1 files changed, 255 insertions, 0 deletions
diff --git a/mpfr/src/set_d.c b/mpfr/src/set_d.c
new file mode 100644
index 0000000000..c076ccf840
--- /dev/null
+++ b/mpfr/src/set_d.c
@@ -0,0 +1,255 @@
+/* mpfr_set_d -- convert a machine double precision float to
+                 a multiple precision floating-point number
+
+Copyright 1999-2004, 2006-2016 Free Software Foundation, Inc.
+Contributed by the AriC and Caramba 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 <float.h>  /* For DOUBLE_ISINF and DOUBLE_ISNAN */
+
+#define MPFR_NEED_LONGLONG_H
+#include "mpfr-impl.h"
+
+/* extracts the bits of d in rp[0..n-1] where n=ceil(53/GMP_NUMB_BITS).
+   Assumes d is neither 0 nor NaN nor Inf. */
+static long
+__gmpfr_extract_double (mpfr_limb_ptr rp, double d)
+     /* e=0 iff GMP_NUMB_BITS=32 and rp has only one limb */
+{
+  long exp;
+  mp_limb_t manl;
+#if GMP_NUMB_BITS == 32
+  mp_limb_t manh;
+#endif
+
+  /* BUGS
+     1. Should handle Inf and NaN in IEEE specific code.
+     2. Handle Inf and NaN also in default code, to avoid hangs.
+     3. Generalize to handle all GMP_NUMB_BITS.
+     4. This lits is incomplete and misspelled.
+   */
+
+  MPFR_ASSERTD(!DOUBLE_ISNAN(d));
+  MPFR_ASSERTD(!DOUBLE_ISINF(d));
+  MPFR_ASSERTD(d != 0.0);
+
+#if _GMP_IEEE_FLOATS
+
+  {
+    union ieee_double_extract x;
+    x.d = d;
+
+    exp = x.s.exp;
+    if (exp)
+      {
+#if GMP_NUMB_BITS >= 64
+        manl = ((MPFR_LIMB_ONE << 63)
+                | ((mp_limb_t) x.s.manh << 43) | ((mp_limb_t) x.s.manl << 11));
+#else
+        manh = (MPFR_LIMB_ONE << 31) | (x.s.manh << 11) | (x.s.manl >> 21);
+        manl = x.s.manl << 11;
+#endif
+      }
+    else /* subnormal number */
+      {
+#if GMP_NUMB_BITS >= 64
+        manl = ((mp_limb_t) x.s.manh << 43) | ((mp_limb_t) x.s.manl << 11);
+#else
+        manh = (x.s.manh << 11) /* high 21 bits */
+          | (x.s.manl >> 21); /* middle 11 bits */
+        manl = x.s.manl << 11; /* low 21 bits */
+#endif
+      }
+
+    if (exp)
+      exp -= 1022;
+    else
+      exp = -1021;
+  }
+
+#else /* _GMP_IEEE_FLOATS */
+
+  {
+    /* Unknown (or known to be non-IEEE) double format.  */
+    exp = 0;
+    if (d >= 1.0)
+      {
+        MPFR_ASSERTN (d * 0.5 != d);
+        while (d >= 32768.0)
+          {
+            d *= (1.0 / 65536.0);
+            exp += 16;
+          }
+        while (d >= 1.0)
+          {
+            d *= 0.5;
+            exp += 1;
+          }
+      }
+    else if (d < 0.5)
+      {
+        while (d < (1.0 / 65536.0))
+          {
+            d *=  65536.0;
+            exp -= 16;
+          }
+        while (d < 0.5)
+          {
+            d *= 2.0;
+            exp -= 1;
+          }
+      }
+
+    d *= MP_BASE_AS_DOUBLE;
+#if GMP_NUMB_BITS >= 64
+    manl = d;
+#else
+    manh = (mp_limb_t) d;
+    manl = (mp_limb_t) ((d - manh) * MP_BASE_AS_DOUBLE);
+#endif
+  }
+
+#endif /* _GMP_IEEE_FLOATS */
+
+#if GMP_NUMB_BITS >= 64
+  rp[0] = manl;
+#else
+  rp[1] = manh;
+  rp[0] = manl;
+#endif
+
+  return exp;
+}
+
+/* End of part included from gmp-2.0.2 */
+
+int
+mpfr_set_d (mpfr_ptr r, double d, mpfr_rnd_t rnd_mode)
+{
+  int signd, inexact;
+  unsigned int cnt;
+  mp_size_t i, k;
+  mpfr_t tmp;
+  mp_limb_t tmpmant[MPFR_LIMBS_PER_DOUBLE];
+  MPFR_SAVE_EXPO_DECL (expo);
+
+  if (MPFR_UNLIKELY(DOUBLE_ISNAN(d)))
+    {
+      MPFR_SET_NAN(r);
+      MPFR_RET_NAN;
+    }
+  else if (MPFR_UNLIKELY(d == 0))
+    {
+#if _GMP_IEEE_FLOATS
+      union ieee_double_extract x;
+
+      MPFR_SET_ZERO(r);
+      /* set correct sign */
+      x.d = d;
+      if (x.s.sig == 1)
+        MPFR_SET_NEG(r);
+      else
+        MPFR_SET_POS(r);
+#else /* _GMP_IEEE_FLOATS */
+      MPFR_SET_ZERO(r);
+      {
+        /* This is to get the sign of zero on non-IEEE hardware
+           Some systems support +0.0, -0.0 and unsigned zero.
