Discussion: What is unspec_volatile?

[Ian Lance Taylor]

Georg Johann Lay <avr@gjlay.de> writes:

> What about liveness? No hard reg, pseudo, mem will live avross the
> unspec volatile. Right?

As Paul noted, this is incorrect.


> Might debug info cross unspec volatiles?
> Can the back end take the decision?

I don't understand what you mean here.  It is not the case that debug
info is created and then moves around.  Asking whether debug info
crosses an unspec_volatile is the same as asking whether any real
instruction crosses an unspec_volatile.

(gcc does currently have DEBUG_INSN, which is used to indicate the
location or value of a variable at a specific point in a program.  Those
insns are not in themselves debug info, and they move around according
to how the rest of the program moves around.)

Ian