new functions mpfr_fits_* and mpfr_get_[us]i

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@2235 280ebfd0-de03-0410-8827-d642c229c3f4

10 files changed, 435 insertions, 0 deletions

diff --git a/fits_s.h b/fits_s.h
new file mode 100644
index 000000000..b2d749ca1
--- /dev/null
+++ b/fits_s.h
@@ -0,0 +1,82 @@
+/* mpfr_fits_*_p -- test whether an mpfr fits a C signed type.
+
+Copyright 2003 Free Software Foundation.
+Contributed by the Spaces project, INRIA Lorraine.
+Copied from mpf/fits_s.h.
+
+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"
+
+int
+FUNCTION (mpfr_srcptr f, mp_rnd_t rnd)
+{
+  mp_exp_t exp;
+  mp_prec_t prec;
+  TYPE s;
+  mpfr_t x;
+  int neg;
+  int res;
+
+  if (MPFR_IS_NAN(f) || MPFR_IS_INF(f))
+    return 0; /* does not fit */
+
+  if (MPFR_IS_ZERO(f))
+    return 1; /* zero always fits */
+
+  /* now it fits if either
+     (a) MINIMUM <= f <= MAXIMUM
+     (b) or MINIMUM <= round(f, prec(slong), rnd) <= MAXIMUM */
+
+  exp = MPFR_EXP(f);
+  if (exp < 1)
+    return 1; /* |f| < 1: always fits */
+
+  neg = (MPFR_SIGN(f) > 0) ? 0 : 1;
+
+  /* let EXTREMUM be MAXIMUM if f > 0, and MINIMUM if f < 0 */
+
+  /* first compute prec(EXTREMUM), this could be done at configure time */
+  s = (neg) ? MINIMUM : MAXIMUM;
+  for (prec = 0; s != 0; s /= 2, prec ++);
+
+  /* EXTREMUM needs prec bits, i.e. 2^(prec-1) <= |EXTREMUM| < 2^prec */
+
+   /* if exp < prec - 1, then f < 2^(prec-1) < |EXTREMUM| */
+  if (exp < prec - 1)
+    return 1;
+
+  /* if exp > prec + 1, then f >= 2^prec > EXTREMUM */
+  if (exp > prec + 1)
+    return 0;
+
+  /* remains cases exp = prec-1 to prec+1 */
+
+  /* hard case: first round to prec bits, then check */
+  mpfr_init2 (x, prec);
+  mpfr_set (x, f, rnd);
+  res = (neg) ? (mpfr_cmp_si (x, MINIMUM) >= 0)
+    : (mpfr_cmp_si (x, MAXIMUM) <= 0);
+  mpfr_clear (x);
+
+  return res;
+}
+
diff --git a/fits_sint.c b/fits_sint.c
new file mode 100644
index 000000000..017f78e20
--- /dev/null
+++ b/fits_sint.c
@@ -0,0 +1,28 @@
+/* mpfr_fits_sint_p -- test whether an mpfr fits an int.
+
+Copyright 2003 Free Software Foundation.
+Contributed by the Spaces project, INRIA Lorraine.
+
+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. */
+
+#define FUNCTION   mpfr_fits_sint_p
+#define MAXIMUM    INT_MAX
+#define MINIMUM    INT_MIN
+#define TYPE       signed int
+
+#include "fits_s.h"
diff --git a/fits_slong.c b/fits_slong.c
new file mode 100644
index 000000000..e6c01a843
--- /dev/null
+++ b/fits_slong.c
@@ -0,0 +1,28 @@
+/* mpfr_fits_slong_p -- test whether an mpfr fits a long.
+
+Copyright 2003 Free Software Foundation.
+Contributed by the Spaces project, INRIA Lorraine.
+
+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. */
+
+#define FUNCTION   mpfr_fits_slong_p
+#define MAXIMUM    LONG_MAX
+#define MINIMUM    LONG_MIN
+#define TYPE       signed long
+
+#include "fits_s.h"
diff --git a/fits_sshort.c b/fits_sshort.c
new file mode 100644
index 000000000..1ca7fc400
--- /dev/null
+++ b/fits_sshort.c
@@ -0,0 +1,28 @@
+/* mpfr_fits_sshort_p -- test whether an mpfr fits a short.
+
+Copyright 2003 Free Software Foundation.
+Contributed by the Spaces project, INRIA Lorraine.
+
+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. */
+
+#define FUNCTION   mpfr_fits_sshort_p
+#define MAXIMUM    SHRT_MAX
+#define MINIMUM    SHRT_MIN
+#define TYPE       signed short
+
+#include "fits_s.h"
diff --git a/fits_u.h b/fits_u.h
new file mode 100644
index 000000000..43101cb6b
--- /dev/null
+++ b/fits_u.h
@@ -0,0 +1,74 @@
+/* mpfr_fits_*_p -- test whether an mpfr fits a C unsigned type.
+
+Copyright 2003 Free Software Foundation.
+Contributed by the Spaces project, INRIA Lorraine.
+
+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"
+
+int
+FUNCTION (mpfr_srcptr f, mp_rnd_t rnd)
+{
+  mp_exp_t exp;
+  mp_prec_t prec;
+  TYPE s;
+  mpfr_t x;
+  int res;
+
+  if (MPFR_IS_NAN(f) || MPFR_IS_INF(f) || MPFR_SIGN(f) < 0)
+    return 0; /* does not fit */
+
+  if (MPFR_IS_ZERO(f))
+    return 1; /* zero always fits */
+
+  /* now it fits if 
+     (a) f <= MAXIMUM
+     (b) round(f, prec(slong), rnd) <= MAXIMUM */
+
+  exp = MPFR_EXP(f);
