Extend some comments around GCModuleInfo, GCFunctionInfo, & GCStrategy

Nothing particularly interesting here, just documenting the way the code currently works before I start changing it...



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223866 91177308-0d34-0410-b5e6-96231b3b80d8
AsmParser: Don't crash if a null byte is inside a quoted string

We don't allow Value* to have names which contain null bytes.  The
AsmParser should reject .ll files that try to do this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223869 91177308-0d34-0410-b5e6-96231b3b80d8
Let tablegen compute maximum lanemask for regs/regclasses.

Let tablegen compute the combination of subregister lanemasks for all
subregisters in a register/register class. This is preparation for further
work subregister allocation

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223873 91177308-0d34-0410-b5e6-96231b3b80d8
Add function that translates subregister lane masks to other subregs.

This works like the composeSubRegisterIndices() function but transforms
a subregister lane mask instead of a subregister index.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223874 91177308-0d34-0410-b5e6-96231b3b80d8
LiveInterval: Add const version of LiveRange::advanceTo().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223875 91177308-0d34-0410-b5e6-96231b3b80d8
LiveInterval: Add a 'covers' operation to LiveRange.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223876 91177308-0d34-0410-b5e6-96231b3b80d8
LiveInterval: Add support to track liveness of subregisters.

This code adds the required data structures. Algorithms to compute it follow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223877 91177308-0d34-0410-b5e6-96231b3b80d8
LiveIntervalAnalysis: Compute subregister ranges.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223878 91177308-0d34-0410-b5e6-96231b3b80d8
LiveIntervalAnalysis: Make computeDeadValues() private.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223879 91177308-0d34-0410-b5e6-96231b3b80d8
LiveIntervalAnalysis: Update SubRanges in shrinkToUses().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223880 91177308-0d34-0410-b5e6-96231b3b80d8
LiveIntervalAnalysis: Adapt handleMove() to subregister ranges.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223881 91177308-0d34-0410-b5e6-96231b3b80d8
LiveRangeEdit: Adapt eliminateDeadDef() to subregister liveness.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223882 91177308-0d34-0410-b5e6-96231b3b80d8
LiveIntervalAnalysis: Adapt repairIntervalsInRange() to subregister liveness.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223883 91177308-0d34-0410-b5e6-96231b3b80d8
Add a flag to enable/disable subregister liveness.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223884 91177308-0d34-0410-b5e6-96231b3b80d8
LiveInterval: Introduce LiveQuery accessor for dead or live out values.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223885 91177308-0d34-0410-b5e6-96231b3b80d8
LiveIntervalAnalysis: Add subregister aware variants pruneValue().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223886 91177308-0d34-0410-b5e6-96231b3b80d8
LiveInterval: Add removeEmptySubRanges().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223887 91177308-0d34-0410-b5e6-96231b3b80d8
RegisterCoalescer: Preserve subregister liveranges.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223888 91177308-0d34-0410-b5e6-96231b3b80d8
Tablegen'erate lanemasks for register units.

Now we can relate lanemasks in a virtual register to register units.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223889 91177308-0d34-0410-b5e6-96231b3b80d8
LiveIntervalUnion: Allow specification of liverange when unifying/extracting.

This allows it to add subregister ranges into the union.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223890 91177308-0d34-0410-b5e6-96231b3b80d8