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Diffstat (limited to 'winsup/cygwin/math/nexttoward.c')
-rw-r--r-- | winsup/cygwin/math/nexttoward.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/winsup/cygwin/math/nexttoward.c b/winsup/cygwin/math/nexttoward.c new file mode 100644 index 0000000..909f6ea --- /dev/null +++ b/winsup/cygwin/math/nexttoward.c @@ -0,0 +1,47 @@ +/** + * This file has no copyright assigned and is placed in the Public Domain. + * This file is part of the mingw-w64 runtime package. + * No warranty is given; refer to the file DISCLAIMER.PD within this package. + */ +/* + nexttoward.c + Contributed by Danny Smith <dannysmith@users.sourceforge.net> + No copyright claimed, absolutely no warranties. + + 2005-05-10 +*/ + +#include <math.h> + +double +nexttoward (double x, long double y) +{ + union + { + double d; + unsigned long long ll; + } u; + + long double xx = x; + + if (isnan (y) || isnan (x)) + return x + y; + + if (xx == y) + /* nextafter (0.0, -O.0) should return -0.0. */ + return y; + u.d = x; + if (x == 0.0) + { + u.ll = 1; + return y > 0.0L ? u.d : -u.d; + } + + /* Non-extended encodings are lexicographically ordered, + with implicit "normal" bit. */ + if (((x > 0.0) ^ (y > xx)) == 0) + u.ll++; + else + u.ll--; + return u.d; +} |