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logbl(3) [osx man page]

LOGB(3) 						   BSD Library Functions Manual 						   LOGB(3)

logb -- return exponent as a floating-point number SYNOPSIS
#include <math.h> double logb(double x); long double logbl(long double x); float logbf(float x); DESCRIPTION
The logb() functions return the exponent of x, represented as a floating-point number. SPECIAL VALUES
logb(+-0) returns -infinity and raises the "divide-by-zero" floating-point exception. logb(+-infinity) returns +infinity. VECTOR OPERATIONS
If you need to apply the logb() functions to SIMD vectors or arrays, using the following functions provided by the Accelerate.framework may give significantly better performance: #include <Accelerate/Accelerate.h> vFloat vlogbf(vFloat x); void vvlogbf(float *y, const float *x, const int *n); void vvlogb(double *y, const double *x, const int *n); SEE ALSO
ilogb(3) log(3) math(3) STANDARDS
The logb() functions conform to ISO/IEC 9899:2011. BSD
August 21, 2012 BSD

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ILOGB(3)						   BSD Library Functions Manual 						  ILOGB(3)

ilogb, ilogbf, ilogbl, logb, logbf, logbl -- extract exponent LIBRARY
Math Library (libm, -lm) SYNOPSIS
#include <math.h> int ilogb(double x); int ilogbf(float x); int ilogbl(long double x); double logb(double x); float logbf(float x); long double logbl(long double x); DESCRIPTION
ilogb(), ilogbf() and ilogbl() return x's exponent in integer format. ilogb(+-infinity) returns INT_MAX, ilogb(+-NaN) returns FP_ILOGBNAN, and ilogb(0) returns FP_ILOGB0. logb(x), logbf(x), and logbl(x) return x's exponent in floating-point format with the same precision as x. logb(+-infinity) returns +infin- ity, and logb(0) returns -infinity with a division by zero exception. SEE ALSO
frexp(3), ieee(3), math(3), scalbn(3) STANDARDS
The ilogb(), ilogbf(), ilogbl(), logb(), logbf(), and logbl() routines conform to ISO/IEC 9899:1999 (``ISO C99''). The latter three imple- ment the logb function recommended by IEEE Std 754-1985. HISTORY
Function First Appeared In logb() 4.3BSD ilogb() FreeBSD 1.1.5 ilogbf() FreeBSD 2.0 logbf() FreeBSD 2.0 ilogbl() FreeBSD 5.4 logbl() FreeBSD 8.0 BSD
December 16, 2007 BSD
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