Add bundle aware API for querying instruction properties and switch the code
generator to it. For non-bundle instructions, these behave exactly the same
as the MC layer API.

For properties like mayL

Add bundle aware API for querying instruction properties and switch the code
generator to it. For non-bundle instructions, these behave exactly the same
as the MC layer API.

For properties like mayLoad / mayStore, look into the bundle and if any of the
bundled instructions has the property it would return true.
For properties like isPredicable, only return true if *all* of the bundled
instructions have the property.
For properties like canFoldAsLoad, isCompare, conservatively return false for
bundles.

llvm-svn: 146026

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Rename SlotIndexes to match how they are used.

The old naming scheme (load/use/def/store) can be traced back to an old
linear scan article, but the names don't match how slots are actually
used.

Th

Rename SlotIndexes to match how they are used.

The old naming scheme (load/use/def/store) can be traced back to an old
linear scan article, but the names don't match how slots are actually
used.

The load and store slots are not needed after the deferred spill code
insertion framework was deleted.

The use and def slots don't make any sense because we are using
half-open intervals as is customary in C code, but the names suggest
closed intervals. In reality, these slots were used to distinguish
early-clobber defs from normal defs.

The new naming scheme also has 4 slots, but the names match how the
slots are really used. This is a purely mechanical renaming, but some
of the code makes a lot more sense now.

llvm-svn: 144503

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Move CalculateRegClass to MRI::recomputeRegClass.

This function doesn't have anything to do with spill weights, and MRI
already has functions for manipulating the register class of a virtual
registe

Move CalculateRegClass to MRI::recomputeRegClass.

This function doesn't have anything to do with spill weights, and MRI
already has functions for manipulating the register class of a virtual
register.

llvm-svn: 137123

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Fix PR10277.

Remat during spilling triggers dead code elimination. If a phi-def
becomes unused, that may also cause live ranges to split into separate
connected components.

This type of splitting i

Fix PR10277.

Remat during spilling triggers dead code elimination. If a phi-def
becomes unused, that may also cause live ranges to split into separate
connected components.

This type of splitting is different from normal live range splitting. In
particular, there may not be a common original interval.

When the split range is its own original, make sure that the new
siblings are also their own originals. The range being split cannot be
used as an original since it doesn't cover the new siblings.

llvm-svn: 134413

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Add some statistics to the splitting and spilling frameworks.

llvm-svn: 130931

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 debug output for rematerializable instructions.

llvm-svn: 129883

Remember to set flag.

llvm-svn: 129579

Don't shrink live ranges after dead code elimination unless it is going to help.

In particular, don't repeatedly recompute the PIC base live range after rematerialization.

llvm-svn: 129275

When dead code elimination removes all but one use, try to fold the single def into the remaining use.

Rematerialization can leave single-use loads behind that we might as well fold whenever possibl

When dead code elimination removes all but one use, try to fold the single def into the remaining use.

Rematerialization can leave single-use loads behind that we might as well fold whenever possible.

llvm-svn: 128918

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Treat clones the same as their origin.

When DCE clones a live range because it separates into connected components,
make sure that the clones enter the same register allocator stage as the
register

Treat clones the same as their origin.

When DCE clones a live range because it separates into connected components,
make sure that the clones enter the same register allocator stage as the
register they were cloned from.

For instance, clones may be split even when they where created during spilling.
Other registers created during spilling are not candidates for splitting or even
(re-)spilling.

llvm-svn: 128524

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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

Remember to use the correct register when rematerializing for snippets.

llvm-svn: 128469

Properly enable rematerialization when spilling after live range splitting.

The instruction to be rematerialized may not be the one defining the register
that is being spilled. The traceSiblingValue

Properly enable rematerialization when spilling after live range splitting.

The instruction to be rematerialized may not be the one defining the register
that is being spilled. The traceSiblingValue() function sees through sibling
copies to find the remat candidate.

llvm-svn: 128449

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Notify the delegate before removing dead values from a live interval.

The register allocator needs to know when the range shrinks.

llvm-svn: 128145

Dead code elimination may separate the live interval into multiple connected components.

I have convinced myself that it can only happen when a phi value dies. When it
happens, allocate new virtual

Dead code elimination may separate the live interval into multiple connected components.

I have convinced myself that it can only happen when a phi value dies. When it
happens, allocate new virtual registers for the components.

llvm-svn: 127827

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Add a LiveRangeEdit delegate callback before shrinking a live range.

The register allocator needs to adjust its live interval unions when that happens.

llvm-svn: 127774

Erase virtual registers that are unused after DCE.

llvm-svn: 127773

Clarify debugging output.

llvm-svn: 127771

Tell the register allocator about new unused virtual registers.

This allows the allocator to free any resources used by the virtual register,
including physical register assignments.

llvm-svn: 1275

Tell the register allocator about new unused virtual registers.

This allows the allocator to free any resources used by the virtual register,
including physical register assignments.

llvm-svn: 127560

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Add a LiveRangeEdit::Delegate protocol.

This will we used for keeping register allocator data structures up to date
while LiveRangeEdit is trimming live intervals.

llvm-svn: 127300

Delete dead code after rematerializing.

LiveRangeEdit::eliminateDeadDefs() will eventually be used by coalescing,
splitting, and spilling for dead code elimination. It can delete chains of dead
inst

Delete dead code after rematerializing.

LiveRangeEdit::eliminateDeadDefs() will eventually be used by coalescing,
splitting, and spilling for dead code elimination. It can delete chains of dead
instructions as long as there are no dependency loops.

llvm-svn: 127287

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Make the UselessRegs argument optional in the LiveRangeEdit constructor.

llvm-svn: 127181

This method belonged in VirtRegMap.

llvm-svn: 126002

Use VirtRegMap's Virt2SplitMap to keep track of the original live range before splitting.

All new virtual registers created for spilling or splitting point back to their original.

llvm-svn: 125980