Function __qsub 

pub unsafe fn __qsub(a: i32, b: i32) -> i32

🔬This is a nightly-only experimental API. (stdarch_arm_dsp #117237)

Available on ARM and (target feature v5te and non-target feature mclass, or target features mclass and dsp) only.

Signed saturating subtraction

Returns the 32-bit saturating signed equivalent of a - b. Sets the Q flag if saturation occurs.