added new function mpfr_fmodquo

(cf https://sympa.inria.fr/sympa/arc/mpfr/2012-03/msg00020.html)


git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@8129 280ebfd0-de03-0410-8827-d642c229c3f4

6 files changed, 149 insertions, 7 deletions

diff --git a/NEWS b/NEWS
index fb733cb5a..01091d3a5 100644
--- a/NEWS
+++ b/NEWS
@@ -25,6 +25,8 @@ Changes from versions 3.1.* to version 3.2.0:
 - New functions: mpfr_fpif_export and mpfr_fpif_import to export and import
   numbers in a floating-point interchange format, independent both on the
   number of bits per word and on the endianness.
+- New function mpfr_fmodquo to return the low bits of the quotient
+  corresponding to mpfr_fmod.
 - Updated tuning parameters.
 - Improved MPFR manual.
 - Bug fixes.
diff --git a/doc/mpfr.texi b/doc/mpfr.texi
index 619b53d76..cf3bdfa74 100644
--- a/doc/mpfr.texi
+++ b/doc/mpfr.texi
@@ -2525,13 +2525,15 @@ corresponding precision of @var{iop} and @var{fop} (equivalent to
 @end deftypefun
 
 @deftypefun int mpfr_fmod (mpfr_t @var{r}, mpfr_t @var{x}, mpfr_t @var{y}, mpfr_rnd_t @var{rnd})
+@deftypefunx int mpfr_fmodquo (mpfr_t @var{r}, long* @var{q}, mpfr_t @var{x}, mpfr_t @var{y}, mpfr_rnd_t @var{rnd})
 @deftypefunx int mpfr_remainder (mpfr_t @var{r}, mpfr_t @var{x}, mpfr_t @var{y}, mpfr_rnd_t @var{rnd})
 @deftypefunx int mpfr_remquo (mpfr_t @var{r}, long* @var{q}, mpfr_t @var{x}, mpfr_t @var{y}, mpfr_rnd_t @var{rnd})
 Set @var{r} to the value of @math{@var{x} - @var{n}@var{y}}, rounded
 according to the direction @var{rnd}, where @var{n} is the integer quotient
 of @var{x} divided by @var{y}, defined as follows: @var{n} is rounded
-toward zero for @code{mpfr_fmod}, and to the nearest integer (ties rounded
-to even) for @code{mpfr_remainder} and @code{mpfr_remquo}.
+toward zero for @code{mpfr_fmod} and @code{mpfr_fmodquo},
+and to the nearest integer (ties rounded to even) for @code{mpfr_remainder}
+and @code{mpfr_remquo}.
 
 Special values are handled as described in Section F.9.7.1 of
 the ISO C99 standard:
@@ -2541,7 +2543,7 @@ to the precision of @var{r}.
 If @var{r} is zero, it has the sign of @var{x}.
 The return value is the ternary value corresponding to @var{r}.
 
-Additionally, @code{mpfr_remquo} stores
+Additionally, @code{mpfr_fmodquo} and @code{mpfr_remquo} store
 the low significant bits from the quotient @var{n} in @var{*q}
 (more precisely the number of bits in a @code{long} minus one),
 with the sign of @var{x} divided by @var{y}
diff --git a/src/mpfr.h b/src/mpfr.h
index d3d7fbeeb..ce29a1eaf 100644
--- a/src/mpfr.h
+++ b/src/mpfr.h
@@ -587,6 +587,8 @@ __MPFR_DECLSPEC int mpfr_remainder _MPFR_PROTO ((mpfr_ptr, mpfr_srcptr,
                                                  mpfr_srcptr, mpfr_rnd_t));
 __MPFR_DECLSPEC int mpfr_fmod _MPFR_PROTO ((mpfr_ptr, mpfr_srcptr,
                                                  mpfr_srcptr, mpfr_rnd_t));
+__MPFR_DECLSPEC int mpfr_fmodquo _MPFR_PROTO ((mpfr_ptr, long*, mpfr_srcptr,
+                                                 mpfr_srcptr, mpfr_rnd_t));
 
