Simplify unrolled_dot

Simplify based on the new restriction (Copy).

Author: bluss

src/numeric_util.rs

@@ -3,9 +3,10 @@ use libnum;
 use std::cmp;
 use std::ops::{
     Add,
-    Mul,
 };
 
+use linalg::LinalgScalar;
+
 /// Compute the sum of the values in `xs`
 pub fn unrolled_sum<A>(mut xs: &[A]) -> A
     where A: Clone + Add<Output=A> + libnum::Zero,
@@ -44,7 +45,7 @@ pub fn unrolled_sum<A>(mut xs: &[A]) -> A
 ///
 /// `xs` and `ys` must be the same length
 pub fn unrolled_dot<A>(xs: &[A], ys: &[A]) -> A
-    where A: Clone + Add<Output=A> + Mul<Output=A> + libnum::Zero,
+    where A: LinalgScalar,
 {
     debug_assert_eq!(xs.len(), ys.len());
     // eightfold unrolled so that floating point can be vectorized
@@ -58,24 +59,24 @@ pub fn unrolled_dot<A>(xs: &[A], ys: &[A]) -> A
         (A::zero(), A::zero(), A::zero(), A::zero(),
          A::zero(), A::zero(), A::zero(), A::zero());
     while xs.len() >= 8 {
-        p0 = p0 + xs[0].clone() * ys[0].clone();
-        p1 = p1 + xs[1].clone() * ys[1].clone();
-        p2 = p2 + xs[2].clone() * ys[2].clone();
-        p3 = p3 + xs[3].clone() * ys[3].clone();
-        p4 = p4 + xs[4].clone() * ys[4].clone();
-        p5 = p5 + xs[5].clone() * ys[5].clone();
-        p6 = p6 + xs[6].clone() * ys[6].clone();
-        p7 = p7 + xs[7].clone() * ys[7].clone();
+        p0 = p0 + xs[0] * ys[0];
+        p1 = p1 + xs[1] * ys[1];
+        p2 = p2 + xs[2] * ys[2];
+        p3 = p3 + xs[3] * ys[3];
+        p4 = p4 + xs[4] * ys[4];
+        p5 = p5 + xs[5] * ys[5];
+        p6 = p6 + xs[6] * ys[6];
+        p7 = p7 + xs[7] * ys[7];
 
         xs = &xs[8..];
         ys = &ys[8..];
     }
-    sum = sum.clone() + (p0 + p4);
-    sum = sum.clone() + (p1 + p5);
-    sum = sum.clone() + (p2 + p6);
-    sum = sum.clone() + (p3 + p7);
+    sum = sum + (p0 + p4);
+    sum = sum + (p1 + p5);
+    sum = sum + (p2 + p6);
+    sum = sum + (p3 + p7);
     for i in 0..xs.len() {
-        sum = sum.clone() + xs[i].clone() * ys[i].clone();
+        sum = sum + xs[i] * ys[i];
     }
     sum
 }