Merged recent tests from the trunk (r12500-12555,12558,12561).

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/branches/4.0@12675 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 116 insertions, 0 deletions

diff --git a/tests/tpow.c b/tests/tpow.c
index 10eddbe95..e4f896440 100644
--- a/tests/tpow.c
+++ b/tests/tpow.c
@@ -1599,6 +1599,121 @@ tst20140422 (void)
   mpfr_clears (x, y, z1, z2, (mpfr_ptr) 0);
 }
 
+static void
+coverage (void)
+{
+  mpfr_t x, y, z, t, u;
+  mpfr_exp_t emin;
+  int inex;
+  int i;
+
+  /* check a corner case with prec(z)=1 */
+  mpfr_init2 (x, 2);
+  mpfr_init2 (y, 8);
+  mpfr_init2 (z, 1);
+  mpfr_set_ui_2exp (x, 3, -2, MPFR_RNDN);   /* x = 3/4 */
+  emin = mpfr_get_emin ();
+  mpfr_set_emin (-40);
+  mpfr_set_ui_2exp (y, 199, -1, MPFR_RNDN); /* y = 99.5 */
+  /* x^y ~ 0.81*2^-41 */
+  mpfr_clear_underflow ();
+  inex = mpfr_pow (z, x, y, MPFR_RNDN);
+  MPFR_ASSERTN(inex > 0);
+  MPFR_ASSERTN(mpfr_cmp_ui_2exp (z, 1, -41) == 0);
+  /* there should be no underflow, since with unbounded exponent range,
+     and a precision of 1 bit, x^y is rounded to 1.0*2^-41 */
+  MPFR_ASSERTN(!mpfr_underflow_p ());
+  mpfr_set_ui_2exp (y, 201, -1, MPFR_RNDN); /* y = 100.5 */
+  /* x^y ~ 0.61*2^-41 */
+  mpfr_clear_underflow ();
+  inex = mpfr_pow (z, x, y, MPFR_RNDN);
+  MPFR_ASSERTN(inex > 0);
+  MPFR_ASSERTN(mpfr_cmp_ui_2exp (z, 1, -41) == 0);
+  /* there should be an underflow, since with unbounded exponent range,
+     and a precision of 1 bit, x^y is rounded to 0.5*2^-41 */
+  MPFR_ASSERTN(mpfr_underflow_p ());
+  mpfr_set_ui_2exp (y, 203, -1, MPFR_RNDN); /* y = 101.5 */
+  /* x^y ~ 0.46*2^-41 */
+  mpfr_clear_underflow ();
+  inex = mpfr_pow (z, x, y, MPFR_RNDN);
+  MPFR_ASSERTN(inex < 0);
+  MPFR_ASSERTN(mpfr_zero_p (z) && mpfr_signbit (z) == 0);
+  MPFR_ASSERTN(mpfr_underflow_p ());
+  mpfr_clears (x, y, z, (mpfr_ptr) 0);
+  mpfr_set_emin (emin);
+
+  /* test for x = -2, y an odd integer with EXP(y) > i */
+  mpfr_inits2 (10, t, u, (mpfr_ptr) 0);
+  mpfr_set_ui_2exp (t, 1, 1UL << 8, MPFR_RNDN);
+  for (i = 8; i <= 300; i++)
+    {
+      mpfr_flags_t flags, flags_u;
+      int inex_u;
+
+      mpfr_mul_si (u, t, -2, MPFR_RNDN);  /* u = (-2)^(2^i + 1) */
+      mpfr_init2 (x, 10);
+      mpfr_init2 (y, i+1);
+      mpfr_init2 (z, 10);
+      mpfr_set_si (x, -2, MPFR_RNDN);
+      mpfr_set_ui_2exp (y, 1, i, MPFR_RNDN);
+      mpfr_nextabove (y);  /* y = 2^i + 1 */
+      if (MPFR_IS_INF (u))
+        {
+          inex_u = -1;
+          flags_u = MPFR_FLAGS_OVERFLOW | MPFR_FLAGS_INEXACT;
+        }
+      else
+        {
+          inex_u = 0;
+          flags_u = 0;
+        }
+      mpfr_clear_flags ();
+      inex = mpfr_pow (z, x, y, MPFR_RNDN);
+      flags = __gmpfr_flags;
+      if (mpfr_cmp0 (z, u) != 0 ||
+          ! SAME_SIGN (inex, inex_u) ||
+          flags != flags_u)
+        {
+          printf ("Error in coverage for (-2)^(2^%d + 1):\n", i);
+          printf ("Expected ");
+          mpfr_dump (u);
+          printf ("  with inex = %d and flags:", inex_u);
+          flags_out (flags_u);
+          printf ("Got      ");
+          mpfr_dump (z);
+          printf ("  with inex = %d and flags:", inex);
+          flags_out (flags);
+          exit (1);
+        }
+      mpfr_sqr (t, t, MPFR_RNDN);
+      mpfr_clears (x, y, z, (mpfr_ptr) 0);
+    }
+  mpfr_clears (t, u, (mpfr_ptr) 0);
+
+#if _MPFR_EXP_FORMAT >= 3 && _MPFR_PREC_FORMAT == 3 && MPFR_PREC_BITS == 64
+  /* thus an unsigned long has at least 64 bits and x will be finite */
+  {
+    mpfr_exp_t emax;
+
+    emax = mpfr_get_emax ();
+    mpfr_set_emax ((1UL << 62) - 1);
+    /* emax = 4611686018427387903 on a 64-bit machine */
+    mpfr_init2 (x, 65);
+    mpfr_init2 (y, 65);
+    mpfr_init2 (z, 64);
+    mpfr_set_ui_2exp (x, 512, 3074457345618258593UL, MPFR_RNDN);
+    mpfr_nextbelow (x);
+    mpfr_set_str_binary (y, "1.1"); /* y = 3/2 */
+    mpfr_nextabove (y);
+    inex = mpfr_pow (z, x, y, MPFR_RNDN);
+    MPFR_ASSERTN(inex > 0);
+    MPFR_ASSERTN(mpfr_inf_p (z));
+    mpfr_clears (x, y, z, (mpfr_ptr) 0);
+    mpfr_set_emax (emax);
+  }
+#endif
+}
+
 int
 main (int argc, char **argv)
 {
@@ -1606,6 +1721,7 @@ main (int argc, char **argv)
 
   tests_start_mpfr ();
 
+  coverage ();
   bug20071127 ();
   special ();
   particular_cases ();