diff --git a/README.md b/README.md
index d35171c..44abd38 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,13 @@
     PASS
     ok  	gmsm/sm2	1.564s
 
+    goos: windows(with amd64 curve implementation, first version)
+    goarch: amd64
+    pkg: github.com/emmansun/gmsm/sm2
+    BenchmarkLessThan32_P256SM2-6   	   10447	    115618 ns/op	    2357 B/op	      46 allocs/op
+    PASS
+    ok  	github.com/emmansun/gmsm/sm2	2.199s
+
     P-256
     goos: windows
     goarch: amd64
diff --git a/sm2/p256_asm.go b/sm2/p256_asm.go
index 3bbdc83..0ab8e13 100644
--- a/sm2/p256_asm.go
+++ b/sm2/p256_asm.go
@@ -109,6 +109,10 @@ func p256PointAddAsm(res, in1, in2 []uint64) int
 //go:noescape
 func p256PointDoubleAsm(res, in []uint64)
 
+var (
+	p256one = []uint64{0x0000000000000001, 0x00000000ffffffff, 0x0000000000000000, 0x0000000100000000}
+)
+
 // Inverse, implements invertible interface, need to test this function's correctness
 func (curve p256Curve) Inverse(k *big.Int) *big.Int {
 	if k.Sign() < 0 {
@@ -224,7 +228,7 @@ func p256GetScalar(out []uint64, in []byte) {
 // p256Mul operates in a Montgomery domain with R = 2^256 mod p, where p is the
 // underlying field of the curve. (See initP256 for the value.) Thus rr here is
 // R×R mod p. See comment in Inverse about how this is used.
-var rr = []uint64{0x0000000000000003, 0x00000002ffffffff, 0x0000000100000001, 0x0000000400000002}
+var rr = []uint64{0x200000003, 0x2ffffffff, 0x100000001, 0x400000002}
 
 func maybeReduceModP(in *big.Int) *big.Int {
 	if in.Cmp(p256.P) < 0 {
@@ -248,10 +252,10 @@ func (curve p256Curve) CombinedMult(bigX, bigY *big.Int, baseScalar, scalar []by
 	p256Mul(r2.xyz[4:8], r2.xyz[4:8], rr[:])
 
 	// This sets r2's Z value to 1, in the Montgomery domain.
-	r2.xyz[8] = 0x0000000000000001
-	r2.xyz[9] = 0x00000000ffffffff
-	r2.xyz[10] = 0x0000000000000000
-	r2.xyz[11] = 0x0000000100000000
+	r2.xyz[8] = p256one[0]
+	r2.xyz[9] = p256one[1]
+	r2.xyz[10] = p256one[2]
+	r2.xyz[11] = p256one[3]
 
 	r2.p256ScalarMult(scalarReversed)
 
@@ -284,10 +288,10 @@ func (curve p256Curve) ScalarMult(bigX, bigY *big.Int, scalar []byte) (x, y *big
 	p256Mul(r.xyz[0:4], r.xyz[0:4], rr[:])
 	p256Mul(r.xyz[4:8], r.xyz[4:8], rr[:])
 	// This sets r2's Z value to 1, in the Montgomery domain.
-	r.xyz[8] = 0x0000000000000001
-	r.xyz[9] = 0x00000000ffffffff
-	r.xyz[10] = 0x0000000000000000
-	r.xyz[11] = 0x0000000100000000
+	r.xyz[8] = p256one[0]
+	r.xyz[9] = p256one[1]
+	r.xyz[10] = p256one[2]
+	r.xyz[11] = p256one[3]
 
 	r.p256ScalarMult(scalarReversed)
 	return r.p256PointToAffine()
@@ -477,17 +481,17 @@ func (p *p256Point) p256BaseMult(scalar []uint64) {
 	p256NegCond(p.xyz[4:8], sign)
 
 	// (This is one, in the Montgomery domain.)
-	p.xyz[8] = 0x0000000000000001
-	p.xyz[9] = 0x00000000ffffffff
-	p.xyz[10] = 0x0000000000000000
-	p.xyz[11] = 0x0000000100000000
+	p.xyz[8] = p256one[0]
+	p.xyz[9] = p256one[1]
+	p.xyz[10] = p256one[2]
+	p.xyz[11] = p256one[3]
 
 	var t0 p256Point
 	// (This is one, in the Montgomery domain.)
-	t0.xyz[8] = 0x0000000000000001
-	t0.xyz[9] = 0x00000000ffffffff
-	t0.xyz[10] = 0x0000000000000000
-	t0.xyz[11] = 0x0000000100000000
+	t0.xyz[8] = p256one[0]
+	t0.xyz[9] = p256one[1]
+	t0.xyz[10] = p256one[2]
+	t0.xyz[11] = p256one[3]
 
 	index := uint(5)
 	zero := sel
diff --git a/sm2/p256_asm_test.go b/sm2/p256_asm_test.go
index ab24b52..86e2425 100644
--- a/sm2/p256_asm_test.go
+++ b/sm2/p256_asm_test.go
@@ -257,7 +257,7 @@ func Test_p256PointAddAsm(t *testing.T) {
 	x2, y2 := params.ScalarBaseMult(k2.Bytes())
 	x3, y3 := params.Add(x1, y1, x2, y2)
 	fmt.Printf("x1=%s, y1=%s\n", hex.EncodeToString(x3.Bytes()), hex.EncodeToString(y3.Bytes()))
-	var in1, in2, r p256Point
+	var in1, in2, rp p256Point
 	fromBig(in1.xyz[0:4], maybeReduceModP(x1))
 	fromBig(in1.xyz[4:8], maybeReduceModP(y1))
 	fromBig(in2.xyz[0:4], maybeReduceModP(x2))
@@ -270,13 +270,17 @@ func Test_p256PointAddAsm(t *testing.T) {
 	in2.xyz[9] = 0x00000000ffffffff
 	in2.xyz[10] = 0x0000000000000000
 	in2.xyz[11] = 0x0000000100000000
+	p256Mul(in1.xyz[0:4], in1.xyz[0:4], rr[:])
+	p256Mul(in1.xyz[4:8], in1.xyz[4:8], rr[:])
+	p256Mul(in2.xyz[0:4], in2.xyz[0:4], rr[:])
+	p256Mul(in2.xyz[4:8], in2.xyz[4:8], rr[:])
 	res := make([]uint64, 12)
 	n := p256PointAddAsm(res, in1.xyz[:], in2.xyz[:])
 	fmt.Printf("n=%d\n", n)
-	copy(r.xyz[:], res)
-	x4, y4 := r.p256PointToAffine()
+	copy(rp.xyz[:], res)
+	x4, y4 := rp.p256PointToAffine()
 	fmt.Printf("x1=%s, y1=%s\n", hex.EncodeToString(x4.Bytes()), hex.EncodeToString(y4.Bytes()))
-	if x3.Cmp(x4) != 0 || y3.Cmp(y4) != 0 {
+	if n == 0 && (x3.Cmp(x4) != 0 || y3.Cmp(y4) != 0) {
 		t.FailNow()
 	}
 }