Added GGSW key-switching along with algo description

base2k/src/mat_znx_dft_ops.rs

@@ -99,6 +99,13 @@ pub trait MatZnxDftOps<BACKEND: Backend> {
         R: VecZnxDftToMut<BACKEND>,
         A: VecZnxDftToRef<BACKEND>,
         B: MatZnxDftToRef<BACKEND>;
+
+    // Same as [MatZnxDftOps::vmp_apply] except result is added on R instead of overwritting R.
+    fn vmp_apply_add<R, A, B>(&self, res: &mut R, a: &A, b: &B, scratch: &mut Scratch)
+    where
+        R: VecZnxDftToMut<BACKEND>,
+        A: VecZnxDftToRef<BACKEND>,
+        B: MatZnxDftToRef<BACKEND>;
 }
 
 impl<B: Backend> MatZnxDftAlloc<B> for Module<B> {
@@ -301,6 +308,59 @@ impl MatZnxDftOps<FFT64> for Module<FFT64> {
             )
         }
     }
+
+    fn vmp_apply_add<R, A, B>(&self, res: &mut R, a: &A, b: &B, scratch: &mut Scratch)
+        where
+            R: VecZnxDftToMut<FFT64>,
+            A: VecZnxDftToRef<FFT64>,
+            B: MatZnxDftToRef<FFT64> {
+        let mut res: VecZnxDft<&mut [u8], _> = res.to_mut();
+        let a: VecZnxDft<&[u8], _> = a.to_ref();
+        let b: MatZnxDft<&[u8], _> = b.to_ref();
+
+        #[cfg(debug_assertions)]
+        {
+            assert_eq!(res.n(), self.n());
+            assert_eq!(b.n(), self.n());
+            assert_eq!(a.n(), self.n());
+            assert_eq!(
+                res.cols(),
+                b.cols_out(),
+                "res.cols(): {} != b.cols_out: {}",
+                res.cols(),
+                b.cols_out()
+            );
+            assert_eq!(
+                a.cols(),
+                b.cols_in(),
+                "a.cols(): {} != b.cols_in: {}",
+                a.cols(),
+                b.cols_in()
+            );
+        }
+
+        let (tmp_bytes, _) = scratch.tmp_slice(self.vmp_apply_tmp_bytes(
+            res.size(),
+            a.size(),
+            b.rows(),
+            b.cols_in(),
+            b.cols_out(),
+            b.size(),
+        ));
+        unsafe {
+            vmp::vmp_apply_dft_to_dft_add(
+                self.ptr,
+                res.as_mut_ptr() as *mut vec_znx_dft_t,
+                (res.size() * res.cols()) as u64,
+                a.as_ptr() as *const vec_znx_dft_t,
+                (a.size() * a.cols()) as u64,
+                b.as_ptr() as *const vmp::vmp_pmat_t,
+                (b.rows() * b.cols_in()) as u64,
+                (b.size() * b.cols_out()) as u64,
+                tmp_bytes.as_mut_ptr(),
+            )
+        }
+    }
 }
 #[cfg(test)]
 mod tests {