From d1e4806e064972b856613676900455a63acf9ee1 Mon Sep 17 00:00:00 2001
From: Sun Yimin <emmansun@users.noreply.github.com>
Date: Thu, 25 Aug 2022 16:54:30 +0800
Subject: [PATCH] sm2: refactoring, reduce duplicated codes

---
 sm2/sm2ec/sm2ec.go     | 18 ------------------
 sm2/sm2ec/sm2ec_asm.go | 28 ++++++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 18 deletions(-)
 create mode 100644 sm2/sm2ec/sm2ec_asm.go

diff --git a/sm2/sm2ec/sm2ec.go b/sm2/sm2ec/sm2ec.go
index dd99624..560d41e 100644
--- a/sm2/sm2ec/sm2ec.go
+++ b/sm2/sm2ec/sm2ec.go
@@ -175,21 +175,3 @@ func (curve *sm2Curve) UnmarshalCompressed(data []byte) (x, y *big.Int) {
 	}
 	return curve.pointToAffine(p)
 }
-
-// Inverse, implements invertible interface, used by Sign()
-func (curve *sm2Curve) Inverse(k *big.Int) *big.Int {
-	if k.Sign() < 0 {
-		// This should never happen.
-		k = new(big.Int).Neg(k)
-	}
-	if k.Cmp(curve.params.N) >= 0 {
-		// This should never happen.
-		k = new(big.Int).Mod(k, curve.params.N)
-	}
-	scalar := k.FillBytes(make([]byte, 32))
-	inverse, err := _sm2ec.P256OrdInverse(scalar)
-	if err != nil {
-		panic("sm2/elliptic: sm2 rejected normalized scalar")
-	}
-	return new(big.Int).SetBytes(inverse)
-}
diff --git a/sm2/sm2ec/sm2ec_asm.go b/sm2/sm2ec/sm2ec_asm.go
new file mode 100644
index 0000000..a6859fe
--- /dev/null
+++ b/sm2/sm2ec/sm2ec_asm.go
@@ -0,0 +1,28 @@
+//go:build (amd64 && !generic) || (arm64 && !generic)
+// +build amd64,!generic arm64,!generic
+
+package sm2ec
+
+import (
+	"math/big"
+
+	_sm2ec "github.com/emmansun/gmsm/internal/sm2ec"
+)
+
+// Inverse, implements invertible interface, used by Sign()
+func (curve *sm2Curve) Inverse(k *big.Int) *big.Int {
+	if k.Sign() < 0 {
+		// This should never happen.
+		k = new(big.Int).Neg(k)
+	}
+	if k.Cmp(curve.params.N) >= 0 {
+		// This should never happen.
+		k = new(big.Int).Mod(k, curve.params.N)
+	}
+	scalar := k.FillBytes(make([]byte, 32))
+	inverse, err := _sm2ec.P256OrdInverse(scalar)
+	if err != nil {
+		panic("sm2/elliptic: sm2 rejected normalized scalar")
+	}
+	return new(big.Int).SetBytes(inverse)
+}