Type Mapping for C++

grCUDA needs to interact with tree different type systems:

• The Java types of the Truffle interop protocol (boolean, byte, short, int, long, float, double, String) as described in InteropLibrary. These types are used in the interop with the different GraalVM langauges.
• C++ language types (see C++ Fundamental Types These types are used to used to bind to GPU kernels as well as to C++ host functions.
• C interface types from TruffleNFI (void, sint8, uint8, sint16, uint16, sint32, uint32, sint64, uint64, float, double, pointer, object, string). NativeSimpleType.java defines these types. grCUDA uses TruffleNFI to invoke native host functions. While TruffleNFI is designed for C APIs, the C++ types are necessary create the mangled symbols names to invoke with TruffleNFI.

Types for clang/gcc under Linux (LP64)

C++ Type	Bytes	Sym	NIDL Type	NFI	Java Type
bool	1	b	bool	uint8	boolean
char	1	c	char	sint8	byte
unsigned char	1	h	uint8	uint8	short
signed char	1	a	sint8	sint8	byte
wchar_t	4	w	wchar	sint32	int
char8_t	1	Du	char8	uint8	short
char16_t	2	Ds	char16	uint16	int
char32_t	4	Di	char32	uint32	long
(signed) short	2	s	sint16	sint16	short
unsigned short	2	t	uint16	uint16	long
(signed) int	4	i	sint32	sint32	int
unsigned int	4	j	uint32	uint32	long
(signed) long	8	l	sint64	sint64	long
unsigned long	8	m	uint64	uint64	long+
(singed) long long	8	x	sll64	sint64	long
unsigned long long	8	y	ull64	uint64	long+
float	4	f	float	float	float
double	8	d	double	double	double
long double	16	e	*	*	*
void	0	v	void	void	void
U *	8	PU	inout pointer V	pointer	n/a
U *	8	PU	out pointer V	pointer	n/a
const U *	8	PKU	in pointer V	pointer	n/a
void *	8	Pv	inout pointer void	pointer	n/a
void *	8	Pv	out pointer void	pointer	n/a
const void *	8	PKv	in pointer void	pointer	n/a
const char *	8	PKc	string	string	String

(*) not supported in grCUDA or NFI (+) does not support all values (NFI limitation)

Synonymous NIDL types

Synonymous types are that can substituted without coercion:

• char, uint8
• bool, char8, uint8
• char16, uint16
• sint32, wchar
• char32, uint32t
• sint64, sll64
• uint64, ull64
• inout pointer V, out pointer U, synonymous(U, V), inout pointer void, out pointer void
• in pointer V, in pointer U, synonymous(U, V), in pointer void