1 files changed, 80 insertions, 0 deletions
diff --git a/src/check.c b/src/check.c
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+++ b/src/check.c
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+/* mpfr_check -- Check if a floating-point number has not been corrupted.
+
+Copyright 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"
+
+/*
+ * Check if x is a valid mpfr_t initializes by mpfr_init
+ * Returns 0 if isn't valid
+ */
+int
+mpfr_check (mpfr_srcptr x)
+{
+  mp_size_t s, i;
+  mp_limb_t tmp;
+  volatile mp_limb_t *xm;
+  int rw;
+
+  /* Check Sign */
+  if (MPFR_SIGN(x) != MPFR_SIGN_POS && MPFR_SIGN(x) != MPFR_SIGN_NEG)
+    return 0;
+  /* Check Precision */
+  if ( (MPFR_PREC(x) < MPFR_PREC_MIN) || (MPFR_PREC(x) > MPFR_PREC_MAX))
+    return 0;
+  /* Check Mantissa */
+  xm = MPFR_MANT(x);
+  if (!xm)
+    return 0;
+  /* Check size of mantissa */
+  s = MPFR_GET_ALLOC_SIZE(x);
+  if (s<=0 || s > MP_SIZE_T_MAX ||
+      MPFR_PREC(x) > ((mpfr_prec_t)s*GMP_NUMB_BITS))
+    return 0;
+  /* Acces all the mp_limb of the mantissa: may do a seg fault */
+  for(i = 0 ; i < s ; i++)
+    tmp = xm[i];
+  /* Check if it isn't singular*/
+  if (! MPFR_IS_SINGULAR (x))
+    {
+      /* Check first mp_limb of mantissa (Must start with a 1 bit) */
+      if ( ((xm[MPFR_LIMB_SIZE(x)-1])>>(GMP_NUMB_BITS-1)) == 0)
+        return 0;
+      /* Check last mp_limb of mantissa */
+      rw = (MPFR_PREC(x) % GMP_NUMB_BITS);
+      if (rw != 0)
+        {
+          tmp = MPFR_LIMB_MASK (GMP_NUMB_BITS - rw);
+          if ((xm[0] & tmp) != 0)
+            return 0;
+        }
+      /* Check exponent range */
+      if ((MPFR_EXP (x) < __gmpfr_emin) || (MPFR_EXP (x) > __gmpfr_emax))
+        return 0;
+    }
+  else
+    {
+      /* Singular value is zero, inf or nan */
+      MPFR_ASSERTD(MPFR_IS_ZERO(x) || MPFR_IS_NAN(x) || MPFR_IS_INF(x));
+    }
+  return 1;
+}
+