[Bug tree-optimization/49911] SRA + DOM + VRP + -fstrict-enums incorrectly remove predicate

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49911

--- Comment #11 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-08-06 15:58:47 UTC ---
> So, Eric - are you still objecting to make VRP and the middle-end aligned
> by ignoring TYPE_MIN/MAX_VALUE in VRP?

Just to give a bit of context to the reader: this problem bit the Ada compiler
since VRP had been introduced in 2004.  At the time, the consensus was that the
Ada compiler was lying to the middle-end, because objects of type T could have
values that are outside [TYPE_MIN_VALUE:TYPE_MAX_VALUE] in some cases and this
breaks an invariant of the middle-end.  So we changed the Ada compiler in 2009.

If it appears that the previous consensus was short-sighted and should now be
reversed, fine with me, but please document what TYPE_MIN_VALUE/TYPE_MAX_VALUE
mean under the new one.  And if they don't mean anything, then remove them.