68 lines
1.6 KiB
C
Executable File
68 lines
1.6 KiB
C
Executable File
/* Copyright (c) 1988 AT&T */
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/* All Rights Reserved */
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/* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T */
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/* The copyright notice above does not evidence any */
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/* actual or intended publication of such source code. */
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#ident "@(#)modff.c 1.9 92/09/12 SMI" /* SVr4.0 1.7 */
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/*LINTLIBRARY*/
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/*
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* modff(value, iptr) returns the signed fractional part of value
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* and stores the integer part indirectly through iptr.
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*
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*/
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#ifdef __STDC__
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#pragma weak modff = _modff
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#endif
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#include <sys/types.h>
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#include "synonyms.h"
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#include <values.h>
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#if _IEEE /* machines with IEEE floating point only */
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#include <signal.h>
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#include <unistd.h>
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typedef union {
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float f;
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unsigned long word;
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} _fval;
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#define EXPMASK 0x7f800000
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#define FRACTMASK 0x7fffff
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#define FWORD(X) (((_fval *)&(X))->word)
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#endif
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float
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#ifdef __STDC__
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modff(float value, register float *iptr)
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#else
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modff(value, iptr)
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float value;
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register float *iptr;
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#endif
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{
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register float absvalue;
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#if _IEEE
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/* raise exception on NaN - 3B only */
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if (((FWORD(value) & EXPMASK) == EXPMASK) &&
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(FWORD(value) & FRACTMASK))
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(void)kill(getpid(), SIGFPE);
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#endif
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if ((absvalue = (value >= (float)0.0) ? value : -value) >= FMAXPOWTWO)
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*iptr = value; /* it must be an integer */
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else {
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*iptr = absvalue + FMAXPOWTWO; /* shift fraction off right */
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*iptr -= FMAXPOWTWO; /* shift back without fraction */
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while (*iptr > absvalue) /* above arithmetic might round */
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*iptr -= (float)1.0; /* test again just to be sure */
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if (value < (float)0.0)
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*iptr = -*iptr;
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}
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return (value - *iptr); /* signed fractional part */
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}
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