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fegetround(3M)

HP-UX 11i Version 3: February 2007
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NAME

fegetround() — get floating-point rounding direction mode

SYNOPSIS

#include <fenv.h>

int fegetround(void);

DESCRIPTION

The fegetround() function gets the current rounding direction, as specified by the IEEE 754 (IEC 60559) floating-point standard.

The default rounding direction mode is round to nearest (FE_TONEAREST).

USAGE

To use this function, compile either with the default -Ae option or with the -Aa and -D_HPUX_SOURCE options. Make sure your program includes <fenv.h>.

For HP Integrity servers, specify +Ofenvaccess on the compiler command line or place the call to this function under the effect of an affirmative FENV_ACCESS pragma:

#pragma STDC FENV_ACCESS ON

If the FENV_ACCESS pragma is placed outside of any top-level declarations in a file, the pragma will apply to all declarations in the compilation following the pragma until another FENV_ACCESS pragma is encountered or until the end of the file is reached.

If the FENV_ACCESS pragma is placed at the beginning of a block (compound statement), the pragma will apply until another FENV_ACCESS pragma is encountered or until the end of the block is reached.

For PA-RISC, you might need to use the +Onomoveflops compiler option in order to prevent optimizations that can undermine the specified behavior of this function.

Link in the math library by specifying -lm on the compiler or linker command line.

For more information, see the HP-UX floating-point guide for HP Integrity servers at the following site: http://www.hp.com/go/fp.

RETURN VALUE

The fegetround() function returns the value of the rounding direction macro representing the current rounding direction. The return value will match one of the following macros, which are defined in <fenv.h>:

FE_TONEAREST

Round to nearest. If the two nearest representable are equally near, the one with its least significant bit zero is delivered.

FE_UPWARD

Round upwards (towards +infinity).

FE_DOWNWARD

Round downwards (towards -infinity).

FE_TOWARDZERO

Round toward zero.

ERRORS

No errors are defined.

EXAMPLES

Save, set, and restore the rounding direction.

#include <fenv.h> /*...*/ { int save_round; save_round = fegetround(); fesetround(FE_UPWARD); /*...*/ fesetround(save_round); /*...*/ }

STANDARDS CONFORMANCE

fegetround() : ISO/IEC C99 (including Annex F, ``IEC 60559 floating-point arithmetic'')

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