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author | Roland McGrath <roland@gnu.org> | 1995-02-18 01:27:10 +0000 |
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committer | Roland McGrath <roland@gnu.org> | 1995-02-18 01:27:10 +0000 |
commit | 28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch) | |
tree | 15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/m68k/fpu/atan2.c | |
download | glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.tar.gz glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.tar.xz glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.zip |
initial import
Diffstat (limited to 'sysdeps/m68k/fpu/atan2.c')
-rw-r--r-- | sysdeps/m68k/fpu/atan2.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/sysdeps/m68k/fpu/atan2.c b/sysdeps/m68k/fpu/atan2.c new file mode 100644 index 0000000000..1efdb1f7a6 --- /dev/null +++ b/sysdeps/m68k/fpu/atan2.c @@ -0,0 +1,71 @@ +/* Copyright (C) 1991, 1992, 1994 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +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., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <ansidecl.h> +#include <math.h> + +#ifdef __GNUC__ + +__CONSTVALUE double +DEFUN(atan2, (y, x), double y AND double x) +{ + static CONST double one = 1.0, zero = 0.0; + double signx, signy; + double pi, PIo4, PIo2; + + if (__isnan(x)) + return x; + if (__isnan(y)) + return y; + + signy = __copysign(one, y); + signx = __copysign(one, x); + + asm("fmovecr%.x %1, %0" : "=f" (pi) : "i" (0)); + PIo2 = pi / 2; + PIo4 = pi / 4; + + if (y == zero) + return signx == one ? y : __copysign(pi, signy); + + if (x == zero) + return __copysign(PIo2, signy); + + if (__isinf(x)) + { + if (__isinf(y)) + return __copysign(signx == one ? PIo4 : 3 * PIo4, signy); + else + return __copysign(signx == one ? zero : pi, signy); + } + + if (__isinf(y)) + return __copysign(PIo2, signy); + + y = fabs(y); + + if (x < 0.0) + /* X is negative. */ + return __copysign(pi - atan(y / -x), signy); + + return __copysign(atan(y / x), signy); +} + +#else +#include <sysdeps/generic/atan2.c> +#endif |