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__SETFPUCW(3) | Linux Programmer's Manual | __SETFPUCW(3) |
NAME¶
__setfpucw - set FPU control word on i386 architecture (obsolete)SYNOPSIS¶
#include <i386/fpu_control.h>void __setfpucw(unsigned short control_word);
DESCRIPTION¶
__setfpucw() transfers control_word to the registers of the FPU (floating-point unit) on the i386 architecture. This was used to control floating-point precision, rounding and floating-point exceptions.CONFORMING TO¶
This function was a nonstandard GNU extension.NOTES¶
As of glibc 2.1 this function does not exist anymore. There are new functions from C99, with prototypes in <fenv.h>, to control FPU rounding modes, like fegetround(3), fesetround(3), and the floating-point environment, like fegetenv(3), feholdexcept(3), fesetenv(3), feupdateenv(3), and FPU exception handling, like feclearexcept(3), fegetexceptflag(3), feraiseexcept(3), fesetexceptflag(3), and fetestexcept(3).If direct access to the FPU control word is still needed, the _FPU_GETCW and _FPU_SETCW macros from <fpu_control.h> can be used.
EXAMPLE¶
__setfpucw(0x1372)Set FPU control word on the i386 architecture to - extended precision - rounding to nearest - exceptions on overflow, zero divide and NaN
SEE ALSO¶
feclearexcept(3)<fpu_control.h>
COLOPHON¶
This page is part of release 4.16 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.2017-09-15 | Linux |