mirror of https://github.com/oxen-io/lokinet
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
217 lines
5.1 KiB
C
217 lines
5.1 KiB
C
#ifdef __AVX2__
|
|
#include <immintrin.h>
|
|
#include "params.h"
|
|
#include "swap.h"
|
|
#include "rq.h"
|
|
|
|
#define v7 _mm256_set1_epi16(7)
|
|
#define v1827_16 _mm256_set1_epi16(1827)
|
|
#define v4591_16 _mm256_set1_epi16(4591)
|
|
#define v29234_16 _mm256_set1_epi16(29234)
|
|
|
|
/* caller must ensure that x-y does not overflow */
|
|
static int smaller_mask(int x,int y)
|
|
{
|
|
return (x - y) >> 31;
|
|
}
|
|
|
|
static inline __m256i product(__m256i x,__m256i y)
|
|
{
|
|
__m256i lo, hi, r0, r1, t0, t1, t, s0, s1;
|
|
|
|
lo = _mm256_mullo_epi16(x,y);
|
|
hi = _mm256_mulhi_epi16(x,y);
|
|
r0 = _mm256_unpacklo_epi16(lo,hi);
|
|
r1 = _mm256_unpackhi_epi16(lo,hi);
|
|
|
|
t0 = _mm256_srai_epi32(r0,16);
|
|
t1 = _mm256_srai_epi32(r1,16);
|
|
t = _mm256_packs_epi32(t0,t1);
|
|
t = _mm256_mulhrs_epi16(t,v29234_16);
|
|
lo = _mm256_mullo_epi16(t,v4591_16);
|
|
hi = _mm256_mulhi_epi16(t,v4591_16);
|
|
s0 = _mm256_unpacklo_epi16(lo,hi);
|
|
s1 = _mm256_unpackhi_epi16(lo,hi);
|
|
s0 = _mm256_slli_epi32(s0,4);
|
|
s1 = _mm256_slli_epi32(s1,4);
|
|
r0 = _mm256_sub_epi32(r0,s0);
|
|
r1 = _mm256_sub_epi32(r1,s1);
|
|
|
|
t0 = _mm256_srai_epi32(r0,8);
|
|
t1 = _mm256_srai_epi32(r1,8);
|
|
t = _mm256_packs_epi32(t0,t1);
|
|
t = _mm256_mulhrs_epi16(t,v1827_16);
|
|
lo = _mm256_mullo_epi16(t,v4591_16);
|
|
hi = _mm256_mulhi_epi16(t,v4591_16);
|
|
s0 = _mm256_unpacklo_epi16(lo,hi);
|
|
s1 = _mm256_unpackhi_epi16(lo,hi);
|
|
r0 = _mm256_sub_epi32(r0,s0);
|
|
r1 = _mm256_sub_epi32(r1,s1);
|
|
|
|
x = _mm256_packs_epi32(r0,r1);
|
|
return x;
|
|
}
|
|
|
|
static inline __m256i minusproduct(__m256i x,__m256i y,__m256i z)
|
|
{
|
|
__m256i t;
|
|
|
|
x = _mm256_sub_epi16(x,product(y,z));
|
|
t = _mm256_mulhrs_epi16(x,v7);
|
|
t = _mm256_mullo_epi16(t,v4591_16);
|
|
x = _mm256_sub_epi16(x,t);
|
|
return x;
|
|
}
|
|
|
|
static void vectormodq_product(modq *z,int len,const modq *x,const modq c)
|
|
{
|
|
__m256i cvec = _mm256_set1_epi16(c);
|
|
while (len >= 16) {
|
|
__m256i xi = _mm256_loadu_si256((__m256i *) x);
|
|
xi = product(xi,cvec);
|
|
_mm256_storeu_si256((__m256i *) z,xi);
|
|
x += 16;
|
|
z += 16;
|
|
len -= 16;
|
|
}
|
|
while (len > 0) {
|
|
*z = modq_product(*x,c);
|
|
++x;
|
|
++z;
|
|
--len;
|
|
}
|
|
}
|
|
|
|
static void vectormodq_minusproduct(modq *z,int len,const modq *x,const modq *y,const modq c)
|
|
{
|
|
__m256i cvec = _mm256_set1_epi16(c);
|
|
while (len >= 16) {
|
|
__m256i xi = _mm256_loadu_si256((__m256i *) x);
|
|
__m256i yi = _mm256_loadu_si256((__m256i *) y);
|
|
xi = minusproduct(xi,yi,cvec);
|
|
_mm256_storeu_si256((__m256i *) z,xi);
|
|
x += 16;
|
|
y += 16;
|
|
z += 16;
|
|
len -= 16;
|
|
}
|
|
while (len > 0) {
|
|
*z = modq_minusproduct(*x,*y,c);
|
|
++x;
|
|
++y;
|
|
++z;
