Edward Bartolo writes:
> The parent compiler and the other compilers must produce identical
> code from the same source code. How is the control (parent source)
> compiler known to produce exactly the same executables as the other
> compilers?

No. David Wheeler's dissertation goes into that in detail. Sixty pages of
detail. https://www.dwheeler.com/trusting-trust/dissertation/

(As an aside, the people who bring up this compiler trust issue seem not to
have thought about how it could work in the modern world. We have several
compilers with open source and long version histories these days, and ditto
operating systems.)

Arnt