From 8bea3627cb6f4c9378908599a146e8896034d793 Mon Sep 17 00:00:00 2001
From: miguel raz <miguelraz@gmail.com>
Date: Tue, 25 May 2021 21:25:42 -0500
Subject: [PATCH] replace sum() with horizontal_sum()

---
 crates/core_simd/examples/nbody.rs | 56 ++++++++++++++----------------
 1 file changed, 27 insertions(+), 29 deletions(-)

diff --git a/crates/core_simd/examples/nbody.rs b/crates/core_simd/examples/nbody.rs
index cbdcf848fee..93d4c902a4d 100644
--- a/crates/core_simd/examples/nbody.rs
+++ b/crates/core_simd/examples/nbody.rs
@@ -5,87 +5,85 @@
 const SOLAR_MASS: f64 = 4.0 * PI * PI;
 const DAYS_PER_YEAR: f64 = 365.24;
 
-#[derive(Debug)]
-#[repr(simd)]
+#[derive(Debug, Clone, Copy)]
 pub struct Body {
-    pub x: Simdf64([f64, 4]),
-    pub v: Simdf64([f64, 4]),
+    pub x: f64x4,
+    pub v: f64x4,
     pub mass: f64,
 }
 
-// Translation attempt is this ^^^ far
-//
+// translation up to here
 const N_BODIES: usize = 5;
 #[allow(clippy::unreadable_literal)]
 const BODIES: [Body; N_BODIES] = [
     // sun:
     Body {
-        x: f64x4::new(0., 0., 0., 0.),
-        v: f64x4::new(0., 0., 0., 0.),
+        x: f64x4::from_array([0., 0., 0., 0.]),
+        v: f64x4::from_array([0., 0., 0., 0.]),
         mass: SOLAR_MASS,
     },
     // jupiter:
     Body {
-        x: f64x4::new(
+        x: f64x4::from_array([
             4.84143144246472090e+00,
             -1.16032004402742839e+00,
             -1.03622044471123109e-01,
             0.,
-        ),
-        v: f64x4::new(
+        ]),
+        v: f64x4::from_array([
             1.66007664274403694e-03 * DAYS_PER_YEAR,
             7.69901118419740425e-03 * DAYS_PER_YEAR,
             -6.90460016972063023e-05 * DAYS_PER_YEAR,
             0.,
-        ),
+        ]),
         mass: 9.54791938424326609e-04 * SOLAR_MASS,
     },
     // saturn:
     Body {
-        x: f64x4::new(
+        x: f64x4::from_array([
             8.34336671824457987e+00,
             4.12479856412430479e+00,
             -4.03523417114321381e-01,
             0.,
-        ),
-        v: f64x4::new(
+        ]),
+        v: f64x4::from_array([
             -2.76742510726862411e-03 * DAYS_PER_YEAR,
             4.99852801234917238e-03 * DAYS_PER_YEAR,
             2.30417297573763929e-05 * DAYS_PER_YEAR,
             0.,
-        ),
+        ]),
         mass: 2.85885980666130812e-04 * SOLAR_MASS,
     },
     // uranus:
     Body {
-        x: f64x4::new(
+        x: f64x4::from_array([
             1.28943695621391310e+01,
             -1.51111514016986312e+01,
             -2.23307578892655734e-01,
             0.,
-        ),
-        v: f64x4::new(
+        ]),
+        v: f64x4::from_array([
             2.96460137564761618e-03 * DAYS_PER_YEAR,
             2.37847173959480950e-03 * DAYS_PER_YEAR,
             -2.96589568540237556e-05 * DAYS_PER_YEAR,
             0.,
-        ),
+        ]),
         mass: 4.36624404335156298e-05 * SOLAR_MASS,
     },
     // neptune:
     Body {
-        x: f64x4::new(
+        x: f64x4::from_array([
             1.53796971148509165e+01,
             -2.59193146099879641e+01,
             1.79258772950371181e-01,
             0.,
-        ),
-        v: f64x4::new(
+        ]),
+        v: f64x4::from_array([
             2.68067772490389322e-03 * DAYS_PER_YEAR,
             1.62824170038242295e-03 * DAYS_PER_YEAR,
             -9.51592254519715870e-05 * DAYS_PER_YEAR,
             0.,
-        ),
+        ]),
         mass: 5.15138902046611451e-05 * SOLAR_MASS,
     },
 ];
@@ -103,10 +101,10 @@ pub struct Body {
     let mut e = 0.;
     for i in 0..N_BODIES {
         let bi = &bodies[i];
-        e += bi.mass * (bi.v * bi.v).sum() * 0.5;
+        e += bi.mass * (bi.v * bi.v).horizontal_sum() * 0.5;
         for bj in bodies.iter().take(N_BODIES).skip(i + 1) {
             let dx = bi.x - bj.x;
-            e -= bi.mass * bj.mass / (dx * dx).sum().sqrt()
+            e -= bi.mass * bj.mass / (dx * dx).horizontal_sum().sqrt()
         }
     }
     e
@@ -130,8 +128,8 @@ pub struct Body {
     let mut mag = [0.0; N];
     let mut i = 0;
     while i < N {
-        let d2s = f64x2::new((r[i] * r[i]).sum(), (r[i + 1] * r[i + 1]).sum());
-        let dmags = f64x2::splat(dt) / (d2s * d2s.sqrte());
+        let d2s = f64x2::from_array([(r[i] * r[i]).horizontal_sum(), (r[i + 1] * r[i + 1]).horizontal_sum()]);
+        let dmags = f64x2::splat(dt) / (d2s * d2s.sqrt());
         dmags.write_to_slice_unaligned(&mut mag[i..]);
         i += 2;
     }
@@ -190,5 +188,5 @@ fn main() {
     //.parse()
     //.expect("argument should be a usize");
     //run(&mut std::io::stdout(), n, alg);
-    println!("{:?}", run_k<10>(10, 10));
+    println!("{:?}", run_k::<10>(10, 10));
 }
-- 
2.44.0