8.2.1 Data Type Storage

For general information about data types, see Section 7.4. Table 8-1 lists register and memory storage for various data types:

Table 8-1 Data Representation in Registers and Memory

Data Type	Register Storage	Memory Storage
char	Bits 0-7 of register	8 bits aligned to 8-bit boundary
unsigned char	Bits 0-7 of register	8 bits aligned to 8-bit boundary
short	Bits 0-15 of register	16 bits aligned to 16-bit boundary
unsigned short	Bits 0-15 of register	16 bits aligned to 16-bit boundary
int	Entire register	32 bits aligned to 32-bit boundary
unsigned int	Entire register	32 bits aligned to 32-bit boundary
enum ⁽¹⁾	Entire register or even/odd register pair	32 bits aligned to 32-bit boundary or 64 bits aligned to 64-bit boundary
float	Entire register	32 bits aligned to 32-bit boundary
float complex ⁽⁴⁾	Even/odd register pair	64 bits aligned to 32-bit boundary
long	Entire register	32 bits aligned to 32-bit boundary
unsigned long	Entire register	32 bits aligned to 32-bit boundary
__int40_t	Even/odd register pair	64 bits aligned to 64-bit boundary
unsigned __int40_t	Even/odd register pair	64 bits aligned to 64-bit boundary
long long	Even/odd register pair	64 bits aligned to 64-bit boundary
unsigned long long	Even/odd register pair	64 bits aligned to 64-bit boundary
double	Even/odd register pair	64 bits aligned to 64-bit boundary
double complex (C6600 only)⁽⁴⁾	Register quad⁽⁵⁾	128 bits aligned to 64-bit boundary
long double	Even/odd register pair	64 bits aligned to 64-bit boundary
long double complex (C6600 only)⁽⁴⁾	Register quad⁽⁵⁾	128 bits aligned to 64-bit boundary
__x128_t (C6600 only)⁽²⁾	Register quad⁽⁵⁾	128-bits aligned to 64-bit boundary
struct	Members are stored as their individual types require.	Storage is a multiple of the alignment to the boundary of largest member type; members are stored and aligned as their individual types require.
array	Members are stored as their individual types require.	Members are stored as their individual types require.⁽³⁾ All arrays inside a structure are aligned according to the type of each element in the array.
pointer to data member	Bits 0-31 of register	32 bits aligned to 32-bit boundary
pointer to member function	Components stored as their individual types require	32 bits aligned to 32-bit boundary

(1) For details about the size of an enum type, see Section 7.4.1.

(2) For details on the __x128_t container type, see Section 8.6.7.

(3) Static scope arrays are aligned to a 64-bit boundary.

(4) To use complex data types, you must include the <complex.h> header file. See Section 7.5.1 for more about how complex data types are stored.

(5) Register quads are supports for C66000 only.