diff --git a/internal/sm2ec/p256_asm_amd64.s b/internal/sm2ec/p256_asm_amd64.s
index 3a66253..7f508ae 100644
--- a/internal/sm2ec/p256_asm_amd64.s
+++ b/internal/sm2ec/p256_asm_amd64.s
@@ -109,65 +109,65 @@ sqrLoop:
 	RET
 	
 sqrBMI2:
-	// y[1:] * y[0]
+	XORQ acc0, acc0
+	XORQ y_ptr, y_ptr
+	// x[1:] * x[0]
 	MOVQ (8*0)(x_ptr), DX
-
 	MULXQ (8*1)(x_ptr), acc1, acc2
 	
 	MULXQ (8*2)(x_ptr), AX, acc3
-	ADDQ AX, acc2
+	ADOXQ AX, acc2
 
 	MULXQ (8*3)(x_ptr), AX, acc4
-	ADCQ AX, acc3
-	ADCQ $0, acc4
+	ADOXQ AX, acc3
+	ADOXQ y_ptr, acc4
 
-	// y[2:] * y[1]
+	// x[2:] * x[1]
 	MOVQ (8*1)(x_ptr), DX
-	
 	MULXQ (8*2)(x_ptr), AX, t1
-	ADDQ AX, acc3
-	ADCQ t1, acc4
+	ADOXQ AX, acc3
 
 	MULXQ (8*3)(x_ptr), AX, acc5
-	ADCQ $0, acc5
-	ADDQ AX, acc4
+	ADCXQ t1, AX
+	ADOXQ AX, acc4
+	ADCXQ y_ptr, acc5
 
-	// y[3] * y[2]
+	// y[x] * x[2]
 	MOVQ (8*2)(x_ptr), DX
+	MULXQ (8*3)(x_ptr), AX, y_ptr 
+	ADOXQ AX, acc5
+	ADOXQ acc0, y_ptr
 
-	MULXQ (8*3)(x_ptr), AX, y_ptr
-	ADCQ AX, acc5 
-	ADCQ $0, y_ptr
 	XORQ t1, t1
 
 	// *2
-	ADDQ acc1, acc1
-	ADCQ acc2, acc2
-	ADCQ acc3, acc3
-	ADCQ acc4, acc4
-	ADCQ acc5, acc5
-	ADCQ y_ptr, y_ptr
-	ADCQ $0, t1
+	ADOXQ acc1, acc1
+	ADOXQ acc2, acc2
+	ADOXQ acc3, acc3
+	ADOXQ acc4, acc4
+	ADOXQ acc5, acc5
+	ADOXQ y_ptr, y_ptr
+	ADOXQ acc0, t1
 
 	// Missing products
 	MOVQ (8*0)(x_ptr), DX
 	MULXQ DX, acc0, t0
-	ADDQ t0, acc1
+	ADCXQ t0, acc1
 
 	MOVQ (8*1)(x_ptr), DX
 	MULXQ DX, AX, t0
-	ADCQ AX, acc2
-	ADCQ t0, acc3
+	ADCXQ AX, acc2
+	ADCXQ t0, acc3
 
 	MOVQ (8*2)(x_ptr), DX
-	MULXQ DX, AX, t0
-	ADCQ AX, acc4
-	ADCQ t0, acc5
+	MULXQ DX, AX, t0 
+	ADCXQ AX, acc4
+	ADCXQ t0, acc5
 
 	MOVQ (8*3)(x_ptr), DX
 	MULXQ DX, AX, x_ptr
-	ADCQ AX, y_ptr
-	ADCQ t1, x_ptr
+	ADCXQ AX, y_ptr
+	ADCXQ t1, x_ptr
 
 	// T = [x_ptr, y_ptr, acc5, acc4, acc3, acc2, acc1, acc0]
 	p256SqrMontReduce()
@@ -901,11 +901,11 @@ TEXT sm2P256SqrInternal(SB),NOSPLIT,$8
 	MULQ acc6
 	ADDQ mul0, acc3
 	ADCQ $0, mul1
-	MOVQ mul1, hlp
+	MOVQ mul1, acc0
 
