Using pointer to access array instead of index

See example below firstly.

   uint8_t parity = 0;
   uint8_t index = 0;
   //flag
   gMUXTask.responseData[index++] = MUX_DATA_BIT_LOW;
   //dirty
   gMUXTask.responseData[index++] = gDeviceStatus.responseStatus.dirty;
   parity += gDeviceStatus.responseStatus.dirty;
   //smoke alarm
   gMUXTask.responseData[index++] = gDeviceStatus.responseStatus.smokeAlarm;
   parity += gDeviceStatus.responseStatus.smokeAlarm;
   //high temperature
   gMUXTask.responseData[index++] = gDeviceStatus.responseStatus.highTemperature;
   parity += gDeviceStatus.responseStatus.highTemperature;
   //low temperature
   gMUXTask.responseData[index++] = gDeviceStatus.responseStatus.lowTemperature;
   parity += gDeviceStatus.responseStatus.lowTemperature;
   //miss Head
   gMUXTask.responseData[index++] = gDeviceStatus.responseStatus.missHead;
   parity += gDeviceStatus.responseStatus.missHead;
   //parity
   gMUXTask.responseData[index++] = CalcParity(isOddAlgorithm(false), parity);
   //outputState
   gMUXTask.responseData[index++] = MUX_DATA_BIT_LOW;

The ASM code generated is below, it is around 120bytes.

Another example here,

   uint8_t* p = gMUXTask.responseData;
   *p++ = MUX_DATA_BIT_LOW;
   //dirty
   *p++ = gDeviceStatus.responseStatus.dirty;
   parity += gDeviceStatus.responseStatus.dirty;
   //smoke alarm
   *p++ = gDeviceStatus.responseStatus.smokeAlarm;
   parity += gDeviceStatus.responseStatus.smokeAlarm;
   //high temperature
   *p++ = gDeviceStatus.responseStatus.highTemperature;
   parity += gDeviceStatus.responseStatus.highTemperature;
   //low temperature
   *p++ = gDeviceStatus.responseStatus.lowTemperature;
   parity += gDeviceStatus.responseStatus.lowTemperature;
   //miss Head
   *p++ = gDeviceStatus.responseStatus.missHead;
   parity += gDeviceStatus.responseStatus.missHead;
   //parity
   *p++ = CalcParity(isOddAlgorithm(false), parity);
   //outputState
   *p++ = MUX_DATA_BIT_LOW;

The ASM code generated, it is about 106 bytes.

Using pointer to access an array which has a better performance.