HP-UX Reference (11i v1 00/12) - 3 Library Functions A-M (vol 6)

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feupdateenv(3M) feupdateenv(3M)

NAME

feupdateenv() - update ﬂoating-point environment

SYNOPSIS

#include <fenv.h>

void feupdateenv(const fenv_t *envp);

DESCRIPTION

The feupdateenv() function saves the current exceptions in its automatic storage, installs the ﬂoating-

point environment represented through envp, and then raises the saved exceptions. The argument envp

must point to an object set by a call to fegetenv() or feholdexcept(), or equal the macro

FE_DFL_ENV.

The ISO/ANSI C committee has approved the feupdateenv() function for inclusion in the C9X draft

standard.

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>. 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.

RETURN VALUE

None.

ERRORS

No errors are deﬁned.

EXAMPLE

Store the current ﬂoating-point environment in

holdenv, hide spurious underﬂow exceptions, and con-

tinue on any exceptions that occur until the call to feupdateenv()

is encountered.

#include <fenv.h>

/*...*/

fenv_t holdenv;

feholdexcept(&holdenv);

/* perform operations */

if (/* test for spurious underflow */)

feclearexcept(FE_UNDERFLOW);

feupdateenv(&holdenv); /* raise accumulated exceptions */