diff --git a/src/float/add.rs b/src/float/add.rs index e6cb726..fae14f0 100644 --- a/src/float/add.rs +++ b/src/float/add.rs @@ -1,5 +1,3 @@ -use core::num::Wrapping; - use int::Int; use float::Float; @@ -8,44 +6,44 @@ macro_rules! add { ($a:expr, $b:expr, $ty:ty) => ({ let a = $a; let b = $b; - let one = Wrapping(<$ty as Float>::Int::ONE); - let zero = Wrapping(<$ty as Float>::Int::ZERO); + let one = <$ty as Float>::Int::ONE; + let zero = <$ty as Float>::Int::ZERO; - let bits = Wrapping(<$ty>::BITS as <$ty as Float>::Int); - let significand_bits = Wrapping(<$ty>::SIGNIFICAND_BITS as <$ty as Float>::Int); - let exponent_bits = bits - significand_bits - one; - let max_exponent = (one << exponent_bits.0 as usize) - one; + let bits = <$ty>::BITS as <$ty as Float>::Int; + let significand_bits = <$ty>::SIGNIFICAND_BITS as <$ty as Float>::Int; + let exponent_bits = <$ty>::EXPONENT_BITS as <$ty as Float>::Int; + let max_exponent = (one << exponent_bits as usize) - one; - let implicit_bit = one << significand_bits.0 as usize; + let implicit_bit = one << significand_bits as usize; let significand_mask = implicit_bit - one; - let sign_bit = one << (significand_bits + exponent_bits).0 as usize; + let sign_bit = <$ty>::SIGN_MASK as <$ty as Float>::Int; let abs_mask = sign_bit - one; let exponent_mask = abs_mask ^ significand_mask; let inf_rep = exponent_mask; let quiet_bit = implicit_bit >> 1; let qnan_rep = exponent_mask | quiet_bit; - let mut a_rep = Wrapping(a.repr()); - let mut b_rep = Wrapping(b.repr()); + let mut a_rep = a.repr(); + let mut b_rep = b.repr(); let a_abs = a_rep & abs_mask; let b_abs = b_rep & abs_mask; // Detect if a or b is zero, infinity, or NaN. - if a_abs - one >= inf_rep - one || - b_abs - one >= inf_rep - one { + if a_abs.wrapping_sub(one) >= inf_rep - one || + b_abs.wrapping_sub(one) >= inf_rep - one { // NaN + anything = qNaN if a_abs > inf_rep { - return <$ty as Float>::from_repr((a_abs | quiet_bit).0); + return <$ty as Float>::from_repr(a_abs | quiet_bit); } // anything + NaN = qNaN if b_abs > inf_rep { - return <$ty as Float>::from_repr((b_abs | quiet_bit).0); + return <$ty as Float>::from_repr(b_abs | quiet_bit); } if a_abs == inf_rep { // +/-infinity + -/+infinity = qNaN - if (a.repr() ^ b.repr()) == sign_bit.0 { - return <$ty as Float>::from_repr(qnan_rep.0); + if (a.repr() ^ b.repr()) == sign_bit { + return <$ty as Float>::from_repr(qnan_rep); } else { // +/-infinity + anything remaining = +/- infinity return a; @@ -58,9 +56,9 @@ macro_rules! add { } // zero + anything = anything - if a_abs.0 == 0 { + if a_abs == 0 { // but we need to get the sign right for zero + zero - if b_abs.0 == 0 { + if b_abs == 0 { return <$ty as Float>::from_repr(a.repr() & b.repr()); } else { return b; @@ -68,7 +66,7 @@ macro_rules! add { } // anything + zero = anything - if b_abs.0 == 0 { + if b_abs == 0 { return a; } } @@ -82,21 +80,21 @@ macro_rules! add { } // Extract the exponent and significand from the (possibly swapped) a and b. - let mut a_exponent = Wrapping((a_rep >> significand_bits.0 as usize & max_exponent).0 as i32); - let mut b_exponent = Wrapping((b_rep >> significand_bits.0 as usize & max_exponent).0 as i32); + let mut a_exponent = ((a_rep >> significand_bits) & max_exponent) as i32; + let mut b_exponent = ((b_rep >> significand_bits) & max_exponent) as i32; let mut a_significand = a_rep & significand_mask; let mut b_significand = b_rep & significand_mask; // normalize any denormals, and adjust the exponent accordingly. - if a_exponent.0 == 0 { - let (exponent, significand) = <$ty>::normalize(a_significand.0); - a_exponent = Wrapping(exponent); - a_significand = Wrapping(significand); + if a_exponent == 0 { + let (exponent, significand) = <$ty>::normalize(a_significand); + a_exponent = exponent; + a_significand = significand; } - if b_exponent.0 == 0 { - let (exponent, significand) = <$ty>::normalize(b_significand.0); - b_exponent = Wrapping(exponent); - b_significand = Wrapping(significand); + if b_exponent == 0 { + let (exponent, significand) = <$ty>::normalize(b_significand); + b_exponent = exponent; + b_significand = significand; } // The sign of the result is the sign of the larger operand, a. If they @@ -113,64 +111,64 @@ macro_rules! add { // Shift the significand of b by the difference in exponents, with a sticky // bottom bit to get rounding correct. - let align = Wrapping((a_exponent - b_exponent).0 as <$ty as Float>::Int); - if align.0 != 0 { + let align = a_exponent.wrapping_sub(b_exponent) as <$ty as Float>::Int; + if align != 0 { if align < bits { - let sticky = ((b_significand << (bits - align).0 as usize).0 != 0) as <$ty as Float>::Int; - b_significand = (b_significand >> align.0 as usize) | Wrapping(sticky); + let sticky = (b_significand << (bits.wrapping_sub(align) as usize) != 0) as <$ty as Float>::Int; + b_significand = (b_significand >> align as usize) | sticky; } else { b_significand = one; // sticky; b is known to be non-zero. } } if subtraction { - a_significand -= b_significand; + a_significand = a_significand.wrapping_sub(b_significand); // If a == -b, return +zero. - if a_significand.0 == 0 { + if a_significand == 0 { return <$ty as Float>::from_repr(0); } // If partial cancellation occured, we need to left-shift the result // and adjust the exponent: if a_significand < implicit_bit << 3 { - let shift = a_significand.0.leading_zeros() as i32 - - (implicit_bit << 3).0.leading_zeros() as i32; + let shift = a_significand.leading_zeros() as i32 + - (implicit_bit << 3).leading_zeros() as i32; a_significand <<= shift as usize; - a_exponent -= Wrapping(shift); + a_exponent -= shift; } } else /* addition */ { a_significand += b_significand; // If the addition carried up, we need to right-shift the result and // adjust the exponent: - if (a_significand & implicit_bit << 4).0 != 0 { - let sticky = ((a_significand & one).0 != 0) as <$ty as Float>::Int; - a_significand = a_significand >> 1 | Wrapping(sticky); - a_exponent += Wrapping(1); + if a_significand & implicit_bit << 4 != 0 { + let sticky = (a_significand & one != 0) as <$ty as Float>::Int; + a_significand = a_significand >> 1 | sticky; + a_exponent += 1; } } // If we have overflowed the type, return +/- infinity: - if a_exponent >= Wrapping(max_exponent.0 as i32) { - return <$ty>::from_repr((inf_rep | result_sign).0); + if a_exponent >= max_exponent as i32 { + return <$ty>::from_repr(inf_rep | result_sign); } - if a_exponent.0 <= 0 { + if a_exponent <= 0 { // Result is denormal before rounding; the exponent is zero and we // need to shift the significand. - let shift = Wrapping((Wrapping(1) - a_exponent).0 as <$ty as Float>::Int); - let sticky = ((a_significand << (bits - shift).0 as usize).0 != 0) as <$ty as Float>::Int; - a_significand = a_significand >> shift.0 as usize | Wrapping(sticky); - a_exponent = Wrapping(0); + let shift = (1 - a_exponent) as <$ty as Float>::Int; + let sticky = ((a_significand << bits.wrapping_sub(shift) as usize) != 0) as <$ty as Float>::Int; + a_significand = a_significand >> shift as usize | sticky; + a_exponent = 0; } // Low three bits are round, guard, and sticky. - let round_guard_sticky: i32 = (a_significand.0 & 0x7) as i32; + let round_guard_sticky: i32 = (a_significand & 0x7) as i32; // Shift the significand into place, and mask off the implicit bit. let mut result = a_significand >> 3 & significand_mask; // Insert the exponent and sign. - result |= Wrapping(a_exponent.0 as <$ty as Float>::Int) << significand_bits.0 as usize; + result |= (a_exponent as <$ty as Float>::Int) << (significand_bits as usize); result |= result_sign; // Final rounding. The result may overflow to infinity, but that is the @@ -178,7 +176,7 @@ macro_rules! add { if round_guard_sticky > 0x4 { result += one; } if round_guard_sticky == 0x4 { result += result & one; } - <$ty>::from_repr(result.0) + <$ty>::from_repr(result) }) }