refact: single generic limbs_of function

src/lib.rs

@@ -5,23 +5,12 @@ use num_bigint::BigUint;
 static COMMON_SRC: &str = include_str!("cl/common.cl");
 static FIELD_SRC: &str = include_str!("cl/field.cl");
 
-/// Divide anything into 64bit chunks
-fn u64_limbs_of<T>(value: T) -> Vec<u64> {
+/// Divide anything into limbs of type `E`
+fn limbs_of<T, E: Clone>(value: T) -> Vec<E> {
     unsafe {
         std::slice::from_raw_parts(
-            &value as *const T as *const u64,
-            std::mem::size_of::<T>() / 8,
-        )
-        .to_vec()
-    }
-}
-
-/// Divide anything into 32bit chunks
-fn u32_limbs_of<T>(value: T) -> Vec<u32> {
-    unsafe {
-        std::slice::from_raw_parts(
-            &value as *const T as *const u32,
-            std::mem::size_of::<T>() / 4,
+            &value as *const T as *const E,
+            std::mem::size_of::<T>() / std::mem::size_of::<E>(),
         )
         .to_vec()
     }
@@ -48,10 +37,10 @@ fn define_field(postfix: &str, limbs: Vec<u64>) -> String {
 
 fn calculate_r2<F: PrimeField>() -> Vec<u64> {
     // R ^ 2 mod P
-    let r2 = BigUint::new(u32_limbs_of(F::one()))
+    let r2 = BigUint::new(limbs_of::<_, u32>(F::one()))
         .modpow(
-            &BigUint::from_slice(&[2]),             // ^ 2
-            &BigUint::new(u32_limbs_of(F::char())), // mod P
+            &BigUint::from_slice(&[2]),                   // ^ 2
+            &BigUint::new(limbs_of::<_, u32>(F::char())), // mod P
         )
         .to_u32_digits();
     r2.iter()
@@ -64,8 +53,8 @@ fn params<F>() -> String
 where
     F: PrimeField,
 {
-    let one = u64_limbs_of(F::one()); // Get Montomery form of F::one()
-    let p = u64_limbs_of(F::char()); // Get regular form of field modulus
+    let one = limbs_of::<_, u64>(F::one()); // Get Montomery form of F::one()
+    let p = limbs_of::<_, u64>(F::char()); // Get regular form of field modulus
     let r2 = calculate_r2::<F>();
     let limbs = one.len(); // Number of limbs
     let inv = calc_inv(p[0]);
@@ -91,7 +80,7 @@ where
     let mut result = String::new();
 
     for op in &["sub", "add"] {
-        let len = u64_limbs_of(F::one()).len();
+        let len = limbs_of::<_, u64>(F::one()).len();
 
         let mut src = format!("FIELD FIELD_{}_(FIELD a, FIELD b) {{\n", op);
         if len > 1 {