 __MPFR_DECLSPEC int mpfr_fits_ulong_p _MPFR_PROTO((mpfr_srcptr, mpfr_rnd_t));
 __MPFR_DECLSPEC int mpfr_fits_slong_p _MPFR_PROTO((mpfr_srcptr, mpfr_rnd_t));
diff --git a/src/rem1.c b/src/rem1.c
index a3f91f0e4..f49f167bd 100644
--- a/src/rem1.c
+++ b/src/rem1.c
@@ -227,3 +227,10 @@ mpfr_fmod (mpfr_ptr rem, mpfr_srcptr x, mpfr_srcptr y, mpfr_rnd_t rnd)
 {
   return mpfr_rem1 (rem, (long *) 0, MPFR_RNDZ, x, y, rnd);
 }
+
+int
+mpfr_fmodquo (mpfr_ptr rem, long *quo, mpfr_srcptr x, mpfr_srcptr y,
+              mpfr_rnd_t rnd)
+{
+  return mpfr_rem1 (rem, quo, MPFR_RNDZ, x, y, rnd);
+}
diff --git a/tests/tremquo.c b/tests/tremquo.c
index ef051a73b..0bbfb2c4d 100644
--- a/tests/tremquo.c
+++ b/tests/tremquo.c
@@ -1,4 +1,4 @@
-/* tremquo -- test file for mpfr_remquo and mpfr_remainder
+/* tremquo -- test file for mpfr_remquo, mpfr_remainder and mpfr_fmodquo.
 
 Copyright 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
 Contributed by the AriC and Caramel projects, INRIA.
@@ -87,32 +87,45 @@ main (int argc, char *argv[])
   mpfr_set_ui (y, 1, MPFR_RNDN);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN(mpfr_nan_p (r));
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN(mpfr_nan_p (r));
 
   mpfr_set_ui (x, 1, MPFR_RNDN);
   mpfr_set_nan (y);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN(mpfr_nan_p (r));
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN(mpfr_nan_p (r));
 
   mpfr_set_inf (x, 1); /* +Inf */
   mpfr_set_ui (y, 1, MPFR_RNDN);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_nan_p (r));
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_nan_p (r));
 
   mpfr_set_inf (x, 1); /* +Inf */
   mpfr_set_ui (y, 0, MPFR_RNDN);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_nan_p (r));
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_nan_p (r));
 
   mpfr_set_inf (x, 1); /* +Inf */
   mpfr_set_inf (y, 1);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_nan_p (r));
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_nan_p (r));
 
   mpfr_set_ui (x, 0, MPFR_RNDN);
   mpfr_set_inf (y, 1);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_ui (r, 0) == 0 && MPFR_IS_POS (r));
   MPFR_ASSERTN (q[0] == (long) 0);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_ui (r, 0) == 0 && MPFR_IS_POS (r));
+  MPFR_ASSERTN (q[0] == (long) 0);
 
   mpfr_set_ui (x, 0, MPFR_RNDN);
   mpfr_neg (x, x, MPFR_RNDN); /* -0 */
@@ -120,23 +133,34 @@ main (int argc, char *argv[])
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_ui (r, 0) == 0 && MPFR_IS_NEG (r));
   MPFR_ASSERTN (q[0] == (long) 0);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_ui (r, 0) == 0 && MPFR_IS_NEG (r));
+  MPFR_ASSERTN (q[0] == (long) 0);
 
   mpfr_set_ui (x, 17, MPFR_RNDN);
   mpfr_set_inf (y, 1);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp (r, x) == 0);
   MPFR_ASSERTN (q[0] == (long) 0);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp (r, x) == 0);
+  MPFR_ASSERTN (q[0] == (long) 0);
 
   mpfr_set_ui (x, 17, MPFR_RNDN);
   mpfr_set_ui (y, 0, MPFR_RNDN);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_nan_p (r));
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_nan_p (r));
 
