[Gmp-commit] /var/hg/gmp: 2 new changesets

[mercurial at gmplib.org]

details:   /var/hg/gmp/rev/89e43a9eab63
changeset: 17622:89e43a9eab63
user:      Marco Bodrato <bodrato at mail.dm.unipi.it>
date:      Mon May 14 21:46:46 2018 +0200
description:
mpn/generic/get_d.c: Enhance generic code using DBL_MANT_DIG.

details:   /var/hg/gmp/rev/274a52c270c0
changeset: 17623:274a52c270c0
user:      Marco Bodrato <bodrato at mail.dm.unipi.it>
date:      Mon May 14 21:47:51 2018 +0200
description:
Changelog

diffstat:

 ChangeLog           |  13 +++++++++++++
 mpn/generic/get_d.c |  45 ++++++++++++++++++++++++++++++++++++---------
 2 files changed, 49 insertions(+), 9 deletions(-)

diffs (96 lines):

diff -r f1f2b927d1c7 -r 274a52c270c0 ChangeLog
--- a/ChangeLog	Sun May 13 09:47:33 2018 +0200
+++ b/ChangeLog	Mon May 14 21:47:51 2018 +0200
@@ -1,3 +1,16 @@
+2018-05-14 Marco Bodrato <bodrato at mail.dm.unipi.it>
+
+	* mpn/generic/dcpi1_bdiv_q.c (mpn_dcpi1_bdiv_q_n): Decl. static.
+	(mpn_dcpi1_bdiv_q_n_itch): Declare static.
+	* mpn/generic/dcpi1_divappr_q.c (mpn_dcpi1_divappr_q_n): static.
+	* mpn/generic/matrix22_mul.c (mpn_matrix22_mul_strassen): static.
+	* mpn/generic/mu_div_qr.c (mpn_mu_div_qr_choose_in): static.
+	* mpn/generic/mu_divappr_q.c (mpn_preinv_mu_divappr_q): static.
+	(mpn_mu_divappr_q_choose_in): static.
+	* gmp-impl.h: Remove declaration of previous functions.
+
+	* mpn/generic/get_d.c: Enhance generic code using DBL_MANT_DIG.
+
 2018-05-04 Marco Bodrato <bodrato at mail.dm.unipi.it>
 
 	* doc/gmp.texi (mpq_*_str): Document the full base allowed range.
diff -r f1f2b927d1c7 -r 274a52c270c0 mpn/generic/get_d.c
--- a/mpn/generic/get_d.c	Sun May 13 09:47:33 2018 +0200
+++ b/mpn/generic/get_d.c	Mon May 14 21:47:51 2018 +0200
@@ -4,7 +4,8 @@
    CERTAIN TO BE SUBJECT TO INCOMPATIBLE CHANGES OR DISAPPEAR COMPLETELY IN
    FUTURE GNU MP RELEASES.
 
-Copyright 2003, 2004, 2007, 2009, 2010, 2012 Free Software Foundation, Inc.
+Copyright 2003, 2004, 2007, 2009, 2010, 2012, 2018 Free Software
+Foundation, Inc.
 
 This file is part of the GNU MP Library.
 
@@ -32,6 +33,12 @@
 GNU Lesser General Public License along with the GNU MP Library.  If not,
 see https://www.gnu.org/licenses/.  */
 
+#include "config.h"
+
+#if HAVE_FLOAT_H
+#include <float.h>  /* for DBL_MANT_DIG and FLT_RADIX */
+#endif
+
 #include "gmp-impl.h"
 #include "longlong.h"
 
@@ -354,21 +361,41 @@
 #endif
 
 #if ! FORMAT_RECOGNIZED
-    {      /* Non-IEEE or strange limb size, do something generic. */
+
+#if !defined(GMP_DBL_MANT_BITS)
+#if defined(DBL_MANT_DIG) && FLT_RADIX == 2
+#define GMP_DBL_MANT_BITS DBL_MANT_DIG
+#else
+/* FIXME: Chose a smarter default value. */
+#define GMP_DBL_MANT_BITS (16 * sizeof (double))
+#endif
+#endif
+
+    { /* Non-IEEE or strange limb size, generically convert
+	 GMP_DBL_MANT_BITS bits. */
+      mp_limb_t l;
+      int m;
       mp_size_t i;
       double d, weight;
       unsigned long uexp;
 
       /* First generate an fp number disregarding exp, instead keeping things
 	 within the numb base factor from 1, which should prevent overflow and
-	 underflow even for the most exponent limited fp formats.  The
-	 termination criteria should be refined, since we now include too many
-	 limbs.  */
-      weight = 1/MP_BASE_AS_DOUBLE;
-      d = up[size - 1];
-      for (i = size - 2; i >= 0; i--)
+	 underflow even for the most exponent limited fp formats.  */
+      i = size - 1;
+      l = up[i];
+      count_leading_zeros (m, l);
+      m = m + GMP_DBL_MANT_BITS - GMP_LIMB_BITS;
+      if (m < 0)
+	l &= GMP_NUMB_MAX << -m;
+      d = l;
+      for (weight = 1/MP_BASE_AS_DOUBLE; m > 0 && --i >= 0;)
 	{
-	  d += up[i] * weight;
+	  l = up[i];
+	  m -= GMP_NUMB_BITS;
+	  if (m < 0)
+	    l &= GMP_NUMB_MAX << -m;
+	  d += l * weight;
 	  weight /= MP_BASE_AS_DOUBLE;
 	  if (weight == 0)
 	    break;