5.3 Data Types

Table 5-1 lists the size, representation, and range of each scalar data type for the C7000 compiler. Many of the range values are available as standard macros in the header file limits.h.

The storage and alignment of data types is described in Section 6.2.1.

Table 5-1 C7000 C/C++ Data Types

			Range
Type	Size	Representation	Minimum	Maximum
char, signed char	8 bits	ASCII	-128	127
unsigned char	8 bits	ASCII	0	255
_Bool, bool	8 bits	ASCII	0 (false)	1 (true)
short	16 bits	Binary	-32 768	32 767
unsigned short	16 bits	Binary	0	65 535
int, signed int	32 bits	Binary	-2 147 483 648	2 147 483 647
unsigned int, wchar_t	32 bits	Binary	0	4 294 967 295
long, signed long	64 bits	Binary	-9 223 372 036 854 775 808	9 223 372 036 854 775 808
unsigned long	64 bits	Binary	0	18 446 744 073 709 551 615
long long, signed long long	64 bits	Binary	-9 223 372 036 854 775 808	9 223 372 036 854 775 807
unsigned long long	64 bits	Binary	0	18 446 744 073 709 551 615
enum ⁽¹⁾	32 bits	Binary	-2 147 483 648	2 147 483 647
float	32 bits	IEEE 32-bit	1.175 494e-38⁽²⁾	3.40 282 346e+38
float complex	64 bits	Array of 2 IEEE 32-bit	1.175 494e-38 for real and imaginary portions separately	3.40 282 346e+38 for real and imaginary portions separately
double	64 bits	IEEE 64-bit	2.22 507 385e-308⁽²⁾	1.79 769 313e+308
double complex	128 bits	Array of 2 IEEE 64-bit	2.22 507 385e-308 for real and imaginary portions separately	1.79 769 313e+308 for real and imaginary portions separately
long double	64 bits	IEEE 64-bit	2.22 507 385e-308⁽²⁾	1.79 769 313e+308
long double complex	128 bits	Array of 2 IEEE 64-bit	2.22 507 385e-308 for real and imaginary portions separately	1.79 769 313e+308 for real and imaginary portions separately
pointers, references, pointer to data members	64 bits	Binary	0	0xFFFFFFFFFFFFFFFF

(1) For details about the size of an enum type, see Section 5.3.1.

(2) Figures are minimum precision.

Negative values for signed types are represented using two's complement.

NOTE

We recommend that your code use the C standard integer types int64_t and int32_t (et al.) when specific data type sizes are needed for portability across different devices and compilers. These standard integer types are defined in stdint.h, which is included as part of the C standard library support included the Runtime Support Library.

The C7000 adopts the LP64 representational convention. That is, the type int is 32 bits, while long and pointer types are 64 bits.

These additional types from C, C99 and C++ are defined as synonyms for standard types:

Table 5-2 C Language Standard Types

Type	Definition
size_t	unsigned long
ptrdiff_t	long
wchar_t	unsigned int
wint_t	int
va_list	char *