+           We can't use d==+0.0 since it should be always true,
+           so we check that the memory representation of d is the
+           same than +0.0. etc */
+        /* FIXME: consider the case where +0.0 or -0.0 may have several
+           representations. */
+        double poszero = +0.0, negzero = DBL_NEG_ZERO;
+        if (memcmp(&d, &poszero, sizeof(double)) == 0)
+          MPFR_SET_POS(r);
+        else if (memcmp(&d, &negzero, sizeof(double)) == 0)
+          MPFR_SET_NEG(r);
+        else
+          MPFR_SET_POS(r);
+      }
+#endif
+      return 0; /* 0 is exact */
+    }
+  else if (MPFR_UNLIKELY(DOUBLE_ISINF(d)))
+    {
+      MPFR_SET_INF(r);
+      if (d > 0)
+        MPFR_SET_POS(r);
+      else
+        MPFR_SET_NEG(r);
+      return 0; /* infinity is exact */
+    }
+
+  /* now d is neither 0, nor NaN nor Inf */
+
+  MPFR_SAVE_EXPO_MARK (expo);
+
+  /* warning: don't use tmp=r here, even if SIZE(r) >= MPFR_LIMBS_PER_DOUBLE,
+     since PREC(r) may be different from PREC(tmp), and then both variables
+     would have same precision in the mpfr_set4 call below. */
+  MPFR_MANT(tmp) = tmpmant;
+  MPFR_PREC(tmp) = IEEE_DBL_MANT_DIG;
+
+  signd = (d < 0) ? MPFR_SIGN_NEG : MPFR_SIGN_POS;
+  d = ABS (d);
+
+  /* don't use MPFR_SET_EXP here since the exponent may be out of range */
+  MPFR_EXP(tmp) = __gmpfr_extract_double (tmpmant, d);
+
+#ifdef MPFR_WANT_ASSERT
+  /* Failed assertion if the stored value is 0 (e.g., if the exponent range
+     has been reduced at the wrong moment and an underflow to 0 occurred).
+     Probably a bug in the C implementation if this happens. */
+  i = 0;
+  while (tmpmant[i] == 0)
+    {
+      i++;
+      MPFR_ASSERTN(i < MPFR_LIMBS_PER_DOUBLE);
+    }
+#endif
+
+  /* determine the index i-1 of the most significant non-zero limb
+     and the number k of zero high limbs */
+  i = MPFR_LIMBS_PER_DOUBLE;
+  MPN_NORMALIZE_NOT_ZERO(tmpmant, i);
+  k = MPFR_LIMBS_PER_DOUBLE - i;
+
+  count_leading_zeros (cnt, tmpmant[i - 1]);
+
+  if (MPFR_LIKELY(cnt != 0))
+    mpn_lshift (tmpmant + k, tmpmant, i, cnt);
+  else if (k != 0)
+    MPN_COPY (tmpmant + k, tmpmant, i);
+
+  if (MPFR_UNLIKELY(k != 0))
+    MPN_ZERO (tmpmant, k);
+
+  /* don't use MPFR_SET_EXP here since the exponent may be out of range */
+  MPFR_EXP(tmp) -= (mpfr_exp_t) (cnt + k * GMP_NUMB_BITS);
+
+  /* tmp is exact since PREC(tmp)=53 */
+  inexact = mpfr_set4 (r, tmp, rnd_mode, signd);
+
+  MPFR_SAVE_EXPO_FREE (expo);
+  return mpfr_check_range (r, inexact, rnd_mode);
+}
+
+
+