From df05c06270f8dccd309352e775dc335c4e566fc2 Mon Sep 17 00:00:00 2001
From: Magnus Ulimoen <magnus@ulimoen.dev>
Date: Tue, 23 Mar 2021 19:12:09 +0100
Subject: [PATCH] Add no_std and forbid(unsafe) in utils

---
 utils/constmatrix/src/lib.rs | 35 +++++++++++++++++++++++++++++------
 utils/float/src/lib.rs       |  6 +++---
 utils/integrate/src/lib.rs   |  2 ++
 3 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/utils/constmatrix/src/lib.rs b/utils/constmatrix/src/lib.rs
index 7de31c3..d7d42f7 100644
--- a/utils/constmatrix/src/lib.rs
+++ b/utils/constmatrix/src/lib.rs
@@ -1,3 +1,4 @@
+#![no_std]
 #![feature(const_fn_floating_point_arithmetic)]
 
 use float::Float;
@@ -27,7 +28,7 @@ impl<T: Copy + Zero + PartialEq, const M: usize, const N: usize> Zero for Matrix
         }
     }
     fn is_zero(&self) -> bool {
-        self == &Self::zero()
+        self.iter().all(|x| x.is_zero())
     }
 }
 
@@ -113,10 +114,31 @@ impl<T, const N: usize> RowVector<T, N> {
     }
 }
 
+impl<const M: usize, const P: usize> Matrix<Float, M, P> {
+    /// A specialised matmul for Float, using fma
+    pub fn matmul_float_into<const N: usize>(
+        &mut self,
+        lhs: &Matrix<Float, M, N>,
+        rhs: &Matrix<Float, N, P>,
+    ) {
+        for i in 0..M {
+            for j in 0..P {
+                let mut t = 0.0;
+                for k in 0..N {
+                    t = Float::mul_add(lhs[(i, k)], rhs[(k, j)], t);
+                    // t = t + lhs[(i, k)] * rhs[(k, j)];
+                }
+                self[(i, j)] = t;
+            }
+        }
+    }
+}
+
 impl<T, const M: usize, const P: usize> Matrix<T, M, P> {
     pub fn matmul_into<const N: usize>(&mut self, lhs: &Matrix<T, M, N>, rhs: &Matrix<T, N, P>)
     where
         T: Default + Copy + core::ops::Mul<Output = T> + core::ops::Add<Output = T>,
+        T: 'static,
     {
         for i in 0..M {
             for j in 0..P {
@@ -135,6 +157,7 @@ macro_rules! impl_op_mul_mul {
         impl<T, const N: usize, const M: usize, const P: usize> core::ops::Mul<$rhs> for $lhs
         where
             T: Copy + Default + core::ops::Add<Output = T> + core::ops::Mul<Output = T>,
+            T: 'static,
         {
             type Output = Matrix<T, M, P>;
             fn mul(self, lhs: $rhs) -> Self::Output {
@@ -351,14 +374,14 @@ mod flipping {
     #[test]
     fn assert_castability_of_alignment() {
         let m = Matrix::new([[1.0], [2.0], [3.0], [4.0_f64]]);
-        assert_eq!(std::mem::align_of_val(&m), std::mem::align_of::<f64>());
+        assert_eq!(core::mem::align_of_val(&m), core::mem::align_of::<f64>());
         let m = Matrix::new([[1.0], [2.0], [3.0], [4.0_f32]]);
-        assert_eq!(std::mem::align_of_val(&m), std::mem::align_of::<f32>());
+        assert_eq!(core::mem::align_of_val(&m), core::mem::align_of::<f32>());
         let m = Matrix::new([[1], [2], [3], [4_i32]]);
-        assert_eq!(std::mem::align_of_val(&m), std::mem::align_of::<i32>());
+        assert_eq!(core::mem::align_of_val(&m), core::mem::align_of::<i32>());
         let m = Matrix::new([[1], [2], [3], [4_u64]]);
-        assert_eq!(std::mem::align_of_val(&m), std::mem::align_of::<u64>());
+        assert_eq!(core::mem::align_of_val(&m), core::mem::align_of::<u64>());
         let m = Matrix::new([[1], [2], [3], [4_u128]]);
-        assert_eq!(std::mem::align_of_val(&m), std::mem::align_of::<u128>());
+        assert_eq!(core::mem::align_of_val(&m), core::mem::align_of::<u128>());
     }
 }
diff --git a/utils/float/src/lib.rs b/utils/float/src/lib.rs
index 92cb5c2..526780a 100644
--- a/utils/float/src/lib.rs
+++ b/utils/float/src/lib.rs
@@ -1,5 +1,5 @@
 //! The Float type used throughout the ecosystem
-
+#![no_std]
 #![cfg_attr(feature = "fast-float", feature(core_intrinsics))]
 
 /// Type used for floats, configure with the `f32` feature
@@ -12,9 +12,9 @@ pub type Float = f64;
 /// Associated constants for [`Float`]
 pub mod consts {
     #[cfg(feature = "f32")]
-    pub use std::f32::consts::*;
+    pub use core::f32::consts::*;
     #[cfg(not(feature = "f32"))]
-    pub use std::f64::consts::*;
+    pub use core::f64::consts::*;
 }
 
 #[cfg(feature = "fast-float")]
diff --git a/utils/integrate/src/lib.rs b/utils/integrate/src/lib.rs
index 1e49e72..085269f 100644
--- a/utils/integrate/src/lib.rs
+++ b/utils/integrate/src/lib.rs
@@ -7,6 +7,8 @@
 //! The integration functions are memory efficient, and relies
 //! on the `k` parameter to hold the system state differences.
 //! This parameter is tied to the Butcher Tableau
+#![forbid(unsafe_code)]
+#![no_std]
 
 use float::Float;