A register unit may be allocatable and non-reserved but some of the
register(tuples) built with it are reserved. We still need to calculate
liveness in this case.
Note to out of tree targets: If you start seeing machine verifier errors
with this commit, it probably means that you do not properly mark super
registers of reserved register as reserved. See for example r292836 or
r292870 for example on how to fix that.
rdar://29996737
Differential Revision: https://reviews.llvm.org/D28881
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- Fix doxygen comments: Do not repeat name, remove duplicated doxygen
comment (on declaration + implementation), etc.
- Use more range based for
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292455 91177308-0d34-0410-b5e6-96231b3b80d8
Specifically avoid implicit conversions from/to integral types to
avoid potential errors when changing the underlying type. For example,
a typical initialization of a "full" mask was "LaneMask = ~0u", which
would result in a value of 0x00000000FFFFFFFF if the type was extended
to uint64_t.
Differential Revision: https://reviews.llvm.org/D27454
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Summary: This makes a change to the state used to maintain visited information for depth first iterator. We know assume a method "completed(...)" which is called after all children of a node have been visited. In all existing cases, this method does nothing so this patch has no functional changes. It will however allow a client to distinguish back from cross edges in a DFS tree.
Reviewers: nadav, mehdi_amini, dberlin
Subscribers: MatzeB, mzolotukhin, twoh, freik, llvm-commits
Differential Revision: https://reviews.llvm.org/D25191
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Subregister definitions are considered uses for the purpose of tracking
liveness of the whole register. At the same time, when calculating live
interval subranges, subregister defs should not be treated as uses.
Differential Revision: https://reviews.llvm.org/D24190
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This reverts commit r280268, it causes all MSVC 2013 to ICE. This
appears to have been fixed in a later MSVC 2013 update, because I cannot
reproduce it locally. That said, all upstream LLVM bots are broken right
now, so I am reverting.
Also reverts dependent change r280275, "[Hexagon] Deal with undefs when
extending live intervals".
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tracksSubRegLiveness only depends on the Subtarget and a cl::opt, there
is not need to change it or save/parse it in a .mir file.
Make the field const and move the initialization LiveIntervalAnalysis to the
MachineRegisterInfo constructor. Also cleanup some code and fix some
instances which better use MachineRegisterInfo::subRegLivenessEnabled() instead
of TargetSubtargetInfo::enableSubRegLiveness().
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The register allocator can split a live interval of a register into a set
of smaller intervals. After the allocation of registers is complete, the
rewriter will modify the IR to replace virtual registers with the corres-
ponding physical registers. At this stage, if a register corresponding
to a subregister of a virtual register is used, the rewriter will check
if that subregister is undefined, and if so, it will add the <undef> flag
to the machine operand. The function verifying liveness of the subregis-
ter would assume that it is undefined, unless any of the subranges of the
live interval proves otherwise.
The problem is that the live intervals created during splitting do not
have any subranges, even if the original parent interval did. This could
result in the <undef> flag placed on a register that is actually defined.
Differential Revision: http://reviews.llvm.org/D21189
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Summary:
See the new test case for one that was (non-deterministically) crashing
on trunk and deterministically hit the assertion that I added in D23302.
Basically, the machine function contains a sequence
DS_WRITE_B32 %vreg4, %vreg14:sub0, ...
DS_WRITE_B32 %vreg4, %vreg14:sub0, ...
%vreg14:sub1<def> = COPY %vreg14:sub0
and SILoadStoreOptimizer::mergeWrite2Pair merges the two DS_WRITE_B32
instructions into one before calling repairIntervalsInRange.
Now repairIntervalsInRange wants to repair %vreg14, in particular, and
ends up trying to repair %vreg14:sub1 as well, but that only becomes
active _after_ the range that is to be repaired, hence the crash due
to LR.find(...) == LR.begin() at the start of repairOldRegInRange.
I believe that just skipping those subrange is fine, but again, not too
familiar with that code.
