poulpy/base2k/src/vec_znx.rs
base2k/src/vec_znx.rsRaw
1use crate::cast_mut_u8_to_mut_i64_slice;
2use crate::ffi::znx::{
3 znx_automorphism_i64, znx_automorphism_inplace_i64, znx_normalize, znx_zero_i64_ref,
4};
5use crate::module::Module;
6use itertools::izip;
7use rand_distr::{Distribution, Normal};
8use sampling::source::Source;
9use std::cmp::min;
10
11impl Module {
12 pub fn new_vec_znx(&self, log_base2k: usize, log_q: usize) -> VecZnx {
13 VecZnx::new(self.n(), log_base2k, log_q)
14 }
15}
16
17#[derive(Clone)]
18pub struct VecZnx {
19 pub n: usize,
20 pub log_base2k: usize,
21 pub log_q: usize,
22 pub data: Vec<i64>,
23}
24
25impl VecZnx {
26 pub fn new(n: usize, log_base2k: usize, log_q: usize) -> Self {
27 Self {
28 n: n,
29 log_base2k: log_base2k,
30 log_q: log_q,
31 data: vec![i64::default(); Self::buffer_size(n, log_base2k, log_q)],
32 }
33 }
34
35 pub fn buffer_size(n: usize, log_base2k: usize, log_q: usize) -> usize {
36 n * ((log_q + log_base2k - 1) / log_base2k)
37 }
38
39 pub fn from_buffer(&mut self, n: usize, log_base2k: usize, log_q: usize, buf: &[i64]) {
40 let size = Self::buffer_size(n, log_base2k, log_q);
41 assert!(
42 buf.len() >= size,
43 "invalid buffer: buf.len()={} < self.buffer_size(n={}, k={}, log_q={})={}",
44 buf.len(),
45 n,
46 log_base2k,
47 log_q,
48 size
49 );
50 self.n = n;
51 self.log_base2k = log_base2k;
52 self.log_q = log_q;
53 self.data = Vec::from(&buf[..size])
54 }
55
56 pub fn log_n(&self) -> u64 {
57 (u64::BITS - (self.n - 1).leading_zeros()) as _
58 }
59
60 pub fn n(&self) -> usize {
61 self.n
62 }
63
64 pub fn log_q(&self) -> usize {
65 self.log_q
66 }
67
68 pub fn limbs(&self) -> usize {
69 self.data.len() / self.n
70 }
71
72 pub fn copy_from(&mut self, a: &VecZnx) {
73 let size = min(self.data.len(), a.data.len());
74 self.data[..size].copy_from_slice(&a.data[..size])
75 }
76
77 pub fn as_ptr(&self) -> *const i64 {
78 self.data.as_ptr()
79 }
80
81 pub fn as_mut_ptr(&mut self) -> *mut i64 {
82 self.data.as_mut_ptr()
83 }
84
85 pub fn at(&self, i: usize) -> &[i64] {
86 &self.data[i * self.n..(i + 1) * self.n]
87 }
88
89 pub fn at_ptr(&self, i: usize) -> *const i64 {
90 &self.data[i * self.n] as *const i64
91 }
92
93 pub fn at_mut_ptr(&mut self, i: usize) -> *mut i64 {
94 &mut self.data[i * self.n] as *mut i64
95 }
96
97 pub fn at_mut(&mut self, i: usize) -> &mut [i64] {
98 &mut self.data[i * self.n..(i + 1) * self.n]
99 }
100
101 pub fn from_i64(&mut self, data: &[i64], log_max: usize) {
102 let size: usize = min(data.len(), self.n());
103 let k_rem: usize = self.log_base2k - (self.log_q % self.log_base2k);
104
105 // If 2^{log_base2k} * 2^{k_rem} < 2^{63}-1, then we can simply copy
106 // values on the last limb.
107 // Else we decompose values base2k.
