fix read_mem and tests for small fields. And add byteConversion for d…

…egree4BabyBear
lambdaclass · Dec 23, 2024 · 9e1cee7 · 9e1cee7
1 parent 44b5933
commit 9e1cee7
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Showing 3 changed files with 357 additions and 153 deletions.
diff --git a/math/src/field/fields/fft_friendly/quartic_babybear.rs b/math/src/field/fields/fft_friendly/quartic_babybear.rs
@@ -262,6 +262,50 @@ impl ByteConversion for [FieldElement<Babybear31PrimeField>; 4] {
     }
 }
 
+impl ByteConversion for FieldElement<Degree4BabyBearExtensionField> {
+    fn to_bytes_be(&self) -> alloc::vec::Vec<u8> {
+        let mut byte_slice = ByteConversion::to_bytes_be(&self.value()[0]);
+        byte_slice.extend(ByteConversion::to_bytes_be(&self.value()[1]));
+        byte_slice.extend(ByteConversion::to_bytes_be(&self.value()[2]));
+        byte_slice.extend(ByteConversion::to_bytes_be(&self.value()[3]));
+        byte_slice
+    }
+
+    fn to_bytes_le(&self) -> alloc::vec::Vec<u8> {
+        let mut byte_slice = ByteConversion::to_bytes_le(&self.value()[0]);
+        byte_slice.extend(ByteConversion::to_bytes_le(&self.value()[1]));
+        byte_slice.extend(ByteConversion::to_bytes_le(&self.value()[2]));
+        byte_slice.extend(ByteConversion::to_bytes_le(&self.value()[3]));
+        byte_slice
+    }
+
+    fn from_bytes_be(bytes: &[u8]) -> Result<Self, crate::errors::ByteConversionError>
+    where
+        Self: Sized,
+    {
+        const BYTES_PER_FIELD: usize = 8;
+        let x0 = FieldElement::from_bytes_be(&bytes[0..BYTES_PER_FIELD])?;
+        let x1 = FieldElement::from_bytes_be(&bytes[BYTES_PER_FIELD..BYTES_PER_FIELD * 2])?;
+        let x2 = FieldElement::from_bytes_be(&bytes[BYTES_PER_FIELD * 2..BYTES_PER_FIELD * 3])?;
+        let x3 = FieldElement::from_bytes_be(&bytes[BYTES_PER_FIELD * 3..BYTES_PER_FIELD * 4])?;
+
+        Ok(Self::new([x0, x1, x2, x3]))
+    }
+
+    fn from_bytes_le(bytes: &[u8]) -> Result<Self, crate::errors::ByteConversionError>
+    where
+        Self: Sized,
+    {
+        const BYTES_PER_FIELD: usize = 8;
+        let x0 = FieldElement::from_bytes_le(&bytes[0..BYTES_PER_FIELD])?;
+        let x1 = FieldElement::from_bytes_le(&bytes[BYTES_PER_FIELD..BYTES_PER_FIELD * 2])?;
+        let x2 = FieldElement::from_bytes_le(&bytes[BYTES_PER_FIELD * 2..BYTES_PER_FIELD * 3])?;
+        let x3 = FieldElement::from_bytes_le(&bytes[BYTES_PER_FIELD * 3..BYTES_PER_FIELD * 4])?;
+
+        Ok(Self::new([x0, x1, x2, x3]))
+    }
+}
+
 impl IsFFTField for Degree4BabyBearExtensionField {
     const TWO_ADICITY: u64 = 29;
     const TWO_ADIC_PRIMITVE_ROOT_OF_UNITY: Self::BaseType = [