LIMB_SIZE(b)-1;
+  cn = MPFR_LIMB_SIZE(c)-1;
+
+  bp = MPFR_MANT(b);
+  cp = MPFR_MANT(c);
+
+  for ( ; bn >= 0 && cn >= 0; bn--, cn--)
+    {
+      if (bp[bn] > cp[cn])
+        return 1;
+      if (bp[bn] < cp[cn])
+        return -1;
+    }
+
+  for ( ; bn >= 0; bn--)
+    if (bp[bn])
+      return 1;
+
+  for ( ; cn >= 0; cn--)
+    if (cp[cn])
+      return -1;
+
+   return 0;
+}