Files
2023-08-12 13:02:21 -04:00

550 lines
22 KiB
C

/*
* Support functions for signatures (hash-to-point, norm).
*
* ==========================(LICENSE BEGIN)============================
*
* Copyright (c) 2017-2019 Falcon Project
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* ===========================(LICENSE END)=============================
*
* @author Thomas Pornin <[email protected]>
*/
#include "inner.h"
#include "macrofx4.h"
#include "macrous.h"
/* see inner.h */
void PQCLEAN_FALCON1024_AARCH64_hash_to_point_vartime(
inner_shake256_context *sc,
uint16_t *x, unsigned logn) {
/*
* This is the straightforward per-the-spec implementation. It
* is not constant-time, thus it might reveal information on the
* plaintext (at least, enough to check the plaintext against a
* list of potential plaintexts) in a scenario where the
* attacker does not have access to the signature value or to
* the public key, but knows the nonce (without knowledge of the
* nonce, the hashed output cannot be matched against potential
* plaintexts).
*/
size_t n;
n = (size_t)1 << logn;
while (n > 0) {
uint8_t buf[2];
uint32_t w;
inner_shake256_extract(sc, (void *)buf, sizeof buf);
w = ((unsigned)buf[0] << 8) | (unsigned)buf[1];
if (w < 5 * FALCON_Q) {
while (w >= FALCON_Q) {
w -= FALCON_Q;
}
*x++ = (uint16_t)w;
n--;
}
}
}
/* see inner.h */
void PQCLEAN_FALCON1024_AARCH64_hash_to_point_ct(
inner_shake256_context *sc,
uint16_t *x, unsigned logn, uint8_t *tmp) {
/*
* Each 16-bit sample is a value in 0..65535. The value is
* kept if it falls in 0..61444 (because 61445 = 5*12289)
* and rejected otherwise; thus, each sample has probability
* about 0.93758 of being selected.
*
* We want to oversample enough to be sure that we will
* have enough values with probability at least 1 - 2^(-256).
* Depending on degree N, this leads to the following
* required oversampling:
*
* logn n oversampling
* 1 2 65
* 2 4 67
* 3 8 71
* 4 16 77
* 5 32 86
* 6 64 100
* 7 128 122
* 8 256 154
* 9 512 205
* 10 1024 287
*
* If logn >= 7, then the provided temporary buffer is large
* enough. Otherwise, we use a stack buffer of 63 entries
* (i.e. 126 bytes) for the values that do not fit in tmp[].
*/
static const uint16_t overtab[] = {
0, /* unused */
65,
67,
71,
77,
86,
100,
122,
154,
205,
287
};
unsigned n, n2, u, m, p, over;
uint16_t *tt1, tt2[63];
/*
* We first generate m 16-bit value. Values 0..n-1 go to x[].
* Values n..2*n-1 go to tt1[]. Values 2*n and later go to tt2[].
* We also reduce modulo q the values; rejected values are set
* to 0xFFFF.
*/
n = 1U << logn;
n2 = n << 1;
over = overtab[logn];
m = n + over;
tt1 = (uint16_t *)tmp;
for (u = 0; u < m; u++) {
uint8_t buf[2];
uint32_t w, wr;
inner_shake256_extract(sc, buf, sizeof buf);
w = ((uint32_t)buf[0] << 8) | (uint32_t)buf[1];
wr = w - ((uint32_t)24578 & (((w - 24578) >> 31) - 1));
wr = wr - ((uint32_t)24578 & (((wr - 24578) >> 31) - 1));
wr = wr - ((uint32_t)12289 & (((wr - 12289) >> 31) - 1));
wr |= ((w - 61445) >> 31) - 1;
if (u < n) {
x[u] = (uint16_t)wr;
} else if (u < n2) {
tt1[u - n] = (uint16_t)wr;
} else {
tt2[u - n2] = (uint16_t)wr;
}
}
/*
* Now we must "squeeze out" the invalid values. We do this in
* a logarithmic sequence of passes; each pass computes where a
* value should go, and moves it down by 'p' slots if necessary,
* where 'p' uses an increasing powers-of-two scale. It can be
* shown that in all cases where the loop decides that a value
* has to be moved down by p slots, the destination slot is
* "free" (i.e. contains an invalid value).
