wip major refactoring (compiles & all test + example passing)

base2k/src/znx_base.rs

@@ -0,0 +1,335 @@
+use crate::{Backend, Module, alloc_aligned, assert_alignement, cast_mut};
+use itertools::izip;
+use std::cmp::min;
+
+pub struct ZnxBase {
+    /// The ring degree
+    pub n: usize,
+
+    /// The number of rows (in the third dimension)
+    pub rows: usize,
+
+    /// The number of polynomials
+    pub cols: usize,
+
+    /// The number of size per polynomial (a.k.a small polynomials).
+    pub size: usize,
+
+    /// Polynomial coefficients, as a contiguous array. Each col is equally spaced by n.
+    pub data: Vec<u8>,
+
+    /// Pointer to data (data can be enpty if [VecZnx] borrows space instead of owning it).
+    pub ptr: *mut u8,
+}
+
+pub trait GetZnxBase {
+    fn znx(&self) -> &ZnxBase;
+    fn znx_mut(&mut self) -> &mut ZnxBase;
+}
+
+pub trait ZnxInfos: GetZnxBase {
+    /// Returns the ring degree of the polynomials.
+    fn n(&self) -> usize {
+        self.znx().n
+    }
+
+    /// Returns the base two logarithm of the ring dimension of the polynomials.
+    fn log_n(&self) -> usize {
+        (usize::BITS - (self.n() - 1).leading_zeros()) as _
+    }
+
+    /// Returns the number of rows.
+    fn rows(&self) -> usize {
+        self.znx().rows
+    }
+    /// Returns the number of polynomials in each row.
+    fn cols(&self) -> usize {
+        self.znx().cols
+    }
+
+    /// Returns the number of size per polynomial.
+    fn size(&self) -> usize {
+        self.znx().size
+    }
+
+    fn data(&self) -> &[u8] {
+        &self.znx().data
+    }
+
+    fn ptr(&self) -> *mut u8 {
+        self.znx().ptr
+    }
+
+    /// Returns the total number of small polynomials.
+    fn poly_count(&self) -> usize {
+        self.rows() * self.cols() * self.size()
+    }
+}
+
+pub trait ZnxSliceSize {
+    /// Returns the slice size, which is the offset between
+    /// two size of the same column.
+    fn sl(&self) -> usize;
+}
+
+impl ZnxBase {
+    pub fn from_bytes(n: usize, rows: usize, cols: usize, size: usize, mut bytes: Vec<u8>) -> Self {
+        let mut res: Self = Self::from_bytes_borrow(n, rows, cols, size, &mut bytes);
+        res.data = bytes;
+        res
+    }
+
+    pub fn from_bytes_borrow(n: usize, rows: usize, cols: usize, size: usize, bytes: &mut [u8]) -> Self {
+        #[cfg(debug_assertions)]
+        {
+            assert_eq!(n & (n - 1), 0, "n must be a power of two");
+            assert!(n > 0, "n must be greater than 0");
+            assert!(rows > 0, "rows must be greater than 0");
+            assert!(cols > 0, "cols must be greater than 0");
+            assert!(size > 0, "size must be greater than 0");
+        }
+        Self {
+            n: n,
+            rows: rows,
+            cols: cols,
+            size: size,
+            data: Vec::new(),
+            ptr: bytes.as_mut_ptr(),
+        }
+    }
+}
+
+pub trait ZnxAlloc<B: Backend>
+where
+    Self: Sized + ZnxInfos,
+{
+    type Scalar;
+    fn new(module: &Module<B>, rows: usize, cols: usize, size: usize) -> Self {
+        let bytes: Vec<u8> = alloc_aligned::<u8>(Self::bytes_of(module, rows, cols, size));
+        Self::from_bytes(module, rows, cols, size, bytes)
+    }
+
+    fn from_bytes(module: &Module<B>, rows: usize, cols: usize, size: usize, mut bytes: Vec<u8>) -> Self {
+        let mut res: Self = Self::from_bytes_borrow(module, rows, cols, size, &mut bytes);
+        res.znx_mut().data = bytes;
+        res
+    }
+
+    fn from_bytes_borrow(module: &Module<B>, rows: usize, cols: usize, size: usize, bytes: &mut [u8]) -> Self;
+
+    fn bytes_of(module: &Module<B>, rows: usize, cols: usize, size: usize) -> usize;
+}
+
+pub trait ZnxLayout: ZnxInfos {
+    type Scalar;
+
+    /// Returns true if the receiver is only borrowing the data.
