Commit Graph

729 Commits

Author SHA1 Message Date
Matthias Braun cebdb17522 LiveIntervalAnalysis: Fix alias regunit reserved definition
A register in CodeGen can be marked as reserved: In that case we
consider the register always live and do not use (or rather ignore)
kill/dead/undef operand flags.

LiveIntervalAnalysis however tracks liveness per register unit (not per
register). We already needed adjustments for this in r292871 to deal
with super/sub registers. However I did not look at aliased register
there. Looking at ARM:

FPSCR (regunits FPSCR, FPSCR~FPSCR_NZCV) aliases with FPSCR_NZCV
(regunits FPSCR_NZCV, FPSCR~FPSCR_NZCV) hence they share a register unit
(FPSCR~FPSCR_NZCV) that represents the aliased parts of the registers.
This shared register unit was previously considered non-reserved,
however given that we uses of the reserved FPSCR potentially violate
some rules (like uses without defs) we should make FPSCR~FPSCR_NZCV
reserved too and stop tracking liveness for it.

This patch:
- Defines a register unit as reserved when: At least for one root
  register, the root register and all its super registers are reserved.
- Adjust LiveIntervals::computeRegUnitRange() for new reserved
  definition.
- Add MachineRegisterInfo::isReservedRegUnit() to have a canonical way
  of testing.
- Stop computing LiveRanges for reserved register units in HMEditor even
  with UpdateFlags enabled.
- Skip verification of uses of reserved reg units in the machine
  verifier (this usually didn't happen because there would be no cached
  liverange but there is no guarantee for that and I would run into this
  case before the HMEditor tweak, so may as well fix the verifier too).

Note that this should only affect ARMs FPSCR/FPSCR_NZCV registers today;
aliased registers are rarely used, the only other cases are hexagons
P0-P3/P3_0 and C8/USR pairs which are not mixing reserved/non-reserved
registers in an alias.

Differential Revision: https://reviews.llvm.org/D37356

llvm-svn: 312348
2017-09-01 18:36:26 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Eugene Zelenko 75480cce12 [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 303820
2017-05-24 23:10:29 +00:00
Stanislav Mekhanoshin b546174b0e Fix subreg value numbers in handleMoveUp
The problem can occur in presence of subregs. If we are swapping two
instructions defining different subregs of the same register we will
get a new liveout from a block. We need to preserve value number for
block's liveout for successor block's livein to match.

Differential Revision: https://reviews.llvm.org/D30558

llvm-svn: 297534
2017-03-11 00:14:52 +00:00
Matthias Braun 8c209aa877 Cleanup dump() functions.
We had various variants of defining dump() functions in LLVM. Normalize
them (this should just consistently implement the things discussed in
http://lists.llvm.org/pipermail/cfe-dev/2014-January/034323.html

For reference:
- Public headers should just declare the dump() method but not use
  LLVM_DUMP_METHOD or #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
- The definition of a dump method should look like this:
  #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
  LLVM_DUMP_METHOD void MyClass::dump() {
    // print stuff to dbgs()...
  }
  #endif

llvm-svn: 293359
2017-01-28 02:02:38 +00:00
Matthias Braun b901d33461 LiveIntervalAnalysis: Calculate liveness even if a superreg is reserved.
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

llvm-svn: 292871
2017-01-24 01:12:58 +00:00
Matthias Braun 9f21a8d787 LiveIntervalAnalysis: Cleanup; NFC
- Fix doxygen comments: Do not repeat name, remove duplicated doxygen
  comment (on declaration + implementation), etc.
- Use more range based for

llvm-svn: 292455
2017-01-19 00:32:13 +00:00
Krzysztof Parzyszek ea9f8ce03c Implement LaneBitmask::any(), use it to replace !none(), NFCI
llvm-svn: 289974
2016-12-16 19:11:56 +00:00
Krzysztof Parzyszek 91b5cf8412 Extract LaneBitmask into a separate type
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

