diff --git a/arch/AArch64/AArch64AddressingModes.h b/arch/AArch64/AArch64AddressingModes.h
index 047ee31e..e162fda2 100644
--- a/arch/AArch64/AArch64AddressingModes.h
+++ b/arch/AArch64/AArch64AddressingModes.h
@@ -213,16 +213,13 @@ static inline float AArch64_AM_getFPImmFloat(unsigned Imm)
 
 static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType10(uint8_t Imm)
 {
-	uint64_t EncVal = 0;
-	if (Imm & 0x80) EncVal |= 0xff00000000000000ULL;
-	if (Imm & 0x40) EncVal |= 0x00ff000000000000ULL;
-	if (Imm & 0x20) EncVal |= 0x0000ff0000000000ULL;
-	if (Imm & 0x10) EncVal |= 0x000000ff00000000ULL;
-	if (Imm & 0x08) EncVal |= 0x00000000ff000000ULL;
-	if (Imm & 0x04) EncVal |= 0x0000000000ff0000ULL;
-	if (Imm & 0x02) EncVal |= 0x000000000000ff00ULL;
-	if (Imm & 0x01) EncVal |= 0x00000000000000ffULL;
-	return EncVal;
+	static const uint32_t lookup[16] = {
+		0x00000000, 0x000000ff, 0x0000ff00, 0x0000ffff, 
+		0x00ff0000, 0x00ff00ff, 0x00ffff00, 0x00ffffff, 
+		0xff000000, 0xff0000ff, 0xff00ff00, 0xff00ffff, 
+		0xffff0000, 0xffff00ff, 0xffffff00, 0xffffffff
+        };
+	return lookup[Imm & 0x0f] | ((uint64_t)lookup[Imm >> 4] << 32);
 }
 
 #endif