Ref. + AVX code & generic tests + benches (#85)

poulpy-hal/src/reference/vec_znx/sub_scalar.rs

@@ -0,0 +1,58 @@
+use crate::layouts::{ScalarZnxToRef, VecZnxToMut, VecZnxToRef};
+use crate::{
+    layouts::{ScalarZnx, VecZnx, ZnxInfos, ZnxView, ZnxViewMut},
+    reference::znx::{ZnxSub, ZnxSubABInplace, ZnxZero},
+};
+
+pub fn vec_znx_sub_scalar<R, A, B, ZNXARI>(res: &mut R, res_col: usize, a: &A, a_col: usize, b: &B, b_col: usize, b_limb: usize)
+where
+    R: VecZnxToMut,
+    A: ScalarZnxToRef,
+    B: VecZnxToRef,
+    ZNXARI: ZnxSub + ZnxZero,
+{
+    let a: ScalarZnx<&[u8]> = a.to_ref();
+    let b: VecZnx<&[u8]> = b.to_ref();
+    let mut res: VecZnx<&mut [u8]> = res.to_mut();
+
+    let min_size: usize = b.size().min(res.size());
+
+    #[cfg(debug_assertions)]
+    {
+        assert!(
+            b_limb < min_size,
+            "b_limb: {} > min_size: {}",
+            b_limb,
+            min_size
+        );
+    }
+
+    for j in 0..min_size {
+        if j == b_limb {
+            ZNXARI::znx_sub(res.at_mut(res_col, j), b.at(b_col, j), a.at(a_col, 0));
+        } else {
+            res.at_mut(res_col, j).copy_from_slice(b.at(b_col, j));
+        }
+    }
+
+    for j in min_size..res.size() {
+        ZNXARI::znx_zero(res.at_mut(res_col, j));
+    }
+}
+
+pub fn vec_znx_sub_scalar_inplace<R, A, ZNXARI>(res: &mut R, res_col: usize, res_limb: usize, a: &A, a_col: usize)
+where
+    R: VecZnxToMut,
+    A: ScalarZnxToRef,
+    ZNXARI: ZnxSubABInplace,
+{
+    let a: ScalarZnx<&[u8]> = a.to_ref();
+    let mut res: VecZnx<&mut [u8]> = res.to_mut();
+
+    #[cfg(debug_assertions)]
+    {
+        assert!(res_limb < res.size());
+    }
+
+    ZNXARI::znx_sub_ab_inplace(res.at_mut(res_col, res_limb), a.at(a_col, 0));
+}