This intrinsic inserts a QSUB instruction or an equivalent code sequence into the instruction stream generated by the compiler. It enables you to obtain the saturating subtraction of two integers from within your C or C++ code.
int __qsub(int val1, int val2)
Where:
val1is the minuend of the saturating subtraction operation
val2is the subtrahend of the saturating subtraction operation.
The __qsub intrinsic returns the saturating subtraction of val1 and val2.