PR10998: It is not legal to sink an instruction past the terminator of a block; make sure we don't do that.

llvm-svn: 140428

DecomposeMERGE_VALUES to "know" that results are legalized in
a particular order, by passing it the number of the result
being legalized (the type legalization core provides this, it
just needs to be passed on).

llvm-svn: 140373

integer-promotion of CONCAT_VECTORS.

Test: test/CodeGen/X86/widen_shuffle-1.ll

This patch fixes the above tests (when running in with -promote-elements).

llvm-svn: 140372

worklist, as it may be possible to perform further optimization on them.

llvm-svn: 140349

Sometimes register class constraints are trivial, like GR32->GR32_NOSP,
or GPR->rGPR.  Teach InstrEmitter to simply constrain the virtual
register instead of emitting a copy in these cases.

Normally, these copies are handled by the coalescer.  This saves some
coalescer work.

llvm-svn: 140340

The function will refuse to use a register class with fewer registers
than MinNumRegs.  This can be used by clients to avoid accidentally
increase register pressure too much.

The default value of MinNumRegs=0 doesn't affect how constrainRegClass()
works.

llvm-svn: 140339

llvm-svn: 140318

Few weeks ago, llvm completely inverted the debug info graph. Earlier each debug info node used to keep track of its compile unit, now compile unit keeps track of important nodes. One impact of this change is that the global variable's do not have any context, which should be checked before deciding to use AT_specification DIE.

llvm-svn: 140282

This inserts a cleanup landingpad instruction and a resume to mimic the old
unwind instruction.

llvm-svn: 140277

llvm-svn: 140275

Vector SetCC result types need to be type-legalized.
This code worked before because scalar result types are known to be legal.

llvm-svn: 140249

This is still a hack until we can teach tblgen to generate the
optional CPSR operand rather than an implicit CPSR def. But the
strangeness is now limited to the selection DAG. ADD/SUB MI's no
longer have implicit CPSR defs, nor do we allow flag setting variants
of these opcodes in machine code. There are several corner cases to
consider, and getting one wrong would previously lead to nasty
miscompilation. It's not the first time I've debugged one, so this
time I added enough verification to ensure it won't happen again.

llvm-svn: 140228

subvector inserts and extracts. Initial patch by Rackover, Zvi with
some tweak done by me.

llvm-svn: 140204

No functionality change. The hook makes it explicit which patterns
require "special" handling. i.e. it self-documents tblgen
deficiencies. I plan to add verification in ExpandISelPseudos and
Thumb2SizeReduce to catch any missing hasPostISelHooks. Otherwise it's
too fragile.

llvm-svn: 140160

Modified ARMISelLowering::AdjustInstrPostInstrSelection to handle the
full gamut of CPSR defs/uses including instructins whose "optional"
cc_out operand is not really optional. This allowed removal of the
hasPostISelHook to simplify the .td files and make the implementation
more robust.
Fixes rdar://10137436: sqlite3 miscompile

llvm-svn: 140134

llvm-svn: 140133

llvm-svn: 139994

llvm-svn: 139892

The leaveIntvAfter() function normally inserts a back-copy after the
requested instruction, making the back-copy kill the live range.

In spill mode, try to insert the back-copy before the last use instead.
That means the last use becomes the kill instead of the back-copy.  This
lowers the register pressure because the last use can now redefine the
same register it was reading.

This will also improve compile time: The back-copy isn't a kill, so
hoisting it in hoistCopiesForSize() won't force a recomputation of the
source live range.  Similarly, if the back-copy isn't hoisted by the
splitter, the spiller will not attempt hoisting it locally.

llvm-svn: 139883

If the source register is live after the copy being spilled, there is no
point to hoisting it.  Hoisting inside a basic block only serves to
resolve interferences by shortening the live range of the source.

llvm-svn: 139882

llvm-svn: 139851

When -split-spill-mode is enabled, spill hoisting is performed by
SplitKit instead of by InlineSpiller.  This hidden command line option
is for testing the splitter spill mode.

llvm-svn: 139845

Fix the stats counters to reflect that.

llvm-svn: 139819

The number of spills could go negative since a folded COPY is just a
spill, and it may be eliminated.

llvm-svn: 139815

Adjust counters when removing spill and reload instructions.

