AVX2 implementations of Barrett reduction, the NTT, and deserializati…

…on for some parameters. (#270)

* NTT and Barrett reduce
* Inverse NTT functions
* inv_ntt_layer_1_step
* deserialize_1
* deserialize_4
* decompress -> decompress_ciphertext_coefficient for clarity
* deserialize_12
* deserialize_10
* ntt_multiply

libcrux-ml-kem/src/serialize.rs

@@ -217,7 +217,7 @@ fn deserialize_then_decompress_10<Vector: Operations>(
     cloop! {
         for (i, bytes) in serialized.chunks_exact(20).enumerate() {
             let coefficient = Vector::deserialize_10(bytes);
-            re.coefficients[i] = Vector::decompress::<10>(coefficient);
+            re.coefficients[i] = Vector::decompress_ciphertext_coefficient::<10>(coefficient);
         }
     }
     re
@@ -234,7 +234,7 @@ fn deserialize_then_decompress_11<Vector: Operations>(
     cloop! {
         for (i, bytes) in serialized.chunks_exact(22).enumerate() {
             let coefficient = Vector::deserialize_11(bytes);
-            re.coefficients[i] = Vector::decompress::<11>(coefficient);
+            re.coefficients[i] = Vector::decompress_ciphertext_coefficient::<11>(coefficient);
         }
     }
 
@@ -266,7 +266,7 @@ fn deserialize_then_decompress_4<Vector: Operations>(
     cloop! {
         for (i, bytes) in serialized.chunks_exact(8).enumerate() {
             let coefficient = Vector::deserialize_4(bytes);
-            re.coefficients[i] = Vector::decompress::<4>(coefficient);
+            re.coefficients[i] = Vector::decompress_ciphertext_coefficient::<4>(coefficient);
         }
     }
     re
@@ -283,7 +283,7 @@ fn deserialize_then_decompress_5<Vector: Operations>(
     cloop! {
         for (i, bytes) in serialized.chunks_exact(10).enumerate() {
             re.coefficients[i] = Vector::deserialize_5(bytes);
-            re.coefficients[i] = Vector::decompress::<5>(re.coefficients[i]);
+            re.coefficients[i] = Vector::decompress_ciphertext_coefficient::<5>(re.coefficients[i]);
         }
     }
     re

polynomials-aarch64/src/lib.rs

@@ -70,8 +70,8 @@ impl Operations for SIMD128Vector {
         compress::<COEFFICIENT_BITS>(v)
     }
 
-    fn decompress<const COEFFICIENT_BITS: i32>(v: Self) -> Self {
-        decompress::<COEFFICIENT_BITS>(v)
+    fn decompress_ciphertext_coefficient<const COEFFICIENT_BITS: i32>(v: Self) -> Self {
+        decompress_ciphertext_coefficient::<COEFFICIENT_BITS>(v)
     }
 
     fn ntt_layer_1_step(a: Self, zeta1: i16, zeta2: i16, zeta3: i16, zeta4: i16) -> Self {

polynomials-aarch64/src/simd128ops.rs

@@ -281,7 +281,9 @@ fn decompress_uint32x4_t<const COEFFICIENT_BITS: i32>(v: uint32x4_t) -> uint32x4
 }
 
 #[inline(always)]
-pub(crate) fn decompress<const COEFFICIENT_BITS: i32>(mut v: SIMD128Vector) -> SIMD128Vector {
+pub(crate) fn decompress_ciphertext_coefficient<const COEFFICIENT_BITS: i32>(
+    mut v: SIMD128Vector,
+) -> SIMD128Vector {
     let mask16 = _vdupq_n_u32(0xffff);
     let low0 = _vandq_u32(_vreinterpretq_u32_s16(v.low), mask16);
     let low1 = _vshrq_n_u32::<16>(_vreinterpretq_u32_s16(v.low));

polynomials-avx2/src/debug.rs

@@ -4,19 +4,25 @@ use core::arch::x86::*;
 use core::arch::x86_64::*;
 
 #[allow(dead_code)]
-fn print_m256i_as_i16s(a: __m256i, prefix: &'static str) {
+pub(crate) fn print_m256i_as_i16s(a: __m256i, prefix: &'static str) {
     let mut a_bytes = [0i16; 16];
     unsafe { _mm256_store_si256(a_bytes.as_mut_ptr() as *mut __m256i, a) };
-    println!("{}: {:04x?}", prefix, a_bytes);
+    println!("{}: {:?}", prefix, a_bytes);
+}
+#[allow(dead_code)]
+pub(crate) fn print_m256i_as_i32s(a: __m256i, prefix: &'static str) {
+    let mut a_bytes = [0i32; 8];
+    unsafe { _mm256_store_si256(a_bytes.as_mut_ptr() as *mut __m256i, a) };
+    println!("{}: {:?}", prefix, a_bytes);
 }
 #[allow(dead_code)]
-fn print_m128i_as_i16s(a: __m128i, prefix: &'static str) {
+pub(crate) fn print_m128i_as_i16s(a: __m128i, prefix: &'static str) {
     let mut a_bytes = [0i16; 8];
     unsafe { _mm_store_si128(a_bytes.as_mut_ptr() as *mut __m128i, a) };
     println!("{}: {:?}", prefix, a_bytes);
 }
 #[allow(dead_code)]
-fn print_m128i_as_i8s(a: __m128i, prefix: &'static str) {
+pub(crate) fn print_m128i_as_i8s(a: __m128i, prefix: &'static str) {
     let mut a_bytes = [0i8; 16];
     unsafe { _mm_store_si128(a_bytes.as_mut_ptr() as *mut __m128i, a) };
     println!("{}: {:?}", prefix, a_bytes);