diff options
Diffstat (limited to 'libc-top-half/musl/src/math/nexttoward.c')
| -rw-r--r-- | libc-top-half/musl/src/math/nexttoward.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/math/nexttoward.c b/libc-top-half/musl/src/math/nexttoward.c new file mode 100644 index 0000000..827ee5c --- /dev/null +++ b/libc-top-half/musl/src/math/nexttoward.c @@ -0,0 +1,42 @@ +#include "libm.h" + +#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 +double nexttoward(double x, long double y) +{ + return nextafter(x, y); +} +#else +double nexttoward(double x, long double y) +{ + union {double f; uint64_t i;} ux = {x}; + int e; + + if (isnan(x) || isnan(y)) + return x + y; + if (x == y) + return y; + if (x == 0) { + ux.i = 1; + if (signbit(y)) + ux.i |= 1ULL<<63; + } else if (x < y) { + if (signbit(x)) + ux.i--; + else + ux.i++; + } else { + if (signbit(x)) + ux.i++; + else + ux.i--; + } + e = ux.i>>52 & 0x7ff; + /* raise overflow if ux.f is infinite and x is finite */ + if (e == 0x7ff) + FORCE_EVAL(x+x); + /* raise underflow if ux.f is subnormal or zero */ + if (e == 0) + FORCE_EVAL(x*x + ux.f*ux.f); + return ux.f; +} +#endif |