 	MOVQ acc5, mul0
 	MULQ acc7
-	ADDQ hlp, t0
+	ADDQ acc0, t0
 	ADCQ $0, mul1
 	ADDQ mul0, t0
 	ADCQ $0, mul1
@@ -955,39 +955,42 @@ TEXT sm2P256SqrInternal(SB),NOSPLIT,$8
 	RET
 
 internalSqrBMI2:
+	XORQ acc0, acc0
+	XORQ t2, t2
 	MOVQ acc4, mul1
 	MULXQ acc5, acc1, acc2
 
 	MULXQ acc6, mul0, acc3
-	ADDQ mul0, acc2
+	ADOXQ mul0, acc2
 
 	MULXQ acc7, mul0, t0
-	ADCQ mul0, acc3
-	ADCQ $0, t0
+	ADOXQ mul0, acc3
+	ADOXQ t2, t0
 
 	MOVQ acc5, mul1
-	MULXQ acc6, mul0, hlp
-	ADDQ mul0, acc3
-	ADCQ hlp, t0
+	MULXQ acc6, mul0, t3
+	ADOXQ mul0, acc3
 
 	MULXQ acc7, mul0, t1
-	ADCQ $0, t1
-	ADDQ mul0, t0
+	ADCXQ t3, mul0
+	ADOXQ mul0, t0
+	ADCXQ t2, t1
 
 	MOVQ acc6, mul1
 	MULXQ acc7, mul0, t2
-	ADCQ mul0, t1
-	ADCQ $0, t2
+	ADOXQ mul0, t1
+	ADOXQ acc0, t2
+
 	XORQ t3, t3
 
 	// *2
-	ADDQ acc1, acc1
-	ADCQ acc2, acc2
-	ADCQ acc3, acc3
-	ADCQ t0, t0
-	ADCQ t1, t1
-	ADCQ t2, t2
-	ADCQ $0, t3
+	ADOXQ acc1, acc1
+	ADOXQ acc2, acc2
+	ADOXQ acc3, acc3
+	ADOXQ t0, t0
+	ADOXQ t1, t1
+	ADOXQ t2, t2
+	ADOXQ acc0, t3
 
 	// Missing products
 	MOVQ acc4, mul1
@@ -996,18 +999,18 @@ internalSqrBMI2:
 
 	MOVQ acc5, mul1
 	MULXQ mul1, mul0, acc4
-	ADCQ mul0, acc2
-	ADCQ  acc4, acc3
+	ADCXQ mul0, acc2
+	ADCXQ acc4, acc3
 
 	MOVQ acc6, mul1
 	MULXQ mul1, mul0, acc4
-	ADCQ mul0, t0
-	ADCQ acc4, t1
+	ADCXQ mul0, t0
+	ADCXQ acc4, t1
 
 	MOVQ acc7, mul1
 	MULXQ mul1, mul0, acc4
-	ADCQ mul0, t2
-	ADCQ acc4, t3
+	ADCXQ mul0, t2
+	ADCXQ acc4, t3
 	// T = [t3, t2,, t1, t0, acc3, acc2, acc1, acc0]
 	sm2P256SqrReductionInternal()
 
diff --git a/internal/sm2ec/p256_common_amd64.s b/internal/sm2ec/p256_common_amd64.s
index 7de66dd..513c0e6 100644
--- a/internal/sm2ec/p256_common_amd64.s
+++ b/internal/sm2ec/p256_common_amd64.s
@@ -168,7 +168,6 @@ TEXT ·p256NegCond(SB),NOSPLIT,$0
 /* ---------------------------------------*/
 // func p256Mul(res, in1, in2 *p256Element)
 TEXT ·p256Mul(SB),NOSPLIT,$0
-	MOVQ res+0(FP), res_ptr
 	MOVQ in1+8(FP), x_ptr
 	MOVQ in2+16(FP), y_ptr
 
