diff --git a/kernel/x86/axpy_sse.S b/kernel/x86/axpy_sse.S
index 291a219ce..e06d90184 100644
--- a/kernel/x86/axpy_sse.S
+++ b/kernel/x86/axpy_sse.S
@@ -1440,6 +1440,12 @@
 .L50:
 	movl	M, %eax
 	movl	Y, YY
+//If incx==0 || incy==0, avoid unloop.
+	cmpl	$0, INCX
+	je  .L56
+	cmpl	$0, INCY
+	je  .L56
+
 	sarl	$3,   %eax
 	jle	.L55
 	ALIGN_3
diff --git a/kernel/x86/axpy_sse2.S b/kernel/x86/axpy_sse2.S
index 5e31d3dba..9b2d5d808 100644
--- a/kernel/x86/axpy_sse2.S
+++ b/kernel/x86/axpy_sse2.S
@@ -698,6 +698,12 @@
 .L40:
 	movl	Y, YY
 	movl	M,  %eax
+//If incx==0 || incy==0, avoid unloop.
+	cmpl	$0, INCX
+	je  .L46
+	cmpl	$0, INCY
+	je  .L46
+
 	sarl	$3, %eax
 	jle	.L45
 	ALIGN_3
diff --git a/kernel/x86/zaxpy_sse.S b/kernel/x86/zaxpy_sse.S
index edd9929cd..9c94cec44 100644
--- a/kernel/x86/zaxpy_sse.S
+++ b/kernel/x86/zaxpy_sse.S
@@ -2857,6 +2857,11 @@
 	unpcklps ALPHA_I, ALPHA_R
 	unpcklps %xmm5, ALPHA_I
 #endif
+//If incx==0 || incy==0, avoid unloop and jump to end.
+	cmpl	$0, INCX
+	je  .L200
+	cmpl	$0, INCY
+	je	.L200
 
 	movl	Y, YY
 
@@ -3090,8 +3095,41 @@
 	addps	%xmm1, %xmm4
 
 	movsd	%xmm4,   (Y)
+	jmp	.L999
 	ALIGN_3
 
+.L200:
+	movl    M, %eax
+	cmpl	$0, %eax
+	jle .L999
+	ALIGN_3
+
+.L201:
+	movsd	 (X), %xmm0
+
+#ifdef HAVE_SSE3
+	movshdup  %xmm0, %xmm1
+	movsldup  %xmm0, %xmm0
+#else
+	movaps	  %xmm0, %xmm1
+	shufps	  $0xa0, %xmm0, %xmm0
+	shufps	  $0xf5, %xmm1, %xmm1
+#endif
+
+	mulps	ALPHA_R, %xmm0
+	mulps	ALPHA_I, %xmm1
+
+	movsd	 (Y), %xmm4
+
+	addps	%xmm0, %xmm4
+	addps	%xmm1, %xmm4
+
+	movsd	%xmm4,   (Y)
+	
+	decl    %eax
+	jg  .L201
+
+	ALIGN_3
 .L999:
 	popl	%ebp
 	popl	%ebx
diff --git a/kernel/x86/zaxpy_sse2.S b/kernel/x86/zaxpy_sse2.S
index 40afdc3fc..9c2caa7e8 100644
--- a/kernel/x86/zaxpy_sse2.S
+++ b/kernel/x86/zaxpy_sse2.S
@@ -1318,6 +1318,12 @@
 
 	movl	Y, YY
 	movl	M,  %eax
+//If incx==0 || incy==0, avoid unloop and jump to end.
+	cmpl	$0, INCX
+	je  .L58
+	cmpl	$0, INCY
+	je	.L58
+
 	sarl	$2, %eax
 	jle	.L55
 
@@ -1498,6 +1504,7 @@
 	andl	$1, %eax
 	jle	.L999
 
+.L58:
 	MOVDDUP( 0 * SIZE, X, %xmm0)
 	MOVDDUP( 1 * SIZE, X, %xmm1)
 
@@ -1510,6 +1517,10 @@
 
 	movlpd	%xmm4,   0 * SIZE(YY)
 	movhpd	%xmm4,   1 * SIZE(YY)
+
+			
+	decl %eax
+	jg	.L58
 	ALIGN_3
 
 .L999: