diff options
Diffstat (limited to 'src/libcore/num')
| -rw-r--r-- | src/libcore/num/flt2dec/decoder.rs | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/src/libcore/num/flt2dec/decoder.rs b/src/libcore/num/flt2dec/decoder.rs index 4b7d00f80e1..d4473e6bc0c 100644 --- a/src/libcore/num/flt2dec/decoder.rs +++ b/src/libcore/num/flt2dec/decoder.rs @@ -75,7 +75,7 @@ pub fn decode<T: DecodableFloat>(v: T) -> (/*negative?*/ bool, FullDecoded) { FpCategory::Infinite => FullDecoded::Infinite, FpCategory::Zero => FullDecoded::Zero, FpCategory::Subnormal => { - // (mant - 2, exp) -- (mant, exp) -- (mant + 2, exp) + // neighbors: (mant - 2, exp) -- (mant, exp) -- (mant + 2, exp) // Float::integer_decode always preserves the exponent, // so the mantissa is scaled for subnormals. FullDecoded::Finite(Decoded { mant: mant, minus: 1, plus: 1, @@ -83,13 +83,13 @@ pub fn decode<T: DecodableFloat>(v: T) -> (/*negative?*/ bool, FullDecoded) { } FpCategory::Normal => { let minnorm = <T as DecodableFloat>::min_pos_norm_value().integer_decode(); - if mant == minnorm.0 && exp == minnorm.1 { - // (maxmant, exp - 1) -- (minnormmant, exp) -- (minnormmant + 1, exp) + if mant == minnorm.0 { + // neighbors: (maxmant, exp - 1) -- (minnormmant, exp) -- (minnormmant + 1, exp) // where maxmant = minnormmant * 2 - 1 - FullDecoded::Finite(Decoded { mant: mant << 1, minus: 1, plus: 2, - exp: exp - 1, inclusive: even }) + FullDecoded::Finite(Decoded { mant: mant << 2, minus: 1, plus: 2, + exp: exp - 2, inclusive: even }) } else { - // (mant - 1, exp) -- (mant, exp) -- (mant + 1, exp) + // neighbors: (mant - 1, exp) -- (mant, exp) -- (mant + 1, exp) FullDecoded::Finite(Decoded { mant: mant << 1, minus: 1, plus: 1, exp: exp - 1, inclusive: even }) } |