Remember to actually update SplitAnalysis statistics now that we have a fancy
function to do it.

llvm-svn: 110994

Handle an empty dupli.

This can happen if the original interval has been broken into two disconnected
parts. Ideally, we should be able to detect when the graph is disconnected and
create separate i

Handle an empty dupli.

This can happen if the original interval has been broken into two disconnected
parts. Ideally, we should be able to detect when the graph is disconnected and
create separate intervals, but that code is not implemented yet.

Example:

Two basic blocks are both branching to a loop header. Our interval is defined in
both basic blocks, and live into the loop along both edges.

We decide to split the interval around the loop. The interval is split into an
inside part and an outside part. The outside part now has two disconnected
segments, one in each basic block.

If we later decide to split the outside interval into single blocks, we get one
interval per basic block and an empty dupli for the remainder.

llvm-svn: 110976

show more ...

Update the SplitAnalysis statistics as uses are moved from curli to the new
split intervals. THis means the analysis can be used for multiple splits as long
as curli doesn't shrink.

llvm-svn: 110975

Also recompute HasPHIKill flags in LiveInterval::RenumberValues.

If a phi-def value were removed from the interval, the phi-kill flags are no
longer valid.

llvm-svn: 110949

Clean up debug output.

llvm-svn: 110940

Implement single block splitting.

Before spilling a live range, we split it into a separate range for each basic
block where it is used. That way we only get one reload per basic block if the
new sm

Implement single block splitting.

Before spilling a live range, we split it into a separate range for each basic
block where it is used. That way we only get one reload per basic block if the
new smaller ranges can allocate to a register.

This type of splitting is already present in the standard spiller.

llvm-svn: 110934

show more ...

More debug spew

llvm-svn: 110720

Implement register class inflation.

When splitting a live range, the new registers have fewer uses and the
permissible register class may be less constrained. Recompute the register class
constraint

Implement register class inflation.

When splitting a live range, the new registers have fewer uses and the
permissible register class may be less constrained. Recompute the register class
constraint from the uses of new registers created for a split. This may let them
be allocated from a larger set, possibly avoiding a spill.

llvm-svn: 110703

show more ...

Recalculate the spill weight and allocation hint for virtual registers created
during live range splitting.

llvm-svn: 110686

Lazily defer duplicating the live interval we are splitting until we know it is
necessary.

Sometimes, live range splitting doesn't shrink the current interval, but simply
changes some instructions t

Lazily defer duplicating the live interval we are splitting until we know it is
necessary.

Sometimes, live range splitting doesn't shrink the current interval, but simply
changes some instructions to use a new interval. That makes the original more
suitable for spilling. In this case, we don't need to duplicate the original.

llvm-svn: 110481

show more ...

Add LiveInterval::RenumberValues - Garbage collection for VNInfos.

After heavy editing of a live interval, it is much easier to simply renumber the
live values instead of trying to keep track of the

Add LiveInterval::RenumberValues - Garbage collection for VNInfos.

After heavy editing of a live interval, it is much easier to simply renumber the
live values instead of trying to keep track of the unused ones.

llvm-svn: 110463

show more ...

Fix swapped COPY operands.

llvm-svn: 110453

Checkpoint SplitKit progress.

We are now at a point where we can split around simple single-entry, single-exit
loops, although still with some bugs.

llvm-svn: 110257

Add SplitEditor to SplitKit. This class will be used to edit live intervals and
rewrite instructions for live range splitting.

Still work in progress.

llvm-svn: 109469

Change the createSpiller interface to take a MachineFunctionPass argument.

The spillers can pluck the analyses they need from the pass reference.

Switch some never-null pointers to references.

llv

Change the createSpiller interface to take a MachineFunctionPass argument.

The spillers can pluck the analyses they need from the pass reference.

Switch some never-null pointers to references.

llvm-svn: 108969

show more ...

Implement loop splitting analysis.
Determine which loop exit blocks need a 'pre-exit' block inserted.
Recognize when this would be impossible.

llvm-svn: 108941

Appease the colonials.

llvm-svn: 108845

Beginning SplitKit - utility classes for live range splitting.

This is a work in progress. So far we have some basic loop analysis to help
determine where it is useful to split a live range around a

Beginning SplitKit - utility classes for live range splitting.

This is a work in progress. So far we have some basic loop analysis to help
determine where it is useful to split a live range around a loop.

The actual loop splitting code from Splitter.cpp is also going to move in here.

llvm-svn: 108842

show more ...