1use poulpy_hal::layouts::{Backend, DataMut, Module, Scratch, VecZnx};
  2
  3use crate::{
  4    GGSWExpandRows, ScratchTakeCore,
  5    keyswitching::glwe_ct::GLWEKeyswitch,
  6    layouts::{GGLWEInfos, GGLWEPreparedToRef, GGSW, GGSWInfos, GGSWToMut, GGSWToRef, prepared::TensorKeyPreparedToRef},
  7};
  8
  9impl GGSW<Vec<u8>> {
 10    pub fn keyswitch_tmp_bytes<R, A, K, T, M, BE: Backend>(
 11        module: &M,
 12        res_infos: &R,
 13        a_infos: &A,
 14        key_infos: &K,
 15        tsk_infos: &T,
 16    ) -> usize
 17    where
 18        R: GGSWInfos,
 19        A: GGSWInfos,
 20        K: GGLWEInfos,
 21        T: GGLWEInfos,
 22        M: GGSWKeyswitch<BE>,
 23    {
 24        module.ggsw_keyswitch_tmp_bytes(res_infos, a_infos, key_infos, tsk_infos)
 25    }
 26}
 27
 28impl<D: DataMut> GGSW<D> {
 29    pub fn keyswitch<M, A, K, T, BE: Backend>(&mut self, module: &M, a: &A, key: &K, tsk: &T, scratch: &mut Scratch<BE>)
 30    where
 31        A: GGSWToRef,
 32        K: GGLWEPreparedToRef<BE>,
 33        T: TensorKeyPreparedToRef<BE>,
 34        Scratch<BE>: ScratchTakeCore<BE>,
 35        M: GGSWKeyswitch<BE>,
 36    {
 37        module.ggsw_keyswitch(self, a, key, tsk, scratch);
 38    }
 39
 40    pub fn keyswitch_inplace<M, K, T, BE: Backend>(&mut self, module: &M, key: &K, tsk: &T, scratch: &mut Scratch<BE>)
 41    where
 42        K: GGLWEPreparedToRef<BE>,
 43        T: TensorKeyPreparedToRef<BE>,
 44        Scratch<BE>: ScratchTakeCore<BE>,
 45        M: GGSWKeyswitch<BE>,
 46    {
 47        module.ggsw_keyswitch_inplace(self, key, tsk, scratch);
 48    }
 49}
 50
 51impl<BE: Backend> GGSWKeyswitch<BE> for Module<BE> where Self: GLWEKeyswitch<BE> + GGSWExpandRows<BE> {}
 52
 53pub trait GGSWKeyswitch<BE: Backend>
 54where
 55    Self: GLWEKeyswitch<BE> + GGSWExpandRows<BE>,
 56{
 57    fn ggsw_keyswitch_tmp_bytes<R, A, K, T>(&self, res_infos: &R, a_infos: &A, key_infos: &K, tsk_infos: &T) -> usize
 58    where
 59        R: GGSWInfos,
 60        A: GGSWInfos,
 61        K: GGLWEInfos,
 62        T: GGLWEInfos,
 63    {
 64        assert_eq!(key_infos.rank_in(), key_infos.rank_out());
 65        assert_eq!(tsk_infos.rank_in(), tsk_infos.rank_out());
 66        assert_eq!(key_infos.rank_in(), tsk_infos.rank_in());
 67
 68        let rank: usize = key_infos.rank_out().into();
 69
 70        let size_out: usize = res_infos.k().div_ceil(res_infos.base2k()) as usize;
 71        let res_znx: usize = VecZnx::bytes_of(self.n(), rank + 1, size_out);
 72        let ci_dft: usize = self.bytes_of_vec_znx_dft(rank + 1, size_out);
 73        let ks: usize = self.glwe_keyswitch_tmp_bytes(res_infos, a_infos, key_infos);
 74        let expand_rows: usize = self.ggsw_expand_rows_tmp_bytes(res_infos, tsk_infos);
 75        let res_dft: usize = self.bytes_of_vec_znx_dft(rank + 1, size_out);
 76
 77        if a_infos.base2k() == tsk_infos.base2k() {
 78            res_znx + ci_dft + (ks | expand_rows | res_dft)
 79        } else {
 80            let a_conv: usize = VecZnx::bytes_of(
 81                self.n(),
 82                1,
 83                res_infos.k().div_ceil(tsk_infos.base2k()) as usize,
 84            ) + self.vec_znx_normalize_tmp_bytes();
 85            res_znx + ci_dft + (a_conv | ks | expand_rows | res_dft)
 86        }
 87    }
 88
 89    fn ggsw_keyswitch<R, A, K, T>(&self, res: &mut R, a: &A, key: &K, tsk: &T, scratch: &mut Scratch<BE>)
 90    where
 91        R: GGSWToMut,
 92        A: GGSWToRef,
 93        K: GGLWEPreparedToRef<BE>,
 94        T: TensorKeyPreparedToRef<BE>,
 95        Scratch<BE>: ScratchTakeCore<BE>,
 96    {
 97        let res: &mut GGSW<&mut [u8]> = &mut res.to_mut();
 98        let a: &GGSW<&[u8]> = &a.to_ref();
 99
100        assert!(res.dnum() <= a.dnum());
101        assert_eq!(res.dsize(), a.dsize());
102
103        for row in 0..a.dnum().into() {
104            // Key-switch column 0, i.e.
105            // col 0: (-(a0s0 + a1s1 + a2s2) + M[i], a0, a1, a2) -> (-(a0s0' + a1s1' + a2s2') + M[i], a0, a1, a2)
106            self.glwe_keyswitch(&mut res.at_mut(row, 0), &a.at(row, 0), key, scratch);
107        }
108
109        self.ggsw_expand_row(res, tsk, scratch);
110    }
111
112    fn ggsw_keyswitch_inplace<R, K, T>(&self, res: &mut R, key: &K, tsk: &T, scratch: &mut Scratch<BE>)
113    where
114        R: GGSWToMut,
115        K: GGLWEPreparedToRef<BE>,
116        T: TensorKeyPreparedToRef<BE>,
117        Scratch<BE>: ScratchTakeCore<BE>,
118    {
119        let res: &mut GGSW<&mut [u8]> = &mut res.to_mut();
120
121        for row in 0..res.dnum().into() {
122            // Key-switch column 0, i.e.
123            // col 0: (-(a0s0 + a1s1 + a2s2) + M[i], a0, a1, a2) -> (-(a0s0' + a1s1' + a2s2') + M[i], a0, a1, a2)
124            self.glwe_keyswitch_inplace(&mut res.at_mut(row, 0), key, scratch);
125        }
126
127        self.ggsw_expand_row(res, tsk, scratch);
128    }
129}