/* The computation of z = pow(x,y) is done by
z = exp(y * log(x)) = x^y
For the special cases, see Section F.9.4.4 of the C standard:
_ pow(±0, y) = ±inf for y an odd integer < 0.
_ pow(±0, y) = +inf for y < 0 and not an odd integer.
_ pow(±0, y) = ±0 for y an odd integer > 0.
_ pow(±0, y) = +0 for y > 0 and not an odd integer.
_ pow(-1, ±inf) = 1.
_ pow(+1, y) = 1 for any y, even a NaN.
_ pow(x, ±0) = 1 for any x, even a NaN.
_ pow(x, y) = NaN for finite x < 0 and finite non-integer y.
_ pow(x, -inf) = +inf for |x| < 1.
_ pow(x, -inf) = +0 for |x| > 1.
_ pow(x, +inf) = +0 for |x| < 1.
_ pow(x, +inf) = +inf for |x| > 1.
_ pow(-inf, y) = -0 for y an odd integer < 0.
_ pow(-inf, y) = +0 for y < 0 and not an odd integer.
_ pow(-inf, y) = -inf for y an odd integer > 0.
_ pow(-inf, y) = +inf for y > 0 and not an odd integer.
_ pow(+inf, y) = +0 for y < 0.
_ pow(+inf, y) = +inf for y > 0. */
int
mpfr_pow (mpfr_ptr z, mpfr_srcptr x, mpfr_srcptr y, mpfr_rnd_t rnd_mode)
{
int inexact;
int cmp_x_1;
int y_is_integer;
MPFR_SAVE_EXPO_DECL (expo);
MPFR_LOG_FUNC
(("x[%Pu]=%.*Rg y[%Pu]=%.*Rg rnd=%d",
mpfr_get_prec (x), mpfr_log_prec, x,
mpfr_get_prec (y), mpfr_log_prec, y, rnd_mode),
("z[%Pu]=%.*Rg inexact=%d",
mpfr_get_prec (z), mpfr_log_prec, z, inexact));
if (MPFR_ARE_SINGULAR (x, y))
{
/* pow(x, 0) returns 1 for any x, even a NaN. */
if (MPFR_UNLIKELY (MPFR_IS_ZERO (y)))
return mpfr_set_ui (z, 1, rnd_mode);
else if (MPFR_IS_NAN (x))
{
MPFR_SET_NAN (z);
MPFR_RET_NAN;
}
else if (MPFR_IS_NAN (y))
{
/* pow(+1, NaN) returns 1. */
if (mpfr_cmp_ui (x, 1) == 0)
return mpfr_set_ui (z, 1, rnd_mode);
MPFR_SET_NAN (z);
MPFR_RET_NAN;
}
else if (MPFR_IS_INF (y))
{
if (MPFR_IS_INF (x))
{
if (MPFR_IS_POS (y))
MPFR_SET_INF (z);
else
MPFR_SET_ZERO (z);
MPFR_SET_POS (z);
MPFR_RET (0);
}
else
{
int cmp;
cmp = mpfr_cmpabs (x, __gmpfr_one) * MPFR_INT_SIGN (y);
MPFR_SET_POS (z);
if (cmp > 0)
{
/* Return +inf. */
MPFR_SET_INF (z);
MPFR_RET (0);
}
else if (cmp < 0)
{
/* Return +0. */
MPFR_SET_ZERO (z);
MPFR_RET (0);
}
else
{
/* Return 1. */
return mpfr_set_ui (z, 1, rnd_mode);
}
}
}
else if (MPFR_IS_INF (x))
{
int negative;
/* Determine the sign now, in case y and z are the same object */
negative = MPFR_IS_NEG (x) && is_odd (y);
if (MPFR_IS_POS (y))
MPFR_SET_INF (z);
else
MPFR_SET_ZERO (z);
if (negative)
MPFR_SET_NEG (z);
else
MPFR_SET_POS (z);
MPFR_RET (0);
}
else
{
int negative;
MPFR_ASSERTD (MPFR_IS_ZERO (x));
/* Determine the sign now, in case y and z are the same object */
negative = MPFR_IS_NEG(x) && is_odd (y);
if (MPFR_IS_NEG (y))
{
MPFR_ASSERTD (! MPFR_IS_INF (y));
MPFR_SET_INF (z);
mpfr_set_divby0 ();
}
else
MPFR_SET_ZERO (z);
if (negative)
MPFR_SET_NEG (z);
else
MPFR_SET_POS (z);
MPFR_RET (0);
}
}
/* x^y for x < 0 and y not an integer is not defined */
y_is_integer = mpfr_integer_p (y);
if (MPFR_IS_NEG (x) && ! y_is_integer)
{
MPFR_SET_NAN (z);
MPFR_RET_NAN;
}
/* now the result cannot be NaN:
(1) either x > 0
(2) or x < 0 and y is an integer */
cmp_x_1 = mpfr_cmpabs (x, __gmpfr_one);
if (cmp_x_1 == 0)
return mpfr_set_si (z, MPFR_IS_NEG (x) && is_odd (y) ? -1 : 1, rnd_mode);
/* now we have:
(1) either x > 0
(2) or x < 0 and y is an integer
and in addition |x| <> 1.
*/
/* detect overflow: an overflow is possible if
(a) |x| > 1 and y > 0
(b) |x| < 1 and y < 0.
FIXME: this assumes 1 is always representable.
FIXME2: maybe we can test overflow and underflow simultaneously.
The idea is the following: first compute an approximation to
y * log2|x|, using rounding to nearest. If |x| is not too near from 1,
this approximation should be accurate enough, and in most cases enable
one to prove that there is no underflow nor overflow.
Otherwise, it should enable one to check only underflow or overflow,
instead of both cases as in the present case.
*/
if (cmp_x_1 * MPFR_SIGN (y) > 0)
{
mpfr_t t;
int negative, overflow;
MPFR_SAVE_EXPO_MARK (expo);
mpfr_init2 (t, 53);
/* we want a lower bound on y*log2|x|:
(i) if x > 0, it suffices to round log2(x) toward zero, and
to round y*o(log2(x)) toward zero too;
(ii) if x < 0, we first compute t = o(-x), with rounding toward 1,
and then follow as in case (1). */
if (MPFR_SIGN (x) > 0)
mpfr_log2 (t, x, MPFR_RNDZ);
else
{
mpfr_neg (t, x, (cmp_x_1 > 0) ? MPFR_RNDZ : MPFR_RNDU);
mpfr_log2 (t, t, MPFR_RNDZ);
}
mpfr_mul (t, t, y, MPFR_RNDZ);
overflow = mpfr_cmp_si (t, __gmpfr_emax) > 0;
mpfr_clear (t);
MPFR_SAVE_EXPO_FREE (expo);
if (overflow)
{
MPFR_LOG_MSG (("early overflow detection\n", 0));
negative = MPFR_SIGN(x) < 0 && is_odd (y);
return mpfr_overflow (z, rnd_mode, negative ? -1 : 1);
}
}
/* Basic underflow checking. One has:
* - if y > 0, |x^y| < 2^(EXP(x) * y);
* - if y < 0, |x^y| <= 2^((EXP(x) - 1) * y);
* so that one can compute a value ebound such that |x^y| < 2^ebound.
* If we have ebound <= emin - 2 (emin - 1 in directed rounding modes),
* then there is an underflow and we can decide the return value.
