mirror of https://github.com/mkerrisk/man-pages
56 lines
1.5 KiB
Groff
56 lines
1.5 KiB
Groff
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.\" Written Sat Mar 8 10:35:08 MEZ 1997 by J. "MUFTI" Scheurich (mufti@csv.ica.uni-stuttgart.de)
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.TH __SETFPUCW 3 1997-03-08 "i386 Linux Man Page" "Linux Programmer's Manual"
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.SH NAME
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__setfpucw \- set fpu control word on i386 architecture (obsolete)
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.SH SYNOPSIS
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.B #include <i386/fpu_control.h>
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.sp
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.BI "void __setfpucw((unsigned short) " control_word );
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.br
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.SH DESCRIPTION
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.B __setfpucw
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transfers
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.I control_word
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to the registers of the fpu (floating point unit) on i386 architecture. This
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was used to control floating point precision, rounding and floating point
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exceptions.
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.SH EXAMPLE
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.BR __setfpucw(0x1372)
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Set fpu control word on i386 architecture to
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.br
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- extended precision
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.br
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- rounding to nearest
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.br
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- exceptions on overflow, zero divide and NaN
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.br
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.SH AVAILABILITY
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As of glibc 2.1 this function does not exist anymore.
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There are new functions from ISO C99, with prototypes in
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.IR /usr/include/fenv.h ,
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to control fpu rounding modes, like
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.IR fegetround ,
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.IR fesetround ,
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and the floating point environment, like
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.IR fegetenv ,
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.IR feholdexcept ,
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.IR fesetenv ,
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.IR feupdateenv
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and fpu exception handling, like
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.IR feclearexcept ,
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.IR fegetexceptflag ,
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.IR feraiseexcept ,
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.IR fesetexceptflag ,
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.IR fetestexcept .
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.PP
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If direct acces to the FPU control word is still needed, the _FPU_GETCW
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and _FPU_SETCW macros from
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.I /usr/include/fpu_control.h
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can be used.
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.SH "SEE ALSO"
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.BR feclearexcept (3)
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.br
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.IR /usr/include/i386/fpu_control.h
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