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88 lines
1.9 KiB
88 lines
1.9 KiB
/*++
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Copyright (c) 1999 Microsoft Corporation
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Module Name:
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modf.c
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Abstract:
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modf() function
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Author:
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Revision History:
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29-sept-1999 ATM Shafiqul Khalid [askhalid] copied from rtl library.
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--*/
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#include <math.h>
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#include <trans.h>
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#include <float.h>
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extern double _frnd(double);
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extern double _copysign (double x, double y);
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/***
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*double modf(double x, double *intptr)
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*
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*Purpose:
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* Split x into fractional and integer part
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* The signed fractional portion is returned
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* The integer portion is stored as a floating point value at intptr
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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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static unsigned int newcw = (ICW & ~IMCW_RC) | (IRC_CHOP & IMCW_RC);
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double modf(double x, double *intptr)
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{
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unsigned int savedcw;
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double result,intpart;
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/* save user fp control word */
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savedcw = _ctrlfp(0, 0); /* get old control word */
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_ctrlfp(newcw,IMCW); /* round towards 0 */
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/* check for infinity or NAN */
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if (IS_D_SPECIAL(x)){
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*intptr = QNAN_MODF;
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switch (_sptype(x)) {
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case T_PINF:
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case T_NINF:
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*intptr = x;
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result = _copysign(0, x);
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RETURN(savedcw,result);
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case T_QNAN:
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*intptr = x;
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return _handle_qnan1(OP_MODF, x, savedcw);
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default: //T_SNAN
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result = _s2qnan(x);
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*intptr = result;
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return _except1(FP_I, OP_MODF, x, result, savedcw);
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}
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}
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if (x == 0.0) {
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*intptr = x;
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result = x;
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}
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else {
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intpart = _frnd(x); //fix needed: this may set the P exception flag
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//and pollute the fp status word
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*intptr = intpart;
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result = x - intpart;
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}
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RETURN(savedcw,result);
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}
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