1__SETFPUCW(3)              Linux Programmer's Manual             __SETFPUCW(3)
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NAME

6       __setfpucw - set FPU control word on i386 architecture (obsolete)
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SYNOPSIS

9       #include <i386/fpu_control.h>
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11       void __setfpucw(unsigned short control_word);
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DESCRIPTION

14       __setfpucw() transfers control_word to the registers of the FPU (float‐
15       ing-point unit) on the i386 architecture.  This  was  used  to  control
16       floating-point precision, rounding and floating-point exceptions.
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CONFORMING TO

19       This function was a nonstandard GNU extension.
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NOTES

22       As  of  glibc  2.1 this function does not exist anymore.  There are new
23       functions from C99, with prototypes in <fenv.h>, to control FPU  round‐
24       ing  modes,  like  fegetround(3), fesetround(3), and the floating-point
25       environment, like fegetenv(3),  feholdexcept(3),  fesetenv(3),  feupda‐
26       teenv(3),  and  FPU exception handling, like feclearexcept(3), fegetex‐
27       ceptflag(3), feraiseexcept(3), fesetexceptflag(3), and fetestexcept(3).
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29       If direct  access  to  the  FPU  control  word  is  still  needed,  the
30       _FPU_GETCW and _FPU_SETCW macros from <fpu_control.h> can be used.
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EXAMPLES

33       __setfpucw(0x1372)
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35       Set FPU control word on the i386 architecture to
36            - extended precision
37            - rounding to nearest
38            - exceptions on overflow, zero divide and NaN
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SEE ALSO

41       feclearexcept(3)
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43       <fpu_control.h>
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COLOPHON

46       This  page  is  part of release 5.07 of the Linux man-pages project.  A
47       description of the project, information about reporting bugs,  and  the
48       latest     version     of     this    page,    can    be    found    at
49       https://www.kernel.org/doc/man-pages/.
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53Linux                             2020-06-09                     __SETFPUCW(3)
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