@@ -372,25 +371,27 @@ TEXT ·p256Mul(SB),NOSPLIT,$0
 	ADCQ acc3, acc1
 	ADCQ $0, acc2
 	
+	MOVQ res+0(FP), res_ptr
 	p256PrimReduce(acc4, acc5, acc0, acc1, acc2, x_ptr, acc3, t0, BX, res_ptr)
 	RET
 
 mulBMI2:
+	XORQ acc5, acc5
+	XORQ res_ptr, res_ptr
 	// x * y[0]
 	MOVQ (8*0)(y_ptr), DX
 	MULXQ (8*0)(x_ptr), acc0, acc1
 
 	MULXQ (8*1)(x_ptr), AX, acc2
-	ADDQ AX, acc1
+	ADCXQ AX, acc1
 
 	MULXQ (8*2)(x_ptr), AX, acc3
-	ADCQ AX, acc2
+	ADCXQ AX, acc2
 
 	MULXQ (8*3)(x_ptr), AX, acc4
-	ADCQ AX, acc3
-	ADCQ $0, acc4
+	ADCXQ AX, acc3
+	ADCXQ acc5, acc4
 
-	XORQ acc5, acc5
 	// First reduction step
 	MOVQ acc0, AX
 	MOVQ acc0, DX
@@ -403,34 +404,32 @@ mulBMI2:
 	MOVQ acc0, AX
 	SBBQ DX, acc0
 
-	ADDQ AX, acc1
-	ADCQ $0, acc2
-	ADCQ $0, acc3
-	ADCQ acc0, acc4
-	ADCQ $0, acc5
+	ADOXQ AX, acc1
+	ADOXQ res_ptr, acc2
+	ADOXQ res_ptr, acc3
+	ADOXQ acc0, acc4
+	ADOXQ res_ptr, acc5
 
 	XORQ acc0, acc0
 	// x * y[1]
 	MOVQ (8*1)(y_ptr), DX
-	MULXQ (8*0)(x_ptr), AX, BX
-	ADDQ AX, acc1
-	ADCQ BX, acc2
+	MULXQ (8*0)(x_ptr), AX, t0
+	ADOXQ AX, acc1
 
 	MULXQ (8*1)(x_ptr), AX, BX
-	ADCQ $0, BX
-	ADDQ AX, acc2
-	ADCQ BX, acc3
+	ADCXQ t0, AX
+	ADOXQ AX, acc2
 
-	MULXQ (8*2)(x_ptr), AX, BX
-	ADCQ $0, BX
-	ADDQ AX, acc3
-	ADCQ BX, acc4
+	MULXQ (8*2)(x_ptr), AX, t0
+	ADCXQ BX, AX
+	ADOXQ AX, acc3
 
 	MULXQ (8*3)(x_ptr), AX, BX
-	ADCQ $0, BX
-	ADDQ AX, acc4
-	ADCQ BX, acc5
-	ADCQ $0, acc0
+	ADCXQ t0, AX
+	ADOXQ AX, acc4
+	ADCXQ acc0, BX
+	ADOXQ BX, acc5
+	ADOXQ res_ptr, acc0
 
 	// Second reduction step
 	MOVQ acc1, AX
@@ -444,35 +443,33 @@ mulBMI2:
 	MOVQ acc1, AX
 	SBBQ DX, acc1
 
-	ADDQ AX, acc2
-	ADCQ $0, acc3
-	ADCQ $0, acc4
-	ADCQ acc1, acc5
-	ADCQ $0, acc0
+	ADOXQ AX, acc2
+	ADOXQ res_ptr, acc3
+	ADOXQ res_ptr, acc4
+	ADOXQ acc1, acc5
+	ADOXQ res_ptr, acc0
 	
