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74 lines
1.9 KiB
C
74 lines
1.9 KiB
C
/* s_modfl.c -- long double version of s_modf.c.
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* Conversion to long double by Ulrich Drepper,
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* Cygnus Support, drepper@cygnus.com.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/*
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* modfl(long double x, long double *iptr)
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* return fraction part of x, and return x's integral part in *iptr.
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* Method:
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* Bit twiddling.
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*
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* Exception:
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* No exception.
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*/
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#include <math.h>
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#include <math_private.h>
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static const long double one = 1.0;
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long double
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__modfl(long double x, long double *iptr)
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{
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int32_t i0,i1,j0;
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u_int32_t i,se;
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GET_LDOUBLE_WORDS(se,i0,i1,x);
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j0 = (se&0x7fff)-0x3fff; /* exponent of x */
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if(j0<32) { /* integer part in high x */
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if(j0<0) { /* |x|<1 */
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SET_LDOUBLE_WORDS(*iptr,se&0x8000,0,0); /* *iptr = +-0 */
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return x;
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} else {
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i = (0x7fffffff)>>j0;
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if(((i0&i)|i1)==0) { /* x is integral */
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*iptr = x;
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SET_LDOUBLE_WORDS(x,se&0x8000,0,0); /* return +-0 */
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return x;
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} else {
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SET_LDOUBLE_WORDS(*iptr,se,i0&(~i),0);
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return x - *iptr;
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}
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}
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} else if (__builtin_expect(j0>63, 0)) { /* no fraction part */
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*iptr = x*one;
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/* We must handle NaNs separately. */
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if (j0 == 0x4000 && ((i0 & 0x7fffffff) | i1))
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return x*one;
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SET_LDOUBLE_WORDS(x,se&0x8000,0,0); /* return +-0 */
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return x;
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} else { /* fraction part in low x */
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i = ((u_int32_t)(0x7fffffff))>>(j0-32);
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if((i1&i)==0) { /* x is integral */
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*iptr = x;
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SET_LDOUBLE_WORDS(x,se&0x8000,0,0); /* return +-0 */
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return x;
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} else {
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SET_LDOUBLE_WORDS(*iptr,se,i0,i1&(~i));
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return x - *iptr;
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}
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}
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}
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weak_alias (__modfl, modfl)
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