*/
for (p = 1; p <= over; p <<= 1) {
unsigned v;
/*
* In the loop below:
*
* - v contains the index of the final destination of
* the value; it is recomputed dynamically based on
* whether values are valid or not.
*
* - u is the index of the value we consider ("source");
* its address is s.
*
* - The loop may swap the value with the one at index
* u-p. The address of the swap destination is d.
*/
v = 0;
for (u = 0; u < m; u++) {
uint16_t *s, *d;
unsigned j, sv, dv, mk;
if (u < n) {
s = &x[u];
} else if (u < n2) {
s = &tt1[u - n];
} else {
s = &tt2[u - n2];
}
sv = *s;
/*
* The value in sv should ultimately go to
* address v, i.e. jump back by u-v slots.
*/
j = u - v;
/*
* We increment v for the next iteration, but
* only if the source value is valid. The mask
* 'mk' is -1 if the value is valid, 0 otherwise,
* so we _subtract_ mk.
*/
mk = (sv >> 15) - 1U;
v -= mk;
/*
* In this loop we consider jumps by p slots; if
* u < p then there is nothing more to do.
*/
if (u < p) {
continue;
}
/*
* Destination for the swap: value at address u-p.
*/
if ((u - p) < n) {
d = &x[u - p];
} else if ((u - p) < n2) {
d = &tt1[(u - p) - n];
} else {
d = &tt2[(u - p) - n2];
}
dv = *d;
/*
* The swap should be performed only if the source
* is valid AND the jump j has its 'p' bit set.
*/
mk &= -(((j & p) + 0x1FF) >> 9);
*s = (uint16_t)(sv ^ (mk & (sv ^ dv)));
*d = (uint16_t)(dv ^ (mk & (sv ^ dv)));
}
}
}
/*
* Acceptance bound for the (squared) l2-norm of the signature depends
* on the degree. This array is indexed by logn (1 to 10). These bounds
* are _inclusive_ (they are equal to floor(beta^2)).
*/
static const uint32_t l2bound[] = {
0, /* unused */
101498,
208714,
428865,
892039,
1852696,
3842630,
7959734,
16468416,
34034726,
70265242
};
/* see inner.h
* In NEON, there is sign saturating doubling add instruction sqdmlal/sqdmlal2,
* thus, we enable 2 parallel dependency rather than 1 for better scheduling.
* Each for loop is tuned for cache locality.
