[tests/tgeneric.c] Do several overflow/underflow tests instead of 1, and

this for each precision. This allows one to detect the mpfr_ai bug found
and fixed on 2018-01-07 (with 32-bit *and* 64-bit ABI):
  https://sympa.inria.fr/sympa/arc/mpfr/2018-01/msg00001.html
Moreover, this makes tlgamma loop with a 32-bit ABI (x86). To be fixed.

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@12088 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 10 insertions, 5 deletions

diff --git a/tests/tgeneric.c b/tests/tgeneric.c
index 464c3a885..942987498 100644
--- a/tests/tgeneric.c
+++ b/tests/tgeneric.c
@@ -157,7 +157,6 @@ test_generic (mpfr_prec_t p0, mpfr_prec_t p1, unsigned int nmax)
   int inexact, compare, compare2;
   unsigned int n;
   unsigned long ctrt = 0, ctrn = 0;
-  int test_of = 1, test_uf = 1;
   mpfr_exp_t old_emin, old_emax;
 
   old_emin = mpfr_get_emin ();
@@ -171,6 +170,12 @@ test_generic (mpfr_prec_t p0, mpfr_prec_t p1, unsigned int nmax)
   /* generic test */
   for (prec = p0; prec <= p1; prec++)
     {
+      /* Number of overflow/underflow tests for each precision.
+         Since MPFR uses several algorithms and there may also be
+         early overflow/underflow detection, several tests may be
+         needed to detect a bug. */
+      int test_of = 3, test_uf = 3;
+
       mpfr_set_prec (z, prec);
       mpfr_set_prec (t, prec);
       yprec = prec + 10;
@@ -425,7 +430,7 @@ test_generic (mpfr_prec_t p0, mpfr_prec_t p1, unsigned int nmax)
               {
                 e = MPFR_GET_EXP (y);  /* exponent of the result */
 
-                if (test_of && e - 1 >= emax)  /* overflow test */
+                if (test_of > 0 && e - 1 >= emax)  /* overflow test */
                   {
                     mpfr_flags_t ex_flags;
 
@@ -485,10 +490,10 @@ test_generic (mpfr_prec_t p0, mpfr_prec_t p1, unsigned int nmax)
                         mpfr_dump (w);
                         exit (1);
                       }
-                    test_of = 0;  /* Overflow is tested only once. */
+                    test_of--;
                   }
 
-                if (test_uf && e + 1 <= emin)  /* underflow test */
+                if (test_uf > 0 && e + 1 <= emin)  /* underflow test */
                   {
                     mpfr_flags_t ex_flags;
 
@@ -548,7 +553,7 @@ test_generic (mpfr_prec_t p0, mpfr_prec_t p1, unsigned int nmax)
                         mpfr_dump (w);
                         exit (1);
                       }
-                    test_uf = 0;  /* Underflow is tested only once. */
+                    test_uf--;
                   }
 
                 if (e < emin)