1 files changed, 72 insertions, 0 deletions
diff --git a/mpfr/cmp_abs.c b/mpfr/cmp_abs.c
new file mode 100644
index 000000000..cae56154e
--- /dev/null
+++ b/mpfr/cmp_abs.c
@@ -0,0 +1,72 @@
+/* mpfr_cmp_abs -- compare the absolute values of two nonzero FP numbers
+
+Copyright (C) 1999, 2001 Free Software Foundation, Inc.
+
+This file is part of the MPFR Library.
+
+The 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 2.1 of the License, or (at your
+option) any later version.
+
+The 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 MPFR 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"
+#include "mpfr.h"
+#include "mpfr-impl.h"
+
+/* returns sign(abs(b) - abs(c))
+   b and c must be nonzero real numbers */
+
+int
+mpfr_cmp_abs (mpfr_srcptr b, mpfr_srcptr c)
+{
+  mp_exp_t be, ce;
+  mp_size_t bn, cn;
+  mp_limb_t *bp, *cp;
+
+  MPFR_ASSERTN(MPFR_IS_FP(b) && MPFR_NOTZERO(b));
+  MPFR_ASSERTN(MPFR_IS_FP(c) && MPFR_NOTZERO(c));
+
+  be = MPFR_EXP(b);
+  ce = MPFR_EXP(c);
+  if (be > ce)
+    return 1;
+  if (be < ce)
+    return -1;
+
+  /* exponents are equal */
+
+  bn = (MPFR_PREC(b)-1)/BITS_PER_MP_LIMB;
+  cn = (MPFR_PREC(c)-1)/BITS_PER_MP_LIMB;
+
+  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;
+}