6.59.12.1 Argument Types

The arguments to the built-in functions can be divided into three groups: register numbers, compile-time constants and run-time values. In order to make this classification clear at a glance, the arguments and return values are given the following pseudo types:

Pseudo type	Real C type	Constant?	Description
uh	unsigned short	No	an unsigned halfword
uw1	unsigned int	No	an unsigned word
sw1	int	No	a signed word
uw2	unsigned long long	No	an unsigned doubleword
sw2	long long	No	a signed doubleword
const	int	Yes	an integer constant
acc	int	Yes	an ACC register number
iacc	int	Yes	an IACC register number

These pseudo types are not defined by GCC, they are simply a notational convenience used in this manual.

Arguments of type uh, uw1, sw1, uw2 and sw2 are evaluated at run time. They correspond to register operands in the underlying FR-V instructions.

const arguments represent immediate operands in the underlying FR-V instructions. They must be compile-time constants.

acc arguments are evaluated at compile time and specify the number of an accumulator register. For example, an acc argument of 2 selects the ACC2 register.

iacc arguments are similar to acc arguments but specify the number of an IACC register. See see Other Built-in Functions for more details.