108 if log_max + k_rem < 63 || k_rem == self.log_base2k {
109 self.at_mut(self.limbs() - 1)[..size].copy_from_slice(&data[..size]);
110 } else {
111 let mask: i64 = (1 << self.log_base2k) - 1;
112 let limbs = self.limbs();
113 let steps: usize = min(limbs, (log_max + self.log_base2k - 1) / self.log_base2k);
114 (limbs - steps..limbs)
115 .rev()
116 .enumerate()
117 .for_each(|(i, i_rev)| {
118 let shift: usize = i * self.log_base2k;
119 izip!(self.at_mut(i_rev)[..size].iter_mut(), data[..size].iter())
120 .for_each(|(y, x)| *y = (x >> shift) & mask);
121 })
122 }
123
124 // Case where self.prec % self.k != 0.
125 if k_rem != self.log_base2k {
126 let limbs = self.limbs();
127 let steps: usize = min(limbs, (log_max + self.log_base2k - 1) / self.log_base2k);
128 (limbs - steps..limbs).rev().for_each(|i| {
129 self.at_mut(i)[..size].iter_mut().for_each(|x| *x <<= k_rem);
130 })
131 }
132 }
133
134 pub fn from_i64_single(&mut self, i: usize, value: i64, log_max: usize) {
135 assert!(i < self.n());
136 let k_rem: usize = self.log_base2k - (self.log_q % self.log_base2k);
137
138 // If 2^{log_base2k} * 2^{k_rem} < 2^{63}-1, then we can simply copy
139 // values on the last limb.
140 // Else we decompose values base2k.
141 if log_max + k_rem < 63 || k_rem == self.log_base2k {
142 self.at_mut(self.limbs() - 1)[i] = value;
143 } else {
144 let mask: i64 = (1 << self.log_base2k) - 1;
145 let limbs = self.limbs();
146 let steps: usize = min(limbs, (log_max + self.log_base2k - 1) / self.log_base2k);
147 (limbs - steps..limbs)
148 .rev()
149 .enumerate()
150 .for_each(|(j, j_rev)| {
151 self.at_mut(j_rev)[i] = (value >> (j * self.log_base2k)) & mask;
152 })
153 }
154
155 // Case where self.prec % self.k != 0.
156 if k_rem != self.log_base2k {
157 let limbs = self.limbs();
158 let steps: usize = min(limbs, (log_max + self.log_base2k - 1) / self.log_base2k);
159 (limbs - steps..limbs).rev().for_each(|j| {
160 self.at_mut(j)[i] <<= k_rem;
161 })
162 }
163 }
164
165 pub fn normalize(&mut self, carry: &mut [u8]) {
166 assert!(
167 carry.len() >= self.n * 8,
168 "invalid carry: carry.len()={} < self.n()={}",
169 carry.len(),
170 self.n()
171 );
172
173 let carry_i64: &mut [i64] = cast_mut_u8_to_mut_i64_slice(carry);
174
175 unsafe {
176 znx_zero_i64_ref(self.n() as u64, carry_i64.as_mut_ptr());
177 (0..self.limbs()).rev().for_each(|i| {
178 znx_normalize(
179 self.n as u64,
180 self.log_base2k as u64,
181 self.at_mut_ptr(i),
182 carry_i64.as_mut_ptr(),
183 self.at_mut_ptr(i),
184 carry_i64.as_mut_ptr(),
185 )
186 });
187 }
188 }
189
190 pub fn to_i64(&self, data: &mut [i64]) {
191 assert!(
192 data.len() >= self.n,
193 "invalid data: data.len()={} < self.n()={}",
194 data.len(),
195 self.n
196 );
197 data.copy_from_slice(self.at(0));
198 let rem: usize = self.log_base2k - (self.log_q % self.log_base2k);
199 (1..self.limbs()).for_each(|i| {
200 if i == self.limbs() - 1 && rem != self.log_base2k {
201 let k_rem: usize = self.log_base2k - rem;
202 izip!(self.at(i).iter(), data.iter_mut()).for_each(|(x, y)| {
203 *y = (*y << k_rem) + (x >> rem);
204 });
205 } else {
