From ce2e8f17ec04fb1e937a2fa7ea37809073d19fef Mon Sep 17 00:00:00 2001
From: Magnus Ulimoen <magnus@ulimoen.dev>
Date: Tue, 23 Mar 2021 19:36:33 +0100
Subject: [PATCH] Move FastFloat to separate crate (archival)

---
 Cargo.toml                  |   1 +
 utils/fast-float/Cargo.toml |  11 ++++
 utils/fast-float/src/lib.rs | 123 ++++++++++++++++++++++++++++++++++++
 utils/float/Cargo.toml      |   2 -
 utils/float/src/lib.rs      |   7 +-
 5 files changed, 136 insertions(+), 8 deletions(-)
 create mode 100644 utils/fast-float/Cargo.toml
 create mode 100644 utils/fast-float/src/lib.rs

diff --git a/Cargo.toml b/Cargo.toml
index 99b8083..7b2788b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,6 +9,7 @@ members = [
     "gridgeneration",
     "heat-equation",
     "utils/float",
+    "utils/fast-float",
     "utils/integrate",
     "utils/constmatrix",
 ]
diff --git a/utils/fast-float/Cargo.toml b/utils/fast-float/Cargo.toml
new file mode 100644
index 0000000..45c8e69
--- /dev/null
+++ b/utils/fast-float/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "fast-float"
+version = "0.1.0"
+authors = ["Magnus Ulimoen <magnus@ulimoen.dev>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+float = { path = "../float" }
+num-traits = "0.2.14"
diff --git a/utils/fast-float/src/lib.rs b/utils/fast-float/src/lib.rs
new file mode 100644
index 0000000..b6a9573
--- /dev/null
+++ b/utils/fast-float/src/lib.rs
@@ -0,0 +1,123 @@
+#![no_std]
+#![feature(core_intrinsics)]
+
+use float::Float;
+
+#[repr(transparent)]
+#[derive(Copy, Clone, Debug, PartialEq, Default)]
+pub struct FastFloat(Float);
+
+use core::intrinsics::{fadd_fast, fdiv_fast, fmul_fast, fsub_fast};
+
+impl core::ops::Mul for FastFloat {
+    type Output = Self;
+    #[inline(always)]
+    fn mul(self, o: Self) -> Self::Output {
+        unsafe { Self(fmul_fast(self.0, o.0)) }
+    }
+}
+
+impl core::ops::Mul<Float> for FastFloat {
+    type Output = FastFloat;
+    #[inline(always)]
+    fn mul(self, o: Float) -> Self::Output {
+        unsafe { Self(fmul_fast(self.0, o)) }
+    }
+}
+
+impl core::ops::Mul<FastFloat> for Float {
+    type Output = FastFloat;
+    #[inline(always)]
+    fn mul(self, o: FastFloat) -> Self::Output {
+        unsafe { FastFloat(fmul_fast(self, o.0)) }
+    }
+}
+
+impl core::ops::Add<FastFloat> for FastFloat {
+    type Output = FastFloat;
+    #[inline(always)]
+    fn add(self, o: FastFloat) -> Self::Output {
+        unsafe { Self(fadd_fast(self.0, o.0)) }
+    }
+}
+
+impl core::ops::Add<Float> for FastFloat {
+    type Output = FastFloat;
+    #[inline(always)]
+    fn add(self, o: Float) -> Self::Output {
+        unsafe { Self(fadd_fast(self.0, o)) }
+    }
+}
+
+impl core::ops::Add<FastFloat> for Float {
+    type Output = FastFloat;
+    #[inline(always)]
+    fn add(self, o: FastFloat) -> Self::Output {
+        unsafe { FastFloat(fadd_fast(self, o.0)) }
+    }
+}
+
+impl core::ops::Sub for FastFloat {
+    type Output = Self;
+    #[inline(always)]
+    fn sub(self, o: FastFloat) -> Self::Output {
+        unsafe { Self(fsub_fast(self.0, o.0)) }
+    }
+}
+
+impl core::ops::Div for FastFloat {
+    type Output = Self;
+    #[inline(always)]
+    fn div(self, o: FastFloat) -> Self::Output {
+        unsafe { Self(fdiv_fast(self.0, o.0)) }
+    }
+}
+
+impl core::ops::MulAssign<FastFloat> for FastFloat {
+    #[inline(always)]
+    fn mul_assign(&mut self, o: FastFloat) {
+        unsafe {
+            self.0 = fmul_fast(self.0, o.0);
+        }
+    }
+}
+
+impl core::ops::Mul for &FastFloat {
+    type Output = FastFloat;
+    #[inline(always)]
+    fn mul(self, o: Self) -> Self::Output {
+        unsafe { FastFloat(fmul_fast(self.0, o.0)) }
+    }
+}
+
+impl From<Float> for FastFloat {
+    #[inline(always)]
+    fn from(f: Float) -> Self {
+        Self(f)
+    }
+}
+impl From<FastFloat> for Float {
+    #[inline(always)]
+    fn from(f: FastFloat) -> Self {
+        f.0
+    }
+}
+
+mod numt {
+    use super::{FastFloat, Float};
+    use num_traits::identities::{One, Zero};
+
+    impl One for FastFloat {
+        fn one() -> Self {
+            Self(Float::one())
+        }
+    }
+    impl Zero for FastFloat {
+        fn zero() -> Self {
+            Self(Float::zero())
+        }
+        fn is_zero(&self) -> bool {
+            self.0.is_zero()
+        }
+    }
+}
diff --git a/utils/float/Cargo.toml b/utils/float/Cargo.toml
index a5fb980..c39f627 100644
--- a/utils/float/Cargo.toml
+++ b/utils/float/Cargo.toml
@@ -6,7 +6,5 @@ edition = "2018"
 
 [features]
 f32 = []
-fast-float = []
 
 [dependencies]
-num-traits = "0.2.14"
diff --git a/utils/float/src/lib.rs b/utils/float/src/lib.rs
index 526780a..7374315 100644
--- a/utils/float/src/lib.rs
+++ b/utils/float/src/lib.rs
@@ -1,6 +1,6 @@
 //! The Float type used throughout the ecosystem
 #![no_std]
-#![cfg_attr(feature = "fast-float", feature(core_intrinsics))]
+#![forbid(unsafe_code)]
 
 /// Type used for floats, configure with the `f32` feature
 #[cfg(feature = "f32")]
@@ -16,8 +16,3 @@ pub mod consts {
     #[cfg(not(feature = "f32"))]
     pub use core::f64::consts::*;
 }
-
-#[cfg(feature = "fast-float")]
-mod fastfloat;
-#[cfg(feature = "fast-float")]
-pub use fastfloat::FastFloat;