move Frobenius to Fp2

4 files changed, 31 insertions, 23 deletions

diff --git a/include/mcl/bn.hpp b/include/mcl/bn.hpp
index ad96eff..4eabd62 100644
--- a/include/mcl/bn.hpp
+++ b/include/mcl/bn.hpp
@@ -436,7 +436,6 @@ struct ParamT {
 	bool isNegative;
 	mpz_class p;
 	mpz_class r;
-	uint32_t pmod4;
 	Fp Z;
 	static const size_t gN = 5;
 	/*
@@ -485,7 +484,6 @@ struct ParamT {
 		const int rCoff[] = { 1, 6, 18, 36, 36 };
 		p = eval(pCoff, z);
 		assert((p % 6) == 1);
-		pmod4 = mcl::gmp::getUnit(p, 0) % 4;
 		r = eval(rCoff, z);
 		Fp::init(p.get_str(), mode);
 		Fp2::init(cp.xi_a);
@@ -520,7 +518,7 @@ struct ParamT {
 		}
 		for (size_t i = 0; i < gN; i++) {
 			Fp2 t(g[i].a, g[i].b);
-			if (pmod4 == 3) Fp::neg(t.b, t.b);
+			if (Fp::getOp().pmod4 == 3) Fp::neg(t.b, t.b);
 			Fp2::mul(g2[i], t, g[i]);
 			g3[i] = g[i] * g2[i];
 		}
@@ -601,23 +599,10 @@ struct BNT {
 		((a + bv + cv^2)w)^p in Fp12
 		= (F(a) g + F(b) g^3 v + F(c) g^5 v^2)w
 	*/
-	static void Frobenius(Fp2& y, const Fp2& x)
-	{
-		if (param.pmod4 == 1) {
-			if (&y != &x) {
-				y = x;
-			}
-		} else {
-			if (&y != &x) {
-				y.a = x.a;
-			}
-			Fp::neg(y.b, x.b);
-		}
-	}
 	static void Frobenius(Fp12& y, const Fp12& x)
 	{
 		for (int i = 0; i < 6; i++) {
-			Frobenius(y.getFp2()[i], x.getFp2()[i]);
+			Fp2::Frobenius(y.getFp2()[i], x.getFp2()[i]);
 		}
 		for (int i = 1; i < 6; i++) {
 			y.getFp2()[i] *= param.g[i - 1];
@@ -630,7 +615,7 @@ struct BNT {
 		Frobenius(y, y);
 #else
 		y.getFp2()[0] = x.getFp2()[0];
-		if (param.pmod4 == 1) {
+		if (Fp::getOp().pmod4 == 1) {
 			for (int i = 1; i < 6; i++) {
 				Fp2::mul(y.getFp2()[i], x.getFp2()[i], param.g2[i]);
 			}
@@ -648,9 +633,9 @@ struct BNT {
 		Frobenius(y, y);
 		Frobenius(y, y);
 #else
-		Frobenius(y.getFp2()[0], x.getFp2()[0]);
+		Fp2::Frobenius(y.getFp2()[0], x.getFp2()[0]);
 		for (int i = 1; i < 6; i++) {
-			Frobenius(y.getFp2()[i], x.getFp2()[i]);
+			Fp2::Frobenius(y.getFp2()[i], x.getFp2()[i]);
 			y.getFp2()[i] *= param.g3[i - 1];
 		}
 #endif
@@ -665,9 +650,9 @@ struct BNT {
 	*/
 	static void FrobeniusOnTwist(G2& D, const G2& S)
 	{
-		Frobenius(D.x, S.x);
-		Frobenius(D.y, S.y);
-		Frobenius(D.z, S.z);
+		Fp2::Frobenius(D.x, S.x);
+		Fp2::Frobenius(D.y, S.y);
+		Fp2::Frobenius(D.z, S.z);
 		D.x *= param.g[0];
 		D.y *= param.g[3];
 	}
diff --git a/include/mcl/fp_tower.hpp b/include/mcl/fp_tower.hpp
index 5d3cae2..d5d06b3 100644
--- a/include/mcl/fp_tower.hpp
+++ b/include/mcl/fp_tower.hpp
@@ -248,6 +248,26 @@ public:
 		Fp::sqr(bb, x.b);
 		Fp::add(y, aa, bb);
 	}
+	/*
+		Frobenius
+		i^2 = -1
+		(a + bi)^p = a + bi^p in Fp
+		= a + bi if p = 1 mod 4
+		= a - bi if p = 3 mod 4
+	*/
+	static void Frobenius(Fp2T& y, const Fp2T& x)
+	{
+		if (Fp::getOp().pmod4 == 1) {
+			if (&y != &x) {
+				y = x;
+			}
+		} else {
+			if (&y != &x) {
+				y.a = x.a;
+			}
+			Fp::neg(y.b, x.b);
+		}
+	}
 
 	static uint32_t get_xi_a() { return xi_a_; }
 	static void init(uint32_t xi_a)
diff --git a/include/mcl/op.hpp b/include/mcl/op.hpp
index b2660dc..1be640e 100644
--- a/include/mcl/op.hpp
+++ b/include/mcl/op.hpp
@@ -143,6 +143,7 @@ struct Op {
 	Unit rp;
 	Unit p[maxUnitSize];
 	mpz_class mp;
+	uint32_t pmod4;
 	mcl::SquareRoot sq;
 	FpGenerator *fg;
 	Unit half[maxUnitSize]; // (p + 1) / 2
@@ -219,6 +220,7 @@ struct Op {
 		rp = 0;
 		memset(p, 0, sizeof(p));
 		mp = 0;
+		pmod4 = 0;
 		sq.clear();
 		// fg is not set
 		memset(half, 0, sizeof(half));
diff --git a/src/fp.cpp b/src/fp.cpp
index 7607b11..a22ed1c 100644
--- a/src/fp.cpp
+++ b/src/fp.cpp
@@ -402,6 +402,7 @@ void Op::init(const std::string& mstr, size_t maxBitSize, Mode mode, size_t mclM
 	}
 	gmp::getArray(p, (maxBitSize + fp::UnitBitSize - 1) / fp::UnitBitSize, mp);
 	bitSize = gmp::getBitSize(mp);
+	pmod4 = gmp::getUnit(mp, 0) % 4;
 /*
 	priority : MCL_USE_XBYAK > MCL_USE_LLVM > none
 	Xbyak > llvm_mont > llvm > gmp_mont > gmp