*/
int PQCLEAN_FALCON1024_AARCH64_is_short(const int16_t *s1, const int16_t *s2) {
// Total SIMD register 18 = 16 + 2
int16x8x4_t neon_s1, neon_s2, neon_s3, neon_s4; // 16
int32x4_t neon_s, neon_sh; // 2
int32x2_t tmp;
uint32_t s;
neon_s = vdupq_n_s32(0);
neon_sh = vdupq_n_s32(0);
for (unsigned u = 0; u < FALCON_N; u += 128) {
vload_s16_x4(neon_s1, &s1[u]);
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s1.val[0]), vget_low_s16(neon_s1.val[0]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s1.val[1]), vget_low_s16(neon_s1.val[1]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s1.val[2]), vget_low_s16(neon_s1.val[2]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s1.val[3]), vget_low_s16(neon_s1.val[3]));
neon_sh = vqdmlal_high_s16(neon_sh, neon_s1.val[0], neon_s1.val[0]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s1.val[1], neon_s1.val[1]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s1.val[2], neon_s1.val[2]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s1.val[3], neon_s1.val[3]);
vload_s16_x4(neon_s2, &s1[u + 32]);
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s2.val[0]), vget_low_s16(neon_s2.val[0]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s2.val[1]), vget_low_s16(neon_s2.val[1]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s2.val[2]), vget_low_s16(neon_s2.val[2]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s2.val[3]), vget_low_s16(neon_s2.val[3]));
neon_sh = vqdmlal_high_s16(neon_sh, neon_s2.val[0], neon_s2.val[0]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s2.val[1], neon_s2.val[1]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s2.val[2], neon_s2.val[2]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s2.val[3], neon_s2.val[3]);
vload_s16_x4(neon_s3, &s1[u + 64]);
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s3.val[0]), vget_low_s16(neon_s3.val[0]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s3.val[1]), vget_low_s16(neon_s3.val[1]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s3.val[2]), vget_low_s16(neon_s3.val[2]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s3.val[3]), vget_low_s16(neon_s3.val[3]));
neon_sh = vqdmlal_high_s16(neon_sh, neon_s3.val[0], neon_s3.val[0]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s3.val[1], neon_s3.val[1]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s3.val[2], neon_s3.val[2]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s3.val[3], neon_s3.val[3]);
vload_s16_x4(neon_s4, &s1[u + 96]);
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s4.val[0]), vget_low_s16(neon_s4.val[0]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s4.val[1]), vget_low_s16(neon_s4.val[1]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s4.val[2]), vget_low_s16(neon_s4.val[2]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s4.val[3]), vget_low_s16(neon_s4.val[3]));
neon_sh = vqdmlal_high_s16(neon_sh, neon_s4.val[0], neon_s4.val[0]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s4.val[1], neon_s4.val[1]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s4.val[2], neon_s4.val[2]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s4.val[3], neon_s4.val[3]);
}
for (unsigned u = 0; u < FALCON_N; u += 128) {
vload_s16_x4(neon_s1, &s2[u]);
