diff --git a/src/core/arm/dyncom/arm_dyncom_run.h b/src/core/arm/dyncom/arm_dyncom_run.h
index c477002b0..b1c0daaf7 100644
--- a/src/core/arm/dyncom/arm_dyncom_run.h
+++ b/src/core/arm/dyncom/arm_dyncom_run.h
@@ -16,8 +16,7 @@
 *
 */
 
-#ifndef __ARM_DYNCOM_RUN__
-#define __ARM_DYNCOM_RUN__
+#pragma once
 
 void switch_mode(arm_core_t *core, uint32_t mode);
 
@@ -49,5 +48,3 @@ static inline addr_t CHECK_READ_REG15_WA(arm_core_t* core, int Rn) {
 static inline u32 CHECK_READ_REG15(arm_core_t* core, int Rn) {
     return (Rn == 15)? ((core->Reg[15] & ~0x1) + GET_INST_SIZE(core) * 2) : core->Reg[Rn];
 }
-
-#endif
diff --git a/src/core/arm/dyncom/arm_dyncom_thumb.h b/src/core/arm/dyncom/arm_dyncom_thumb.h
index 7ca8062bf..a1785abb8 100644
--- a/src/core/arm/dyncom/arm_dyncom_thumb.h
+++ b/src/core/arm/dyncom/arm_dyncom_thumb.h
@@ -24,8 +24,7 @@
 * @date 2011-11-07
 */
 
-#ifndef __ARM_DYNCOM_THUMB_H__
-#define __ARM_DYNCOM_THUMB_H__
+#pragma once
 
 #include "core/arm/skyeye_common/armdefs.h"
 
@@ -46,5 +45,3 @@ static inline u32 get_thumb_instr(u32 instr, addr_t pc) {
         tinstr = instr & 0xFFFF;
     return tinstr;
 }
-
-#endif
diff --git a/src/core/arm/skyeye_common/arm_regformat.h b/src/core/arm/skyeye_common/arm_regformat.h
index 4dac1a8bf..997874764 100644
--- a/src/core/arm/skyeye_common/arm_regformat.h
+++ b/src/core/arm/skyeye_common/arm_regformat.h
@@ -1,7 +1,6 @@
-#ifndef __ARM_REGFORMAT_H__
-#define __ARM_REGFORMAT_H__
+#pragma once
 
-enum arm_regno{
+enum {
     R0 = 0,
     R1,
     R2,
@@ -20,7 +19,7 @@ enum arm_regno{
     R15, //PC,
     CPSR_REG,
     SPSR_REG,
-#if 1
+
     PHYS_PC,
     R13_USR,
     R14_USR,
@@ -95,11 +94,9 @@ enum arm_regno{
     VFP_FPSID = VFP_BASE,
     VFP_FPSCR,
     VFP_FPEXC,
-#endif    
+
     MAX_REG_NUM,
 };
 
 #define CP15(idx)       (idx - CP15_BASE)
 #define VFP_OFFSET(x)   (x - VFP_BASE)
-
-#endif
diff --git a/src/core/arm/skyeye_common/armemu.h b/src/core/arm/skyeye_common/armemu.h
index 686b2a3f6..7e10dad86 100644
--- a/src/core/arm/skyeye_common/armemu.h
+++ b/src/core/arm/skyeye_common/armemu.h
@@ -14,14 +14,10 @@
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
-#ifndef __ARMEMU_H__
-#define __ARMEMU_H__
 
+#pragma once
 
 #include "core/arm/skyeye_common/armdefs.h"
-//#include "skyeye.h"
-
-//extern ARMword isize;
 
 /* Shift Opcodes.  */
 #define LSL 0
@@ -625,6 +621,3 @@ extern unsigned DSPCDP5 (ARMul_State *, unsigned, ARMword);
 extern unsigned DSPMCR6 (ARMul_State *, unsigned, ARMword, ARMword);
 extern unsigned DSPMRC6 (ARMul_State *, unsigned, ARMword, ARMword *);
 extern unsigned DSPCDP6 (ARMul_State *, unsigned, ARMword);
-
-
-#endif
diff --git a/src/core/arm/skyeye_common/vfp/asm_vfp.h b/src/core/arm/skyeye_common/vfp/asm_vfp.h
index f4ab34fd4..e113eaf29 100644
--- a/src/core/arm/skyeye_common/vfp/asm_vfp.h
+++ b/src/core/arm/skyeye_common/vfp/asm_vfp.h
@@ -5,6 +5,8 @@
  * First, the standard VFP set.
  */
 
+#pragma once
+
 #define FPSID			cr0
 #define FPSCR			cr1
 #define MVFR1			cr6
diff --git a/src/core/arm/skyeye_common/vfp/vfp.h b/src/core/arm/skyeye_common/vfp/vfp.h
index 5ff213e08..09c7520db 100644
--- a/src/core/arm/skyeye_common/vfp/vfp.h
+++ b/src/core/arm/skyeye_common/vfp/vfp.h
@@ -18,8 +18,7 @@
     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
 
-#ifndef __VFP_H__
-#define __VFP_H__
+#pragma once
 
 #include "core/arm/skyeye_common/vfp/vfp_helper.h" /* for references to cdp SoftFloat functions */
 
@@ -109,5 +108,3 @@ int VLDR(ARMul_State * state, int type, ARMword instr, ARMword value);
 #ifdef __cplusplus
  }
 #endif
-
-#endif
diff --git a/src/core/arm/skyeye_common/vfp/vfp_helper.h b/src/core/arm/skyeye_common/vfp/vfp_helper.h
index b1949603a..55e63f553 100644
--- a/src/core/arm/skyeye_common/vfp/vfp_helper.h
+++ b/src/core/arm/skyeye_common/vfp/vfp_helper.h
@@ -30,8 +30,7 @@
  * published by the Free Software Foundation.
  */
 
-#ifndef __VFP_HELPER_H__
-#define __VFP_HELPER_H__
+#pragma once
 
 /* Custom edit */
 
@@ -536,5 +535,3 @@ u32 vfp_double_normaliseroundintern(ARMul_State* state, struct vfp_double *vd, u
 u32 vfp_double_multiply(struct vfp_double *vdd, struct vfp_double *vdn, struct vfp_double *vdm, u32 fpscr);
 u32 vfp_double_add(struct vfp_double *vdd, struct vfp_double *vdn, struct vfp_double *vdm, u32 fpscr);
 u32 vfp_double_fcvtsinterncutting(ARMul_State* state, int sd, struct vfp_double* dm, u32 fpscr);
-
-#endif