*/
if (MPFR_IS_NEG (y) ? (MPFR_GET_EXP (x) > 1) : (MPFR_GET_EXP (x) < 0))
{
mpfr_t tmp;
mpfr_eexp_t ebound;
int inex2;
/* We must restore the flags. */
MPFR_SAVE_EXPO_MARK (expo);
mpfr_init2 (tmp, sizeof (mpfr_exp_t) * CHAR_BIT);
inex2 = mpfr_set_exp_t (tmp, MPFR_GET_EXP (x), MPFR_RNDN);
MPFR_ASSERTN (inex2 == 0);
if (MPFR_IS_NEG (y))
{
inex2 = mpfr_sub_ui (tmp, tmp, 1, MPFR_RNDN);
MPFR_ASSERTN (inex2 == 0);
}
mpfr_mul (tmp, tmp, y, MPFR_RNDU);
if (MPFR_IS_NEG (y))
mpfr_nextabove (tmp);
/* tmp doesn't necessarily fit in ebound, but that doesn't matter
since we get the minimum value in such a case. */
ebound = mpfr_get_exp_t (tmp, MPFR_RNDU);
mpfr_clear (tmp);
MPFR_SAVE_EXPO_FREE (expo);
if (MPFR_UNLIKELY (ebound <=
__gmpfr_emin - (rnd_mode == MPFR_RNDN ? 2 : 1)))
{
/* warning: mpfr_underflow rounds away from 0 for MPFR_RNDN */
MPFR_LOG_MSG (("early underflow detection\n", 0));
return mpfr_underflow (z,
rnd_mode == MPFR_RNDN ? MPFR_RNDZ : rnd_mode,
MPFR_SIGN (x) < 0 && is_odd (y) ? -1 : 1);
}
}
/* If y is an integer, we can use mpfr_pow_z (based on multiplications),
but if y is very large (I'm not sure about the best threshold -- VL),
we shouldn't use it, as it can be very slow and take a lot of memory
(and even crash or make other programs crash, as several hundred of
MBs may be necessary). Note that in such a case, either x = +/-2^b
(this case is handled below) or x^y cannot be represented exactly in
any precision supported by MPFR (the general case uses this property).
*/
if (y_is_integer && (MPFR_GET_EXP (y) <= 256))
{
mpz_t zi;
MPFR_LOG_MSG (("special code for y not too large integer\n", 0));
mpz_init (zi);
mpfr_get_z (zi, y, MPFR_RNDN);
inexact = mpfr_pow_z (z, x, zi, rnd_mode);
mpz_clear (zi);
return inexact;
}
/* Special case (+/-2^b)^Y which could be exact. If x is negative, then
necessarily y is a large integer. */
{
mpfr_exp_t b = MPFR_GET_EXP (x) - 1;
MPFR_ASSERTN (b >= LONG_MIN && b <= LONG_MAX); /* FIXME... */
if (mpfr_cmp_si_2exp (x, MPFR_SIGN(x), b) == 0)
{
mpfr_t tmp;
int sgnx = MPFR_SIGN (x);
MPFR_LOG_MSG (("special case (+/-2^b)^Y\n", 0));
/* now x = +/-2^b, so x^y = (+/-1)^y*2^(b*y) is exact whenever b*y is
an integer */
MPFR_SAVE_EXPO_MARK (expo);
mpfr_init2 (tmp, MPFR_PREC (y) + sizeof (long) * CHAR_BIT);
inexact = mpfr_mul_si (tmp, y, b, MPFR_RNDN); /* exact */
MPFR_ASSERTN (inexact == 0);
/* Note: as the exponent range has been extended, an overflow is not
possible (due to basic overflow and underflow checking above, as
the result is ~ 2^tmp), and an underflow is not possible either
because b is an integer (thus either 0 or >= 1). */
MPFR_CLEAR_FLAGS ();
inexact = mpfr_exp2 (z, tmp, rnd_mode);
mpfr_clear (tmp);
if (sgnx < 0 && is_odd (y))
{
mpfr_neg (z, z, rnd_mode);
inexact = -inexact;
}
/* Without the following, the overflows3 test in tpow.c fails. */
MPFR_SAVE_EXPO_UPDATE_FLAGS (expo, __gmpfr_flags);
MPFR_SAVE_EXPO_FREE (expo);
return mpfr_check_range (z, inexact, rnd_mode);
}
}
MPFR_SAVE_EXPO_MARK (expo);
/* Case where |y * log(x)| is very small. Warning: x can be negative, in
that case y is a large integer. */
{
mpfr_t t;
mpfr_exp_t err;
/* We need an upper bound on the exponent of y * log(x). */
mpfr_init2 (t, 16);
if (MPFR_IS_POS(x))
mpfr_log (t, x, cmp_x_1 < 0 ? MPFR_RNDD : MPFR_RNDU); /* away from 0 */
else
{
/* if x < -1, round to +Inf, else round to zero */
mpfr_neg (t, x, (mpfr_cmp_si (x, -1) < 0) ? MPFR_RNDU : MPFR_RNDD);
mpfr_log (t, t, (mpfr_cmp_ui (t, 1) < 0) ? MPFR_RNDD : MPFR_RNDU);
}
MPFR_ASSERTN (MPFR_IS_PURE_FP (t));
err = MPFR_GET_EXP (y) + MPFR_GET_EXP (t);
mpfr_clear (t);
MPFR_CLEAR_FLAGS ();
MPFR_SMALL_INPUT_AFTER_SAVE_EXPO (z, __gmpfr_one, - err, 0,
(MPFR_SIGN (y) > 0) ^ (cmp_x_1 < 0),
rnd_mode, expo, {});
}
/* General case */
inexact = mpfr_pow_general (z, x, y, rnd_mode, y_is_integer, &expo);
MPFR_SAVE_EXPO_FREE (expo);
return mpfr_check_range (z, inexact, rnd_mode);
}
/* return non zero iff x^y is exact.
