diff options
Diffstat (limited to 'vendor/compiler_builtins/libm/src/math/nextafter.rs')
-rw-r--r-- | vendor/compiler_builtins/libm/src/math/nextafter.rs | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/vendor/compiler_builtins/libm/src/math/nextafter.rs b/vendor/compiler_builtins/libm/src/math/nextafter.rs new file mode 100644 index 000000000..13094a17c --- /dev/null +++ b/vendor/compiler_builtins/libm/src/math/nextafter.rs @@ -0,0 +1,37 @@ +#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] +pub fn nextafter(x: f64, y: f64) -> f64 { + if x.is_nan() || y.is_nan() { + return x + y; + } + + let mut ux_i = x.to_bits(); + let uy_i = y.to_bits(); + if ux_i == uy_i { + return y; + } + + let ax = ux_i & !1_u64 / 2; + let ay = uy_i & !1_u64 / 2; + if ax == 0 { + if ay == 0 { + return y; + } + ux_i = (uy_i & 1_u64 << 63) | 1; + } else if ax > ay || ((ux_i ^ uy_i) & 1_u64 << 63) != 0 { + ux_i -= 1; + } else { + ux_i += 1; + } + + let e = ux_i.wrapping_shr(52 & 0x7ff); + // raise overflow if ux.f is infinite and x is finite + if e == 0x7ff { + force_eval!(x + x); + } + let ux_f = f64::from_bits(ux_i); + // raise underflow if ux.f is subnormal or zero + if e == 0 { + force_eval!(x * x + ux_f * ux_f); + } + ux_f +} |