[GVN] Pass the phi-translated address of a load instead of the untranslated
address to AnalyzeLoadFromClobberingLoad. This fixes a bug in load-PRE where
PRE is applied to a load that is not partially redundant.

<rdar://problem/16638765>.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207853 91177308-0d34-0410-b5e6-96231b3b80d8
Teach GlobalDCE how to remove empty global_ctor entries.

This moves most of GlobalOpt's constructor optimization
code out of GlobalOpt into Transforms/Utils/CDtorUtils.{h,cpp}. The
public interface is a single function OptimizeGlobalCtorsList() that
takes a predicate returning which constructors to remove.

GlobalOpt calls this with a function that statically evaluates all
constructors, just like it did before. This part of the change is
behavior-preserving.

Also add a call to this from GlobalDCE with a filter that removes global
constructors that contain a "ret" instruction and nothing else – this
fixes PR19590.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207856 91177308-0d34-0410-b5e6-96231b3b80d8
Remove dead declaration.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207857 91177308-0d34-0410-b5e6-96231b3b80d8