XS1 Data Types

The size and alignment of C and XC’s data types are not specified by the language. This allows the size of int to be set to the natural word size of the target device, ensuring the fastest possible performance for many computations. It also allows the alignment to be set wide enough to enable efficient memory loads and stores. the table below represents the size and alignment of the data types specified by the xCORE Application Binary Interface, which provides a standard interface for linking objects compiled from both C and XC.

Data Type	Size	Align	Supported		Meaning
	(bits)	(bits)	XC	C

`char`	8	8	Y	Y	Character type
`short`	16	16	Y	Y	Short integer
`int`	32	32	Y	Y	Native integer
`long`	32	32	N	Y	Long integer
`long long`	64	32	N	Y	Long long integer
`float`	32	32	N	Y	32-bit IEEE float
`double`	64	32	N	Y	64-bit IEEE float
`long double`	64	32	N	Y	64-bit IEEE float
`void *`	32	32	N	Y	Data pointer
`port`	32	32	Y	N	Port
`timer`	32	32	Y	N	Timer
`chanend`	32	32	Y	N	Channel end

In addition:

The char type is by default unsigned.
The types char, short and int may be specified in a bit-field’s declaration.
A zero-width bit-field forces padding until the next bit-offset aligned with the bit-field’s declared type.
The notional transfer type of a port is unsigned int (32 bits).
The notional counter type of a port is unsigned short (16 bits).
The notional counter type of a timer is unsigned int (32 bits).