+    fn borrowing(&self) -> bool {
+        self.znx().data.len() == 0
+    }
+
+    /// Returns a non-mutable pointer to the underlying coefficients array.
+    fn as_ptr(&self) -> *const Self::Scalar {
+        self.znx().ptr as *const Self::Scalar
+    }
+
+    /// Returns a mutable pointer to the underlying coefficients array.
+    fn as_mut_ptr(&mut self) -> *mut Self::Scalar {
+        self.znx_mut().ptr as *mut Self::Scalar
+    }
+
+    /// Returns a non-mutable reference to the entire underlying coefficient array.
+    fn raw(&self) -> &[Self::Scalar] {
+        unsafe { std::slice::from_raw_parts(self.as_ptr(), self.n() * self.poly_count()) }
+    }
+
+    /// Returns a mutable reference to the entire underlying coefficient array.
+    fn raw_mut(&mut self) -> &mut [Self::Scalar] {
+        unsafe { std::slice::from_raw_parts_mut(self.as_mut_ptr(), self.n() * self.poly_count()) }
+    }
+
+    /// Returns a non-mutable pointer starting at the (i, j)-th small polynomial.
+    fn at_ptr(&self, i: usize, j: usize) -> *const Self::Scalar {
+        #[cfg(debug_assertions)]
+        {
+            assert!(i < self.cols());
+            assert!(j < self.size());
+        }
+        let offset = self.n() * (j * self.cols() + i);
+        unsafe { self.as_ptr().add(offset) }
+    }
+
+    /// Returns a mutable pointer starting at the (i, j)-th small polynomial.
+    fn at_mut_ptr(&mut self, i: usize, j: usize) -> *mut Self::Scalar {
+        #[cfg(debug_assertions)]
+        {
+            assert!(i < self.cols());
+            assert!(j < self.size());
+        }
+        let offset = self.n() * (j * self.cols() + i);
+        unsafe { self.as_mut_ptr().add(offset) }
+    }
+
+    /// Returns non-mutable reference to the (i, j)-th small polynomial.
+    fn at(&self, i: usize, j: usize) -> &[Self::Scalar] {
+        unsafe { std::slice::from_raw_parts(self.at_ptr(i, j), self.n()) }
+    }
+
+    /// Returns mutable reference to the (i, j)-th small polynomial.
+    fn at_mut(&mut self, i: usize, j: usize) -> &mut [Self::Scalar] {
+        unsafe { std::slice::from_raw_parts_mut(self.at_mut_ptr(i, j), self.n()) }
+    }
+
+    /// Returns non-mutable reference to the i-th limb.
+    fn at_limb(&self, j: usize) -> &[Self::Scalar] {
+        unsafe { std::slice::from_raw_parts(self.at_ptr(0, j), self.n() * self.cols()) }
+    }
+
+    /// Returns mutable reference to the i-th limb.