   mpfr_set_ui (x, 0, MPFR_RNDN);
   mpfr_set_ui (y, 17, MPFR_RNDN);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_ui (r, 0) == 0 && MPFR_IS_POS (r));
   MPFR_ASSERTN (q[0] == (long) 0);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_ui (r, 0) == 0 && MPFR_IS_POS (r));
+  MPFR_ASSERTN (q[0] == (long) 0);
 
   mpfr_set_ui (x, 0, MPFR_RNDN);
   mpfr_neg (x, x, MPFR_RNDN);
@@ -144,32 +168,88 @@ main (int argc, char *argv[])
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_ui (r, 0) == 0 && MPFR_IS_NEG (r));
   MPFR_ASSERTN (q[0] == (long) 0);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_ui (r, 0) == 0 && MPFR_IS_NEG (r));
+  MPFR_ASSERTN (q[0] == (long) 0);
 
   mpfr_set_prec (x, 53);
   mpfr_set_prec (y, 53);
 
-  /* check four possible sign combinations */
+  /* check four possible sign combinations for 42/17 */
   mpfr_set_ui (x, 42, MPFR_RNDN);
   mpfr_set_ui (y, 17, MPFR_RNDN);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_ui (r, 8) == 0);
   MPFR_ASSERTN (q[0] == (long) 2);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_ui (r, 8) == 0);
+  MPFR_ASSERTN (q[0] == (long) 2);
+
   mpfr_set_si (x, -42, MPFR_RNDN);
   mpfr_set_ui (y, 17, MPFR_RNDN);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_si (r, -8) == 0);
   MPFR_ASSERTN (q[0] == (long) -2);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_si (r, -8) == 0);
+  MPFR_ASSERTN (q[0] == (long) -2);
+
   mpfr_set_si (x, -42, MPFR_RNDN);
   mpfr_set_si (y, -17, MPFR_RNDN);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_si (r, -8) == 0);
   MPFR_ASSERTN (q[0] == (long) 2);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_si (r, -8) == 0);
+  MPFR_ASSERTN (q[0] == (long) 2);
+
   mpfr_set_ui (x, 42, MPFR_RNDN);
   mpfr_set_si (y, -17, MPFR_RNDN);
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_ui (r, 8) == 0);
   MPFR_ASSERTN (q[0] == (long) -2);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_ui (r, 8) == 0);
+  MPFR_ASSERTN (q[0] == (long) -2);
+
+  /* same tests for 43/17, rounded to 3 to nearest, and to 2 to zero */
+  mpfr_set_ui (x, 43, MPFR_RNDN);
+  mpfr_set_ui (y, 17, MPFR_RNDN);
+  mpfr_remquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_si (r, -8) == 0);
+  MPFR_ASSERTN (q[0] == (long) 3);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_ui (r, 9) == 0);
+  MPFR_ASSERTN (q[0] == (long) 2);
 
+  mpfr_set_si (x, -43, MPFR_RNDN);
+  mpfr_set_ui (y, 17, MPFR_RNDN);
+  mpfr_remquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_si (r, 8) == 0);
+  MPFR_ASSERTN (q[0] == (long) -3);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_si (r, -9) == 0);
+  MPFR_ASSERTN (q[0] == (long) -2);
+
+  mpfr_set_si (x, -43, MPFR_RNDN);
+  mpfr_set_si (y, -17, MPFR_RNDN);
+  mpfr_remquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_si (r, 8) == 0);
+  MPFR_ASSERTN (q[0] == (long) 3);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_si (r, -9) == 0);
+  MPFR_ASSERTN (q[0] == (long) 2);
+
+  mpfr_set_ui (x, 43, MPFR_RNDN);
+  mpfr_set_si (y, -17, MPFR_RNDN);
+  mpfr_remquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_si (r, -8) == 0);
+  MPFR_ASSERTN (q[0] == (long) -3);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_ui (r, 9) == 0);
+  MPFR_ASSERTN (q[0] == (long) -2);
+
+  /* other tests */
   mpfr_set_prec (x, 100);
   mpfr_set_prec (y, 50);
   mpfr_set_ui (x, 42, MPFR_RNDN);
@@ -178,6 +258,9 @@ main (int argc, char *argv[])
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_ui_2exp (r, 1, -94) == 0);
   MPFR_ASSERTN (q[0] == (long) 2);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_ui_2exp (r, 1, -94) == 0);
+  MPFR_ASSERTN (q[0] == (long) 2);
 
