All data items are held in the native byte order of the MSP430 processor. The plain character type is signed by default. The floating-point types float and double are implemented as 32-bit and 64-bit IEEE floating-point.

Data Type | Size in bytes | Alignment in bytes
char | 1 | 1
signed char | 1 | 1
unsigned char | 1 | 1
int | 2 | 2
unsigned int | 2 | 2
short | 2 | 2
unsigned short | 2 | 2
long | 4 | 2
unsigned long | 4 | 2
long long | 8 | 2
unsigned long long | 8 | 2
float | 4 | 2
double (compiled with -msd) | 4 | 2
double | 8 | 2
long double | 8 | 2
type * (pointer) | 2 | 2
enum (enumeration) | 2 | 2