added digit decomposition

math/src/lib.rs

@@ -146,7 +146,6 @@ pub mod macros {
     macro_rules! apply_sv {
         ($self:expr, $f:expr, $a:expr, $b:expr, $CHUNK:expr) => {
             let n: usize = $b.len();
-
             debug_assert!(
                 CHUNK & (CHUNK - 1) == 0,
                 "invalid CHUNK const: not a power of two"
@@ -426,13 +425,13 @@ pub mod macros {
                     )
                     .for_each(|(a, b, e)| {
                         $f(&$self, &a[0], &b[0], $c, $d, &mut e[0]);
-                        $f(&$self, &a[1], &b[1], $c, $d,  &mut e[1]);
+                        $f(&$self, &a[1], &b[1], $c, $d, &mut e[1]);
-                        $f(&$self, &a[2], &b[2], $c, $d,  &mut e[2]);
+                        $f(&$self, &a[2], &b[2], $c, $d, &mut e[2]);
-                        $f(&$self, &a[3], &b[3], $c, $d,  &mut e[3]);
+                        $f(&$self, &a[3], &b[3], $c, $d, &mut e[3]);
-                        $f(&$self, &a[4], &b[4], $c, $d,  &mut e[4]);
+                        $f(&$self, &a[4], &b[4], $c, $d, &mut e[4]);
-                        $f(&$self, &a[5], &b[5], $c, $d,  &mut e[5]);
+                        $f(&$self, &a[5], &b[5], $c, $d, &mut e[5]);
-                        $f(&$self, &a[6], &b[6], $c, $d,  &mut e[6]);
+                        $f(&$self, &a[6], &b[6], $c, $d, &mut e[6]);
-                        $f(&$self, &a[7], &b[7], $c, $d,  &mut e[7]);
+                        $f(&$self, &a[7], &b[7], $c, $d, &mut e[7]);
                     });
 
                     let m = n - (n & 7);
@@ -450,4 +449,59 @@ pub mod macros {
             }
         };
     }
+
+    #[macro_export]
+    macro_rules! apply_vsssvv {
+        ($self:expr, $f:expr, $a:expr, $b:expr, $c:expr, $d:expr, $e:expr, $g:expr, $CHUNK:expr) => {
+            let n: usize = $a.len();
+            debug_assert!(
+                $e.len() == n,
+                "invalid argument b: e.len() = {} != a.len() = {}",
+                $e.len(),
+                n
+            );
+            debug_assert!(
+                $g.len() == n,
+                "invalid argument g: g.len() = {} != a.len() = {}",
+                $g.len(),
+                n
+            );
+            debug_assert!(
+                CHUNK & (CHUNK - 1) == 0,
+                "invalid CHUNK const: not a power of two"
+            );
+
+            match CHUNK {
+                8 => {
+                    izip!(
+                        $a.chunks_exact(8),
+                        $e.chunks_exact_mut(8),
+                        $g.chunks_exact_mut(8)
+                    )
+                    .for_each(|(a, e, g)| {
+                        $f(&$self, &a[0], $b, $c, $d, &mut e[0], &mut g[0]);
+                        $f(&$self, &a[1], $b, $c, $d, &mut e[1], &mut g[1]);
+                        $f(&$self, &a[2], $b, $c, $d, &mut e[2], &mut g[2]);
+                        $f(&$self, &a[3], $b, $c, $d, &mut e[3], &mut g[3]);
+                        $f(&$self, &a[4], $b, $c, $d, &mut e[4], &mut g[4]);
+                        $f(&$self, &a[5], $b, $c, $d, &mut e[5], &mut g[5]);
+                        $f(&$self, &a[6], $b, $c, $d, &mut e[6], &mut g[6]);
+                        $f(&$self, &a[7], $b, $c, $d, &mut e[7], &mut g[7]);
+                    });
+
+                    let m = n - (n & 7);
+                    izip!($a[m..].iter(), $e[m..].iter_mut(), $g[m..].iter_mut()).for_each(
+                        |(a, e, g)| {
+                            $f(&$self, a, $b, $c, $d, e, g);
+                        },
+                    );
+                }
+                _ => {
+                    izip!($a.iter(), $e.iter_mut(), $g.iter_mut()).for_each(|(a, e, g)| {
+                        $f(&$self, a, $b, $c, $d, e, g);
+                    });
+                }
+            }
+        };
+    }
 }

