#### 6.60.25 RX Built-in Functions

GCC supports some of the RX instructions which cannot be expressed in the C programming language via the use of built-in functions. The following functions are supported:

Built-in Function: void __builtin_rx_brk (void)

  Generates the `brk` machine instruction.

Built-in Function: void __builtin_rx_clrpsw (int)

  Generates the `clrpsw` machine instruction to clear the specified bit in the processor status word.

Built-in Function: void __builtin_rx_int (int)

  Generates the `int` machine instruction to generate an interrupt with the specified value.

Built-in Function: void __builtin_rx_machi (int, int)

  Generates the `machi` machine instruction to add the result of multiplying the top 16 bits of the two arguments into the accumulator.

Built-in Function: void __builtin_rx_maclo (int, int)

  Generates the `maclo` machine instruction to add the result of multiplying the bottom 16 bits of the two arguments into the accumulator.

Built-in Function: void __builtin_rx_mulhi (int, int)

  Generates the `mulhi` machine instruction to place the result of multiplying the top 16 bits of the two arguments into the accumulator.

Built-in Function: void __builtin_rx_mullo (int, int)

  Generates the `mullo` machine instruction to place the result of multiplying the bottom 16 bits of the two arguments into the accumulator.

Built-in Function: int __builtin_rx_mvfachi (void)

  Generates the `mvfachi` machine instruction to read the top 32 bits of the accumulator.

Built-in Function: int __builtin_rx_mvfacmi (void)

  Generates the `mvfacmi` machine instruction to read the middle 32 bits of the accumulator.

Built-in Function: int __builtin_rx_mvfc (int)

  Generates the `mvfc` machine instruction which reads the control register specified in its argument and returns its value.

Built-in Function: void __builtin_rx_mvtachi (int)

  Generates the `mvtachi` machine instruction to set the top 32 bits of the accumulator.

Built-in Function: void __builtin_rx_mvtaclo (int)

  Generates the `mvtaclo` machine instruction to set the bottom 32 bits of the accumulator.

Built-in Function: void __builtin_rx_mvtc (int reg, int val)

  Generates the `mvtc` machine instruction which sets control register number `reg` to `val`.

Built-in Function: void __builtin_rx_mvtipl (int)

  Generates the `mvtipl` machine instruction set the interrupt priority level.

Built-in Function: void __builtin_rx_racw (int)

  Generates the `racw` machine instruction to round the accumulator according to the specified mode.

Built-in Function: int __builtin_rx_revw (int)

  Generates the `revw` machine instruction which swaps the bytes in the argument so that bits 0–7 now occupy bits 8–15 and vice versa, and also bits 16–23 occupy bits 24–31 and vice versa.

Built-in Function: void __builtin_rx_rmpa (void)

  Generates the `rmpa` machine instruction which initiates a repeated multiply and accumulate sequence.

Built-in Function: void __builtin_rx_round (float)

  Generates the `round` machine instruction which returns the floating-point argument rounded according to the current rounding mode set in the floating-point status word register.

Built-in Function: int __builtin_rx_sat (int)

  Generates the `sat` machine instruction which returns the saturated value of the argument.

Built-in Function: void __builtin_rx_setpsw (int)

  Generates the `setpsw` machine instruction to set the specified bit in the processor status word.

Built-in Function: void __builtin_rx_wait (void)

  Generates the `wait` machine instruction.