[urandomb.c] modified to leave the GMP random generator in the same state,

	     independent of GMP_NUMB_BITS
[trandom.c] test of the above
[urandom.c] added FIXME's
[turandom.c] check we leave the GMP random generator in the same state,
	     independent of GMP_NUMB_BITS. Currently this fails on 64-bit
	     computers.


git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@7133 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/trandom.c b/tests/trandom.c
index 09968fe1b..1a977f283 100644
--- a/tests/trandom.c
+++ b/tests/trandom.c
@@ -103,6 +103,36 @@ test_urandomb (long nbtests, mpfr_prec_t prec, int verbose)
   return;
 }
 
+/* Problem reported by Carl Witty: check mpfr_urandomb give similar results
+   on 32-bit and 64-bit machines.
+   We assume the default GMP random generator does not depend on the machine
+   word size, not on the GMP version.
+*/
+static void
+bug20100914 (void)
+{
+  mpfr_t x;
+  gmp_randstate_t s;
+
+  gmp_randinit_default (s);
+  gmp_randseed_ui (s, 42);
+  mpfr_init2 (x, 17);
+  mpfr_urandomb (x, s);
+  if (mpfr_cmp_str1 (x, "0.895943") != 0)
+    {
+      mpfr_printf ("Error in bug20100914, got %Rf, expected 0.895943\n", x);
+      exit (1);
+    }
+  mpfr_urandomb (x, s);
+  if (mpfr_cmp_str1 (x, "0.848824") != 0)
+    {
+      mpfr_printf ("Error in bug20100914, got %Rf, expected 0.848824\n", x);
+      exit (1);
+    }
+  mpfr_clear (x);
+  gmp_randclear (s);
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -135,6 +165,8 @@ main (int argc, char *argv[])
       test_urandomb (nbtests, 2, 0);
     }
 
+  bug20100914 ();
+
   tests_end_mpfr ();
   return 0;
 }