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- /* s_modfl.c -- long double version of s_modf.c.
- * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
- */
- /*
- * ====================================================
- * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
- *
- * Developed at SunPro, a Sun Microsystems, Inc. business.
- * Permission to use, copy, modify, and distribute this
- * software is freely granted, provided that this notice
- * is preserved.
- * ====================================================
- */
- #if defined(LIBM_SCCS) && !defined(lint)
- static char rcsid[] = "$NetBSD: $";
- #endif
- /*
- * modfq(long double x, long double *iptr)
- * return fraction part of x, and return x's integral part in *iptr.
- * Method:
- * Bit twiddling.
- *
- * Exception:
- * No exception.
- */
- #include "quadmath-imp.h"
- static const __float128 one = 1.0;
- __float128 modfq(__float128 x, __float128 *iptr)
- {
- int64_t i0,i1,j0;
- uint64_t i;
- GET_FLT128_WORDS64(i0,i1,x);
- j0 = ((i0>>48)&0x7fff)-0x3fff; /* exponent of x */
- if(j0<48) { /* integer part in high x */
- if(j0<0) { /* |x|<1 */
- /* *iptr = +-0 */
- SET_FLT128_WORDS64(*iptr,i0&0x8000000000000000ULL,0);
- return x;
- } else {
- i = (0x0000ffffffffffffLL)>>j0;
- if(((i0&i)|i1)==0) { /* x is integral */
- *iptr = x;
- /* return +-0 */
- SET_FLT128_WORDS64(x,i0&0x8000000000000000ULL,0);
- return x;
- } else {
- SET_FLT128_WORDS64(*iptr,i0&(~i),0);
- return x - *iptr;
- }
- }
- } else if (j0>111) { /* no fraction part */
- *iptr = x*one;
- /* We must handle NaNs separately. */
- if (j0 == 0x4000 && ((i0 & 0x0000ffffffffffffLL) | i1))
- return x*one;
- /* return +-0 */
- SET_FLT128_WORDS64(x,i0&0x8000000000000000ULL,0);
- return x;
- } else { /* fraction part in low x */
- i = -1ULL>>(j0-48);
- if((i1&i)==0) { /* x is integral */
- *iptr = x;
- /* return +-0 */
- SET_FLT128_WORDS64(x,i0&0x8000000000000000ULL,0);
- return x;
- } else {
- SET_FLT128_WORDS64(*iptr,i0,i1&(~i));
- return x - *iptr;
- }
- }
- }
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