math/src/modulus.rs

@@ -187,6 +187,22 @@ pub trait ScalarOperations<O> {
         d: &barrett::Barrett<u64>,
         a: &mut u64,
     );
+
+    fn sa_rsh_sb_mask_sc_into_sa(&self, c: &u64, b: &u64, a: &mut u64);
+
+    fn sa_rsh_sb_mask_sc_into_sd(&self, a: &u64, b: &u64, c: &u64, d: &mut u64);
+
+    fn sa_rsh_sb_mask_sc_add_sd_into_sd(&self, a: &u64, b: &u64, c: &u64, d: &mut u64);
+
+    fn sa_signed_digit_into_sb<const CARRYOVERWRITE: bool, const BALANCED: bool>(
+        &self,
+        a: &u64,
+        base: &u64,
+        shift: &u64,
+        mask: &u64,
+        carry: &mut u64,
+        b: &mut u64,
+    );
 }
 
 pub trait VectorOperations<O> {
@@ -354,4 +370,48 @@ pub trait VectorOperations<O> {
         sd: &barrett::Barrett<u64>,
         va: &mut [u64],
     );
+
+    // vec(a) <- (vec(a)>>scalar(b)) & scalar(c).
+    fn va_rsh_sb_mask_sd_into_va<const CHUNK: usize>(&self, sb: &u64, sc: &u64, va: &mut [u64]);
+
+    // vec(d) <- (vec(a)>>scalar(b)) & scalar(c).
+    fn va_rsh_sb_mask_sc_into_vd<const CHUNK: usize>(
+        &self,
+        va: &[u64],
+        sb: &u64,
+        sc: &u64,
+        vd: &mut [u64],
+    );
+
+    // vec(d) <- vec(d) + (vec(a)>>scalar(b)) & scalar(c).
+    fn va_rsh_sb_mask_sc_add_vd_into_vd<const CHUNK: usize>(
+        &self,
+        va: &[u64],
+        sb: &u64,
+        sc: &u64,
+        vd: &mut [u64],
+    );
+
+    // vec(c) <- i-th unsigned digit base 2^{sb} of vec(a).
+    // vec(c) is ensured to be in the range [0, 2^{sb}-1[ with E[vec(c)] = 2^{sb}-1.
+    fn va_ith_digit_unsigned_base_sb_into_vc<const CHUNK: usize>(
+        &self,
+        i: usize,
+        va: &[u64],
+        sb: &u64,
+        vc: &mut [u64],
+    );
+
+    // vec(c) <- i-th signed digit base 2^{w} of vec(a).
+    // Reads the carry of the i-1-th iteration and write the carry on the i-th iteration on carry.
+    // if i > 0, carry of the i-1th iteration must be provided.
+    // if BALANCED: vec(c) is ensured to be [-2^{sb-1}, 2^{sb-1}[ with E[vec(c)] = 0, else E[vec(c)] = -0.5
+    fn va_ith_digit_signed_base_sb_into_vc<const CHUNK: usize, const BALANCED: bool>(
+        &self,
+        i: usize,
+        va: &[u64],
+        sb: &u64,
+        carry: &mut [u64],
+        vc: &mut [u64],
+    );
 }

math/src/modulus/impl_u64/operations.rs

@@ -4,8 +4,8 @@ use crate::modulus::prime::Prime;
 use crate::modulus::{ScalarOperations, VectorOperations};
 use crate::modulus::{NONE, REDUCEMOD};
 use crate::{
-    apply_ssv, apply_sv, apply_svv, apply_v, apply_vssv, apply_vsv, apply_vv, apply_vvssv,
+    apply_ssv, apply_sv, apply_svv, apply_v, apply_vsssvv, apply_vssv, apply_vsv, apply_vv,
-    apply_vvsv, apply_vvv,
+    apply_vvssv, apply_vvsv, apply_vvv,
 };
 use itertools::izip;
 
@@ -211,6 +211,47 @@ impl ScalarOperations<u64> for Prime<u64> {
         self.sa_sub_sb_into_sb::<SBRANGE, NONE>(&(b + c), a);
         self.barrett.mul_external_assign::<REDUCE>(*d, a);
     }
+
+    #[inline(always)]
+    fn sa_rsh_sb_mask_sc_into_sa(&self, b: &u64, c: &u64, a: &mut u64) {
+        *a = (*a >> b) & c
+    }
+
+    #[inline(always)]
+    fn sa_rsh_sb_mask_sc_into_sd(&self, a: &u64, b: &u64, c: &u64, d: &mut u64) {
+        *d = (*a >> b) & c
+    }
+
+    #[inline(always)]
+    fn sa_rsh_sb_mask_sc_add_sd_into_sd(&self, a: &u64, b: &u64, c: &u64, d: &mut u64) {
+        *d += (*a >> b) & c
+    }
+
+    #[inline(always)]
+    fn sa_signed_digit_into_sb<const CARRYOVERWRITE: bool, const BALANCED: bool>(
+        &self,
+        a: &u64,
+        base: &u64,
+        shift: &u64,
+        mask: &u64,
+        carry: &mut u64,
+        b: &mut u64,
+    ) {
+        if CARRYOVERWRITE {
+            self.sa_rsh_sb_mask_sc_into_sd(a, shift, mask, carry);
+        } else {
+            self.sa_rsh_sb_mask_sc_add_sd_into_sd(a, shift, mask, carry);
+        }
+
+        let c: u64 = if BALANCED && *carry == base >> 1 {
+            a & 1
+        } else {
+            ((*carry | (*carry << 1)) >> base) & 1
+        };
+
+        *b = *carry + (self.q - base) * c;
+        *carry = c;
+    }
 }
 
