67 lines
1.4 KiB
C
67 lines
1.4 KiB
C
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/***
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*fabs.c - absolute value of a floating point number
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*
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* Copyright (c) 1991-2001, Microsoft Corporation. All rights reserved.
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*
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*Purpose:
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*
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*Revision History:
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* 8-24-91 GDP written
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* 12-10-91 GDP Domain error for NAN, use fp negation
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* 1-13-91 GDP support IEEE exceptions
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* 6-23-92 GDP fabs(-0) is now +0 (NCEG spec)
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* 02-06-95 JWM Mac merge
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* 10-07-97 RDL Added IA64.
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* 05-17-99 PML Remove all Macintosh support.
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*
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*******************************************************************************/
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#include <math.h>
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#include <trans.h>
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#if defined(_M_IX86) || defined(_M_PPC) || defined(_M_IA64)
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#pragma function(fabs)
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#endif
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/***
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*double fabs(double x)
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*
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*Purpose:
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* Compute |x|
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*
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*Entry:
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*
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*Exit:
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*
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*Exceptions:
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* I
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*
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*******************************************************************************/
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double fabs(double x)
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{
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uintptr_t savedcw;
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double result;
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/* save user fp control word */
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savedcw = _maskfp();
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if (IS_D_SPECIAL(x)){
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switch (_sptype(x)) {
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case T_PINF:
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RETURN(savedcw,x);
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case T_NINF:
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RETURN(savedcw,-x);
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case T_QNAN:
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return _handle_qnan1(OP_ABS, x, savedcw);
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default: //T_SNAN
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return _except1(FP_I, OP_ABS, x, _s2qnan(x), savedcw);
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}
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}
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*D_HI(result) = *D_HI(x) & ~(1<<31);
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*D_LO(result) = *D_LO(x);
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RETURN(savedcw,result);
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}
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