+  if (exp < 1)
+    return 1; /* |f| < 1: always fits */
+
+  /* first compute prec(MAXIMUM) */
+  for (s = MAXIMUM, prec = 0; s != 0; s /= 2, prec ++);
+
+  /* MAXIMUM needs prec bits, i.e. 2^(prec-1) <= |MAXIMUM| < 2^prec */
+
+   /* if exp < prec - 1, then f < 2^(prec-1) < |MAXIMUM| */
+  if (exp < prec - 1)
+    return 1;
+
+  /* if exp > prec + 1, then f >= 2^prec > MAXIMUM */
+  if (exp > prec + 1)
+    return 0;
+
+  /* remains cases exp = prec-1 to prec+1 */
+
+  /* hard case: first round to prec bits, then check */
+  mpfr_init2 (x, prec);
+  mpfr_set (x, f, rnd);
+  res = mpfr_cmp_ui (x, MAXIMUM) <= 0;
+  mpfr_clear (x);
+
+  return res;
+}
+
diff --git a/fits_uint.c b/fits_uint.c
new file mode 100644
index 000000000..4cce32ea7
--- /dev/null
+++ b/fits_uint.c
@@ -0,0 +1,27 @@
+/* mpfr_fits_uint_p -- test whether an mpfr fits an unsigned int.
+
+Copyright 2003 Free Software Foundation.
+Contributed by the Spaces project, INRIA Lorraine.
+
+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. */
+
+#define FUNCTION   mpfr_fits_uint_p
+#define MAXIMUM    UINT_MAX
+#define TYPE       unsigned int
+
+#include "fits_u.h"
diff --git a/fits_ulong.c b/fits_ulong.c
new file mode 100644
index 000000000..9dfec2506
--- /dev/null
+++ b/fits_ulong.c
@@ -0,0 +1,27 @@
+/* mpfr_fits_ulong_p -- test whether an mpfr fits an unsigned long.
+
+Copyright 2003 Free Software Foundation.
+Contributed by the Spaces project, INRIA Lorraine.
+
+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. */
+
+#define FUNCTION   mpfr_fits_ulong_p
+#define MAXIMUM    ULONG_MAX
+#define TYPE       unsigned long
+
+#include "fits_u.h"
diff --git a/fits_ushort.c b/fits_ushort.c
new file mode 100644
index 000000000..f42a69df0
--- /dev/null
+++ b/fits_ushort.c
@@ -0,0 +1,27 @@
+/* mpfr_fits_ushort_p -- test whether an mpfr fits an unsigned short.
+
+Copyright 2003 Free Software Foundation.
+Contributed by the Spaces project, INRIA Lorraine.
+
+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. */
+
+#define FUNCTION   mpfr_fits_ushort_p
+#define MAXIMUM    USHRT_MAX
+#define TYPE       unsigned short
+
+#include "fits_u.h"
diff --git a/get_si.c b/get_si.c
new file mode 100644
index 000000000..9a11ceae0
--- /dev/null
+++ b/get_si.c
@@ -0,0 +1,57 @@
+/* mpfr_get_si -- convert a floating-point number to a signed long.
+
+Copyright 2003 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"
+
+long
+mpfr_get_si (mpfr_srcptr f, mp_rnd_t rnd)
+{
+  mp_prec_t prec;
+  long s;
+  mpfr_t x;
+  mp_size_t n;
+  mp_exp_t exp;
+
+  if (!mpfr_fits_slong_p (f, rnd) || MPFR_IS_ZERO(f))
+    return (long) 0;
+
+  /* determine prec of long */
+  for (s = LONG_MIN, prec = 0; s != 0; s /= 2, prec ++);
+
+  /* first round to prec bits */
+  mpfr_init2 (x, prec);
+  mpfr_set (x, f, rnd);
+
+  ASSERT(GMP_NAIL_BITS == 0); /* otherwise we may have to consider two or
+				 more limbs */
+
+  /* now the result is in the most significant limb of x */
+  exp = MPFR_EXP(x); /* since |x| >= 1, exp >= 1 */
+  n = MPFR_ABSSIZE(x);
+  s = MPFR_MANT(x)[n - 1] >> (GMP_NUMB_BITS - exp);
+
+  mpfr_clear (x);
+
+  return MPFR_SIGN(f) * s;
+}
diff --git a/get_ui.c b/get_ui.c
new file mode 100644
index 000000000..b89619206
--- /dev/null
+++ b/get_ui.c
@@ -0,0 +1,57 @@
+/* mpfr_get_ui -- convert a floating-point number to an unsigned long.
+
+Copyright 2003 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"
+
+unsigned long
+mpfr_get_ui (mpfr_srcptr f, mp_rnd_t rnd)
+{
+  mp_prec_t prec;
+  unsigned long s;
+  mpfr_t x;
+  mp_size_t n;
+  mp_exp_t exp;
+
+  if (!mpfr_fits_ulong_p (f, rnd) || MPFR_IS_ZERO(f))
+    return (long) 0;
+
+  /* determine prec of unsigned long */
+  for (s = ULONG_MAX, prec = 0; s != 0; s /= 2, prec ++);
+
+  /* first round to prec bits */
+  mpfr_init2 (x, prec);
+  mpfr_set (x, f, rnd);
+
+  ASSERT(GMP_NAIL_BITS == 0); /* otherwise we may have to consider two or
+				 more limbs */
+
+  /* now the result is in the most significant limb of x */
+  exp = MPFR_EXP(x); /* since |x| >= 1, exp >= 1 */
+  n = MPFR_ABSSIZE(x);
+  s = MPFR_MANT(x)[n - 1] >> (GMP_NUMB_BITS - exp);
+
+  mpfr_clear (x);
+
+  return s;
+}