Be more strict about detecting multi-use blocks for isolation.

When a block has exactly two uses and the register is both live-in and live-out,
don't isolate the block. We would be inserting two cop

Be more strict about detecting multi-use blocks for isolation.

When a block has exactly two uses and the register is both live-in and live-out,
don't isolate the block. We would be inserting two copies, so we haven't really
made any progress.

If the live-in and live-out values separate into disconnected components after
splitting, we would be making progress. We can't detect that for now.

llvm-svn: 117169

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Be more strict when detecting critical edges before loop splitting.

An exit block with a critical edge must only have predecessors in the loop, or
just before the loop. This guarantees that the inse

Be more strict when detecting critical edges before loop splitting.

An exit block with a critical edge must only have predecessors in the loop, or
just before the loop. This guarantees that the inserted copies in the loop
predecessors dominate the exit block.

llvm-svn: 117144

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Add print methods

llvm-svn: 117143

Don't include the destination interval in the union when computing
Parent - union(Y, ...). Doh.

llvm-svn: 117042

Eliminate curli from SplitEditor. Use the LiveRangeEdit reference instead.

llvm-svn: 116547

Move stack slot assignments into LiveRangeEdit.

All registers created during splitting or spilling are assigned to the same
stack slot as the parent register.

When splitting or rematting, we may no

Move stack slot assignments into LiveRangeEdit.

All registers created during splitting or spilling are assigned to the same
stack slot as the parent register.

When splitting or rematting, we may not spill at all. In that case the stack
slot is still assigned, but it will be dead.

llvm-svn: 116546

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Create a new LiveRangeEdit class to keep track of the new registers created when
splitting or spillling, and to help with rematerialization.

Use LiveRangeEdit in InlineSpiller and SplitKit. This wil

Create a new LiveRangeEdit class to keep track of the new registers created when
splitting or spillling, and to help with rematerialization.

Use LiveRangeEdit in InlineSpiller and SplitKit. This will eventually make it
possible to share remat code between InlineSpiller and SplitKit.

llvm-svn: 116543

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Only split around a loop if the live range has uses outside the loop periphery.

Before we would also split around a loop if any peripheral block had multiple
uses. This could cause repeated splittin

Only split around a loop if the live range has uses outside the loop periphery.

Before we would also split around a loop if any peripheral block had multiple
uses. This could cause repeated splitting when splitting a different live range
would insert uses into the periphery.

Now -spiller=inline passes the nightly test suite again.

llvm-svn: 116494

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Rename SplitEditor::rewrite to finish() and break it out into a couple of new
functions: computeRemainder and rewrite.

When the remainder breaks up into multiple components, remember to rewrite thos

Rename SplitEditor::rewrite to finish() and break it out into a couple of new
functions: computeRemainder and rewrite.

When the remainder breaks up into multiple components, remember to rewrite those
uses as well.

llvm-svn: 116121

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After splitting, the remaining LiveInterval may be fragmented into multiple
connected components. These components should be allocated different virtual
registers because there is no reason for them

After splitting, the remaining LiveInterval may be fragmented into multiple
connected components. These components should be allocated different virtual
registers because there is no reason for them to be allocated together.

Add the ConnectedVNInfoEqClasses class to calculate the connected components,
and move values to new LiveIntervals.

Use it from SplitKit::rewrite by creating new virtual registers for the
components.

llvm-svn: 116006

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Print more loop info.

llvm-svn: 115951

Print out MBB number when rewriting.

llvm-svn: 115950

Cache interval iterators in SplitEditor::addTruncSimpleRange so we only have to
do one find().

llvm-svn: 115929

Clean up debug printing.

llvm-svn: 115928

Count uses in all nested loops, not just the deepest.

llvm-svn: 115710

Remove SplitAnalysis::removeUse. It was only used to make SplitAnalysis
reusable, but that is no longer relevant since a split will always replace the
original.

llvm-svn: 115709

dupli always has an interval now.

llvm-svn: 115708

We can split around loops with multiple exits now.

llvm-svn: 115696

Update SplitEditor API to reflect the fact that the original live interval is
never kept after splitting.

Keeping the original interval made sense when the split region doesn't modify
the register,

Update SplitEditor API to reflect the fact that the original live interval is
never kept after splitting.

Keeping the original interval made sense when the split region doesn't modify
the register, and the original is spilled. We can get the same effect by
detecting reloaded values when spilling around copies.

llvm-svn: 115695

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Intervals are half-open.

llvm-svn: 115694

When we find a reaching definition, make sure it is visited from all paths by
erasing it from the visited set. That ensures we create the right phi defs.

llvm-svn: 115666

Don't use nextIndex to check for live out of instruction.
Insert copy after defining instruction.

Fix LiveIntervalMap::extendTo to properly handle live segments starting before
the current basic blo

Don't use nextIndex to check for live out of instruction.
Insert copy after defining instruction.

Fix LiveIntervalMap::extendTo to properly handle live segments starting before
the current basic block.

Make sure the open live range is extended to the inserted copy's use slot.

llvm-svn: 115665

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Removed VNInfo::isDefAccurate(). Def "accuracy" can be checked by testing whether LiveIntervals::getInstructionFromIndex(def) returns NULL.

llvm-svn: 114791

Build the complement interval dupli after the split intervals instead of
creating it before and subtracting split ranges.

This way, the SSA update code in LiveIntervalMap can properly create and use

Build the complement interval dupli after the split intervals instead of
creating it before and subtracting split ranges.

This way, the SSA update code in LiveIntervalMap can properly create and use new
phi values in dupli. Now it is possible to create split regions where a value
escapes along two different CFG edges, creating phi values outside the split
region.

This is a work in progress and probably quite broken.

llvm-svn: 114492

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Use the value mapping provided by LiveIntervalMap. This simplifies the code a
great deal because we don't have to worry about maintaining SSA form.

Unconditionally copy back to dupli when the regist

Use the value mapping provided by LiveIntervalMap. This simplifies the code a
great deal because we don't have to worry about maintaining SSA form.

Unconditionally copy back to dupli when the register is live out of the split
range, even if the live-out value was defined outside the range. Skipping the
back-copy only makes sense when the live range is going to spill outside the
split range, and we don't know that it will. Besides, this was a hack to avoid
SSA update issues.

Clear up some confusion about the end point of a half-open LiveRange. Methinks
LiveRanges need to be closed so both start and end are included in the range.
The low bits of a SlotIndex are symbolic, so a half-open range doesn't really
make sense. This would be a pervasive change, though.

llvm-svn: 114043

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