Q:

Is nesting ARM Thumb2 "IT" instructions well defined?

If I have an ARM Thumb 2 instruction stream that looks like the following:
itt NZ
mov r1,r2
it MI
mov r3,r4

The IT block of the first IT instruction contains mov and a second it. Is this sequence allowable, or is it undefined behavior?

A:

An IT block must not contain another IT instruction. The result of your code is unpredictable.

