[llvm-dev] Understanding SlotIndexes

[via llvm-dev]

via llvm-dev <llvm-dev at lists.llvm.org> writes:

> My problem boils down to trying to find the defining instruction for a
> virtual register use.  Given an instruction using register A, I want to
> be able to look at the VNInfo at the instruction's register use slot and
> see what VNInfo::def points to.

Ok, so I think LiveQuery::valueIn is what I want.  That at least seems
to be pointing to the correct defining value.

I still don't understand SlotIndexes but at least I got by my current
issue.  I gather the Register and EarlyClobber slots are *not* actually
register use points (LiveQuery seems to use the Base/Block slot), which
pretty much directly contradicts the comments...

                              -David