206 izip!(self.at(i).iter(), data.iter_mut()).for_each(|(x, y)| {
207 *y = (*y << self.log_base2k) + x;
208 });
209 }
210 })
211 }
212
213 pub fn to_i64_single(&self, i: usize) -> i64 {
214 assert!(i < self.n());
215 let mut res: i64 = self.data[i];
216 let rem: usize = self.log_base2k - (self.log_q % self.log_base2k);
217 (1..self.limbs()).for_each(|i| {
218 let x = self.data[i * self.n];
219 if i == self.limbs() - 1 && rem != self.log_base2k {
220 let k_rem: usize = self.log_base2k - rem;
221 res = (res << k_rem) + (x >> rem);
222 } else {
223 res = (res << self.log_base2k) + x;
224 }
225 });
226 res
227 }
228
229 pub fn automorphism_inplace(&mut self, gal_el: i64) {
230 unsafe {
231 (0..self.limbs()).for_each(|i| {
232 znx_automorphism_inplace_i64(self.n as u64, gal_el, self.at_mut_ptr(i))
233 })
234 }
235 }
236 pub fn automorphism(&mut self, gal_el: i64, a: &mut VecZnx) {
237 unsafe {
238 (0..self.limbs()).for_each(|i| {
239 znx_automorphism_i64(self.n as u64, gal_el, a.at_mut_ptr(i), self.at_ptr(i))
240 })
241 }
242 }
243
244 pub fn fill_uniform(&mut self, source: &mut Source) {
245 let mut base2k: u64 = 1 << self.log_base2k;
246 let mut mask: u64 = base2k - 1;
247 let mut base2k_half: i64 = (base2k >> 1) as i64;
248
249 let size: usize = self.n() * (self.limbs() - 1);
250
251 self.data[..size]
252 .iter_mut()
253 .for_each(|x| *x = (source.next_u64n(base2k, mask) as i64) - base2k_half);
254
255 let log_base2k_rem: usize = self.log_q % self.log_base2k;
256
257 if log_base2k_rem != 0 {
258 base2k = 1 << log_base2k_rem;
259 mask = (base2k - 1) << (self.log_base2k - log_base2k_rem);
260 base2k_half = ((mask >> 1) + 1) as i64;
261 }
262
263 self.data[size..]
264 .iter_mut()
265 .for_each(|x| *x = (source.next_u64n(base2k, mask) as i64) - base2k_half);
266 }
267
268 pub fn add_dist_f64<T: Distribution<f64>>(&mut self, source: &mut Source, dist: T, bound: f64) {
269 let log_base2k_rem: usize = self.log_q % self.log_base2k;
270
271 if log_base2k_rem != 0 {
272 self.at_mut(self.limbs() - 1).iter_mut().for_each(|a| {
273 let mut dist_f64: f64 = dist.sample(source);
274 while dist_f64.abs() > bound {
275 dist_f64 = dist.sample(source)
276 }
277 *a += (dist_f64.round() as i64) << log_base2k_rem
278 });
279 } else {
280 self.at_mut(self.limbs() - 1).iter_mut().for_each(|a| {
281 let mut dist_f64: f64 = dist.sample(source);
282 while dist_f64.abs() > bound {
283 dist_f64 = dist.sample(source)
284 }
285 *a += dist_f64.round() as i64
286 });
287 }
288 }
289
290 pub fn add_normal(&mut self, source: &mut Source, sigma: f64, bound: f64) {
291 self.add_dist_f64(source, Normal::new(0.0, sigma).unwrap(), bound);
292 }
293
294 pub fn trunc_pow2(&mut self, k: usize) {
295 if k == 0 {
296 return;
297 }
298
299 assert!(
300 k <= self.log_q,
301 "invalid argument k: k={} > self.prec()={}",
302 k,
303 self.log_q()
304 );
305
306 self.log_q -= k;
307 self.data
308 .truncate((self.limbs() - k / self.log_base2k) * self.n());
309
310 let k_rem: usize = k % self.log_base2k;
311
312 if k_rem != 0 {
313 let mask: i64 = ((1 << (self.log_base2k - k_rem - 1)) - 1) << k_rem;
