NAME
ldexp,
ldexpf,
ldexpl
—
multiply floating-point number by integral power of
2
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
ldexp(
double
x,
int exp);
float
ldexpf(
float
x,
int exp);
long double
ldexpl(
long
double x,
int exp);
DESCRIPTION
The
ldexp() family of functions compute
x * 2^
exp
for a real floating-point number
x.
RETURN VALUES
The functions return the value of
x times 2 raised to the
power
exp. Otherwise the following may occur:
- If x is NaN, a NaN is returned.
- If exp is zero or
x is either ± 0 or ±∞,
x is returned.
- If the call would cause an overflow, a range error occurs
and either
±HUGE_VAL
,
±HUGE_VALF
, or
±HUGE_VALL
is returned, depending on the sign
of x and the type of the return value.
- If an underflow would be caused by the correct value, and
the value is not representable, either 0.0 or an implementation-defined
value is returned.
SEE ALSO
frexp(3),
math(3),
modf(3)
STANDARDS
The described functions conform to
ISO/IEC 9899:1999
(“ISO C99”).