div work

Author: tgross35

src/float/div.rs

@@ -78,21 +78,27 @@ use core::mem::size_of;
 
 macro_rules! guess {
     ($ty:ty) => {
-        const { (INITIAL_GUESS >> (u128::BITS - <$ty>::BITS)) as $ty }
+        const { (C_U128 >> (u128::BITS - <$ty>::BITS)) as $ty }
     };
 }
 
-const INITIAL_GUESS: u128 = 0x7504f333f9de6108b2fb1366eaa6a542;
+const C_U128: u128 = 0x7504f333f9de6108b2fb1366eaa6a542;
+
+/// C is (3/4 + 1/sqrt(2)) - 1 truncated to W0 fractional bits as UQ0.HW
+/// with W0 being either 16 or 32 and W0 <= HW.
+/// That is, C is the aforementioned 3/4 + 1/sqrt(2) constant (from which
+/// b/2 is subtracted to obtain x0) wrapped to [0, 1) range.
+macro_rules! half_width_c {
+    ($ty:ty) => {
+        const { (C_U128 >> (u128::BITS - <$ty>::BITS)) as $ty }
+    };
+}
 
 /// Type-specific configuration used for float division
 trait FloatDivision: Float
 where
     Self::Int: DInt,
 {
-    /// C is (3/4 + 1/sqrt(2)) - 1 truncated to W0 fractional bits as UQ0.HW
-    /// with W0 being either 16 or 32 and W0 <= HW.
-    /// That is, C is the aforementioned 3/4 + 1/sqrt(2) constant (from which
-    /// b/2 is subtracted to obtain x0) wrapped to [0, 1) range.
     const C_HW: HalfRep<Self>;
 }