Skip to content

Commit

Permalink
Merge bitcoin#437: Unroll secp256k1_fe_(get|set)_b32 to make them muc…
Browse files Browse the repository at this point in the history 
…h faster.

a2b6b19 Fix benchmark print_number infinite loop. (Gregory Maxwell)
8b7680a Unroll secp256k1_fe_(get|set)_b32 for 10x26. (Gregory Maxwell)
aa84990 Unroll secp256k1_fe_(get|set)_b32 for 5x52. (CryptoGuru)

Tree-SHA512: b17fa454dc4ef614305e10575b0f87c3b37d398d6d3996d5bbbb8e27b0d9841aa13b3cffe93d13dc637c8c3071f8565919574ec0b07f02bf3b0eb6faf4b93251
  • Loading branch information
@sipa
sipa committed Apr 25, 2017
2 parents 1199492 + a2b6b19 commit 4cc8f52
Show file tree
Hide file tree
Showing 3 changed files with 110 additions and 44 deletions.
2 changes: 1 addition & 1 deletion src/bench.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@ void print_number(double x) {
if (y < 0.0) {
y = -y;
}
while (y < 100.0) {
while (y > 0 && y < 100.0) {
y *= 10.0;
c++;
}
Expand Down
65 changes: 43 additions & 22 deletions src/field_10x26_impl.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -321,17 +321,17 @@ static int secp256k1_fe_cmp_var(const secp256k1_fe *a, const secp256k1_fe *b) {
}

static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a) {
int i;
r->n[0] = r->n[1] = r->n[2] = r->n[3] = r->n[4] = 0;
r->n[5] = r->n[6] = r->n[7] = r->n[8] = r->n[9] = 0;
for (i=0; i<32; i++) {
int j;
for (j=0; j<4; j++) {
int limb = (8*i+2*j)/26;
int shift = (8*i+2*j)%26;
r->n[limb] |= (uint32_t)((a[31-i] >> (2*j)) & 0x3) << shift;
}
}
r->n[0] = (uint32_t)a[31] | ((uint32_t)a[30] << 8) | ((uint32_t)a[29] << 16) | ((uint32_t)(a[28] & 0x3) << 24);
r->n[1] = (uint32_t)((a[28] >> 2) & 0x3f) | ((uint32_t)a[27] << 6) | ((uint32_t)a[26] << 14) | ((uint32_t)(a[25] & 0xf) << 22);
r->n[2] = (uint32_t)((a[25] >> 4) & 0xf) | ((uint32_t)a[24] << 4) | ((uint32_t)a[23] << 12) | ((uint32_t)(a[22] & 0x3f) << 20);
r->n[3] = (uint32_t)((a[22] >> 6) & 0x3) | ((uint32_t)a[21] << 2) | ((uint32_t)a[20] << 10) | ((uint32_t)a[19] << 18);
r->n[4] = (uint32_t)a[18] | ((uint32_t)a[17] << 8) | ((uint32_t)a[16] << 16) | ((uint32_t)(a[15] & 0x3) << 24);
r->n[5] = (uint32_t)((a[15] >> 2) & 0x3f) | ((uint32_t)a[14] << 6) | ((uint32_t)a[13] << 14) | ((uint32_t)(a[12] & 0xf) << 22);
r->n[6] = (uint32_t)((a[12] >> 4) & 0xf) | ((uint32_t)a[11] << 4) | ((uint32_t)a[10] << 12) | ((uint32_t)(a[9] & 0x3f) << 20);
r->n[7] = (uint32_t)((a[9] >> 6) & 0x3) | ((uint32_t)a[8] << 2) | ((uint32_t)a[7] << 10) | ((uint32_t)a[6] << 18);
r->n[8] = (uint32_t)a[5] | ((uint32_t)a[4] << 8) | ((uint32_t)a[3] << 16) | ((uint32_t)(a[2] & 0x3) << 24);
r->n[9] = (uint32_t)((a[2] >> 2) & 0x3f) | ((uint32_t)a[1] << 6) | ((uint32_t)a[0] << 14);

if (r->n[9] == 0x3FFFFFUL && (r->n[8] & r->n[7] & r->n[6] & r->n[5] & r->n[4] & r->n[3] & r->n[2]) == 0x3FFFFFFUL && (r->n[1] + 0x40UL + ((r->n[0] + 0x3D1UL) >> 26)) > 0x3FFFFFFUL) {
return 0;
}
Expand All @@ -345,21 +345,42 @@ static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a) {