314 self.at_mut(self.limbs() - 1)
315 .iter_mut()
316 .for_each(|x: &mut i64| *x &= mask)
317 }
318 }
319
320 pub fn rsh(&mut self, k: usize, carry: &mut [u8]) {
321 let limbs: usize = self.limbs();
322 let limbs_steps: usize = k / self.log_base2k;
323
324 self.data.rotate_right(self.n * limbs_steps);
325 unsafe {
326 znx_zero_i64_ref((self.n * limbs_steps) as u64, self.data.as_mut_ptr());
327 }
328
329 let k_rem = k % self.log_base2k;
330
331 if k_rem != 0 {
332 let carry_i64: &mut [i64] = cast_mut_u8_to_mut_i64_slice(carry);
333
334 unsafe {
335 znx_zero_i64_ref(self.n() as u64, carry_i64.as_mut_ptr());
336 }
337
338 let mask: i64 = (1 << k_rem) - 1;
339 let log_base2k: usize = self.log_base2k;
340
341 (limbs_steps..limbs).for_each(|i| {
342 izip!(carry_i64.iter_mut(), self.at_mut(i).iter_mut()).for_each(|(ci, xi)| {
343 *xi += *ci << log_base2k;
344 *ci = *xi & mask;
345 *xi /= 1 << k_rem;
346 });
347 })
348 }
349 }
350}
351
352#[cfg(test)]
353mod tests {
354 use crate::VecZnx;
355 use itertools::izip;
356 use sampling::source::Source;
357
358 #[test]
359 fn test_set_get_i64_lo_norm() {
360 let n: usize = 32;
361 let k: usize = 19;
362 let prec: usize = 128;
363 let mut a: VecZnx = VecZnx::new(n, k, prec);
364 let mut have: Vec<i64> = vec![i64::default(); n];
365 have.iter_mut()
366 .enumerate()
367 .for_each(|(i, x)| *x = (i as i64) - (n as i64) / 2);
368 a.from_i64(&have, 10);
369 let mut want = vec![i64::default(); n];
370 a.to_i64(&mut want);
371 izip!(want, have).for_each(|(a, b)| assert_eq!(a, b));
372 }
373
374 #[test]
375 fn test_set_get_i64_hi_norm() {
376 let n: usize = 8;
377 let k: usize = 17;
378 let prec: usize = 84;
379 let mut a: VecZnx = VecZnx::new(n, k, prec);
380 let mut have: Vec<i64> = vec![i64::default(); n];
381 let mut source = Source::new([1; 32]);
382 have.iter_mut().for_each(|x| {
383 *x = source
384 .next_u64n(u64::MAX, u64::MAX)
385 .wrapping_sub(u64::MAX / 2 + 1) as i64;
386 });
387 a.from_i64(&have, 63);
388 //(0..a.limbs()).for_each(|i| println!("i:{} -> {:?}", i, a.at(i)));
389 let mut want = vec![i64::default(); n];
390 //(0..a.limbs()).for_each(|i| println!("i:{} -> {:?}", i, a.at(i)));
391 a.to_i64(&mut want);
392 izip!(want, have).for_each(|(a, b)| assert_eq!(a, b, "{} != {}", a, b));
393 }
394 #[test]
395 fn test_normalize() {
396 let n: usize = 8;
397 let k: usize = 17;
398 let prec: usize = 84;
399 let mut a: VecZnx = VecZnx::new(n, k, prec);
400 let mut have: Vec<i64> = vec![i64::default(); n];
401 let mut source = Source::new([1; 32]);
402 have.iter_mut().for_each(|x| {
403 *x = source
404 .next_u64n(u64::MAX, u64::MAX)
405 .wrapping_sub(u64::MAX / 2 + 1) as i64;
406 });
407 a.from_i64(&have, 63);
408 let mut carry: Vec<u8> = vec![u8::default(); n * 8];
409 a.normalize(&mut carry);
410
411 let base_half = 1 << (k - 1);
412 a.data
413 .iter()
414 .for_each(|x| assert!(x.abs() <= base_half, "|x|={} > 2^(k-1)={}", x, base_half));
415 let mut want = vec![i64::default(); n];
416 a.to_i64(&mut want);
417 izip!(want, have).for_each(|(a, b)| assert_eq!(a, b, "{} != {}", a, b));
418 }
419}