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s1.val[0]), vget_low_s16(neon_s1.val[0]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s1.val[1]), vget_low_s16(neon_s1.val[1]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s1.val[2]), vget_low_s16(neon_s1.val[2]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s1.val[3]), vget_low_s16(neon_s1.val[3]));
neon_sh = vqdmlal_high_s16(neon_sh, neon_s1.val[0], neon_s1.val[0]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s1.val[1], neon_s1.val[1]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s1.val[2], neon_s1.val[2]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s1.val[3], neon_s1.val[3]);
vload_s16_x4(neon_s2, &s2[u + 32]);
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s2.val[0]), vget_low_s16(neon_s2.val[0]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s2.val[1]), vget_low_s16(neon_s2.val[1]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s2.val[2]), vget_low_s16(neon_s2.val[2]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s2.val[3]), vget_low_s16(neon_s2.val[3]));
neon_sh = vqdmlal_high_s16(neon_sh, neon_s2.val[0], neon_s2.val[0]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s2.val[1], neon_s2.val[1]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s2.val[2], neon_s2.val[2]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s2.val[3], neon_s2.val[3]);
vload_s16_x4(neon_s3, &s2[u + 64]);
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s3.val[0]), vget_low_s16(neon_s3.val[0]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s3.val[1]), vget_low_s16(neon_s3.val[1]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s3.val[2]), vget_low_s16(neon_s3.val[2]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s3.val[3]), vget_low_s16(neon_s3.val[3]));
neon_sh = vqdmlal_high_s16(neon_sh, neon_s3.val[0], neon_s3.val[0]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s3.val[1], neon_s3.val[1]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s3.val[2], neon_s3.val[2]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s3.val[3], neon_s3.val[3]);
vload_s16_x4(neon_s4, &s2[u + 96]);
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s4.val[0]), vget_low_s16(neon_s4.val[0]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s4.val[1]), vget_low_s16(neon_s4.val[1]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s4.val[2]), vget_low_s16(neon_s4.val[2]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_s4.val[3]), vget_low_s16(neon_s4.val[3]));
neon_sh = vqdmlal_high_s16(neon_sh, neon_s4.val[0], neon_s4.val[0]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s4.val[1], neon_s4.val[1]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s4.val[2], neon_s4.val[2]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_s4.val[3], neon_s4.val[3]);
}
// 32x4
neon_s = vhaddq_s32(neon_s, neon_sh);
// 32x4 -> 32x2
tmp = vqadd_s32(vget_low_s32(neon_s), vget_high_s32(neon_s));
// 32x2 -> 32x1
// Use saturating add to prevent overflow
s = (uint32_t) vqadds_s32(vget_lane_s32(tmp, 0), vget_lane_s32(tmp, 1));
return s <= l2bound[FALCON_LOGN];
}
int PQCLEAN_FALCON1024_AARCH64_is_short_tmp(int16_t *s1tmp, int16_t *s2tmp,
const int16_t *hm, const fpr *t0,
const fpr *t1) {
// Total SIMD registers: 26 = 16 + 8 + 2
int16x8x4_t neon_hm, neon_ts; // 8
float64x2x4_t neon_tf0, neon_tf1, neon_tf2, neon_tf3; // 16
int64x2x4_t neon_ts0, neon_ts1, neon_ts2, neon_ts3; // 16
