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https://github.com/saymrwulf/curve25519-dalek-source.git
synced 2026-09-04 20:24:10 +00:00
Simplify mul, square implementations
This commit is contained in:
Henry de Valence
parent
f28635ab4e
commit
208180dc72
1 changed files with 48 additions and 70 deletions
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@ -412,8 +412,6 @@ impl FieldElement32x4 {
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let v19 = u32x8::new(19,0,19,0,19,0,19,0);
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let mut z = [u64x4::splat(0); 10];
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let (x0, x1) = unpack_pair(self.0[0]);
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let (x2, x3) = unpack_pair(self.0[1]);
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let (x4, x5) = unpack_pair(self.0[2]);
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@ -435,37 +433,24 @@ impl FieldElement32x4 {
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let x8_19 = m_lo(v19, x8);
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let x9_19 = m_lo(v19, x9);
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z[0] = m(x0, x0) + m(x2_2,x8_19) + m(x4_2,x6_19) + ((m(x1_2,x9_19) + m(x3_2,x7_19) + m(x5,x5_19)) << 1);
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z[1] = m(x0_2,x1) + m(x3_2,x8_19) + m(x5_2,x6_19) + ((m(x2,x9_19) + m(x4,x7_19)) << 1);
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z[2] = m(x0_2,x2) + m(x1_2,x1) + m(x4_2,x8_19) + m(x6,x6_19) + ((m(x3_2,x9_19) + m(x5_2,x7_19)) << 1);
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z[3] = m(x0_2,x3) + m(x1_2,x2) + m(x5_2,x8_19) + ((m(x4,x9_19) + m(x6,x7_19)) << 1);
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z[4] = m(x0_2,x4) + m(x1_2,x3_2) + m(x2, x2) + m(x6_2,x8_19) + ((m(x5_2,x9_19) + m(x7,x7_19)) << 1);
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z[5] = m(x0_2,x5) + m(x1_2,x4) + m(x2_2,x3) + m(x7_2,x8_19) + ((m(x6,x9_19)) << 1);
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z[6] = m(x0_2,x6) + m(x1_2,x5_2) + m(x2_2,x4) + m(x3_2,x3) + m(x8,x8_19) + ((m(x7_2,x9_19)) << 1);
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z[7] = m(x0_2,x7) + m(x1_2,x6) + m(x2_2,x5) + m(x3_2,x4) + ((m(x8,x9_19)) << 1);
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z[8] = m(x0_2,x8) + m(x1_2,x7_2) + m(x2_2,x6) + m(x3_2,x5_2) + m(x4,x4) + ((m(x9,x9_19)) << 1);
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z[9] = m(x0_2,x9) + m(x1_2,x8) + m(x2_2,x7) + m(x3_2,x6) + m(x4_2,x5);
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let z0 = m(x0, x0) + m(x2_2,x8_19) + m(x4_2,x6_19) + ((m(x1_2,x9_19) + m(x3_2,x7_19) + m(x5,x5_19)) << 1);
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let z1 = m(x0_2,x1) + m(x3_2,x8_19) + m(x5_2,x6_19) + ((m(x2,x9_19) + m(x4,x7_19)) << 1);
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let z2 = m(x0_2,x2) + m(x1_2,x1) + m(x4_2,x8_19) + m(x6,x6_19) + ((m(x3_2,x9_19) + m(x5_2,x7_19)) << 1);
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let z3 = m(x0_2,x3) + m(x1_2,x2) + m(x5_2,x8_19) + ((m(x4,x9_19) + m(x6,x7_19)) << 1);
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let z4 = m(x0_2,x4) + m(x1_2,x3_2) + m(x2, x2) + m(x6_2,x8_19) + ((m(x5_2,x9_19) + m(x7,x7_19)) << 1);
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let z5 = m(x0_2,x5) + m(x1_2,x4) + m(x2_2,x3) + m(x7_2,x8_19) + ((m(x6,x9_19)) << 1);
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let z6 = m(x0_2,x6) + m(x1_2,x5_2) + m(x2_2,x4) + m(x3_2,x3) + m(x8,x8_19) + ((m(x7_2,x9_19)) << 1);
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let z7 = m(x0_2,x7) + m(x1_2,x6) + m(x2_2,x5) + m(x3_2,x4) + ((m(x8,x9_19)) << 1);
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let z8 = m(x0_2,x8) + m(x1_2,x7_2) + m(x2_2,x6) + m(x3_2,x5_2) + m(x4,x4) + ((m(x9,x9_19)) << 1);
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let z9 = m(x0_2,x9) + m(x1_2,x8) + m(x2_2,x7) + m(x3_2,x6) + m(x4_2,x5);
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return FieldElement32x4::reduce64(z);
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FieldElement32x4::reduce64([z0, z1, z2, z3, z4, z5, z6, z7, z8, z9])
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}
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}
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impl<'a, 'b> Mul<&'b FieldElement32x4> for &'a FieldElement32x4 {
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type Output = FieldElement32x4;
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fn mul(self, _rhs: &'b FieldElement32x4) -> FieldElement32x4 {
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let mut b = [u32x8::splat(0); 10];
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let mut c = [u64x4::splat(0); 10];
