diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_remquof.c')
| -rw-r--r-- | sysdeps/libm-ieee754/s_remquof.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_remquof.c b/sysdeps/libm-ieee754/s_remquof.c new file mode 100644 index 0000000000..cce5495ce8 --- /dev/null +++ b/sysdeps/libm-ieee754/s_remquof.c @@ -0,0 +1,105 @@ +/* Compute remainder and a congruent to the quotient. + Copyright (C) 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <math.h> + +#include "math_private.h" + + +static const float zero = 0.0; + + +float +__remquof (float x, float y, int *quo) +{ + int32_t hx,hp; + u_int32_t sx; + int cquo; + + GET_FLOAT_WORD (hx, x); + GET_FLOAT_WORD (hp, p); + sx = hx & 0x80000000; + qs = (sx ^ (hp & 0x80000000)) >> 31; + hp &= 0x7fffffff; + hx &= 0x7fffffff; + + /* Purge off exception values. */ + if (hp == 0) + return (x * p) / (x * p); /* p = 0 */ + if ((hx >= 0x7f800000) /* x not finite */ + || (hp > 0x7f800000)) /* p is NaN */ + return (x * p) / (x * p); + + if (hp <= 0x7dffffff) + { + x = __ieee754_fmodf (x, 8 * p); /* now x < 8p */ + + if (fabs (x) >= 4 * fabs (p)) + cquo += 4; + } + + if ((hx - hp) == 0) + { + *quo = qs ? -1 : 1; + return zero * x; + } + + x = fabsf (x); + p = fabsf (p); + cquo = 0; + + if (x >= 2 * p) + { + x -= 4 * p; + cquo += 2; + } + if (x >= p) + { + x -= 2 * p; + ++cquo; + } + + if (hp < 0x01000000) + { + if (x + x > p) + { + x -= p; + if (x + x >= p) + x -= p; + } + } + else + { + float p_half = 0.5 * p; + if(x > p_half) + { + x -= p; + if (x >= p_half) + x -= p; + } + } + + *quo = qs ? -cquo : cquo; + + GET_FLOAT_WORD (hx, x); + SET_FLOAT_WORD (x, hx ^ sx); + return x; +} +weak_alias (__remquof, remquof) |