int32x4x4_t neon_ts4, neon_ts5; // 8
int32x4_t neon_s, neon_sh; // 2
int32x2_t tmp;
uint32_t s;
neon_s = vdupq_n_s32(0);
neon_sh = vdupq_n_s32(0);
// s1tmp
for (int i = 0; i < FALCON_N; i += 32) {
vloadx4(neon_tf0, &t0[i]);
vloadx4(neon_tf1, &t0[i + 8]);
vfrintx4(neon_ts0, neon_tf0);
vfrintx4(neon_ts1, neon_tf1);
neon_ts4.val[0] = vmovn_high_s64(vmovn_s64(neon_ts0.val[0]), neon_ts0.val[1]);
neon_ts4.val[1] = vmovn_high_s64(vmovn_s64(neon_ts0.val[2]), neon_ts0.val[3]);
neon_ts4.val[2] = vmovn_high_s64(vmovn_s64(neon_ts1.val[0]), neon_ts1.val[1]);
neon_ts4.val[3] = vmovn_high_s64(vmovn_s64(neon_ts1.val[2]), neon_ts1.val[3]);
vloadx4(neon_tf2, &t0[i + 16]);
vloadx4(neon_tf3, &t0[i + 24]);
vfrintx4(neon_ts2, neon_tf2);
vfrintx4(neon_ts3, neon_tf3);
neon_ts5.val[0] = vmovn_high_s64(vmovn_s64(neon_ts2.val[0]), neon_ts2.val[1]);
neon_ts5.val[1] = vmovn_high_s64(vmovn_s64(neon_ts2.val[2]), neon_ts2.val[3]);
neon_ts5.val[2] = vmovn_high_s64(vmovn_s64(neon_ts3.val[0]), neon_ts3.val[1]);
neon_ts5.val[3] = vmovn_high_s64(vmovn_s64(neon_ts3.val[2]), neon_ts3.val[3]);
neon_ts.val[0] = vmovn_high_s32(vmovn_s32(neon_ts4.val[0]), neon_ts4.val[1]);
neon_ts.val[1] = vmovn_high_s32(vmovn_s32(neon_ts4.val[2]), neon_ts4.val[3]);
neon_ts.val[2] = vmovn_high_s32(vmovn_s32(neon_ts5.val[0]), neon_ts5.val[1]);
neon_ts.val[3] = vmovn_high_s32(vmovn_s32(neon_ts5.val[2]), neon_ts5.val[3]);
// hm = hm - fpr_rint(t0)
vload_s16_x4(neon_hm, &hm[i]);
neon_hm.val[0] = vsubq_s16(neon_hm.val[0], neon_ts.val[0]);
neon_hm.val[1] = vsubq_s16(neon_hm.val[1], neon_ts.val[1]);
neon_hm.val[2] = vsubq_s16(neon_hm.val[2], neon_ts.val[2]);
neon_hm.val[3] = vsubq_s16(neon_hm.val[3], neon_ts.val[3]);
vstore_s16_x4(&s1tmp[i], neon_hm);
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_hm.val[0]), vget_low_s16(neon_hm.val[0]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_hm.val[1]), vget_low_s16(neon_hm.val[1]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_hm.val[2]), vget_low_s16(neon_hm.val[2]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_hm.val[3]), vget_low_s16(neon_hm.val[3]));
neon_sh = vqdmlal_high_s16(neon_sh, neon_hm.val[0], neon_hm.val[0]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_hm.val[1], neon_hm.val[1]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_hm.val[2], neon_hm.val[2]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_hm.val[3], neon_hm.val[3]);
}
// s2tmp
for (int i = 0; i < FALCON_N; i += 32) {
vloadx4(neon_tf0, &t1[i]);
vloadx4(neon_tf1, &t1[i + 8]);
vfrintx4(neon_ts0, neon_tf0);
vfrintx4(neon_ts1, neon_tf1);
neon_ts4.val[0] = vmovn_high_s64(vmovn_s64(neon_ts0.val[0]), neon_ts0.val[1]);
neon_ts4.val[1] = vmovn_high_s64(vmovn_s64(neon_ts0.val[2]), neon_ts0.val[3]);
neon_ts4.val[2] = vmovn_high_s64(vmovn_s64(neon_ts1.val[0]), neon_ts1.val[1]);
neon_ts4.val[3] = vmovn_high_s64(vmovn_s64(neon_ts1.val[2]), neon_ts1.val[3]);
vloadx4(neon_tf2, &t1[i + 16]);
vloadx4(neon_tf3, &t1[i + 24]);
vfrintx4(neon_ts2, neon_tf2);
vfrintx4(neon_ts3, neon_tf3);
neon_ts5.val[0] = vmovn_high_s64(vmovn_s64(neon_ts2.val[0]), neon_ts2.val[1]);
neon_ts5.val[1] = vmovn_high_s64(vmovn_s64(neon_ts2.val[2]), neon_ts2.val[3]);
neon_ts5.val[2] = vmovn_high_s64(vmovn_s64(neon_ts3.val[0]), neon_ts3.val[1]);
neon_ts5.val[3] = vmovn_high_s64(vmovn_s64(neon_ts3.val[2]), neon_ts3.val[3]);
