1SCALBLN(3)                 Linux Programmer's Manual                SCALBLN(3)
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NAME

6       scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply float‐
7       ing-point number by integral power of radix
8

SYNOPSIS

10       #include <math.h>
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12       double scalbln(double x, long int exp);
13       float scalblnf(float x, long int exp);
14       long double scalblnl(long double x, long int exp);
15
16       double scalbn(double x, int exp);
17       float scalbnf(float x, int exp);
18       long double scalbnl(long double x, int exp);
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20       Link with -lm.
21
22   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
23
24       scalbln(), scalblnf(), scalblnl():
25              _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
26                  || /* Since glibc 2.19: */ _DEFAULT_SOURCE
27       scalbn(), scalbnf(), scalbnl():
28              _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
29                  || /* Since glibc 2.19: */ _DEFAULT_SOURCE
30                  || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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DESCRIPTION

33       These functions multiply their first argument x by FLT_RADIX  (probably
34       2) to the power of exp, that is:
35
36           x * FLT_RADIX ** exp
37
38       The definition of FLT_RADIX can be obtained by including <float.h>.
39

RETURN VALUE

41       On success, these functions return x * FLT_RADIX ** exp.
42
43       If x is a NaN, a NaN is returned.
44
45       If x is positive infinity (negative infinity), positive infinity (nega‐
46       tive infinity) is returned.
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48       If x is +0 (-0), +0 (-0) is returned.
49
50       If the result overflows, a range error occurs, and the functions return
51       HUGE_VAL,  HUGE_VALF,  or HUGE_VALL, respectively, with a sign the same
52       as x.
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54       If the result underflows, a  range  error  occurs,  and  the  functions
55       return zero, with a sign the same as x.
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ERRORS

58       See  math_error(7) for information on how to determine whether an error
59       has occurred when calling these functions.
60
61       The following errors can occur:
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63       Range error, overflow
64              An overflow floating-point exception (FE_OVERFLOW) is raised.
65
66       Range error, underflow
67              errno is set to ERANGE.  An underflow  floating-point  exception
68              (FE_UNDERFLOW) is raised.
69

VERSIONS

71       These functions first appeared in glibc in version 2.1.
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ATTRIBUTES

74       For   an   explanation   of   the  terms  used  in  this  section,  see
75       attributes(7).
76
77       ┌──────────────────────────────────┬───────────────┬─────────┐
78Interface                         Attribute     Value   
79       ├──────────────────────────────────┼───────────────┼─────────┤
80scalbn(), scalbnf(), scalbnl(),   │ Thread safety │ MT-Safe │
81scalbln(), scalblnf(), scalblnl() │               │         │
82       └──────────────────────────────────┴───────────────┴─────────┘

CONFORMING TO

84       C99, POSIX.1-2001, POSIX.1-2008.
85

NOTES

87       These  functions  differ  from  the  obsolete  functions  described  in
88       scalb(3) in the type of their second argument.  The functions described
89       on this page have a second argument of an integral type, while those in
90       scalb(3) have a second argument of type double.
91
92       If  FLT_RADIX equals 2 (which is usual), then scalbn() is equivalent to
93       ldexp(3).
94

BUGS

96       Before glibc 2.20, these functions did not set errno for range errors.
97

SEE ALSO

99       ldexp(3), scalb(3)
100

COLOPHON

102       This page is part of release 5.07 of the Linux  man-pages  project.   A
103       description  of  the project, information about reporting bugs, and the
104       latest    version    of    this    page,    can     be     found     at
105       https://www.kernel.org/doc/man-pages/.
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109                                  2020-06-09                        SCALBLN(3)
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