Assumes x and y are ordinary numbers,
y is not an integer, x is not a power of 2 and x is positive
If x^y is exact, it computes it and sets *inexact.
*/
static int
mpfr_pow_is_exact (mpfr_ptr z, mpfr_srcptr x, mpfr_srcptr y,
mpfr_rnd_t rnd_mode, int *inexact)
{
mpz_t a, c;
mpfr_exp_t d, b;
unsigned long i;
int res;
MPFR_ASSERTD (!MPFR_IS_SINGULAR (y));
MPFR_ASSERTD (!MPFR_IS_SINGULAR (x));
MPFR_ASSERTD (!mpfr_integer_p (y));
MPFR_ASSERTD (mpfr_cmp_si_2exp (x, MPFR_INT_SIGN (x),
MPFR_GET_EXP (x) - 1) != 0);
MPFR_ASSERTD (MPFR_IS_POS (x));
if (MPFR_IS_NEG (y))
return 0; /* x is not a power of two => x^-y is not exact */
/* compute d such that y = c*2^d with c odd integer */
mpz_init (c);
d = mpfr_get_z_2exp (c, y);
i = mpz_scan1 (c, 0);
mpz_fdiv_q_2exp (c, c, i);
d += i;
/* now y=c*2^d with c odd */
/* Since y is not an integer, d is necessarily < 0 */
MPFR_ASSERTD (d < 0);
/* Compute a,b such that x=a*2^b */
mpz_init (a);
b = mpfr_get_z_2exp (a, x);
i = mpz_scan1 (a, 0);
mpz_fdiv_q_2exp (a, a, i);
b += i;
/* now x=a*2^b with a is odd */
for (res = 1 ; d != 0 ; d++)
{
/* a*2^b is a square iff
(i) a is a square when b is even
(ii) 2*a is a square when b is odd */
if (b % 2 != 0)
{
mpz_mul_2exp (a, a, 1); /* 2*a */
b --;
}
MPFR_ASSERTD ((b % 2) == 0);
if (!mpz_perfect_square_p (a))
{
res = 0;
goto end;
}
mpz_sqrt (a, a);
b = b / 2;
}
/* Now x = (a'*2^b')^(2^-d) with d < 0
so x^y = ((a'*2^b')^(2^-d))^(c*2^d)
= ((a'*2^b')^c with c odd integer */
{
mpfr_t tmp;
mpfr_prec_t p;
MPFR_MPZ_SIZEINBASE2 (p, a);
mpfr_init2 (tmp, p); /* prec = 1 should not be possible */
res = mpfr_set_z (tmp, a, MPFR_RNDN);
MPFR_ASSERTD (res == 0);
res = mpfr_mul_2si (tmp, tmp, b, MPFR_RNDN);
MPFR_ASSERTD (res == 0);
*inexact = mpfr_pow_z (z, tmp, c, rnd_mode);
mpfr_clear (tmp);
res = 1;
}
end:
mpz_clear (a);
mpz_clear (c);
return res;
}
void power_mpz(ElementType &result, const ElementType& a, mpz_ptr n) const
{
mpfr_pow_z(&result, &a, n, GMP_RNDN);
}
static PyObject *
GMPy_Real_Pow(PyObject *base, PyObject *exp, PyObject *mod, CTXT_Object *context)
{
MPFR_Object *tempb = NULL, *tempe = NULL, *result = NULL;
MPZ_Object *tempz = NULL;
MPC_Object *mpc_result = NULL;
if (mod != Py_None) {
TYPE_ERROR("pow() 3rd argument not allowed unless all arguments are integers");
return NULL;
}
CHECK_CONTEXT(context);
result = GMPy_MPFR_New(0, context);
tempb = GMPy_MPFR_From_Real(base, 1, context);
if (!result || !tempb) {
goto err;
}
mpfr_clear_flags();
if (PyIntOrLong_Check(exp)) {
int error;
long temp_exp = GMPy_Integer_AsLongAndError(exp, &error);
if (!error) {
result->rc = mpfr_pow_si(result->f, tempb->f, temp_exp, GET_MPFR_ROUND(context));
}
else {
mpz_t tempzz;
mpz_inoc(tempzz);
mpz_set_PyIntOrLong(tempzz, exp);
result->rc = mpfr_pow_z(result->f, tempb->f, tempzz, GET_MPFR_ROUND(context));
mpz_cloc(tempzz);
}
}
else if (IS_INTEGER(exp)) {
if (!(tempz = GMPy_MPZ_From_Integer(exp, context))) {
goto err;
}
result->rc = mpfr_pow_z(result->f, tempb->f, tempz->z, GET_MPFR_ROUND(context));
}
else {
if (!(tempe = GMPy_MPFR_From_Real(exp, 1, context))) {
goto err;
}
result->rc = mpfr_pow(result->f, tempb->f, tempe->f, GET_MPFR_ROUND(context));
}