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let (b0, b1) = unpack_pair(_rhs.0[0]);
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b[0] = b0; b[1] = b1;
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let (b2, b3) = unpack_pair(_rhs.0[1]);
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b[2] = b2; b[3] = b3;
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let (b4, b5) = unpack_pair(_rhs.0[2]);
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b[4] = b4; b[5] = b5;
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let (b6, b7) = unpack_pair(_rhs.0[3]);
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b[6] = b6; b[7] = b7;
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let (b8, b9) = unpack_pair(_rhs.0[4]);
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b[8] = b8; b[9] = b9;
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#[inline(always)]
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fn m(x: u32x8, y: u32x8) -> u64x4 {
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@ -479,55 +464,48 @@ impl<'a, 'b> Mul<&'b FieldElement32x4> for &'a FieldElement32x4 {
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unsafe { u32x8::from(_mm256_mul_epu32(x,y)) }
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}
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let (x0, x1) = unpack_pair(self.0[0]);
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let (x2, x3) = unpack_pair(self.0[1]);
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let (x4, x5) = unpack_pair(self.0[2]);
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let (x6, x7) = unpack_pair(self.0[3]);
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let (x8, x9) = unpack_pair(self.0[4]);
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let (y0, y1) = unpack_pair(_rhs.0[0]);
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let (y2, y3) = unpack_pair(_rhs.0[1]);
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let (y4, y5) = unpack_pair(_rhs.0[2]);
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let (y6, y7) = unpack_pair(_rhs.0[3]);
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let (y8, y9) = unpack_pair(_rhs.0[4]);
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let v19 = u32x8::new(19,0,19,0,19,0,19,0);
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// XXX clean up this horrifying abomination
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//
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// The idea is to take the standard "schoolbook multiplication square" (see
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// FieldElement32), and walk up each column from top to bottom, then left to right.
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//
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// Instead of multiplying by 19 in a precomputation, we overwrite the b[i] value with
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// b[i]*19 as soon as we will no longer need it.
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//
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let y1_19 = m_lo(v19, y1); // This fits in a u32
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let y2_19 = m_lo(v19, y2); // iff 26 + b + lg(19) < 32
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let y3_19 = m_lo(v19, y3); // if b < 32 - 26 - 4.248 = 1.752
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let y4_19 = m_lo(v19, y4);
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let y5_19 = m_lo(v19, y5); // below, b<2.5: this is a bottleneck,
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let y6_19 = m_lo(v19, y6); // could be avoided by promoting to
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let y7_19 = m_lo(v19, y7); // u64 here instead of in m()
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let y8_19 = m_lo(v19, y8);
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let y9_19 = m_lo(v19, y9);
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macro_rules! loop_body {
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($i:expr) => {
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let (ai, ai1) = unpack_pair(self.0[$i/2]);
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let x1_2 = x1 + x1; // This fits in a u32 iff 25 + b + 1 < 32
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let x3_2 = x3 + x3; // iff b < 6
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let x5_2 = x5 + x5;
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let x7_2 = x7 + x7;
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let x9_2 = x9 + x9;
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c[9] = c[9] + m(ai, b[(100 + 9-$i) % 10]);
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b[(100 + 9-$i) % 10] = m_lo(b[(100 + 9-$i) % 10], v19);