 	XORQ acc1, acc1
 	// x * y[2]
 	MOVQ (8*2)(y_ptr), DX
-
-	MULXQ (8*0)(x_ptr), AX, BX
-	ADDQ AX, acc2
-	ADCQ BX, acc3
+	MULXQ (8*0)(x_ptr), AX, t0
+	ADOXQ AX, acc2
 
 	MULXQ (8*1)(x_ptr), AX, BX
-	ADCQ $0, BX
-	ADDQ AX, acc3
-	ADCQ BX, acc4
+	ADCXQ t0, AX
+	ADOXQ AX, acc3
 
-	MULXQ (8*2)(x_ptr), AX, BX
-	ADCQ $0, BX
-	ADDQ AX, acc4
-	ADCQ BX, acc5
+	MULXQ (8*2)(x_ptr), AX, t0
+	ADCXQ BX, AX
+	ADOXQ AX, acc4
 
 	MULXQ (8*3)(x_ptr), AX, BX
-	ADCQ $0, BX
-	ADDQ AX, acc5
-	ADCQ BX, acc0
-	ADCQ $0, acc1
+	ADCXQ t0, AX
+	ADOXQ AX, acc5
+	ADCXQ res_ptr, BX
+	ADOXQ BX, acc0
+	ADOXQ res_ptr, acc1
+
 	// Third reduction step
 	MOVQ acc2, AX
 	MOVQ acc2, DX
@@ -485,35 +482,33 @@ mulBMI2:
 	MOVQ acc2, AX
 	SBBQ DX, acc2
 
-	ADDQ AX, acc3
-	ADCQ $0, acc4
-	ADCQ $0, acc5
-	ADCQ acc2, acc0
-	ADCQ $0, acc1
+	ADOXQ AX, acc3
+	ADOXQ res_ptr, acc4
+	ADOXQ res_ptr, acc5
+	ADOXQ acc2, acc0
+	ADOXQ res_ptr, acc1
 	
 	XORQ acc2, acc2
 	// x * y[3]
 	MOVQ (8*3)(y_ptr), DX
-
-	MULXQ (8*0)(x_ptr), AX, BX
-	ADDQ AX, acc3
-	ADCQ BX, acc4
+	MULXQ (8*0)(x_ptr), AX, t0
+	ADOXQ AX, acc3
 
 	MULXQ (8*1)(x_ptr), AX, BX
-	ADCQ $0, BX
-	ADDQ AX, acc4
-	ADCQ BX, acc5
+	ADCXQ t0, AX
+	ADOXQ AX, acc4
 
-	MULXQ (8*2)(x_ptr), AX, BX
-	ADCQ $0, BX
-	ADDQ AX, acc5
-	ADCQ BX, acc0
+	MULXQ (8*2)(x_ptr), AX, t0
+	ADCXQ BX, AX
+	ADOXQ AX, acc5
 
 	MULXQ (8*3)(x_ptr), AX, BX
-	ADCQ $0, BX
-	ADDQ AX, acc0
-	ADCQ BX, acc1
-	ADCQ $0, acc2
+	ADCXQ t0, AX
+	ADOXQ AX, acc0
+	ADCXQ res_ptr, BX
+	ADOXQ BX, acc1
+	ADOXQ res_ptr, acc2
+
 	// Last reduction step
 	MOVQ acc3, AX
 	MOVQ acc3, DX
@@ -526,12 +521,13 @@ mulBMI2:
 	MOVQ acc3, AX
 	SBBQ DX, acc3
 
-	ADDQ AX, acc4
-	ADCQ $0, acc5
-	ADCQ $0, acc0
-	ADCQ acc3, acc1
-	ADCQ $0, acc2
+	ADOXQ AX, acc4
+	ADOXQ res_ptr, acc5
+	ADOXQ res_ptr, acc0
+	ADOXQ acc3, acc1
+	ADOXQ res_ptr, acc2
 	
