Update mem2reg's comments to conform to the new doxygen standards. No
functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186772 91177308-0d34-0410-b5e6-96231b3b80d8
Remove a DenseMapInfo specialization for std::pair -- we have one of
those baked into DenseMap now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186773 91177308-0d34-0410-b5e6-96231b3b80d8
Comment: try to clarify loop iteration order.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186774 91177308-0d34-0410-b5e6-96231b3b80d8
Reformat the implementation of mem2reg with clang-format so that my
subsequent changes don't introduce inconsistencies.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186775 91177308-0d34-0410-b5e6-96231b3b80d8
Rename constructor parameters to follow the common member-shadowing
pattern and conform to the naming conventions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186776 91177308-0d34-0410-b5e6-96231b3b80d8
Don't allocate the DIBuilder on the heap and remove all the complexity
that ensued from that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186777 91177308-0d34-0410-b5e6-96231b3b80d8
Don't crash when llvm.compiler.used becomes empty.

GlobalOpt simplifies llvm.compiler.used by removing any members that are also
in the more strict llvm.used. Handle the special case where llvm.compiler.used
becomes empty.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186778 91177308-0d34-0410-b5e6-96231b3b80d8
Sink a typedef and comparator down to the function that actually uses them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186779 91177308-0d34-0410-b5e6-96231b3b80d8
Hoist the AllocaInfo struct to the top of the file.

This struct is nicely independent of everything else, and we already
needed a foward declaration here. It's simpler to just define it
immediately.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186780 91177308-0d34-0410-b5e6-96231b3b80d8
Hoist the two trivial promotion routines out of the big class that
handles the general cases.

The hope is to refactor this so that we don't end up building the entire
class for the trivial cases. I also want to lift a lot of the early
pre-processing in the initial segment of run() into a separate routine,
and really none of it needs to happen inside the primary promotion
class.

These routines in particular used none of the actual state in the
promotion class, so they don't really make sense as members.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186781 91177308-0d34-0410-b5e6-96231b3b80d8
Remove a method made dead by the prior refactoring.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186782 91177308-0d34-0410-b5e6-96231b3b80d8
Hoist the rest of the logic for fully promoting allocas with all uses in
a single block into the helper routine. This takes advantage of the fact
that we can directly replace uses prior to any store with undef to
simplify matters and unconditionally promote allocas only used within
one block.

I've removed the special handling for the case of no stores existing.
This has no semantic effect but might slow things down. I'll fix that in
a later patch when I refactor this entire thing to be easier to manage
the different cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186783 91177308-0d34-0410-b5e6-96231b3b80d8
Hoist the rest of the logic for promoting single-store allocas into the
helper function. This leaves both trivial cases handled entirely in
helper functions and merely manages the list of allocas to process in
the run method.

The next step will be to handle all of the trivial promotion work prior
to even creating the core class and the subsequent simplifications that
enables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186784 91177308-0d34-0410-b5e6-96231b3b80d8
Fix exception demo: Add mcjit to link component.

Fix exception demo when we are building the examples with configure/make.
This commit updates the link components in the Makefile.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186785 91177308-0d34-0410-b5e6-96231b3b80d8
Revert a part of r186420. Don't forbid multiple store chains that merge.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186786 91177308-0d34-0410-b5e6-96231b3b80d8
Mark that the _ftol2 function used by windows on x86 to handle fptoui modifies ECX.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186787 91177308-0d34-0410-b5e6-96231b3b80d8
Make the mem2reg interface use an ArrayRef as it keeps a copy of these
to iterate over.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186788 91177308-0d34-0410-b5e6-96231b3b80d8