[src/jyn_asympt.c] Fixed bug when s=0 at the end of the for loop.

[tests/mpfr-test.h] Added mpfr_cmp_si_2exp0 macro (check NaN).
[tests/tj1.c] Added testcase.
(merged changesets r14431,14434 from the trunk)

git-svn-id: https://scm.gforge.inria.fr/anonscm/svn/mpfr/branches/4.1@14436 280ebfd0-de03-0410-8827-d642c229c3f4

3 files changed, 31 insertions, 7 deletions

diff --git a/src/jyn_asympt.c b/src/jyn_asympt.c
index 6e5c7c37d..1f6f4cbb3 100644
--- a/src/jyn_asympt.c
+++ b/src/jyn_asympt.c
@@ -69,7 +69,7 @@ FUNCTION (mpfr_ptr res, long n, mpfr_srcptr z, mpfr_rnd_t r)
   MPFR_ZIV_INIT (loop, w);
   for (;;)
     {
-      int ok = 1;
+      int ok = 0;
 
       mpfr_set_prec (c, w);
       mpfr_init2 (s, w);
@@ -96,10 +96,7 @@ FUNCTION (mpfr_ptr res, long n, mpfr_srcptr z, mpfr_rnd_t r)
 
       /* if s or c is zero, MPFR_GET_EXP will fail below */
       if (MPFR_IS_ZERO(s) || MPFR_IS_ZERO(c))
-        {
-          ok = 0;
-          goto clear;
-        }
+        goto clear; /* with ok=0 */
 
       /* precompute 1/(8|z|) */
       mpfr_si_div (iz, MPFR_IS_POS(z) ? 1 : -1, z, MPFR_RNDN);   /* err <= 1 */
@@ -227,6 +224,9 @@ FUNCTION (mpfr_ptr res, long n, mpfr_srcptr z, mpfr_rnd_t r)
           mpfr_sub (s, c, s, MPFR_RNDN);
 #endif
         }
+      if (MPFR_IS_ZERO(s))
+        goto clear; /* with ok=0 */
+      ok = 1;
       if ((n & 2) != 0)
         mpfr_neg (s, s, MPFR_RNDN);
       if (MPFR_GET_EXP (s) > err)
diff --git a/tests/mpfr-test.h b/tests/mpfr-test.h
index 570e095a5..0103e8ba9 100644
--- a/tests/mpfr-test.h
+++ b/tests/mpfr-test.h
@@ -191,6 +191,8 @@ int mpfr_cmp_str (mpfr_srcptr x, const char *, int, mpfr_rnd_t);
 
 #define mpfr_cmp0(x,y) (MPFR_ASSERTN (!MPFR_IS_NAN (x) && !MPFR_IS_NAN (y)), mpfr_cmp (x,y))
 #define mpfr_cmp_ui0(x,i) (MPFR_ASSERTN (!MPFR_IS_NAN (x)), mpfr_cmp_ui (x,i))
+#define mpfr_cmp_si_2exp0(x,i,e) (MPFR_ASSERTN (!MPFR_IS_NAN (x)), \
+                                  mpfr_cmp_si_2exp (x,i,e))
 
 /* define CHECK_EXTERNAL if you want to check mpfr against another library
    with correct rounding. You'll probably have to modify mpfr_print_raw()
diff --git a/tests/tj1.c b/tests/tj1.c
index 880da58a3..1fea6928e 100644
--- a/tests/tj1.c
+++ b/tests/tj1.c
@@ -55,14 +55,14 @@ test_small (void)
               /* since |x| is just above 2^e, |j1(x)| is just above 2^(e-1),
                  thus y should be 2^(e-1) and the inexact flag should be
                  of opposite sign of x */
-              MPFR_ASSERTN(mpfr_cmp_si_2exp (y, sign, e - 1) == 0);
+              MPFR_ASSERTN(mpfr_cmp_si_2exp0 (y, sign, e - 1) == 0);
               MPFR_ASSERTN(VSIGN (inex) * sign < 0);
             }
           else
             {
               /* here |y| should be 0.5*2^emin and the inexact flag should
                  have the sign of x */
-              MPFR_ASSERTN(mpfr_cmp_si_2exp (y, sign, e) == 0);
+              MPFR_ASSERTN(mpfr_cmp_si_2exp0 (y, sign, e) == 0);
               MPFR_ASSERTN(VSIGN (inex) * sign > 0);
             }
         }
@@ -72,6 +72,26 @@ test_small (void)
   mpfr_clear (y);
 }
 
+/* a test that fails with GMP_CHECK_RANDOMIZE=1613146232984428
+   on revision 14429 */
+static void
+bug20210215 (void)
+{
+  mpfr_t x, y;
+  int inex;
+
+  mpfr_init2 (x, 221);
+  mpfr_init2 (y, 1);
+  mpfr_set_str (x, "1.6484611511696130037307738844228498447763863563070374544054791168614e+01", 10, MPFR_RNDN);
+  mpfr_clear_flags ();
+  inex = mpfr_j1 (y, x, MPFR_RNDZ);
+  MPFR_ASSERTN (mpfr_cmp_si_2exp0 (y, -1, -9) == 0);
+  MPFR_ASSERTN (inex > 0);
+  MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_INEXACT);
+  mpfr_clear (x);
+  mpfr_clear (y);
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -79,6 +99,8 @@ main (int argc, char *argv[])
 
   tests_start_mpfr ();
 
+  bug20210215 ();
+
   test_small ();
 
   mpfr_init (x);