+	MOVQ res+0(FP), res_ptr
 	p256PrimReduce(acc4, acc5, acc0, acc1, acc2, x_ptr, acc3, t0, BX, res_ptr)
 	RET
 
diff --git a/internal/sm2ec/p256_plugin_amd64.s b/internal/sm2ec/p256_plugin_amd64.s
index cdf4b65..018c5b8 100644
--- a/internal/sm2ec/p256_plugin_amd64.s
+++ b/internal/sm2ec/p256_plugin_amd64.s
@@ -109,65 +109,64 @@ sqrLoop:
 	RET
 	
 sqrBMI2:
-	// y[1:] * y[0]
+	XORQ acc0, acc0
+	XORQ y_ptr, y_ptr
+	// x[1:] * x[0]
 	MOVQ (8*0)(x_ptr), DX
-
 	MULXQ (8*1)(x_ptr), acc1, acc2
-	
+
 	MULXQ (8*2)(x_ptr), AX, acc3
-	ADDQ AX, acc2
+	ADOXQ AX, acc2
 
 	MULXQ (8*3)(x_ptr), AX, acc4
-	ADCQ AX, acc3
-	ADCQ $0, acc4
+	ADOXQ AX, acc3
+	ADOXQ y_ptr, acc4
 
-	// y[2:] * y[1]
+	// x[2:] * x[1]
 	MOVQ (8*1)(x_ptr), DX
-	
 	MULXQ (8*2)(x_ptr), AX, BX
-	ADDQ AX, acc3
-	ADCQ BX, acc4
+	ADOXQ AX, acc3
 
 	MULXQ (8*3)(x_ptr), AX, acc5
-	ADCQ $0, acc5
-	ADDQ AX, acc4
+	ADCXQ BX, AX
+	ADOXQ AX, acc4
+	ADCXQ y_ptr, acc5
 
-	// y[3] * y[2]
+	// x[3] * x[2]
 	MOVQ (8*2)(x_ptr), DX
-
 	MULXQ (8*3)(x_ptr), AX, y_ptr
-	ADCQ AX, acc5 
-	ADCQ $0, y_ptr
+	ADOXQ AX, acc5
+	ADOXQ acc0, y_ptr
 	XORQ BX, BX
 
 	// *2
-	ADDQ acc1, acc1
-	ADCQ acc2, acc2
-	ADCQ acc3, acc3
-	ADCQ acc4, acc4
-	ADCQ acc5, acc5
-	ADCQ y_ptr, y_ptr
-	ADCQ $0, BX
+	ADOXQ acc1, acc1
+	ADOXQ acc2, acc2
+	ADOXQ acc3, acc3
+	ADOXQ acc4, acc4
+	ADOXQ acc5, acc5
+	ADOXQ y_ptr, y_ptr
+	ADOXQ acc0, BX
 
 	// Missing products
 	MOVQ (8*0)(x_ptr), DX
 	MULXQ DX, acc0, t0
-	ADDQ t0, acc1
+	ADCXQ t0, acc1
 
 	MOVQ (8*1)(x_ptr), DX
 	MULXQ DX, AX, t0
-	ADCQ AX, acc2
-	ADCQ t0, acc3
+	ADCXQ AX, acc2
+	ADCXQ t0, acc3
 
 	MOVQ (8*2)(x_ptr), DX
 	MULXQ DX, AX, t0
-	ADCQ AX, acc4
-	ADCQ t0, acc5
+	ADCXQ AX, acc4
+	ADCXQ t0, acc5
 
 	MOVQ (8*3)(x_ptr), DX
 	MULXQ DX, AX, x_ptr
-	ADCQ AX, y_ptr
-	ADCQ BX, x_ptr
+	ADCXQ AX, y_ptr
+	ADCXQ BX, x_ptr
 