neon_ts.val[0] = vmovn_high_s32(vmovn_s32(neon_ts4.val[0]), neon_ts4.val[1]);
neon_ts.val[1] = vmovn_high_s32(vmovn_s32(neon_ts4.val[2]), neon_ts4.val[3]);
neon_ts.val[2] = vmovn_high_s32(vmovn_s32(neon_ts5.val[0]), neon_ts5.val[1]);
neon_ts.val[3] = vmovn_high_s32(vmovn_s32(neon_ts5.val[2]), neon_ts5.val[3]);
neon_ts.val[0] = vnegq_s16(neon_ts.val[0]);
neon_ts.val[1] = vnegq_s16(neon_ts.val[1]);
neon_ts.val[2] = vnegq_s16(neon_ts.val[2]);
neon_ts.val[3] = vnegq_s16(neon_ts.val[3]);
vstore_s16_x4(&s2tmp[i], neon_ts);
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_ts.val[0]), vget_low_s16(neon_ts.val[0]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_ts.val[1]), vget_low_s16(neon_ts.val[1]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_ts.val[2]), vget_low_s16(neon_ts.val[2]));
neon_s = vqdmlal_s16(neon_s, vget_low_s16(neon_ts.val[3]), vget_low_s16(neon_ts.val[3]));
neon_sh = vqdmlal_high_s16(neon_sh, neon_ts.val[0], neon_ts.val[0]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_ts.val[1], neon_ts.val[1]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_ts.val[2], neon_ts.val[2]);
neon_sh = vqdmlal_high_s16(neon_sh, neon_ts.val[3], neon_ts.val[3]);
}
// 32x4
neon_s = vhaddq_s32(neon_s, neon_sh);
// 32x4 -> 32x2
tmp = vqadd_s32(vget_low_s32(neon_s), vget_high_s32(neon_s));
// 32x2 -> 32x1
// Use saturating add to prevent overflow
s = (uint32_t) vqadds_s32(vget_lane_s32(tmp, 0), vget_lane_s32(tmp, 1));
return s <= l2bound[FALCON_LOGN];
}
int32_t PQCLEAN_FALCON1024_AARCH64_poly_small_sqnorm(const int8_t *f) {
int8x16x4_t a;
int16x8x4_t b, c;
int32x4_t norm, norm_sh;
norm = vdupq_n_s32(0);
norm_sh = vdupq_n_s32(0);
for (int i = 0; i < FALCON_N; i += 64) {
a = vld1q_s8_x4(&f[0]);
b.val[0] = vmovl_s8(vget_low_s8(a.val[0]));
b.val[1] = vmovl_high_s8(a.val[0]);
b.val[2] = vmovl_s8(vget_low_s8(a.val[1]));
b.val[3] = vmovl_high_s8(a.val[1]);
c.val[0] = vmovl_s8(vget_low_s8(a.val[2]));
c.val[1] = vmovl_high_s8(a.val[2]);
c.val[2] = vmovl_s8(vget_low_s8(a.val[3]));
c.val[3] = vmovl_high_s8(a.val[3]);
norm = vqdmlal_s16(norm, vget_low_s16(b.val[0]), vget_low_s16(b.val[0]));
norm = vqdmlal_s16(norm, vget_low_s16(b.val[1]), vget_low_s16(b.val[1]));
norm = vqdmlal_s16(norm, vget_low_s16(b.val[2]), vget_low_s16(b.val[2]));
norm = vqdmlal_s16(norm, vget_low_s16(b.val[3]), vget_low_s16(b.val[3]));
norm = vqdmlal_high_s16(norm, b.val[0], b.val[0]);
norm = vqdmlal_high_s16(norm, b.val[1], b.val[1]);
norm = vqdmlal_high_s16(norm, b.val[2], b.val[2]);
norm = vqdmlal_high_s16(norm, b.val[3], b.val[3]);
norm_sh = vqdmlal_s16(norm_sh, vget_low_s16(c.val[0]), vget_low_s16(c.val[0]));
norm_sh = vqdmlal_s16(norm_sh, vget_low_s16(c.val[1]), vget_low_s16(c.val[1]));
norm_sh = vqdmlal_s16(norm_sh, vget_low_s16(c.val[2]), vget_low_s16(c.val[2]));
norm_sh = vqdmlal_s16(norm_sh, vget_low_s16(c.val[3]), vget_low_s16(c.val[3]));
norm_sh = vqdmlal_high_s16(norm_sh, c.val[0], c.val[0]);
norm_sh = vqdmlal_high_s16(norm_sh, c.val[1], c.val[1]);
norm_sh = vqdmlal_high_s16(norm_sh, c.val[2], c.val[2]);
norm_sh = vqdmlal_high_s16(norm_sh, c.val[3], c.val[3]);
}
// 32x4
norm = vhaddq_s32(norm, norm_sh);
// 32x4 -> 32x2
int32x2_t tmp;
tmp = vqadd_s32(vget_low_s32(norm), vget_high_s32(norm));
// 32x2 -> 32x1
// Use saturating add to prevent overflow
int32_t s;
s = vqadds_s32(vget_lane_s32(tmp, 0), vget_lane_s32(tmp, 1));
return s;
}