Reviewers: MatzeB, kparzysz, tstellarAMD
Subscribers: llvm-commits, MatzeB
Differential Revision: https://reviews.llvm.org/D23303
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If we move a last-use register read to a later position we may skip
intermediate segments. This may require us to not only extend the
segment before the NewIdx, but also extend the segment live-in to
OldIdx.
This switches LiveIntervalTest to use AMDGPU so we can test subregister
liveness.
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undef uses are no real uses of a register and must be ignored by
findLastUseBefore() so that handleMove() does not produce invalid live
intervals in some cases.
This fixed http://llvm.org/PR28083
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Refactor LiveIntervals::renameDisconnectedComponents() to be a pass.
Also change the name to "RenameIndependentSubregs":
- renameDisconnectedComponents() worked on a MachineFunction at a time
so it is a natural candidate for a machine function pass.
- The algorithm is testable with a .mir test now.
- This also fixes a problem where the lazy renaming as part of the
MachineScheduler introduced IMPLICIT_DEF instructions after the number
of a nodes in a region were counted leading to a mismatch.
Differential Revision: http://reviews.llvm.org/D20507
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This fixes a bug introduced in:
r262115 - CodeGen: Take MachineInstr& in SlotIndexes and LiveIntervals, NFC
The iterator End here might == MBB->end(), and so we can't unconditionally
dereference it. This often goes unnoticed (I don't have a test case that always
crashes, and ASAN does not catch it either) because the function call arguments are
turned right back into iterators. MachineInstrBundleIterator's constructor,
however, does have an assert which might randomly fire.
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We now use LiveRangeCalc::extendToUses() instead of a specially designed
algorithm in constructMainRangeFromSubranges():
- The original motivation for constructMainRangeFromSubranges() were
differences between the main liverange and subranges because of hidden
dead definitions. This case however cannot happen anymore with the
DetectDeadLaneMasks pass in place.
- It simplifies the code.
- This fixes a longstanding bug where we did not properly create new SSA
values on merging control flow (the MachineVerifier missed most of
these cases).
- Move constructMainRangeFromSubranges() to LiveIntervalAnalysis and
LiveRangeCalc to better match the implementation/available helper
functions.
This re-applies r269016. The fixes from r270290 and r270259 should avoid
the machine verifier problems this time.
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Fix renameDisconnectedComponents() creating vreg uses that can be
reached from function begin withouthaving a definition (or explicit
live-in). Fix this by inserting IMPLICIT_DEF instruction before
control-flow joins as necessary.
Removes an assert from MachineScheduler because we may now get
additional IMPLICIT_DEF when preparing the scheduling policy.
This fixes the underlying problem of http://llvm.org/PR27705
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We now use LiveRangeCalc::extendToUses() instead of a specially designed
algorithm in constructMainRangeFromSubranges():
- The original motivation for constructMainRangeFromSubranges() were
differences between the main liverange and subranges because of hidden
dead definitions. This case however cannot happen anymore with the
DetectDeadLaneMasks pass in place.
- It simplifies the code.
- This fixes a longstanding bug where we did not properly create new SSA
values on merging control flow (the MachineVerifier missed most of
these cases).
- Move constructMainRangeFromSubranges() to LiveIntervalAnalysis and
LiveRangeCalc to better match the implementation/available helper
functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269016 91177308-0d34-0410-b5e6-96231b3b80d8
Fix handleMove() incorrectly extending liveranges when an undef input of
a vreg was moved past the (current) end of the liverange.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268805 91177308-0d34-0410-b5e6-96231b3b80d8
This requirement was a huge hack to keep LiveVariables alive because it
was optionally used by TwoAddressInstructionPass and PHIElimination.
However we have AnalysisUsage::addUsedIfAvailable() which we can use in
those passes.
This re-applies r260806 with LiveVariables manually added to PowerPC to
hopefully not break the stage 2 bots this time.
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The DetectDeadLaneMask already ensures that we have no dead subregister
definitions making the special handling in LiveIntervalAnalysis
unnecessary. This reverts most of r248335.
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Matthias Braun
Krzysztof Parzyszek
David Callahan
Reid Kleckner
Nicolai Haehnle
Hal Finkel
Tom Stellard