7.9.14 The FUNC_INTERRUPT_THRESHOLD Pragma

The compiler allows interrupts to be disabled around software pipelined loops for threshold cycles within the function. This implements the --interrupt_threshold option for a single function (see Section 3.12). The FUNC_INTERRUPT_THRESHOLD pragma always overrides the --interrupt_threshold=n command line option. A threshold value less than 0 assumes that the function is never interrupted, which is equivalent to an interrupt threshold of infinity.

The syntax of the pragma in C is:

The syntax of the pragma in C++ is:

The following examples demonstrate the use of different thresholds:

• The function foo( ) must be interruptible at least every 2,000 cycles:
#pragma FUNC_INTERRUPT_THRESHOLD (foo, 2000)
• The function foo( ) must always be interruptible.
#pragma FUNC_INTERRUPT_THRESHOLD (foo, 1)
• The function foo( ) is never interrupted.
#pragma FUNC_INTERRUPT_THRESHOLD (foo, -1)