   mpfr_set_prec (x, 50);
   mpfr_set_prec (y, 100);
@@ -187,6 +270,9 @@ main (int argc, char *argv[])
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_ui_2exp (r, 1, -44) == 0);
   MPFR_ASSERTN (q[0] == (long) 2);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_ui_2exp (r, 1, -44) == 0);
+  MPFR_ASSERTN (q[0] == (long) 2);
 
   mpfr_set_prec (x, 100);
   mpfr_set_prec (y, 50);
@@ -197,6 +283,11 @@ main (int argc, char *argv[])
   /* r should be 42 - 2*(21 + 2^(-45)) = -2^(-44) */
   MPFR_ASSERTN (mpfr_cmp_si_2exp (r, -1, -44) == 0);
   MPFR_ASSERTN (q[0] == (long) 2);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  /* r should be 42 - (21 + 2^(-45) = 21 - 2^(-45) */
+  mpfr_sub_ui (r, r, 21, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_si_2exp (r, -1, -45) == 0);
+  MPFR_ASSERTN (q[0] == (long) 1);
 
   mpfr_set_prec (x, 50);
   mpfr_set_prec (y, 100);
@@ -207,6 +298,11 @@ main (int argc, char *argv[])
   /* r should be 42 - 2*(21 + 2^(-95)) = -2^(-94) */
   MPFR_ASSERTN (mpfr_cmp_si_2exp (r, -1, -94) == 0);
   MPFR_ASSERTN (q[0] == (long) 2);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  /* r should be 42 - (21 + 2^(-95) = 21 - 2^(-94), which rounded to 53 bits
+     should give 21 */
+  MPFR_ASSERTN (mpfr_cmp_ui (r, 21) == 0);
+  MPFR_ASSERTN (q[0] == (long) 1);
 
   /* exercise large quotient */
   mpfr_set_ui_2exp (x, 1, 65, MPFR_RNDN);
@@ -215,6 +311,9 @@ main (int argc, char *argv[])
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_si (r, 0) == 0);
   MPFR_ASSERTN (q[0] % 1073741824L == 0L);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_cmp_si (r, 0) == 0);
+  MPFR_ASSERTN (q[0] % 1073741824L == 0L);
 
   /* another large quotient */
   mpfr_set_prec (x, 65);
@@ -227,6 +326,10 @@ main (int argc, char *argv[])
   /* q should be 41803643793084085130, r should be 605/2048 */
   MPFR_ASSERTN (mpfr_cmp_ui_2exp (r, 605, -11) == 0);
   MPFR_ASSERTN ((q[0] > 0) && ((q[0] % 1073741824L) == 733836170L));
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  /* q should be 41803643793084085130, r should be 605/2048 */
+  MPFR_ASSERTN (mpfr_cmp_ui_2exp (r, 605, -11) == 0);
+  MPFR_ASSERTN ((q[0] > 0) && ((q[0] % 1073741824L) == 733836170L));
 
