diff options
Diffstat (limited to 'src/field_5x52_int128_impl.h')
| -rw-r--r-- | src/field_5x52_int128_impl.h | 84 |
1 files changed, 41 insertions, 43 deletions
diff --git a/src/field_5x52_int128_impl.h b/src/field_5x52_int128_impl.h index c476428672..e552fb4319 100644 --- a/src/field_5x52_int128_impl.h +++ b/src/field_5x52_int128_impl.h @@ -15,7 +15,7 @@ #define VERIFY_BITS(x, n) do { } while(0) #endif -SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uint64_t *b, uint64_t *r) { +SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uint64_t * SECP256K1_RESTRICT b, uint64_t *r) { VERIFY_BITS(a[0], 56); VERIFY_BITS(a[1], 56); VERIFY_BITS(a[2], 56); @@ -26,6 +26,7 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin VERIFY_BITS(b[2], 56); VERIFY_BITS(b[3], 56); VERIFY_BITS(b[4], 52); + VERIFY_CHECK(r != b); const uint64_t M = 0xFFFFFFFFFFFFFULL, R = 0x1000003D10ULL; /* [... a b c] is a shorthand for ... + a<<104 + b<<52 + c<<0 mod n. @@ -33,15 +34,17 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin * Note that [x 0 0 0 0 0] = [x*R]. */ + uint64_t a0 = a[0], a1 = a[1], a2 = a[2], a3 = a[3], a4 = a[4]; + __int128 c, d; - d = (__int128)a[0] * b[3] - + (__int128)a[1] * b[2] - + (__int128)a[2] * b[1] - + (__int128)a[3] * b[0]; + d = (__int128)a0 * b[3] + + (__int128)a1 * b[2] + + (__int128)a2 * b[1] + + (__int128)a3 * b[0]; VERIFY_BITS(d, 114); /* [d 0 0 0] = [p3 0 0 0] */ - c = (__int128)a[4] * b[4]; + c = (__int128)a4 * b[4]; VERIFY_BITS(c, 112); /* [c 0 0 0 0 d 0 0 0] = [p8 0 0 0 0 p3 0 0 0] */ d += (c & M) * R; c >>= 52; @@ -53,11 +56,11 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin VERIFY_BITS(d, 63); /* [c 0 0 0 0 d t3 0 0 0] = [p8 0 0 0 0 p3 0 0 0] */ - d += (__int128)a[0] * b[4] - + (__int128)a[1] * b[3] - + (__int128)a[2] * b[2] - + (__int128)a[3] * b[1] - + (__int128)a[4] * b[0]; + d += (__int128)a0 * b[4] + + (__int128)a1 * b[3] + + (__int128)a2 * b[2] + + (__int128)a3 * b[1] + + (__int128)a4 * b[0]; VERIFY_BITS(d, 115); /* [c 0 0 0 0 d t3 0 0 0] = [p8 0 0 0 p4 p3 0 0 0] */ d += c * R; @@ -72,13 +75,13 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin VERIFY_BITS(t4, 48); /* [d t4+(tx<<48) t3 0 0 0] = [p8 0 0 0 p4 p3 0 0 0] */ - c = (__int128)a[0] * b[0]; + c = (__int128)a0 * b[0]; VERIFY_BITS(c, 112); /* [d t4+(tx<<48) t3 0 0 c] = [p8 0 0 0 p4 p3 0 0 p0] */ - d += (__int128)a[1] * b[4] - + (__int128)a[2] * b[3] - + (__int128)a[3] * b[2] - + (__int128)a[4] * b[1]; + d += (__int128)a1 * b[4] + + (__int128)a2 * b[3] + + (__int128)a3 * b[2] + + (__int128)a4 * b[1]; VERIFY_BITS(d, 115); /* [d t4+(tx<<48) t3 0 0 c] = [p8 0 0 p5 p4 p3 0 0 p0] */ uint64_t u0 = d & M; d >>= 52; @@ -92,48 +95,43 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin c += (__int128)u0 * (R >> 4); VERIFY_BITS(c, 115); /* [d 0 t4 t3 0 0 c] = [p8 0 0 p5 p4 p3 0 0 p0] */ - uint64_t t0 = c & M; c >>= 52; - VERIFY_BITS(t0, 52); + r[0] = c & M; c >>= 52; + VERIFY_BITS(r[0], 52); VERIFY_BITS(c, 61); - /* [d 0 t4 t3 0 c t0] = [p8 0 0 p5 p4 p3 0 0 p0] */ + /* [d 0 t4 t3 0 c r0] = [p8 0 0 p5 p4 p3 0 0 p0] */ - c += (__int128)a[0] * b[1] - + (__int128)a[1] * b[0]; + c += (__int128)a0 * b[1] + + (__int128)a1 * b[0]; VERIFY_BITS(c, 114); - /* [d 0 t4 t3 0 c t0] = [p8 0 0 p5 p4 p3 0 p1 p0] */ - d += (__int128)a[2] * b[4] - + (__int128)a[3] * b[3] - + (__int128)a[4] * b[2]; + /* [d 0 t4 t3 0 c r0] = [p8 0 0 p5 p4 p3 0 p1 p0] */ + d += (__int128)a2 * b[4] + + (__int128)a3 * b[3] + + (__int128)a4 * b[2]; VERIFY_BITS(d, 114); - /* [d 0 t4 t3 0 c t0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */ + /* [d 0 t4 t3 0 c r0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */ c += (d & M) * R; d >>= 52; VERIFY_BITS(c, 115); VERIFY_BITS(d, 62); - /* [d 0 0 t4 t3 0 c t0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */ - uint64_t t1 = c & M; c >>= 52; - VERIFY_BITS(t1, 52); + /* [d 0 0 t4 t3 0 c r0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */ + r[1] = c & M; c >>= 52; + VERIFY_BITS(r[1], 52); VERIFY_BITS(c, 63); - /* [d 0 0 t4 t3 c t1 t0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */ + /* [d 0 0 t4 t3 c r1 r0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */ - c += (__int128)a[0] * b[2] - + (__int128)a[1] * b[1] - + (__int128)a[2] * b[0]; + c += (__int128)a0 * b[2] + + (__int128)a1 * b[1] + + (__int128)a2 * b[0]; VERIFY_BITS(c, 114); - /* [d 0 0 t4 t3 c t1 t0] = [p8 0 p6 p5 p4 p3 p2 p1 p0] */ - d += (__int128)a[3] * b[4] - + (__int128)a[4] * b[3]; + /* [d 0 0 t4 t3 c r1 r0] = [p8 0 p6 p5 p4 p3 p2 p1 p0] */ + d += (__int128)a3 * b[4] + + (__int128)a4 * b[3]; VERIFY_BITS(d, 114); - /* [d 0 0 t4 t3 c t1 t0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */ + /* [d 0 0 t4 t3 c t1 r0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */ c += (d & M) * R; d >>= 52; VERIFY_BITS(c, 115); VERIFY_BITS(d, 62); - /* [d 0 0 0 t4 t3 c t1 t0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */ + /* [d 0 0 0 t4 t3 c r1 r0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */ - r[0] = t0; - VERIFY_BITS(r[0], 52); - /* [d 0 0 0 t4 t3 c t1 r0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */ - r[1] = t1; - VERIFY_BITS(r[1], 52); /* [d 0 0 0 t4 t3 c r1 r0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */ r[2] = c & M; c >>= 52; VERIFY_BITS(r[2], 52); |