From d23b47e9d6c09f6cf0d2c5baade854add4d4c8b2 Mon Sep 17 00:00:00 2001
From: MITSUNARI Shigeo <herumi@nifty.com>
Date: Wed, 7 Nov 2018 10:49:41 +0900
Subject: [PATCH] add Fp2::mul_xi for bls12

---
 src/fp_generator.hpp | 81 +++++++++++++++++++++++++++-----------------
 1 file changed, 50 insertions(+), 31 deletions(-)

diff --git a/src/fp_generator.hpp b/src/fp_generator.hpp
index 8c0c3b7..0855ad6 100644
--- a/src/fp_generator.hpp
+++ b/src/fp_generator.hpp
@@ -3579,16 +3579,6 @@ private:
 		gen_raw_fp_sub(sf.p[0], sf.p[1], sf.p[2], sf.t, false);
 		gen_raw_fp_sub(sf.p[0] + FpByte_, sf.p[1] + FpByte_, sf.p[2] + FpByte_, sf.t, false);
 	}
-	void2u gen_fp2_mul_xi()
-	{
-		align(16);
-		void2u func = getCurr<void2u>();
-		if (pn_ == 4 && !isFullBit_) {
-			gen_fp2_mul_xi4();
-			return func;
-		}
-		return 0;
-	}
 	/*
 		for only xi_a = 1
 		y.a = a - b
@@ -3597,14 +3587,17 @@ private:
 	void gen_fp2_mul_xi4()
 	{
 		assert(!isFullBit_);
-#if 0
-		StackFrame sf(this, 2, 10 | UseRDX | UseRCX);
+		StackFrame sf(this, 2, 11 | UseRDX);
+		const Reg64& py = sf.p[0];
+		const Reg64& px = sf.p[1];
 		Pack a = sf.t.sub(0, 4);
 		Pack b = sf.t.sub(4, 4);
-		Pack t(rdx, rcx, sf.t[8], sf.t[9]);
-		load_rm(a, sf.p[1]);
-		load_rm(b, sf.p[1] + FpByte_);
-		for (int i = 0; i < 4; i++) {
+		Pack t = sf.t.sub(8);
+		t.append(rdx);
+		assert(t.size() == 4);
+		load_rm(a, px);
+		load_rm(b, px + FpByte_);
+		for (int i = 0; i < pn_; i++) {
 			mov(t[i], a[i]);
 			if (i == 0) {
 				add(t[i], b[i]);
@@ -3613,30 +3606,56 @@ private:
 			}
 		}
 		sub_rr(a, b);
-		mov(rax, (size_t)p_);
+		mov(rax, pL_);
 		load_rm(b, rax);
 		sbb(rax, rax);
-		for (int i = 0; i < 4; i++) {
+		for (int i = 0; i < pn_; i++) {
 			and_(b[i], rax);
 		}
 		add_rr(a, b);
-		store_mr(sf.p[0], a);
-		mov(rax, (size_t)p_);
+		store_mr(py, a);
+		mov(rax, pL_);
 		mov_rr(a, t);
 		sub_rm(t, rax);
-		for (int i = 0; i < 4; i++) {
-			cmovc(t[i], a[i]);
+		cmovc_rr(t, a);
+		store_mr(py + FpByte_, t);
+	}
+	void gen_fp2_mul_xi6()
+	{
+		assert(!isFullBit_);
+		StackFrame sf(this, 2, 12);
+		const Reg64& py = sf.p[0];
+		const Reg64& px = sf.p[1];
+		Pack a = sf.t.sub(0, 6);
+		Pack b = sf.t.sub(6);
+		load_rm(a, px);
+		mov_rr(b, a);
+		add_rm(b, px + FpByte_);
+		sub_rm(a, px + FpByte_);
+		mov(rax, pL_);
+		jnc("@f");
+		add_rm(a, rax);
+	L("@@");
+		store_mr(py, a);
+		mov_rr(a, b);
+		sub_rm(b, rax);
+		cmovc_rr(b, a);
+		store_mr(py + FpByte_, b);
+	}
+	void2u gen_fp2_mul_xi()
+	{
+		if (isFullBit_) return 0;
+		align(16);
+		void2u func = getCurr<void2u>();
+		if (pn_ == 4) {
+			gen_fp2_mul_xi4();
+			return func;
 		}
-		store_mr(sf.p[0] + FpByte_, t);
-#else
-		StackFrame sf(this, 2, 8, 8 * 4);
-		gen_raw_fp_add(rsp, sf.p[1], sf.p[1] + FpByte_, sf.t, false);
-		gen_raw_fp_sub(sf.p[0], sf.p[1], sf.p[1] + FpByte_, sf.t, false);
-		for (int i = 0; i < 4; i++) {
-			mov(rax, ptr [rsp + i * 8]);
-			mov(ptr[sf.p[0] + FpByte_ + i * 8], rax);
+		if (pn_ == 6) {
+			gen_fp2_mul_xi6();
+			return func;
 		}
-#endif
+		return 0;
 	}
 	void2u gen_fp2_neg()
 	{