diff options
Diffstat (limited to 'sysdeps/ieee754/dbl-64/mpatan2.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/mpatan2.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/sysdeps/ieee754/dbl-64/mpatan2.c b/sysdeps/ieee754/dbl-64/mpatan2.c new file mode 100644 index 0000000000..6e0c587685 --- /dev/null +++ b/sysdeps/ieee754/dbl-64/mpatan2.c @@ -0,0 +1,69 @@ + +/* + * IBM Accurate Mathematical Library + * Copyright (c) International Business Machines Corp., 2001 + * + * This program 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 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ +/******************************************************************/ +/* MODULE_NAME: mpatan2.c */ +/* */ +/* FUNCTIONS:mpatan2 */ +/* */ +/* FILES NEEDED: mpa.h */ +/* mpa.c mpatan.c mpsqrt.c */ +/* */ +/* Multi-Precision Atan2(y,x) function subroutine, */ +/* for precision p >= 4. */ +/* y=0 is not permitted if x<=0. No error messages are given. */ +/* The relative error of the result is bounded by 44.84*r**(1-p) */ +/* if x <= 0, y != 0 and by 37.33*r**(1-p) if x>0. here r=2**24. */ +/* */ +/******************************************************************/ + + + +#include "mpa.h" + +void mpsqrt(mp_no *, mp_no *, int); +void mpatan(mp_no *, mp_no *, int); + +/* Multi-Precision Atan2(y,x) function subroutine, for p >= 4. */ +/* y=0 is not permitted if x<=0. No error messages are given. */ +void mpatan2(mp_no *y, mp_no *x, mp_no *z, int p) { + + static const double ZERO = 0.0, ONE = 1.0; + + mp_no mpone = {0, 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0, + 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0, + 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,}; + mp_no mpt1,mpt2,mpt3; + + + if (X[0] <= ZERO) { + mpone.e = 1; mpone.d[0] = mpone.d[1] = ONE; + dvd(x,y,&mpt1,p); mul(&mpt1,&mpt1,&mpt2,p); + if (mpt1.d[0] != ZERO) mpt1.d[0] = ONE; + add(&mpt2,&mpone,&mpt3,p); mpsqrt(&mpt3,&mpt2,p); + add(&mpt1,&mpt2,&mpt3,p); mpt3.d[0]=Y[0]; + mpatan(&mpt3,&mpt1,p); add(&mpt1,&mpt1,z,p); + } + else + { dvd(y,x,&mpt1,p); + mpatan(&mpt1,z,p); + } + + return; +} |