   /* check cases where quotient is 1.5 +/- eps */
   mpfr_set_prec (x, 65);
@@ -238,6 +341,11 @@ main (int argc, char *argv[])
   /* x/y = 1.5, quotient should be 2 (even rule), remainder should be -1 */
   MPFR_ASSERTN (mpfr_cmp_si (r, -1) == 0);
   MPFR_ASSERTN (q[0] == 2L);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  /* x/y = 1.5, quotient should be 1, remainder should be 1 */
+  MPFR_ASSERTN (mpfr_cmp_si (r, 1) == 0);
+  MPFR_ASSERTN (q[0] == 1L);
+
   mpfr_set_ui (x, 3, MPFR_RNDN);
   mpfr_nextabove (x); /* 3 + 2^(-63) */
   mpfr_set_ui (y, 2, MPFR_RNDN);
@@ -246,6 +354,14 @@ main (int argc, char *argv[])
   MPFR_ASSERTN (mpfr_add_ui (r, r, 1, MPFR_RNDN) == 0);
   MPFR_ASSERTN (mpfr_cmp_ui_2exp (r, 1, -63) == 0);
   MPFR_ASSERTN (q[0] == 2L);
+  mpfr_set_prec (r, 64);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  /* x/y = 1.5 + 2^(-64), quo should be 1, r should be 1 + 2^(-63) */
+  MPFR_ASSERTN (mpfr_sub_ui (r, r, 1, MPFR_RNDN) == 0);
+  MPFR_ASSERTN (mpfr_cmp_ui_2exp (r, 1, -63) == 0);
+  MPFR_ASSERTN (q[0] == 1L);
+
+  mpfr_set_prec (r, 63);
   mpfr_set_ui (x, 3, MPFR_RNDN);
   mpfr_set_ui (y, 2, MPFR_RNDN);
   mpfr_nextabove (y); /* 2 + 2^(-63) */
@@ -254,10 +370,16 @@ main (int argc, char *argv[])
   MPFR_ASSERTN (mpfr_sub_ui (r, r, 1, MPFR_RNDN) == 0);
   MPFR_ASSERTN (mpfr_cmp_si_2exp (r, -1, -63) == 0);
   MPFR_ASSERTN (q[0] == 1L);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  /* x/y = 1.5 - eps, quo should be 1, r should be 1 - 2^(-63) */
+  MPFR_ASSERTN (mpfr_sub_ui (r, r, 1, MPFR_RNDN) == 0);
+  MPFR_ASSERTN (mpfr_cmp_si_2exp (r, -1, -63) == 0);
+  MPFR_ASSERTN (q[0] == 1L);
 
   /* bug founds by Kaveh Ghazi, 3 May 2007 */
   mpfr_set_ui (x, 2, MPFR_RNDN);
   mpfr_set_ui (y, 3, MPFR_RNDN);
+  /* quotient rounded to nearest is 1, thus remainder is -1 */
   mpfr_remainder (r, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_cmp_si (r, -1) == 0);
 
@@ -277,6 +399,9 @@ main (int argc, char *argv[])
   mpfr_remquo (r, q, x, y, MPFR_RNDN);
   MPFR_ASSERTN (mpfr_zero_p (r) && MPFR_SIGN (r) > 0);
   MPFR_ASSERTN (q[0] == 0);
+  mpfr_fmodquo (r, q, x, y, MPFR_RNDN);
+  MPFR_ASSERTN (mpfr_zero_p (r) && MPFR_SIGN (r) > 0);
+  MPFR_ASSERTN (q[0] == 0);
 
   mpfr_clear (x);
   mpfr_clear (y);
diff --git a/tools/cfarm.sh b/tools/cfarm.sh
index fb1040679..232d099c5 100755
--- a/tools/cfarm.sh
+++ b/tools/cfarm.sh
@@ -22,9 +22,13 @@ fi
 wget http://www.loria.fr/~zimmerma/mpfr-3.2.0-dev.tar.bz2
 tar jxf mpfr-3.2.0-dev.tar.bz2
 cd  mpfr-3.2.0-dev
-./configure --with-gmp=$HOME --prefix=$HOME
+if [ "`hostname`" = "dingo" ]; then
+   # http://websympa.loria.fr/wwsympa/arc/mpfr/2011-10/msg00048.html
+   ./configure --with-gmp=$HOME --disable-thread-safe
+else
+   ./configure --with-gmp=$HOME
+fi
 make
-make install
 make check
 
 # results with mpfr-3.1.0-rc1.tar.bz2