 impl VectorOperations<u64> for Prime<u64> {
@@ -518,4 +559,92 @@ impl VectorOperations<u64> for Prime<u64> {
             CHUNK
         );
     }
+
+    // vec(a) <- (vec(a)>>scalar(b)) & scalar(c).
+    fn va_rsh_sb_mask_sd_into_va<const CHUNK: usize>(&self, sb: &u64, sc: &u64, va: &mut [u64]) {
+        apply_ssv!(self, Self::sa_rsh_sb_mask_sc_into_sa, sb, sc, va, CHUNK);
+    }
+
+    // vec(d) <- (vec(a)>>scalar(b)) & scalar(c).
+    fn va_rsh_sb_mask_sc_into_vd<const CHUNK: usize>(
+        &self,
+        va: &[u64],
+        sb: &u64,
+        sc: &u64,
+        vd: &mut [u64],
+    ) {
+        apply_vssv!(self, Self::sa_rsh_sb_mask_sc_into_sd, va, sb, sc, vd, CHUNK);
+    }
+
+    // vec(d) <- vec(d) + (vec(a)>>scalar(b)) & scalar(c).
+    fn va_rsh_sb_mask_sc_add_vd_into_vd<const CHUNK: usize>(
+        &self,
+        va: &[u64],
+        sb: &u64,
+        sc: &u64,
+        vd: &mut [u64],
+    ) {
+        apply_vssv!(
+            self,
+            Self::sa_rsh_sb_mask_sc_add_sd_into_sd,
+            va,
+            sb,
+            sc,
+            vd,
+            CHUNK
+        );
+    }
+
+    // vec(c) <- i-th unsigned digit base 2^{sb} of vec(a).
+    // vec(c) is ensured to be in the range [0, 2^{sb}-1[ with E[vec(c)] = 2^{sb}-1.
+    fn va_ith_digit_unsigned_base_sb_into_vc<const CHUNK: usize>(
+        &self,
+        i: usize,
+        va: &[u64],
+        sb: &u64,
+        vc: &mut [u64],
+    ) {
+        self.va_rsh_sb_mask_sc_into_vd::<CHUNK>(va, &((i as u64) * sb), &((1 << sb) - 1), vc);
+    }
+
+    // vec(c) <- i-th signed digit base 2^{w} of vec(a).
+    // Reads the carry of the i-1-th iteration and write the carry on the i-th iteration on carry.
+    // if i > 0, carry of the i-1th iteration must be provided.
+    // if BALANCED: vec(c) is ensured to be [-2^{sb-1}, 2^{sb-1}[ with E[vec(c)] = 0, else E[vec(c)] = -0.5
+    fn va_ith_digit_signed_base_sb_into_vc<const CHUNK: usize, const BALANCED: bool>(
+        &self,
+        i: usize,
+        va: &[u64],
+        sb: &u64,
+        carry: &mut [u64],
+        vc: &mut [u64],
+    ) {
+        let base: u64 = 1 << sb;
+        let mask: u64 = base - 1;
+        if i == 0 {
+            apply_vsssvv!(
+                self,
+                Self::sa_signed_digit_into_sb::<true, BALANCED>,
+                va,
+                &base,
+                &(i as u64 * sb),
+                &mask,
+                carry,
+                vc,
+                CHUNK
+            );
+        } else {
+            apply_vsssvv!(
+                self,
+                Self::sa_signed_digit_into_sb::<false, BALANCED>,
+                va,
+                &base,
+                &(i as u64 * sb),
+                &mask,
+                carry,
+                vc,
+                CHUNK
+            );
+        }
+    }
 }

math/src/ring/impl_u64/sampling.rs

@@ -35,7 +35,7 @@ impl Ring<u64> {
         });
     }
 
-    pub fn fill_normal(&self, source: &mut Source, sigma: f64, bound: f64, a: &mut Poly<u64>){
+    pub fn fill_normal(&self, source: &mut Source, sigma: f64, bound: f64, a: &mut Poly<u64>) {
         self.fill_dist_f64(source, Normal::new(0.0, sigma).unwrap(), bound, a);
     }
 }