/** Convert a field element to a 32-byte big endian value. Requires the input to be normalized */
static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe *a) {
int i;
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
secp256k1_fe_verify(a);
#endif
for (i=0; i<32; i++) {
int j;
int c = 0;
for (j=0; j<4; j++) {
int limb = (8*i+2*j)/26;
int shift = (8*i+2*j)%26;
c |= ((a->n[limb] >> shift) & 0x3) << (2 * j);
}
r[31-i] = c;
}
r[0] = (a->n[9] >> 14) & 0xff;
r[1] = (a->n[9] >> 6) & 0xff;
r[2] = ((a->n[9] & 0x3F) << 2) | ((a->n[8] >> 24) & 0x3);
r[3] = (a->n[8] >> 16) & 0xff;
r[4] = (a->n[8] >> 8) & 0xff;
r[5] = a->n[8] & 0xff;
r[6] = (a->n[7] >> 18) & 0xff;
r[7] = (a->n[7] >> 10) & 0xff;
r[8] = (a->n[7] >> 2) & 0xff;
r[9] = ((a->n[7] & 0x3) << 6) | ((a->n[6] >> 20) & 0x3f);
r[10] = (a->n[6] >> 12) & 0xff;
r[11] = (a->n[6] >> 4) & 0xff;
r[12] = ((a->n[6] & 0xf) << 4) | ((a->n[5] >> 22) & 0xf);
r[13] = (a->n[5] >> 14) & 0xff;
r[14] = (a->n[5] >> 6) & 0xff;
r[15] = ((a->n[5] & 0x3f) << 2) | ((a->n[4] >> 24) & 0x3);
r[16] = (a->n[4] >> 16) & 0xff;
r[17] = (a->n[4] >> 8) & 0xff;
r[18] = a->n[4] & 0xff;
r[19] = (a->n[3] >> 18) & 0xff;
r[20] = (a->n[3] >> 10) & 0xff;
r[21] = (a->n[3] >> 2) & 0xff;
r[22] = ((a->n[3] & 0x3) << 6) | ((a->n[2] >> 20) & 0x3f);
r[23] = (a->n[2] >> 12) & 0xff;
r[24] = (a->n[2] >> 4) & 0xff;
r[25] = ((a->n[2] & 0xf) << 4) | ((a->n[1] >> 22) & 0xf);
r[26] = (a->n[1] >> 14) & 0xff;
r[27] = (a->n[1] >> 6) & 0xff;
r[28] = ((a->n[1] & 0x3f) << 2) | ((a->n[0] >> 24) & 0x3);
r[29] = (a->n[0] >> 16) & 0xff;
r[30] = (a->n[0] >> 8) & 0xff;
r[31] = a->n[0] & 0xff;
}

SECP256K1_INLINE static void secp256k1_fe_negate(secp256k1_fe *r, const secp256k1_fe *a, int m) {
Expand Down
87 changes: 66 additions & 21 deletions src/field_5x52_impl.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -284,16 +284,40 @@ static int secp256k1_fe_cmp_var(const secp256k1_fe *a, const secp256k1_fe *b) {
}