/* If the result is NaN, check if a complex result works. */
if (result && mpfr_nanflag_p() && context->ctx.allow_complex) {
mpc_result = (MPC_Object*)GMPy_Complex_Pow(base, exp, Py_None, context);
if (!mpc_result || MPC_IS_NAN_P(mpc_result)) {
Py_XDECREF((PyObject*)mpc_result);
context->ctx.invalid = 1;
GMPY_INVALID("pow() invalid operation");
goto err;
}
/* return a valid complex result */
Py_XDECREF((PyObject*)tempe);
Py_XDECREF((PyObject*)tempz);
Py_XDECREF((PyObject*)tempb);
Py_XDECREF((PyObject*)result);
return (PyObject*)mpc_result;
}
GMPY_MPFR_CLEANUP(result, context, "pow()");
Py_XDECREF((PyObject*)tempz);
Py_XDECREF((PyObject*)tempe);
Py_XDECREF((PyObject*)tempb);
return (PyObject*)result;
err:
Py_XDECREF((PyObject*)result);
Py_XDECREF((PyObject*)tempz);
Py_XDECREF((PyObject*)tempe);
Py_XDECREF((PyObject*)tempb);
return NULL;
}
/* Compare the result (z1,inex1) of mpfr_pow with all flags cleared
with those of mpfr_pow with all flags set and of the other power
functions. Arguments x and y are the input values; sx and sy are
their string representations (sx may be null); rnd contains the
rounding mode; s is a string containing the function that called
test_others. */
static void
test_others (const void *sx, const char *sy, mpfr_rnd_t rnd,
mpfr_srcptr x, mpfr_srcptr y, mpfr_srcptr z1,
int inex1, unsigned int flags, const char *s)
{
mpfr_t z2;
int inex2;
int spx = sx != NULL;
if (!spx)
sx = x;
mpfr_init2 (z2, mpfr_get_prec (z1));
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_pow (z2, x, y, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_pow, flags set");
/* If y is an integer that fits in an unsigned long and is not -0,
we can test mpfr_pow_ui. */
if (MPFR_IS_POS (y) && mpfr_integer_p (y) &&
mpfr_fits_ulong_p (y, MPFR_RNDN))
{
unsigned long yy = mpfr_get_ui (y, MPFR_RNDN);
mpfr_clear_flags ();
inex2 = mpfr_pow_ui (z2, x, yy, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_pow_ui, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_pow_ui (z2, x, yy, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_pow_ui, flags set");
/* If x is an integer that fits in an unsigned long and is not -0,
we can also test mpfr_ui_pow_ui. */
if (MPFR_IS_POS (x) && mpfr_integer_p (x) &&
mpfr_fits_ulong_p (x, MPFR_RNDN))
{
unsigned long xx = mpfr_get_ui (x, MPFR_RNDN);
mpfr_clear_flags ();
inex2 = mpfr_ui_pow_ui (z2, xx, yy, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_ui_pow_ui, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_ui_pow_ui (z2, xx, yy, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_ui_pow_ui, flags set");
}
}
/* If y is an integer but not -0 and not huge, we can test mpfr_pow_z,
and possibly mpfr_pow_si (and possibly mpfr_ui_div). */
if (MPFR_IS_ZERO (y) ? MPFR_IS_POS (y) :
(mpfr_integer_p (y) && MPFR_GET_EXP (y) < 256))
{
mpz_t yyy;
/* If y fits in a long, we can test mpfr_pow_si. */
if (mpfr_fits_slong_p (y, MPFR_RNDN))
{
long yy = mpfr_get_si (y, MPFR_RNDN);
mpfr_clear_flags ();
inex2 = mpfr_pow_si (z2, x, yy, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_pow_si, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_pow_si (z2, x, yy, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_pow_si, flags set");
