Fix PR9883. Make sure all caches are invalidated when a live range is repaired.

The previous invalidation missed the alias interference caches.

Also add a stats counter for the number of repaired r

Fix PR9883. Make sure all caches are invalidated when a live range is repaired.

The previous invalidation missed the alias interference caches.

Also add a stats counter for the number of repaired ranges.

llvm-svn: 131133

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Add some statistics to the splitting and spilling frameworks.

llvm-svn: 130931

Gracefully handle invalid live ranges. Fix PR9831.

Register coalescing can sometimes create live ranges that end in the middle of a
basic block without any killing instruction. When SplitKit detects

Gracefully handle invalid live ranges. Fix PR9831.

Register coalescing can sometimes create live ranges that end in the middle of a
basic block without any killing instruction. When SplitKit detects this, it will
repair the live range by shrinking it to its uses.

Live range splitting also needs to know about this. When the range shrinks so
much that it becomes allocatable, live range splitting fails because it can't
find a good split point. It is paranoid about making progress, so an allocatable
range is considered an error.

The coalescer should really not be creating these bad live ranges. They appear
when coalescing dead copies.

llvm-svn: 130787

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Minimize the slot indexes spanned by register ranges created when splitting.

When an interfering live range ends at a dead slot index between two
instructions, make sure that the inserted copy instr

Minimize the slot indexes spanned by register ranges created when splitting.

When an interfering live range ends at a dead slot index between two
instructions, make sure that the inserted copy instruction gets a slot index
after the dead ones. This makes it possible to avoid the interference.

Ideally, there shouldn't be interference ending at a deleted instruction, but
physical register coalescing can sometimes do that to sub-registers.

This fixes PR9823.

llvm-svn: 130687

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Add a safe-guard against repeated splitting for some rare cases.

The number of blocks covered by a live range must be strictly decreasing when
splitting, otherwise we can't allow repeated splitting.

Add a safe-guard against repeated splitting for some rare cases.

The number of blocks covered by a live range must be strictly decreasing when
splitting, otherwise we can't allow repeated splitting.

llvm-svn: 130249

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Don't recycle loop variables.

llvm-svn: 129928

Allow allocatable ranges from global live range splitting to be split again.

These intervals are allocatable immediately after splitting, but they may be
evicted because of later splitting. This is

Allow allocatable ranges from global live range splitting to be split again.

These intervals are allocatable immediately after splitting, but they may be
evicted because of later splitting. This is rare, but when it happens they
should be split again.

The remainder intervals that cannot be allocated after splitting still move
directly to spilling.

SplitEditor::finish can optionally provide a mapping from new live intervals
back to the original interval indexes returned by openIntv().

Each original interval index can map to multiple new intervals after connected
components have been separated. Dead code elimination may also add existing
intervals to the list.

The reverse mapping allows the SplitEditor client to treat the new intervals
differently depending on the split region they came from.

llvm-svn: 129925

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Unbreak the MSVC 2010 build.
For further information on this particular issue see: http://connect.microsoft.com/VisualStudio/feedback/details/520043/error-converting-from-null-to-a-pointer-type-in-st

Unbreak the MSVC 2010 build.
For further information on this particular issue see: http://connect.microsoft.com/VisualStudio/feedback/details/520043/error-converting-from-null-to-a-pointer-type-in-std-pair

llvm-svn: 129642

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Teach the SplitKit blitter to handle multiply defined values as well.

The transferValues() function can now handle both singly and multiply defined
values, as long as the resulting live range is kno

Teach the SplitKit blitter to handle multiply defined values as well.

The transferValues() function can now handle both singly and multiply defined
values, as long as the resulting live range is known. Only rematerialized values
have their live range recomputed by extendRange().

The updateSSA() function can now insert PHI values in bulk across multiple
values in multiple target registers in one pass. The list of blocks received
from transferValues() is in layout order which seems to work well for the
iterative algorithm. Blocks from extendRange() are still in reverse BFS order,
but this function is used so rarely now that it doesn't matter.

llvm-svn: 129580

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Stop using dead function.

llvm-svn: 129442

Create new intervals for isolated blocks during region splitting.

This merges the behavior of splitSingleBlocks into splitAroundRegion, so the
RS_Region and RS_Block register stages can be coalesced

Create new intervals for isolated blocks during region splitting.

This merges the behavior of splitSingleBlocks into splitAroundRegion, so the
RS_Region and RS_Block register stages can be coalesced. That means the leftover
intervals after region splitting go directly to spilling instead of a second
pass of per-block splitting.

llvm-svn: 129379

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Add SplitKit API to query and select the current interval being worked on.

This makes it possible to target multiple registers in one pass.

llvm-svn: 129374

Build the Hopfield network incrementally when splitting global live ranges.

It is common for large live ranges to have few basic blocks with register uses
and many live-through blocks without any us

Build the Hopfield network incrementally when splitting global live ranges.

It is common for large live ranges to have few basic blocks with register uses
and many live-through blocks without any uses. This approach grows the Hopfield
network incrementally around the use blocks, completely avoiding checking
interference for some through blocks.

llvm-svn: 129188

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Analyze blocks with uses separately from live-through blocks without uses.

About 90% of the relevant blocks are live-through without uses, and the only
information required about them is their numbe

Analyze blocks with uses separately from live-through blocks without uses.

About 90% of the relevant blocks are live-through without uses, and the only
information required about them is their number. This saves memory and enables
later optimizations that need to look at only the use-blocks.

llvm-svn: 128985

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Sign error

llvm-svn: 128963

Don't crash when a value is defined after the last split point.

llvm-svn: 128962

Use std::unique instead of a SmallPtrSet to ensure unique instructions in UseSlots.

This allows us to always keep the smaller slot for an instruction which is what
we want when a register has early

Use std::unique instead of a SmallPtrSet to ensure unique instructions in UseSlots.

This allows us to always keep the smaller slot for an instruction which is what
we want when a register has early clobber defines.

Drop the UsingInstrs set and the UsingBlocks map. They are no longer needed.

llvm-svn: 128886

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Stop precomputing last split points, query the SplitAnalysis cache on demand.

llvm-svn: 128875

Cache the fairly expensive last split point computation and provide a fast
inlined path for the common case.

Most basic blocks don't contain a call that may throw, so the last split point
os simply

Cache the fairly expensive last split point computation and provide a fast
inlined path for the common case.

Most basic blocks don't contain a call that may throw, so the last split point
os simply the first terminator.

llvm-svn: 128874

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Stop caching basic block index ranges now that SlotIndexes can keep up.

llvm-svn: 128821

Recompute register class and hint for registers created during spilling.

The spill weight is not recomputed for an unspillable register - it stays infinite.

llvm-svn: 128490

Handle the special case when all uses follow the last split point.

llvm-svn: 128450

Amend debug output.

llvm-svn: 128398

Process all dead defs after rematerializing during splitting.

llvm-svn: 127973

Be more accurate about the slot index reading a register when dealing with defs
and early clobbers.

Assert when trying to find an undefined value.

llvm-svn: 127856