Reserved register live ranges look like a set of dead defs - any uses of
reserved registers are ignored.

Instead of skipping the updating of reserved register operands entirely,
just ignore the use operands and treat the def operands normally.

No test case, handleMove() is not commonly used yet.

llvm-svn: 165060

The old-fashioned many-to-one value mapping doesn't always work when
merging vector lanes. A value can map to multiple different values, and
it can even be necessary to insert new PHIs.

When a value number is defined by a copy from a value number that
required SSa update, include the live range of the copied value number
in the SSA update as well. It is not necessarily a copy of the original
value number any longer.

llvm-svn: 164329

Add LIS::pruneValue() and extendToIndices(). These two functions are
used by the register coalescer when merging two live ranges requires
more than a trivial value mapping as supported by LiveInterval::join().

The pruneValue() function can remove the part of a value number that is
going to conflict in join(). Afterwards, extendToIndices can restore the
live range, using any new dominating value numbers and updating the SSA
form.

Use this complex value mapping to support merging a register into a
vector lane that has a conflicting value, but the clobbered lane is
undef.

llvm-svn: 164074

findLastUseBefore was previous considering virtreg liveness only, leading to
incorrect live intervals for reg units when instrs with physreg operands were
moved up.
 

llvm-svn: 163685

"#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)"

No functional change. Update r163339.

llvm-svn: 163653

llvm-svn: 163547

No functional change.

llvm-svn: 163339

We will soon allow virtual register live ranges to overlap regunit live
ranges when the physreg is defined as a copy of the virtreg:

  %EAX = COPY %vreg5
  FOO %vreg5
  BAR %EAX<kill>

There is no real interference since %vreg5 and %EAX have the same value
where they overlap.

This patch prevents addKillFlags from adding virtreg kill flags to FOO
where the assigned physreg is overlapping the virtual register live
range.

llvm-svn: 163335

Fixs PR13719.

llvm-svn: 163107

Based on CR feedback from r162301 and Craig Topper's refactoring in r162347
here are a few other places that could use the same API (& in one instance drop
a Function.h dependency).

llvm-svn: 162367

This option runs LiveIntervals before TwoAddressInstructionPass which
will eventually learn to exploit and update the analysis.

Eventually, LiveIntervals will run before PHIElimination, and we can get
rid of LiveVariables.

llvm-svn: 161270

The 'unused' state of a value number can be represented as an invalid
def SlotIndex. This also exposed code that shouldn't have been looking
at unused value VNInfos.

llvm-svn: 161258

The only real user of the flag was removeCopyByCommutingDef(), and it
has been switched to LiveIntervals::hasPHIKill().

All the code changed by this patch was only concerned with computing and
propagating the flag.

llvm-svn: 161255

The VNInfo::HAS_PHI_KILL is only half supported. We precompute it in
LiveIntervalAnalysis, but it isn't properly updated by live range
splitting and functions like shrinkToUses().

It is only used in one place: RegisterCoalescer::removeCopyByCommutingDef().

This patch changes that function to use a new LiveIntervals::hasPHIKill()
function that computes the flag for a given value number.

llvm-svn: 161254

llvm-svn: 160898

A value number is a PHI def if and only if it begins at a block
boundary. This can be derived from the def slot, a separate flag is not
necessary.

llvm-svn: 160893

This option replaces the existing live interval computation with one
based on LiveRangeCalc.cpp. The new algorithm does not depend on
LiveVariables, and it can be run at any time, before or after leaving
SSA form.

llvm-svn: 160892

llvm-svn: 159030

It is both smaller and faster than DenseMap.

llvm-svn: 159029

There is no need to check for physreg live ranges. They don't exist any
more.

llvm-svn: 159019

Everyone is using on-demand regunit ranges now.

llvm-svn: 159018

With regunit liveness permanently enabled, this function would always
return true.

Also remove now obsolete code for checking physreg interference.

llvm-svn: 159006

Register allocators depend on it being permanently enabled now.

llvm-svn: 158873

Deterministically enumerate the virtual registers instead.

llvm-svn: 158872

Soon we won't need to compute live intervals for physical registers.

llvm-svn: 158865

Regunit live ranges are computed on demand, so when mi-sched calls
handleMove, some regunits may not have live ranges yet.

That makes updating them easier: Just skip the non-existing ranges. They
will be computed correctly from the rescheduled machine code when they
are needed.

llvm-svn: 158831

llvm-svn: 158827

When LiveIntervals is tracking fixed interference in regunits, make sure
to update those intervals as well. Currently guarded by -live-regunits.

llvm-svn: 158766

llvm-svn: 158755

Remat has been stable for years, and it isn't done by
LiveIntervalAnalysis any longer. (See LiveRangeEdit).

llvm-svn: 158079

llvm-svn: 158037

Don't print out the register number and spill weight, making the TRI
argument unnecessary.

This allows callers to interpret the reg field. It can currently be a
virtual register, a physical register, a spill slot, or a register unit.

llvm-svn: 158031

Instead of computing a live interval per physreg, LiveIntervals can
compute live intervals per register unit. This makes impossible the
confusing situation where aliasing registers could have overlapping live
intervals. It should also make fixed interferernce checking cheaper
since registers have fewer register units than aliases.

Live intervals for regunits are computed on demand, using MRI use-def
chains and the new LiveRangeCalc class. Only regunits live in to ABI
blocks are precomputed during LiveIntervals::runOnMachineFunction().

The regunit liveness computations don't depend on LiveVariables.

llvm-svn: 158029

Rematerialization is handled by LiveRangeEdit now.

llvm-svn: 157974

llvm-svn: 157963

No functional change.

llvm-svn: 157957

ranges for the instruction about to be bundled. This fixes a bug in an external
project where an assertion was triggered due to spurious 'multiple defs' within
the bundle.

Patch by Ivan Llopard. Thanks Ivan!

llvm-svn: 157632

llvm-svn: 157145

LiveIntervalUpdate validators weren't recorded after the calls to std::for_each.  Turns out std::for_each doesn't update the variable passed in for the functor but instead copy constructs a new one.

llvm-svn: 155041

llvm-svn: 153162