Imported gcc-4.4.3

[msp430-gcc.git] / mpfr / cmp_ui.c

diff --git a/mpfr/cmp_ui.c b/mpfr/cmp_ui.c
new file mode 100644 (file)
index 0000000..29843eb
--- /dev/null
+++ b/mpfr/cmp_ui.c
@@ -0,0 +1,101 @@
+/* mpfr_cmp_ui_2exp -- compare a floating-point number with an unsigned
+machine integer multiplied by a power of 2
+
+Copyright 1999, 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+Contributed by the Arenaire and Cacao 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 2.1 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.LIB.  If not, write to
+the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+MA 02110-1301, USA. */
+
+#define MPFR_NEED_LONGLONG_H
+#include "mpfr-impl.h"
+
+/* returns a positive value if b > i*2^f,
+           a negative value if b < i*2^f,
+           zero if b = i*2^f.
+   b must not be NaN
+*/
+
+int
+mpfr_cmp_ui_2exp (mpfr_srcptr b, unsigned long int i, mp_exp_t f)
+{
+  if (MPFR_UNLIKELY( MPFR_IS_SINGULAR(b) ))
+    {
+      if (MPFR_IS_NAN (b))
+        {
+          MPFR_SET_ERANGE ();
+          return 0;
+        }
+      else if (MPFR_IS_INF(b))
+        return MPFR_INT_SIGN (b);
+      else /* since b cannot be NaN, b=0 here */
+        return i != 0 ? -1 : 0;
+    }
+
+  if (MPFR_IS_NEG (b))
+    return -1;
+  /* now b > 0 */
+  else if (MPFR_UNLIKELY(i == 0))
+    return 1;
+  else /* b > 0, i > 0 */
+    {
+      mp_exp_t e;
+      int k;
+      mp_size_t bn;
+      mp_limb_t c, *bp;
+
+      /* i must be representable in a mp_limb_t */
+      MPFR_ASSERTN(i == (mp_limb_t) i);
+
+      e = MPFR_GET_EXP (b); /* 2^(e-1) <= b < 2^e */
+      if (e <= f)
+        return -1;
+      if (f < MPFR_EMAX_MAX - BITS_PER_MP_LIMB &&
+          e > f + BITS_PER_MP_LIMB)
+        return 1;
+
+      /* now f < e <= f + BITS_PER_MP_LIMB */
+      c = (mp_limb_t) i;
+      count_leading_zeros(k, c);
+      if ((int) (e - f) > BITS_PER_MP_LIMB - k)
+        return 1;
+      if ((int) (e - f) < BITS_PER_MP_LIMB - k)
+        return -1;
+
+      /* now b and i*2^f have the same exponent */
+      c <<= k;
+      bn = (MPFR_PREC(b) - 1) / BITS_PER_MP_LIMB;
+      bp = MPFR_MANT(b);
+      if (bp[bn] > c)
+        return 1;
+      if (bp[bn] < c)
+        return -1;
+
+      /* most significant limbs agree, check remaining limbs from b */
+      while (bn > 0)
+        if (bp[--bn] != 0)
+          return 1;
+      return 0;
+    }
+}
+
+#undef mpfr_cmp_ui
+int
+mpfr_cmp_ui (mpfr_srcptr b, unsigned long int i)
+{
+  return mpfr_cmp_ui_2exp (b, i, 0);
+}