feat: configurable nightly optimizations

field/Cargo.toml

@@ -9,6 +9,7 @@ homepage.workspace = true
 repository.workspace = true
 keywords.workspace = true
 categories.workspace = true
+build = "build.rs"
 
 [dependencies]
 anyhow = { workspace = true }
@@ -29,3 +30,6 @@ rustdoc-args = ["--html-in-header", ".cargo/katex-header.html"]
 
 [lints]
 workspace = true
+
+[build-dependencies]
+rustc_version = "0.4"

field/build.rs

@@ -0,0 +1,12 @@
+use rustc_version::{Channel, VersionMeta};
+
+fn main() {
+    let version_meta = VersionMeta::for_command(std::process::Command::new("rustc")).unwrap();
+
+    if version_meta.channel == Channel::Nightly {
+        println!("cargo:rustc-cfg=nightly");
+    }
+
+    // Declare `nightly` as a valid `cfg` condition for rustc to prevent warnings
+    println!("cargo::rustc-check-cfg=cfg(nightly)")
+}

field/src/extension/quadratic.rs

@@ -6,6 +6,7 @@ use num::bigint::BigUint;
 use serde::{Deserialize, Serialize};
 
 use crate::extension::{Extendable, FieldExtension, Frobenius, OEF};
+#[cfg(nightly)]
 use crate::ops::Square;
 use crate::types::{Field, Sample};
 
@@ -177,6 +178,7 @@ impl<F: Extendable<2>> SubAssign for QuadraticExtension<F> {
     }
 }
 
+#[cfg(nightly)]
 impl<F: Extendable<2>> Mul for QuadraticExtension<F> {
     type Output = Self;
 
@@ -192,13 +194,30 @@ impl<F: Extendable<2>> Mul for QuadraticExtension<F> {
     }
 }
 
+#[cfg(not(nightly))]
+impl<F: Extendable<2>> Mul for QuadraticExtension<F> {
+    type Output = Self;
+
+    #[inline]
+    fn mul(self, rhs: Self) -> Self {
+        let Self([a0, a1]) = self;
+        let Self([b0, b1]) = rhs;
+
+        let c0 = a0 * b0 + <Self as OEF<2>>::W * a1 * b1;
+        let c1 = a0 * b1 + a1 * b0;
+
+        Self([c0, c1])
+    }
+}
+
 impl<F: Extendable<2>> MulAssign for QuadraticExtension<F> {
     #[inline]
     fn mul_assign(&mut self, rhs: Self) {
         *self = *self * rhs;
     }
 }
 
+#[cfg(nightly)]
 impl<F: Extendable<2>> Square for QuadraticExtension<F> {
     #[inline(always)]
     fn square(&self) -> Self {

field/src/extension/quartic.rs

@@ -7,6 +7,7 @@ use num::traits::Pow;
 use serde::{Deserialize, Serialize};
 
 use crate::extension::{Extendable, FieldExtension, Frobenius, OEF};
+#[cfg(nightly)]
 use crate::ops::Square;
 use crate::types::{Field, Sample};
 
@@ -201,6 +202,7 @@ impl<F: Extendable<4>> SubAssign for QuarticExtension<F> {
     }
 }
 
+#[cfg(nightly)]
 impl<F: Extendable<4>> Mul for QuarticExtension<F> {
     type Output = Self;
 
@@ -218,13 +220,32 @@ impl<F: Extendable<4>> Mul for QuarticExtension<F> {
     }
 }
 
+#[cfg(not(nightly))]
+impl<F: Extendable<4>> Mul for QuarticExtension<F> {
+    type Output = Self;
+
+    #[inline]
+    fn mul(self, rhs: Self) -> Self {
+        let Self([a0, a1, a2, a3]) = self;
+        let Self([b0, b1, b2, b3]) = rhs;
+
+        let c0 = a0 * b0 + <Self as OEF<4>>::W * (a1 * b3 + a2 * b2 + a3 * b1);
+        let c1 = a0 * b1 + a1 * b0 + <Self as OEF<4>>::W * (a2 * b3 + a3 * b2);
+        let c2 = a0 * b2 + a1 * b1 + a2 * b0 + <Self as OEF<4>>::W * a3 * b3;
+        let c3 = a0 * b3 + a1 * b2 + a2 * b1 + a3 * b0;
+
+        Self([c0, c1, c2, c3])
+    }
+}
+
 impl<F: Extendable<4>> MulAssign for QuarticExtension<F> {
     #[inline]
     fn mul_assign(&mut self, rhs: Self) {
         *self = *self * rhs;
     }
 }
 
+#[cfg(nightly)]
 impl<F: Extendable<4>> Square for QuarticExtension<F> {
     #[inline(always)]
     fn square(&self) -> Self {

field/src/extension/quintic.rs

@@ -7,6 +7,7 @@ use num::traits::Pow;
 use serde::{Deserialize, Serialize};
 
 use crate::extension::{Extendable, FieldExtension, Frobenius, OEF};
+#[cfg(nightly)]
 use crate::ops::Square;
 use crate::types::{Field, Sample};
 
@@ -210,6 +211,7 @@ impl<F: Extendable<5>> SubAssign for QuinticExtension<F> {
     }
 }
 
+#[cfg(nightly)]
 impl<F: Extendable<5>> Mul for QuinticExtension<F> {
     type Output = Self;
 
@@ -229,13 +231,34 @@ impl<F: Extendable<5>> Mul for QuinticExtension<F> {
     }
 }
 
+#[cfg(not(nightly))]
+impl<F: Extendable<5>> Mul for QuinticExtension<F> {
+    type Output = Self;
+
+    #[inline]
+    fn mul(self, rhs: Self) -> Self {
+        let Self([a0, a1, a2, a3, a4]) = self;
+        let Self([b0, b1, b2, b3, b4]) = rhs;
+        let w = <Self as OEF<5>>::W;
+
+        let c0 = a0 * b0 + w * (a1 * b4 + a2 * b3 + a3 * b2 + a4 * b1);
+        let c1 = a0 * b1 + a1 * b0 + w * (a2 * b4 + a3 * b3 + a4 * b2);
+        let c2 = a0 * b2 + a1 * b1 + a2 * b0 + w * (a3 * b4 + a4 * b3);
+        let c3 = a0 * b3 + a1 * b2 + a2 * b1 + a3 * b0 + w * a4 * b4;
+        let c4 = a0 * b4 + a1 * b3 + a2 * b2 + a3 * b1 + a4 * b0;
+
+        Self([c0, c1, c2, c3, c4])
+    }
+}
+
 impl<F: Extendable<5>> MulAssign for QuinticExtension<F> {
     #[inline]
     fn mul_assign(&mut self, rhs: Self) {
         *self = *self * rhs;
     }
 }
 
+#[cfg(nightly)]
 impl<F: Extendable<5>> Square for QuinticExtension<F> {
     #[inline(always)]
     fn square(&self) -> Self {