scalb, scalbf, scalbl - multiply floating-point number by integral power of radix (OBSOLETE)
long double scalbl(long double
x, long double
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
These functions multiply their first argument
x by FLT_RADIX (probably 2) to the power of
exp, that is:
x * FLT_RADIX ** exp
The definition of FLT_RADIX can be obtained by including
On success, these functions return
x * FLT_RADIX **
exp is a NaN, a NaN is returned.
x is positive infinity (negative infinity), and
exp is not negative infinity, positive infinity (negative infinity) is returned.
x is +0 (-0), and
exp is not positive infinity, +0 (-0) is returned.
x is zero, and
exp is positive infinity, a domain error occurs, and a NaN is returned.
x is an infinity, and
exp is negative infinity, a domain error occurs, and a NaN is returned.
If the result overflows, a range error occurs, and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively, with a sign the same as
If the result underflows, a range error occurs, and the functions return zero, with a sign the same as
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
xis 0, and
expis positive infinity, or
xis positive infinity and
expis negative infinity and the other argument is not a NaN
errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.
errno is set to ERANGE. An overflow floating-point exception (FE_OVERFLOW) is raised.
errno is set to ERANGE. An underflow floating-point exception (FE_UNDERFLOW) is raised.
scalb() is specified in POSIX.1-2001, but marked obsolescent. POSIX.1-2008 removes the specification of scalb(), recommending the use of scalbln(3), scalblnf(3), or scalblnl(3) instead. The scalb() function is from 4.3BSD.
Before glibc 2.20, these functions did not set
errno for domain and range errors.
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