diff options
Diffstat (limited to 'libquadmath/math/modfq.c')
| -rw-r--r-- | libquadmath/math/modfq.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/libquadmath/math/modfq.c b/libquadmath/math/modfq.c new file mode 100644 index 000000000..dc564fe35 --- /dev/null +++ b/libquadmath/math/modfq.c @@ -0,0 +1,64 @@ +/* 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. + * ==================================================== + */ + +#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; + } + } +} |