##### 6.56.6.5 Other Built-in Functions

This section describes built-in functions that are not named after a specific FR-V instruction.

`sw2 __IACCreadll (iacc` reg`)`
  Return the full 64-bit value of IACC0. The reg argument is reserved for future expansion and must be 0.
`sw1 __IACCreadl (iacc` reg`)`
  Return the value of IACC0H if reg is 0 and IACC0L if reg is 1. Other values of reg are rejected as invalid.
`void __IACCsetll (iacc` reg`, sw2` x`)`
  Set the full 64-bit value of IACC0 to x. The reg argument is reserved for future expansion and must be 0.
`void __IACCsetl (iacc` reg`, sw1` x`)`
  Set IACC0H to x if reg is 0 and IACC0L to x if reg is 1. Other values of reg are rejected as invalid.
`void __data_prefetch0 (const void *`x`)`
  Use the `dcpl` instruction to load the contents of address x into the data cache.
`void __data_prefetch (const void *`x`)`
  Use the `nldub` instruction to load the contents of address x into the data cache. The instruction is issued in slot I1.