fegetround(3m)

1fegetround(3M)          Mathematical Library Functions          fegetround(3M)
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NAME

6       fegetround, fesetround - get and set current rounding direction
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SYNOPSIS

9       c99 [ flag... ] file... -lm [ library... ]
10       #include <fenv.h>
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12       int fegetround(void);
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15       int fesetround(int round);
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DESCRIPTION

19       The fegetround function gets the current rounding direction.
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22       The  fesetround function establishes the rounding direction represented
23       by its argument round. If the argument is not equal to the value  of  a
24       rounding direction macro, the rounding direction is not changed.
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RETURN VALUES

27       The  fegetround  function  returns  the value of the rounding direction
28       macro representing the current rounding direction, or a negative  value
29       if  there  is  no such rounding direction macro or the current rounding
30       direction is not determinable.
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33       The fesetround function returns a 0 value if and only if the  requested
34       rounding direction was established.
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ERRORS

37       No errors are defined.
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EXAMPLES

40       The following example saves, sets, and restores the rounding direction,
41       reporting an error and  aborting  if  setting  the  rounding  direction
42       fails:
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44       Example 1 Save, set, and restore the rounding direction.
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46         #include <fenv.h>
47         #include <assert.h>
48         void f(int round_dir)
49         {
50               #pragma STDC FENV_ACCESS ON
51               int save_round;
52               int setround_ok;
53               save_round = fegetround();
54               setround_ok = fesetround(round_dir);
55               assert(setround_ok == 0);
56               /* ... */
57               fesetround(save_round);
58               /* ... */
59         }
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ATTRIBUTES

63       See attributes(5) for descriptions of the following attributes:
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68       ┌─────────────────────────────┬─────────────────────────────┐
69       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
70       ├─────────────────────────────┼─────────────────────────────┤
71       │Interface Stability          │Standard                     │
72       ├─────────────────────────────┼─────────────────────────────┤
73       │MT-Level                     │MT-Safe                      │
74       └─────────────────────────────┴─────────────────────────────┘
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