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__SETFPUCW(3) Linux Programmer's Manual __SETFPUCW(3)
__setfpucw - set FPU control word on i386 architecture (obsolete)
#include <i386/fpu_control.h>
void __setfpucw(unsigned short control_word);
__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.
This function was a nonstandard GNU extension.
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.
__setfpucw(0x1372)
Set FPU control word on the i386 architecture to
- extended precision
- rounding to nearest
- exceptions on overflow, zero divide and NaN
feclearexcept(3)
<fpu_control.h>
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Linux 2017-09-15 __SETFPUCW(3)
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