Added mpfr_z_sub (function/test/doc)

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@7457 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 154 insertions, 0 deletions

diff --git a/tests/tgmpop.c b/tests/tgmpop.c
index ef6809c8d..c8d234935 100644
--- a/tests/tgmpop.c
+++ b/tests/tgmpop.c
@@ -412,6 +412,81 @@ test_specialz (int (*mpfr_func)(mpfr_ptr, mpfr_srcptr, mpz_srcptr, mpfr_rnd_t),
 }
 
 static void
+test_special2z (int (*mpfr_func)(mpfr_ptr, mpz_srcptr, mpfr_srcptr, mpfr_rnd_t),
+               void (*mpz_func)(mpz_ptr, mpz_srcptr, mpz_srcptr),
+               const char *op)
+{
+  mpfr_t x1, x2;
+  mpz_t  z1, z2;
+  int res;
+
+  mpfr_inits2 (128, x1, x2, (mpfr_ptr) 0);
+  mpz_init (z1); mpz_init(z2);
+  mpz_fac_ui (z1, 19); /* 19!+1 fits perfectly in a 128 bits mantissa */
+  mpz_add_ui (z1, z1, 1);
+  mpz_fac_ui (z2, 20); /* 20!+1 fits perfectly in a 128 bits mantissa */
+  mpz_add_ui (z2, z2, 1);
+
+  res = mpfr_set_z(x1, z1, MPFR_RNDN);
+  if (res)
+    {
+      printf("Specialz %s: set_z1 error\n", op);
+      exit(1);
+    }
+  mpfr_set_z (x2, z2, MPFR_RNDN);
+  if (res)
+    {
+      printf("Specialz %s: set_z2 error\n", op);
+      exit(1);
+    }
+
+  /* (19!+1) * (20!+1) fits in a 128 bits number */
+  res = mpfr_func(x1, z1, x2, MPFR_RNDN);
+  if (res)
+    {
+      printf("Specialz %s: wrong inexact flag.\n", op);
+      exit(1);
+    }
+  mpz_func(z1, z1, z2);
+  res = mpfr_set_z (x2, z1, MPFR_RNDN);
+  if (res)
+    {
+      printf("Specialz %s: set_z2 error\n", op);
+      exit(1);
+    }
+  if (mpfr_cmp(x1, x2))
+    {
+      printf("Specialz %s: results differ.\nx1=", op);
+      mpfr_print_binary(x1);
+      printf("\nx2=");
+      mpfr_print_binary(x2);
+      printf ("\nZ2=");
+      mpz_out_str (stdout, 2, z1);
+      putchar('\n');
+      exit(1);
+    }
+
+  mpz_set_ui (z1, 1);
+  mpz_set_ui (z2, 0);
+  mpfr_set_ui (x2, 0, MPFR_RNDN);
+  res = mpfr_func(x1, z1, x2, MPFR_RNDN);
+  mpz_func (z1, z1, z2);
+  mpfr_set_z (x2, z1, MPFR_RNDN);
+  if (mpfr_cmp(x1, x2))
+    {
+      printf("Specialz %s: results differ(2).\nx1=", op);
+      mpfr_print_binary(x1);
+      printf("\nx2=");
+      mpfr_print_binary(x2);
+      putchar('\n');
+      exit(1);
+    }
+
+  mpz_clear (z1); mpz_clear(z2);
+  mpfr_clears (x1, x2, (mpfr_ptr) 0);
+}
+
+static void
 test_genericz (mpfr_prec_t p0, mpfr_prec_t p1, unsigned int N,
                int (*func)(mpfr_ptr, mpfr_srcptr, mpz_srcptr, mpfr_rnd_t),
                const char *op)
@@ -489,6 +564,83 @@ test_genericz (mpfr_prec_t p0, mpfr_prec_t p1, unsigned int N,
 }
 
