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ldexp, ldexpf, ldexpl - multiply floating-point number by integral power of 2

#include<math.h>doubleldexp(doublex,intexp);floatldexpf(floatx,intexp);longdoubleldexpl(longdoublex,intexp);Link with-lm. Feature Test Macro Requirements for glibc (seefeature_test_macros(7)):ldexpf(),ldexpl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; orcc-std=c99

Theldexp() function returns the result of multiplying the floating- point numberxby 2 raised to the powerexp.

On success, these functions returnx*(2^exp). Ifexpis zero, thenxis returned. Ifxis a NaN, a NaN is returned. Ifxis positive infinity (negative infinity), positive infinity (negative infinity) is returned. If the result underflows, an range error occurs, and zero is returned. If the result overflows, a range error occurs, and the functions returnHUGE_VAL,HUGE_VALF, orHUGE_VALL, respectively, with a sign the same asx.

Seemath_error(7) for information on how to determine whether an error has occurred when calling these functions. The following errors can occur: Range error, overflowerrnois set toERANGE. An overflow floating-point exception (FE_OVERFLOW) is raised. Range error, underflowerrnois set toERANGE. An underflow floating-point exception (FE_UNDERFLOW) is raised.

C99, POSIX.1-2001. The variant returningdoublealso conforms to SVr4, 4.3BSD, C89.

frexp(3),modf(3),scalbln(3)

This page is part of release 3.24 of the Linuxman-pagesproject. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. 2008-08-05 LDEXP(3)