public static int mpfr_check_range(
	mpfr_t x,
	int t,
	mpfr_rnd_t rnd
)

Public Shared Function mpfr_check_range ( 
	x As mpfr_t,
	t As Integer,
	rnd As mpfr_rnd_t
) As Integer

public:
static int mpfr_check_range(
	mpfr_t^ x, 
	int t, 
	mpfr_rnd_t rnd
)

static member mpfr_check_range : 
        x : mpfr_t * 
        t : int * 
        rnd : mpfr_rnd_t -> int 

Parameters

x

Type: Math.Mpfr.Nativempfr_t
The operand floating-point number.

t

Type: SystemInt32
The input ternary value.

rnd

Type: Math.Mpfr.Nativempfr_rnd_t
The rounding direction.

Return Value

This function assumes that x is the correctly-rounded value of some real value y in the direction rnd and some extended exponent range, and that t is the corresponding ternary value. For example, one performed t = mpfr_log(x, u, rnd), and y is the exact logarithm of u. Thus t is negative if x is smaller than y, positive if x is larger than y, and zero if x equals y. This function modifies x if needed to be in the current range of acceptable values: It generates an underflow or an overflow if the exponent of x is outside the current allowed range; the value of t may be used to avoid a double rounding. This function returns zero if the new value of x equals the exact one y, a positive value if that new value is larger than y, and a negative value if it is smaller than y. Note that unlike most functions, the new result x is compared to the (unknown) exact one y, not the input value x, i.e., the ternary value is propagated.

Note: If x is an infinity and t is different from zero (i.e., if the rounded result is an inexact infinity), then the overflow flag is set. This is useful because mpfr_check_range is typically called (at least in MPFR functions) after restoring the flags that could have been set due to internal computations.

Reference