 static void
+test_generic2z (mpfr_prec_t p0, mpfr_prec_t p1, unsigned int N,
+               int (*func)(mpfr_ptr, mpz_srcptr, mpfr_srcptr, mpfr_rnd_t),
+               const char *op)
+{
+  mpfr_prec_t prec;
+  mpfr_t arg1, dst_big, dst_small, tmp;
+  mpz_t  arg2;
+  mpfr_rnd_t rnd;
+  int inexact, compare, compare2;
+  unsigned int n;
+
+  mpfr_inits (arg1, dst_big, dst_small, tmp, (mpfr_ptr) 0);
+  mpz_init (arg2);
+
+  for (prec = p0; prec <= p1; prec++)
+    {
+      mpfr_set_prec (arg1, prec);
+      mpfr_set_prec (tmp, prec);
+      mpfr_set_prec (dst_small, prec);
+
+      for (n=0; n<N; n++)
+        {
+          mpfr_urandomb (arg1, RANDS);
+          mpz_urandomb (arg2, RANDS, 1024);
+          rnd = RND_RAND ();
+          mpfr_set_prec (dst_big, 2*prec);
+          compare = func(dst_big, arg2, arg1, rnd);
+          if (mpfr_can_round (dst_big, 2*prec, rnd, rnd, prec))
+            {
+              mpfr_set (tmp, dst_big, rnd);
+              inexact = func(dst_small, arg2, arg1, rnd);
+              if (mpfr_cmp (tmp, dst_small))
+                {
+                  printf ("Results differ for prec=%u rnd_mode=%s and %s_z:\n"
+                          "arg1=",
+                          (unsigned) prec, mpfr_print_rnd_mode (rnd), op);
+                  mpfr_print_binary (arg1);
+                  printf("\narg2=");
+                  mpz_out_str (stdout, 10, arg2);
+                  printf ("\ngot      ");
+                  mpfr_dump (dst_small);
+                  printf ("expected ");
+                  mpfr_dump (tmp);
+                  printf ("approx   ");
+                  mpfr_dump (dst_big);
+                  exit (1);
+                }
+              compare2 = mpfr_cmp (tmp, dst_big);
+              /* if rounding to nearest, cannot know the sign of t - f(x)
+                 because of composed rounding: y = o(f(x)) and t = o(y) */
+              if (compare * compare2 >= 0)
+                compare = compare + compare2;
+              else
+                compare = inexact; /* cannot determine sign(t-f(x)) */
+              if (((inexact == 0) && (compare != 0)) ||
+                  ((inexact > 0) && (compare <= 0)) ||
+                  ((inexact < 0) && (compare >= 0)))
+                {
+                  printf ("Wrong inexact flag for rnd=%s and %s_z:\n"
+                          "expected %d, got %d\n",
+                          mpfr_print_rnd_mode (rnd), op, compare, inexact);
+                  printf ("\narg1="); mpfr_print_binary (arg1);
+                  printf ("\narg2="); mpz_out_str(stdout, 2, arg2);
+                  printf ("\ndstl="); mpfr_print_binary (dst_big);
+                  printf ("\ndsts="); mpfr_print_binary (dst_small);
+                  printf ("\ntmp ="); mpfr_dump (tmp);
+                  exit (1);
+                }
+            }
+        }
+    }
+
+  mpz_clear (arg2);
+  mpfr_clears (arg1, dst_big, dst_small, tmp, (mpfr_ptr) 0);
+}
+
+static void
 test_genericq (mpfr_prec_t p0, mpfr_prec_t p1, unsigned int N,
                int (*func)(mpfr_ptr, mpfr_srcptr, mpq_srcptr, mpfr_rnd_t),
                const char *op)
@@ -969,6 +1121,8 @@ main (int argc, char *argv[])
   test_genericz (2, 100, 100, mpfr_sub_z, "sub");
   test_genericz (2, 100, 100, mpfr_mul_z, "mul");
   test_genericz (2, 100, 100, mpfr_div_z, "div");
+  test_special2z (mpfr_z_sub, mpz_sub, "sub");
+  test_generic2z (2, 100, 100, mpfr_z_sub, "sub");
 
   test_genericq (2, 100, 100, mpfr_add_q, "add");
   test_genericq (2, 100, 100, mpfr_sub_q, "sub");