SeedValue seed_mpfr_sub (SeedContext ctx,
SeedObject function,
SeedObject this_object,
gsize argument_count,
const SeedValue args[],
SeedException *exception)
{
mpfr_rnd_t rnd;
mpfr_ptr rop, op1, op2;
gdouble dop1, dop2;
gint ret;
seed_mpfr_t argt1, argt2;
/* only want 1 double argument. alternatively, could accept 2,
add those, and set from the result*/
CHECK_ARG_COUNT("mpfr.sub", 3);
rop = seed_object_get_private(this_object);
rnd = seed_value_to_mpfr_rnd_t(ctx, args[2], exception);
argt1 = seed_mpfr_arg_type(ctx, args[0], exception);
argt2 = seed_mpfr_arg_type(ctx, args[1], exception);
if ( (argt1 & argt2) == SEED_MPFR_MPFR )
{
/* both mpfr_t */
op1 = seed_object_get_private(args[0]);
op2 = seed_object_get_private(args[1]);
ret = mpfr_sub(rop, op1, op2, rnd);
}
else if ( (argt1 | argt2) == (SEED_MPFR_MPFR | SEED_MPFR_DOUBLE) )
{
/* a double and an mpfr_t. Figure out the order */
if ( argt1 == SEED_MPFR_MPFR )
{
op1 = seed_object_get_private(args[0]);
dop2 = seed_value_to_double(ctx, args[1], exception);
mpfr_sub_d(rop, op1, dop2, rnd);
}
else
{
dop1 = seed_value_to_double(ctx, args[0], exception);
op2 = seed_object_get_private(args[1]);
mpfr_d_sub(rop, dop1, op2, rnd);
}
}
else if ( (argt1 & argt2) == SEED_MPFR_DOUBLE )
{
/* 2 doubles. hopefully doesn't happen */
dop1 = seed_value_to_double(ctx, args[0], exception);
dop2 = seed_value_to_double(ctx, args[1], exception);
ret = mpfr_set_d(rop, dop1 - dop2, rnd);
}
else
{
TYPE_EXCEPTION("mpfr.sub", "double or mpfr_t");
}
return seed_value_from_int(ctx, ret, exception);
}
static void
check_nans (void)
{
mpfr_t x, y;
int inexact;
mpfr_init2 (x, 123);
mpfr_init2 (y, 123);
/* 1.0 - nan is nan */
mpfr_set_nan (x);
mpfr_clear_flags ();
inexact = mpfr_d_sub (y, 1.0, x, MPFR_RNDN);
MPFR_ASSERTN (inexact == 0);
MPFR_ASSERTN ((__gmpfr_flags ^ MPFR_FLAGS_NAN) == 0);
MPFR_ASSERTN (mpfr_nan_p (y));
/* 1.0 - +inf == -inf */
mpfr_set_inf (x, 1);
mpfr_clear_flags ();
inexact = mpfr_d_sub (y, 1.0, x, MPFR_RNDN);
MPFR_ASSERTN (inexact == 0);
MPFR_ASSERTN (__gmpfr_flags == 0);
MPFR_ASSERTN (mpfr_inf_p (y));
MPFR_ASSERTN (MPFR_IS_NEG (y));
/* 1.0 - -inf == +inf */
mpfr_set_inf (x, -1);
mpfr_clear_flags ();
inexact = mpfr_d_sub (y, 1.0, x, MPFR_RNDN);
MPFR_ASSERTN (inexact == 0);
MPFR_ASSERTN (__gmpfr_flags == 0);
MPFR_ASSERTN (mpfr_inf_p (y));
MPFR_ASSERTN (MPFR_IS_POS (y));
mpfr_clear (x);
mpfr_clear (y);
}
int
main (void)
{
mpfr_t x, y, z;
double d;
int inexact;
tests_start_mpfr ();
/* check with enough precision */
mpfr_init2 (x, IEEE_DBL_MANT_DIG);
mpfr_init2 (y, IEEE_DBL_MANT_DIG);
mpfr_init2 (z, IEEE_DBL_MANT_DIG);
mpfr_set_str (y, "4096", 10, MPFR_RNDN);
d = 0.125;
mpfr_clear_flags ();
inexact = mpfr_d_sub (x, d, y, MPFR_RNDN);
if (inexact != 0)
{
printf ("Inexact flag error in mpfr_d_sub\n");
exit (1);
}
mpfr_set_str (z, "-4095.875", 10, MPFR_RNDN);
if (mpfr_cmp (z, x))
{
printf ("Error in mpfr_d_sub (");
mpfr_out_str (stdout, 10, 7, y, MPFR_RNDN);
printf (" + %.20g)\nexpected ", d);
mpfr_out_str (stdout, 10, 0, z, MPFR_RNDN);
printf ("\ngot ");
mpfr_out_str (stdout, 10, 0, x, MPFR_RNDN);
printf ("\n");
exit (1);
}
mpfr_clears (x, y, z, (mpfr_ptr) 0);
check_nans ();
test_generic (2, 1000, 100);
tests_end_mpfr ();
return 0;
}
MpfrFloat operator-(double lhs, const MpfrFloat& rhs)
{
MpfrFloat retval(MpfrFloat::kNoInitialization);
mpfr_d_sub(retval.mData->mFloat, lhs, rhs.mData->mFloat, GMP_RNDN);
return retval;
}