We still don't account for reloads being removed by eliminateDeadDefs().

llvm-svn: 139806

When traceSiblingValue() encounters a PHI-def value created by live
range splitting, don't look at all the predecessor blocks.  That can be
very expensive in a complicated CFG.

Instead, consider that all the non-PHI defs jointly dominate all the
PHI-defs.  Tracing directly to all the non-PHI defs is much faster that
zipping around in the CFG when there are many PHIs with many
predecessors.

This significantly improves compile time for indirectbr interpreters.

llvm-svn: 139797

Blocks with multiple PHI successors only need to go on the worklist
once.  Use a SmallPtrSet to track the live-out blocks that have already
been handled.  This is a lot faster than the two live range check we
would otherwise do.

Also stop recomputing hasPHIKill flags.  Like RenumberValues(), it is
conservatively correct to leave them in, and they are not used for
anything important.

llvm-svn: 139792

It does, after all.

RemoveCopyByCommutingDef rewrites the uses of one particular value
number in A. It doesn't know how to rewrite phi uses, so there can't be
any.

llvm-svn: 139787

There is only one legitimate use remaining, in addIntervalsForSpills().
All other calls to hasPHIKill() are only used to update PHIKill flags.

The addIntervalsForSpills() function is part of the old spilling
framework, only used by linearscan.

llvm-svn: 139783

Instead, let HasOtherReachingDefs() test for defs in B that overlap any
phi-defs in A as well.  This test is slightly different, but almost
identical.

A perfectly precise test would only check those phi-defs in A that are
reachable from AValNo.

llvm-svn: 139782

The source live range is recomputed using shrinkToUses() which does
handle phis correctly.  The hasPHIKill() condition was relevant in the
old days when ReMaterializeTrivialDef() tried to recompute the live
range itself.

The shrinkToUses() function will mark the original def as dead when no
more uses and phi kills remain.  It is then removed by
runOnMachineFunction().

llvm-svn: 139781

It is conservatively correct to keep the hasPHIKill flags, even after
deleting PHI-defs.

The calculation can be very expensive after taildup has created a
quadratic number of indirectbr edges in the CFG, and the hasPHIKill flag
isn't used for anything after RenumberValues().

llvm-svn: 139780

An improper SlotIndex->VNInfo lookup was leading to unsafe copy removal.
Fixes PR10920 401.bzip2 miscompile with no IV rewrite.

llvm-svn: 139765

llvm-svn: 139751

THe LRE_DidCloneVirtReg callback may be called with vitual registers
that RAGreedy doesn't even know about yet.  In that case, there are no
data structures to update.

llvm-svn: 139702

When a back-copy is hoisted to the nearest common dominator, keep
looking up the dominator tree for a less loopy dominator, and place the
back-copy there instead.

Don't do this when a single existing back-copy dominates all the others.
Assume the client knows what he is doing, and keep the dominating
back-copy.

This prevents us from hoisting back-copies into loops in most cases.  If
a value is defined in a loop with multiple exits, we may still hoist
back-copies into that loop.  That is the speed/size tradeoff.

llvm-svn: 139698

llvm-svn: 139692

When a ParentVNI maps to multiple defs in a new interval, its live range
may still be derived directly from RegAssign by transferValues().

On the other hand, when instructions have been rematerialized or
hoisted, it may be necessary to completely recompute live ranges using
LiveRangeCalc::extend() to all uses.

Use a bit in the value map to indicate that a live range must be
recomputed.  Rename markComplexMapped() to forceRecompute().

This fixes some live range verification errors when
-split-spill-mode=size hoists back-copies by recomputing source ranges
when RegAssign kills can't be moved.

llvm-svn: 139660

Whenever the complement interval is defined by multiple copies of the
same value, hoist those back-copies to the nearest common dominator.

This ensures that at most one copy is inserted per value in the
complement inteval, and no phi-defs are needed.

llvm-svn: 139651

llvm-svn: 139649