diff options
Diffstat (limited to 'src/math/nextafter.c')
| -rw-r--r-- | src/math/nextafter.c | 30 |
1 files changed, 13 insertions, 17 deletions
diff --git a/src/math/nextafter.c b/src/math/nextafter.c index 9ee82518..ab5795a4 100644 --- a/src/math/nextafter.c +++ b/src/math/nextafter.c @@ -1,35 +1,31 @@ #include "libm.h" -#define SIGN ((uint64_t)1<<63) - double nextafter(double x, double y) { - union dshape ux, uy; + union {double f; uint64_t i;} ux={x}, uy={y}; uint64_t ax, ay; int e; if (isnan(x) || isnan(y)) return x + y; - ux.value = x; - uy.value = y; - if (ux.bits == uy.bits) + if (ux.i == uy.i) return y; - ax = ux.bits & ~SIGN; - ay = uy.bits & ~SIGN; + ax = ux.i & -1ULL/2; + ay = uy.i & -1ULL/2; if (ax == 0) { if (ay == 0) return y; - ux.bits = (uy.bits & SIGN) | 1; - } else if (ax > ay || ((ux.bits ^ uy.bits) & SIGN)) - ux.bits--; + ux.i = (uy.i & 1ULL<<63) | 1; + } else if (ax > ay || ((ux.i ^ uy.i) & 1ULL<<63)) + ux.i--; else - ux.bits++; - e = ux.bits >> 52 & 0x7ff; - /* raise overflow if ux.value is infinite and x is finite */ + 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.value is subnormal or zero */ + /* raise underflow if ux.f is subnormal or zero */ if (e == 0) - FORCE_EVAL(x*x + ux.value*ux.value); - return ux.value; + FORCE_EVAL(x*x + ux.f*ux.f); + return ux.f; } |