/* If y = -1, we can test mpfr_ui_div. */
if (yy == -1)
{
mpfr_clear_flags ();
inex2 = mpfr_ui_div (z2, 1, x, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_ui_div, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_ui_div (z2, 1, x, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_ui_div, flags set");
}
/* If y = 2, we can test mpfr_sqr. */
if (yy == 2)
{
mpfr_clear_flags ();
inex2 = mpfr_sqr (z2, x, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_sqr, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_sqr (z2, x, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_sqr, flags set");
}
}
/* Test mpfr_pow_z. */
mpz_init (yyy);
mpfr_get_z (yyy, y, MPFR_RNDN);
mpfr_clear_flags ();
inex2 = mpfr_pow_z (z2, x, yyy, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_pow_z, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_pow_z (z2, x, yyy, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_pow_z, flags set");
mpz_clear (yyy);
}
/* If y = 0.5, we can test mpfr_sqrt, except if x is -0 or -Inf (because
the rule for mpfr_pow on these special values is different). */
if (MPFR_IS_PURE_FP (y) && mpfr_cmp_str1 (y, "0.5") == 0 &&
! ((MPFR_IS_ZERO (x) || MPFR_IS_INF (x)) && MPFR_IS_NEG (x)))
{
mpfr_clear_flags ();
inex2 = mpfr_sqrt (z2, x, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_sqrt, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_sqrt (z2, x, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_sqrt, flags set");
}
#if MPFR_VERSION >= MPFR_VERSION_NUM(2,4,0)
/* If y = -0.5, we can test mpfr_rec_sqrt, except if x = -Inf
(because the rule for mpfr_pow on -Inf is different). */
if (MPFR_IS_PURE_FP (y) && mpfr_cmp_str1 (y, "-0.5") == 0 &&
! (MPFR_IS_INF (x) && MPFR_IS_NEG (x)))
{
mpfr_clear_flags ();
inex2 = mpfr_rec_sqrt (z2, x, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_rec_sqrt, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_rec_sqrt (z2, x, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_rec_sqrt, flags set");
}
#endif
/* If x is an integer that fits in an unsigned long and is not -0,
we can test mpfr_ui_pow. */
if (MPFR_IS_POS (x) && mpfr_integer_p (x) &&
mpfr_fits_ulong_p (x, MPFR_RNDN))
{
unsigned long xx = mpfr_get_ui (x, MPFR_RNDN);
mpfr_clear_flags ();
inex2 = mpfr_ui_pow (z2, xx, y, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_ui_pow, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_ui_pow (z2, xx, y, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_ui_pow, flags set");
/* If x = 2, we can test mpfr_exp2. */
if (xx == 2)
{
mpfr_clear_flags ();
inex2 = mpfr_exp2 (z2, y, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_exp2, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_exp2 (z2, y, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_exp2, flags set");
}
/* If x = 10, we can test mpfr_exp10. */
if (xx == 10)
{
mpfr_clear_flags ();
inex2 = mpfr_exp10 (z2, y, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, flags,
s, "mpfr_exp10, flags cleared");
__gmpfr_flags = MPFR_FLAGS_ALL;
inex2 = mpfr_exp10 (z2, y, rnd);
cmpres (spx, sx, sy, rnd, z1, inex1, z2, inex2, MPFR_FLAGS_ALL,
s, "mpfr_exp10, flags set");
}
}
mpfr_clear (z2);
}