 	// T = [x_ptr, y_ptr, acc5, acc4, acc3, acc2, acc1, acc0]
 	p256SqrMontReduce()
@@ -931,65 +930,68 @@ TEXT sm2P256SqrInternal(SB),NOSPLIT,$8
 	MOVQ acc4, mul0
 	MULQ mul0
 	MOVQ mul0, acc0
-	MOVQ DX, acc4
+	MOVQ mul1, acc4
 
 	MOVQ acc5, mul0
 	MULQ mul0
 	ADDQ acc4, acc1
 	ADCQ mul0, acc2
-	ADCQ $0, DX
-	MOVQ DX, acc4
+	ADCQ $0, mul1
+	MOVQ mul1, acc4
 
 	MOVQ acc6, mul0
 	MULQ mul0
 	ADDQ acc4, acc3
 	ADCQ mul0, t0
-	ADCQ $0, DX
-	MOVQ DX, acc4
+	ADCQ $0, mul1
+	MOVQ mul1, acc4
 
 	MOVQ acc7, mul0
 	MULQ mul0
 	ADDQ acc4, t1
 	ADCQ mul0, t2
-	ADCQ DX, t3
+	ADCQ mul1, t3
 	// T = [t3, t2,, t1, t0, acc3, acc2, acc1, acc0]
 	sm2P256SqrReductionInternal()
 	RET
 
 internalSqrBMI2:
+	XORQ acc0, acc0
+	XORQ t2, t2
 	MOVQ acc4, mul1
 	MULXQ acc5, acc1, acc2
 
 	MULXQ acc6, mul0, acc3
-	ADDQ mul0, acc2
+	ADOXQ mul0, acc2
 
 	MULXQ acc7, mul0, t0
-	ADCQ mul0, acc3
-	ADCQ $0, t0
+	ADOXQ mul0, acc3
+	ADOXQ t2, t0
 
 	MOVQ acc5, mul1
-	MULXQ acc6, mul0, acc0
-	ADDQ mul0, acc3
-	ADCQ acc0, t0
+	MULXQ acc6, mul0, t3
+	ADOXQ mul0, acc3
 
 	MULXQ acc7, mul0, t1
-	ADCQ $0, t1
-	ADDQ mul0, t0
+	ADCXQ t3, mul0
+	ADOXQ mul0, t0
+	ADCXQ t2, t1
 
 	MOVQ acc6, mul1
 	MULXQ acc7, mul0, t2
-	ADCQ mul0, t1
-	ADCQ $0, t2
+	ADOXQ mul0, t1
+	ADOXQ acc0, t2
+
 	XORQ t3, t3
 
 	// *2
-	ADDQ acc1, acc1
-	ADCQ acc2, acc2
-	ADCQ acc3, acc3
-	ADCQ t0, t0
-	ADCQ t1, t1
-	ADCQ t2, t2
-	ADCQ $0, t3
+	ADOXQ acc1, acc1
+	ADOXQ acc2, acc2
+	ADOXQ acc3, acc3
+	ADOXQ t0, t0
+	ADOXQ t1, t1
+	ADOXQ t2, t2
+	ADOXQ acc0, t3
 
 	// Missing products
 	MOVQ acc4, mul1
@@ -998,18 +1000,18 @@ internalSqrBMI2:
 
 	MOVQ acc5, mul1
 	MULXQ mul1, mul0, acc4
-	ADCQ mul0, acc2
-	ADCQ  acc4, acc3
+	ADCXQ mul0, acc2
+	ADCXQ acc4, acc3
 
 	MOVQ acc6, mul1
 	MULXQ mul1, mul0, acc4
-	ADCQ mul0, t0
-	ADCQ acc4, t1
+	ADCXQ mul0, t0
+	ADCXQ acc4, t1
 
 	MOVQ acc7, mul1
 	MULXQ mul1, mul0, acc4
-	ADCQ mul0, t2
-	ADCQ acc4, t3
+	ADCXQ mul0, t2
+	ADCXQ acc4, t3
 	// T = [t3, t2,, t1, t0, acc3, acc2, acc1, acc0]
 	sm2P256SqrReductionInternal()