1FMA(3) Linux Programmer's Manual FMA(3)
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6 fma, fmaf, fmal - floating-point multiply and add
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9 #include <math.h>
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11 double fma(double x, double y, double z);
12 float fmaf(float x, float y, float z);
13 long double fmal(long double x, long double y, long double z);
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15 Link with -lm.
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17 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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19 fma(), fmaf(), fmal():
20 _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
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23 These functions compute x * y + z. The result is rounded as one
24 ternary operation according to the current rounding mode (see fenv(3)).
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27 These functions return the value of x * y + z, rounded as one ternary
28 operation.
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30 If x or y is a NaN, a NaN is returned.
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32 If x times y is an exact infinity, and z is an infinity with the oppo‐
33 site sign, a domain error occurs, and a NaN is returned.
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35 If one of x or y is an infinity, the other is 0, and z is not a NaN, a
36 domain error occurs, and a NaN is returned.
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38 If one of x or y is an infinity, and the other is 0, and z is a NaN, a
39 domain error occurs, and a NaN is returned.
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41 If x times y is not an infinity times zero (or vice versa), and z is a
42 NaN, a NaN is returned.
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44 If the result overflows, a range error occurs, and an infinity with the
45 correct sign is returned.
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47 If the result underflows, a range error occurs, and a signed 0 is
48 returned.
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51 See math_error(7) for information on how to determine whether an error
52 has occurred when calling these functions.
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54 The following errors can occur:
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56 Domain error: x * y + z, or x * y is invalid and z is not a NaN
57 An invalid floating-point exception (FE_INVALID) is raised.
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59 Range error: result overflow
60 An overflow floating-point exception (FE_OVERFLOW) is raised.
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62 Range error: result underflow
63 An underflow floating-point exception (FE_UNDERFLOW) is raised.
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65 These functions do not set errno.
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68 These functions first appeared in glibc in version 2.1.
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71 For an explanation of the terms used in this section, see
72 attributes(7).
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74 ┌──────────────────────┬───────────────┬─────────┐
75 │Interface │ Attribute │ Value │
76 ├──────────────────────┼───────────────┼─────────┤
77 │fma(), fmaf(), fmal() │ Thread safety │ MT-Safe │
78 └──────────────────────┴───────────────┴─────────┘
80 C99, POSIX.1-2001, POSIX.1-2008.
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83 remainder(3), remquo(3)
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86 This page is part of release 5.04 of the Linux man-pages project. A
87 description of the project, information about reporting bugs, and the
88 latest version of this page, can be found at
89 https://www.kernel.org/doc/man-pages/.
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93 2017-09-15 FMA(3)