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c[8] = c[8] + m(ai, b[(100 + 8-$i) % 10]);
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c[7] = c[7] + m(ai, b[(100 + 7-$i) % 10]);
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c[6] = c[6] + m(ai, b[(100 + 6-$i) % 10]);
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c[5] = c[5] + m(ai, b[(100 + 5-$i) % 10]);
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c[4] = c[4] + m(ai, b[(100 + 4-$i) % 10]);
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c[3] = c[3] + m(ai, b[(100 + 3-$i) % 10]);
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c[2] = c[2] + m(ai, b[(100 + 2-$i) % 10]);
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c[1] = c[1] + m(ai, b[(100 + 1-$i) % 10]);
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c[0] = c[0] + m(ai, b[(100 + 0-$i) % 10]);
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let z0 = m(x0,y0) + m(x1_2,y9_19) + m(x2,y8_19) + m(x3_2,y7_19) + m(x4,y6_19) + m(x5_2,y5_19) + m(x6,y4_19) + m(x7_2,y3_19) + m(x8,y2_19) + m(x9_2,y1_19);
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let z1 = m(x0,y1) + m(x1,y0) + m(x2,y9_19) + m(x3,y8_19) + m(x4,y7_19) + m(x5,y6_19) + m(x6,y5_19) + m(x7,y4_19) + m(x8,y3_19) + m(x9,y2_19);
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let z2 = m(x0,y2) + m(x1_2,y1) + m(x2,y0) + m(x3_2,y9_19) + m(x4,y8_19) + m(x5_2,y7_19) + m(x6,y6_19) + m(x7_2,y5_19) + m(x8,y4_19) + m(x9_2,y3_19);
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let z3 = m(x0,y3) + m(x1,y2) + m(x2,y1) + m(x3,y0) + m(x4,y9_19) + m(x5,y8_19) + m(x6,y7_19) + m(x7,y6_19) + m(x8,y5_19) + m(x9,y4_19);
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let z4 = m(x0,y4) + m(x1_2,y3) + m(x2,y2) + m(x3_2,y1) + m(x4,y0) + m(x5_2,y9_19) + m(x6,y8_19) + m(x7_2,y7_19) + m(x8,y6_19) + m(x9_2,y5_19);
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let z5 = m(x0,y5) + m(x1,y4) + m(x2,y3) + m(x3,y2) + m(x4,y1) + m(x5,y0) + m(x6,y9_19) + m(x7,y8_19) + m(x8,y7_19) + m(x9,y6_19);
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let z6 = m(x0,y6) + m(x1_2,y5) + m(x2,y4) + m(x3_2,y3) + m(x4,y2) + m(x5_2,y1) + m(x6,y0) + m(x7_2,y9_19) + m(x8,y8_19) + m(x9_2,y7_19);
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let z7 = m(x0,y7) + m(x1,y6) + m(x2,y5) + m(x3,y4) + m(x4,y3) + m(x5,y2) + m(x6,y1) + m(x7,y0) + m(x8,y9_19) + m(x9,y8_19);
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let z8 = m(x0,y8) + m(x1_2,y7) + m(x2,y6) + m(x3_2,y5) + m(x4,y4) + m(x5_2,y3) + m(x6,y2) + m(x7_2,y1) + m(x8,y0) + m(x9_2,y9_19);
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let z9 = m(x0,y9) + m(x1,y8) + m(x2,y7) + m(x3,y6) + m(x4,y5) + m(x5,y4) + m(x6,y3) + m(x7,y2) + m(x8,y1) + m(x9,y0);
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let ai1_2 = ai1 + ai1;
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c[9] = c[9] + m(ai1, b[(100 + 9-($i+1)) % 10]);
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b[(100 + 9-($i+1)) % 10] = m_lo(b[(100 + 9-($i+1)) % 10], v19);
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c[8] = c[8] + m(ai1_2, b[(100 + 8-($i+1)) % 10]);
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c[7] = c[7] + m(ai1, b[(100 + 7-($i+1)) % 10]);
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c[6] = c[6] + m(ai1_2, b[(100 + 6-($i+1)) % 10]);
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c[5] = c[5] + m(ai1, b[(100 + 5-($i+1)) % 10]);
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c[4] = c[4] + m(ai1_2, b[(100 + 4-($i+1)) % 10]);
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c[3] = c[3] + m(ai1, b[(100 + 3-($i+1)) % 10]);
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c[2] = c[2] + m(ai1_2, b[(100 + 2-($i+1)) % 10]);
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c[1] = c[1] + m(ai1, b[(100 + 1-($i+1)) % 10]);
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c[0] = c[0] + m(ai1_2, b[(100 + 0-($i+1)) % 10]);
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};
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}
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loop_body!(0);
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loop_body!(2);
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loop_body!(4);
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loop_body!(6);
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loop_body!(8);
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return FieldElement32x4::reduce64(c);
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FieldElement32x4::reduce64([z0, z1, z2, z3, z4, z5, z6, z7, z8, z9])
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}
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}
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