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 exp);
13       float scalblnf(float x, long exp);
14       long double scalblnl(long double x, long 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
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28       scalbn(), scalbnf(), scalbnl():
29           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
30               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
31               || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
32

DESCRIPTION

34       These functions multiply their first argument x by FLT_RADIX  (probably
35       2) to the power of exp, that is:
36
37           x * FLT_RADIX ** exp
38
39       The definition of FLT_RADIX can be obtained by including <float.h>.
40

RETURN VALUE

42       On success, these functions return x * FLT_RADIX ** exp.
43
44       If x is a NaN, a NaN is returned.
45
46       If x is positive infinity (negative infinity), positive infinity (nega‐
47       tive infinity) is returned.
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49       If x is +0 (-0), +0 (-0) is returned.
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51       If the result overflows, a range error occurs, and the functions return
52       HUGE_VAL,  HUGE_VALF,  or HUGE_VALL, respectively, with a sign the same
53       as x.
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55       If the result underflows, a range error occurs, and the  functions  re‐
56       turn zero, with a sign the same as x.
57

ERRORS

59       See  math_error(7) for information on how to determine whether an error
60       has occurred when calling these functions.
61
62       The following errors can occur:
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64       Range error, overflow
65              An overflow floating-point exception (FE_OVERFLOW) is raised.
66
67       Range error, underflow
68              errno is set to ERANGE.  An underflow  floating-point  exception
69              (FE_UNDERFLOW) is raised.
70

VERSIONS

72       These functions first appeared in glibc in version 2.1.
73

ATTRIBUTES

75       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
76       tributes(7).
77
78       ┌────────────────────────────────────────────┬───────────────┬─────────┐
79Interface                                   Attribute     Value   
80       ├────────────────────────────────────────────┼───────────────┼─────────┤
81scalbn(), scalbnf(), scalbnl(), scalbln(),  │ Thread safety │ MT-Safe │
82scalblnf(), scalblnl()                      │               │         │
83       └────────────────────────────────────────────┴───────────────┴─────────┘
84

CONFORMING TO

86       C99, POSIX.1-2001, POSIX.1-2008.
87

NOTES

89       These  functions  differ  from  the  obsolete  functions  described  in
90       scalb(3) in the type of their second argument.  The functions described
91       on this page have a second argument of an integral type, while those in
92       scalb(3) have a second argument of type double.
93
94       If FLT_RADIX equals 2 (which is usual), then scalbn() is equivalent  to
95       ldexp(3).
96

BUGS

98       Before glibc 2.20, these functions did not set errno for range errors.
99

SEE ALSO

101       ldexp(3), scalb(3)
102

COLOPHON

104       This  page  is  part of release 5.13 of the Linux man-pages project.  A
105       description of the project, information about reporting bugs,  and  the
106       latest     version     of     this    page,    can    be    found    at
107       https://www.kernel.org/doc/man-pages/.
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111                                  2021-03-22                        SCALBLN(3)
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