+    fn at_limb_mut(&mut self, j: usize) -> &mut [Self::Scalar] {
+        unsafe { std::slice::from_raw_parts_mut(self.at_mut_ptr(0, j), self.n() * self.cols()) }
+    }
+}
+
+use std::convert::TryFrom;
+use std::num::TryFromIntError;
+use std::ops::{Add, AddAssign, Div, Mul, Neg, Shl, Shr, Sub};
+pub trait IntegerType:
+    Copy
+    + std::fmt::Debug
+    + Default
+    + PartialEq
+    + PartialOrd
+    + Add<Output = Self>
+    + Sub<Output = Self>
+    + Mul<Output = Self>
+    + Div<Output = Self>
+    + Neg<Output = Self>
+    + Shr<Output = Self>
+    + Shl<Output = Self>
+    + AddAssign
+    + TryFrom<usize, Error = TryFromIntError>
+{
+    const BITS: u32;
+}
+
+impl IntegerType for i64 {
+    const BITS: u32 = 64;
+}
+
+impl IntegerType for i128 {
+    const BITS: u32 = 128;
+}
+
+pub trait ZnxBasics: ZnxLayout
+where
+    Self: Sized,
+    Self::Scalar: IntegerType,
+{
+    fn zero(&mut self) {
+        unsafe {
+            std::ptr::write_bytes(self.as_mut_ptr(), 0, self.n() * size_of::<Self::Scalar>());
+        }
+    }
+
+    fn zero_at(&mut self, i: usize, j: usize) {
+        unsafe {
+            std::ptr::write_bytes(
+                self.at_mut_ptr(i, j),
+                0,
+                self.n() * size_of::<Self::Scalar>(),
+            );
+        }
+    }
+
+    fn rsh(&mut self, log_base2k: usize, k: usize, carry: &mut [u8]) {
+        rsh(log_base2k, self, k, carry)
+    }
+}
+
+pub fn rsh<V: ZnxBasics>(log_base2k: usize, a: &mut V, k: usize, tmp_bytes: &mut [u8])
+where
+    V::Scalar: IntegerType,
+{
+    let n: usize = a.n();
+    let size: usize = a.size();
+    let cols: usize = a.cols();
+
+    #[cfg(debug_assertions)]
+    {
+        assert!(
+            tmp_bytes.len() >= rsh_tmp_bytes::<V::Scalar>(n, cols),
+            "invalid carry: carry.len()/size_ofSelf::Scalar={} < rsh_tmp_bytes({}, {})",
+            tmp_bytes.len() / size_of::<V::Scalar>(),
+            n,
+            size,
+        );
+        assert_alignement(tmp_bytes.as_ptr());
+    }
+
+    let size: usize = a.size();
+    let steps: usize = k / log_base2k;
+
+    a.raw_mut().rotate_right(n * steps * cols);
+    (0..cols).for_each(|i| {
+        (0..steps).for_each(|j| {
+            a.zero_at(i, j);
+        })
+    });
+
+    let k_rem: usize = k % log_base2k;
+
+    if k_rem != 0 {
+        let carry: &mut [V::Scalar] = cast_mut(tmp_bytes);
+
+        unsafe {
+            std::ptr::write_bytes(carry.as_mut_ptr(), 0, n * size_of::<V::Scalar>());
+        }
+
+        let log_base2k_t: V::Scalar = V::Scalar::try_from(log_base2k).unwrap();
+        let shift: V::Scalar = V::Scalar::try_from(V::Scalar::BITS as usize - k_rem).unwrap();
+        let k_rem_t: V::Scalar = V::Scalar::try_from(k_rem).unwrap();
+
+        (steps..size).for_each(|i| {
+            izip!(carry.iter_mut(), a.at_limb_mut(i).iter_mut()).for_each(|(ci, xi)| {
+                *xi += *ci << log_base2k_t;
+                *ci = get_base_k_carry(*xi, shift);
+                *xi = (*xi - *ci) >> k_rem_t;
+            });
+        })
+    }
+}
+
+#[inline(always)]
+fn get_base_k_carry<T: IntegerType>(x: T, shift: T) -> T {
+    (x << shift) >> shift
+}
+
+pub fn rsh_tmp_bytes<T: IntegerType>(n: usize, cols: usize) -> usize {
+    n * cols * std::mem::size_of::<T>()
+}
+
+pub fn switch_degree<T: ZnxLayout + ZnxBasics>(b: &mut T, col_b: usize, a: &T, col_a: usize)
+where
+    <T as ZnxLayout>::Scalar: IntegerType,
+{
+    let (n_in, n_out) = (a.n(), b.n());
+    let (gap_in, gap_out): (usize, usize);
+
+    if n_in > n_out {
+        (gap_in, gap_out) = (n_in / n_out, 1)
+    } else {
+        (gap_in, gap_out) = (1, n_out / n_in);
+        b.zero();
+    }
+
+    let size: usize = min(a.size(), b.size());
+
+    (0..size).for_each(|i| {
+        izip!(
+            a.at(col_a, i).iter().step_by(gap_in),
+            b.at_mut(col_b, i).iter_mut().step_by(gap_out)
+        )
+        .for_each(|(x_in, x_out)| *x_out = *x_in);
+    });
+}