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Diffstat (limited to 'libquadmath/math/remquoq.c')
-rw-r--r-- | libquadmath/math/remquoq.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/libquadmath/math/remquoq.c b/libquadmath/math/remquoq.c new file mode 100644 index 000000000..f7001afc3 --- /dev/null +++ b/libquadmath/math/remquoq.c @@ -0,0 +1,107 @@ +/* Compute remainder and a congruent to the quotient. + Copyright (C) 1997, 1999, 2002 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and + Jakub Jelinek <jj@ultra.linux.cz>, 1999. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include "quadmath-imp.h" + + +static const __float128 zero = 0.0; + + +__float128 +remquoq (__float128 x, __float128 y, int *quo) +{ + int64_t hx,hy; + uint64_t sx,lx,ly,qs; + int cquo; + + GET_FLT128_WORDS64 (hx, lx, x); + GET_FLT128_WORDS64 (hy, ly, y); + sx = hx & 0x8000000000000000ULL; + qs = sx ^ (hy & 0x8000000000000000ULL); + hy &= 0x7fffffffffffffffLL; + hx &= 0x7fffffffffffffffLL; + + /* Purge off exception values. */ + if ((hy | ly) == 0) + return (x * y) / (x * y); /* y = 0 */ + if ((hx >= 0x7fff000000000000LL) /* x not finite */ + || ((hy >= 0x7fff000000000000LL) /* y is NaN */ + && (((hy - 0x7fff000000000000LL) | ly) != 0))) + return (x * y) / (x * y); + + if (hy <= 0x7ffbffffffffffffLL) + x = fmodq (x, 8 * y); /* now x < 8y */ + + if (((hx - hy) | (lx - ly)) == 0) + { + *quo = qs ? -1 : 1; + return zero * x; + } + + x = fabsq (x); + y = fabsq (y); + cquo = 0; + + if (x >= 4 * y) + { + x -= 4 * y; + cquo += 4; + } + if (x >= 2 * y) + { + x -= 2 * y; + cquo += 2; + } + + if (hy < 0x0002000000000000LL) + { + if (x + x > y) + { + x -= y; + ++cquo; + if (x + x >= y) + { + x -= y; + ++cquo; + } + } + } + else + { + __float128 y_half = 0.5Q * y; + if (x > y_half) + { + x -= y; + ++cquo; + if (x >= y_half) + { + x -= y; + ++cquo; + } + } + } + + *quo = qs ? -cquo : cquo; + + if (sx) + x = -x; + return x; +} |