|
|
--len;
|
|
}
|
|
}
|
|
|
|
static void vectormodq_shift(modq *z,int len)
|
|
{
|
|
int i;
|
|
while (len >= 17) {
|
|
__m256i zi = _mm256_loadu_si256((__m256i *) (z + len - 17));
|
|
_mm256_storeu_si256((__m256i *) (z + len - 16),zi);
|
|
len -= 16;
|
|
}
|
|
for (i = len - 1;i > 0;--i) z[i] = z[i - 1];
|
|
z[0] = 0;
|
|
}
|
|
|
|
/*
|
|
r = (3s)^(-1) mod m, returning 0, if s is invertible mod m
|
|
or returning -1 if s is not invertible mod m
|
|
r,s are polys of degree <p
|
|
m is x^p-x-1
|
|
*/
|
|
int rq_recip3(modq *r,const small *s)
|
|
{
|
|
const int loops = 2*p + 1;
|
|
int loop;
|
|
modq f[768];
|
|
modq g[769];
|
|
modq u[1536];
|
|
modq v[1537];
|
|
modq c;
|
|
int i;
|
|
int d = p;
|
|
int e = p;
|
|
int swapmask;
|
|
|
|
for (i = 2;i < p;++i) f[i] = 0;
|
|
f[0] = -1;
|
|
f[1] = -1;
|
|
f[p] = 1;
|
|
/* generalization: can initialize f to any polynomial m */
|
|
/* requirements: m has degree exactly p, nonzero constant coefficient */
|
|
|
|
for (i = 0;i < p;++i) g[i] = 3 * s[i];
|
|
g[p] = 0;
|
|
|
|
for (i = 0;i <= loops;++i) u[i] = 0;
|
|
|
|
v[0] = 1;
|
|
for (i = 1;i <= loops;++i) v[i] = 0;
|
|
|
|
loop = 0;
|
|
for (;;) {
|
|
/* e == -1 or d + e + loop <= 2*p */
|
|
|
|
/* f has degree p: i.e., f[p]!=0 */
|
|
/* f[i]==0 for i < p-d */
|
|
|
|
/* g has degree <=p (so it fits in p+1 coefficients) */
|
|
/* g[i]==0 for i < p-e */
|
|
|
|
/* u has degree <=loop (so it fits in loop+1 coefficients) */
|
|
/* u[i]==0 for i < p-d */
|
|
/* if invertible: u[i]==0 for i < loop-p (so can look at just p+1 coefficients) */
|
|
|
|
/* v has degree <=loop (so it fits in loop+1 coefficients) */
|
|
/* v[i]==0 for i < p-e */
|
|
/* v[i]==0 for i < loop-p (so can look at just p+1 coefficients) */
|
|
|
|
if (loop >= loops) break;
|
|
|
|
c = modq_quotient(g[p],f[p]);
|
|
|
|
vectormodq_minusproduct(g,768,g,f,c);
|
|
vectormodq_shift(g,769);
|
|
|
|
#ifdef SIMPLER
|
|
vectormodq_minusproduct(v,1536,v,u,c);
|
|
vectormodq_shift(v,1537);
|
|
#else
|
|
if (loop < p) {
|
|
vectormodq_minusproduct(v,loop + 1,v,u,c);
|
|
vectormodq_shift(v,loop + 2);
|
|
} else {
|
|
vectormodq_minusproduct(v + loop - p,p + 1,v + loop - p,u + loop - p,c);
|
|
vectormodq_shift(v + loop - p,p + 2);
|
|
}
|
|
#endif
|
|
|
|
e -= 1;
|
|
|
|
++loop;
|
|
|
|
swapmask = smaller_mask(e,d) & modq_nonzero_mask(g[p]);
|
|
swap(&e,&d,sizeof e,swapmask);
|
|
swap(f,g,768 * sizeof(modq),swapmask);
|
|
|
|
#ifdef SIMPLER
|
|
swap(u,v,1536 * sizeof(modq),swapmask);
|
|
#else
|
|
if (loop < p) {
|
|
swap(u,v,(loop + 1) * sizeof(modq),swapmask);
|
|
} else {
|
|
swap(u + loop - p,v + loop - p,(p + 1) * sizeof(modq),swapmask);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
c = modq_reciprocal(f[p]);
|
|
vectormodq_product(r,p,u + p,c);
|
|
for (i = 0;i < p;++i) r[i] = modq_freeze(r[i]);
|
|
for (i = p;i < 768;++i) r[i] = 0;
|
|
return smaller_mask(0,d);
|
|
}
|
|
#endif |