static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a) {
int i;
r->n[0] = r->n[1] = r->n[2] = r->n[3] = r->n[4] = 0;
for (i=0; i<32; i++) {
int j;
for (j=0; j<2; j++) {
int limb = (8*i+4*j)/52;
int shift = (8*i+4*j)%52;
r->n[limb] |= (uint64_t)((a[31-i] >> (4*j)) & 0xF) << shift;
}
}
r->n[0] = (uint64_t)a[31]
| ((uint64_t)a[30] << 8)
| ((uint64_t)a[29] << 16)
| ((uint64_t)a[28] << 24)
| ((uint64_t)a[27] << 32)
| ((uint64_t)a[26] << 40)
| ((uint64_t)(a[25] & 0xF) << 48);
r->n[1] = (uint64_t)((a[25] >> 4) & 0xF)
| ((uint64_t)a[24] << 4)
| ((uint64_t)a[23] << 12)
| ((uint64_t)a[22] << 20)
| ((uint64_t)a[21] << 28)
| ((uint64_t)a[20] << 36)
| ((uint64_t)a[19] << 44);
r->n[2] = (uint64_t)a[18]
| ((uint64_t)a[17] << 8)
| ((uint64_t)a[16] << 16)
| ((uint64_t)a[15] << 24)
| ((uint64_t)a[14] << 32)
| ((uint64_t)a[13] << 40)
| ((uint64_t)(a[12] & 0xF) << 48);
r->n[3] = (uint64_t)((a[12] >> 4) & 0xF)
| ((uint64_t)a[11] << 4)
| ((uint64_t)a[10] << 12)
| ((uint64_t)a[9] << 20)
| ((uint64_t)a[8] << 28)
| ((uint64_t)a[7] << 36)
| ((uint64_t)a[6] << 44);
r->n[4] = (uint64_t)a[5]
| ((uint64_t)a[4] << 8)
| ((uint64_t)a[3] << 16)
| ((uint64_t)a[2] << 24)
| ((uint64_t)a[1] << 32)
| ((uint64_t)a[0] << 40);
if (r->n[4] == 0x0FFFFFFFFFFFFULL && (r->n[3] & r->n[2] & r->n[1]) == 0xFFFFFFFFFFFFFULL && r->n[0] >= 0xFFFFEFFFFFC2FULL) {
return 0;
}
Expand All @@ -307,21 +331,42 @@ static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a) {

/** Convert a field element to a 32-byte big endian value. Requires the input to be normalized */
static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe *a) {
int i;
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
secp256k1_fe_verify(a);
#endif
for (i=0; i<32; i++) {
int j;
int c = 0;
for (j=0; j<2; j++) {
int limb = (8*i+4*j)/52;
int shift = (8*i+4*j)%52;
c |= ((a->n[limb] >> shift) & 0xF) << (4 * j);
}
r[31-i] = c;
}
r[0] = (a->n[4] >> 40) & 0xFF;
r[1] = (a->n[4] >> 32) & 0xFF;
r[2] = (a->n[4] >> 24) & 0xFF;
r[3] = (a->n[4] >> 16) & 0xFF;
r[4] = (a->n[4] >> 8) & 0xFF;
r[5] = a->n[4] & 0xFF;
r[6] = (a->n[3] >> 44) & 0xFF;
r[7] = (a->n[3] >> 36) & 0xFF;
r[8] = (a->n[3] >> 28) & 0xFF;
r[9] = (a->n[3] >> 20) & 0xFF;
r[10] = (a->n[3] >> 12) & 0xFF;
r[11] = (a->n[3] >> 4) & 0xFF;
r[12] = ((a->n[2] >> 48) & 0xF) | ((a->n[3] & 0xF) << 4);
r[13] = (a->n[2] >> 40) & 0xFF;
r[14] = (a->n[2] >> 32) & 0xFF;
r[15] = (a->n[2] >> 24) & 0xFF;
r[16] = (a->n[2] >> 16) & 0xFF;
r[17] = (a->n[2] >> 8) & 0xFF;
r[18] = a->n[2] & 0xFF;
r[19] = (a->n[1] >> 44) & 0xFF;
r[20] = (a->n[1] >> 36) & 0xFF;
r[21] = (a->n[1] >> 28) & 0xFF;
r[22] = (a->n[1] >> 20) & 0xFF;
r[23] = (a->n[1] >> 12) & 0xFF;
r[24] = (a->n[1] >> 4) & 0xFF;
r[25] = ((a->n[0] >> 48) & 0xF) | ((a->n[1] & 0xF) << 4);
r[26] = (a->n[0] >> 40) & 0xFF;
r[27] = (a->n[0] >> 32) & 0xFF;
r[28] = (a->n[0] >> 24) & 0xFF;
r[29] = (a->n[0] >> 16) & 0xFF;
r[30] = (a->n[0] >> 8) & 0xFF;
r[31] = a->n[0] & 0xFF;
}

SECP256K1_INLINE static void secp256k1_fe_negate(secp256k1_fe *r, const secp256k1_fe *a, int m) {
Expand Down

0 comments on commit 4cc8f52

Please sign in to comment.