llvm-svn: 289820
2016-12-15 14:36:06 +00:00
David Callahan c1051ab26e Modify df_iterator to support post-order actions
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

llvm-svn: 283391
2016-10-05 21:36:16 +00:00
Krzysztof Parzyszek 3bf4aeccd6 Do not consider subreg defs as reads when computing subrange liveness
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

llvm-svn: 280532
2016-09-02 19:48:55 +00:00
Krzysztof Parzyszek 4f863d75f4 Add an optional parameter with a list of undefs to extendToIndices
Reapply r280268, hopefully in a version that MSVC likes.

llvm-svn: 280358
2016-09-01 12:10:36 +00:00
Reid Kleckner 109448ee81 Revert "Add an optional parameter with a list of undefs to extendToIndices"
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".

llvm-svn: 280301
2016-08-31 22:36:02 +00:00
Krzysztof Parzyszek 576225daf5 Add an optional parameter with a list of undefs to extendToIndices
llvm-svn: 280268
2016-08-31 18:02:19 +00:00
Matthias Braun f1b20c5225 MachineRegisterInfo/MIR: Initialize tracksSubRegLiveness early, do not print/parser it
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().

llvm-svn: 279676
2016-08-24 22:17:45 +00:00
Krzysztof Parzyszek a7ed090bba Create subranges for new intervals resulting from live interval splitting
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

llvm-svn: 279625
2016-08-24 13:37:55 +00:00
Nicolai Haehnle 02d784172c LiveIntervalAnalysis: fix a crash in repairOldRegInRange
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

llvm-svn: 278268
2016-08-10 18:51:14 +00:00
Matthias Braun 3865b1d35b LiveIntervalAnalysis: Fix handleMoveDown() problem
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.

llvm-svn: 276724
2016-07-26 03:57:45 +00:00
Krzysztof Parzyszek 98c0f482d6 Fix printing of debugging information in LiveIntervals::shrinkToUses
Print VNI->def before calling VNI->markUnused(), since markUnused makes
the def invalid.

llvm-svn: 275196
2016-07-12 17:55:28 +00:00
Matthias Braun 959a8c974d LiveIntervalAnalysis: findLastUseBefore() must ignore undef uses.
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

llvm-svn: 272446
2016-06-11 00:31:28 +00:00
Matthias Braun f9acacaa92 CodeGen: Refactor renameDisconnectedComponents() as a pass
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

llvm-svn: 271345
2016-05-31 22:38:06 +00:00
Matthias Braun fc4c8a1e46 LiveIntervalAnalysis: Fix handleMove() re-using the wrong value number
This fixes http://llvm.org/PR27856

llvm-svn: 270619
2016-05-24 21:54:01 +00:00
Hal Finkel 7b1b3daf6e [LiveIntervalAnalysis] Don't dereference an end iterator in repairIntervalsInRange
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.

llvm-svn: 270323
2016-05-21 16:03:50 +00:00
Matthias Braun 71f9564e7f LiveIntervalAnalysis: Rework constructMainRangeFromSubranges()
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.

llvm-svn: 270291
2016-05-20 23:14:56 +00:00
Matthias Braun 858d1df246 LiveIntervalAnalysis: Fix missing defs in renameDisconnectedComponents().
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

llvm-svn: 270259
2016-05-20 19:46:13 +00:00
Tom Stellard 740af6f3b0 Revert "LiveIntervalAnalysis: Rework constructMainRangeFromSubranges()"
This reverts commit r269016 and also the follow-up commit r269020.

This patch caused PR27705.

llvm-svn: 269344
2016-05-12 20:27:40 +00:00
Matthias Braun 8d6e57b216 LiveIntervalAnalysis: Rework constructMainRangeFromSubranges()
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.

llvm-svn: 269016
2016-05-10 04:51:14 +00:00
Matthias Braun 71474e8d22 LiveIntervalAnalysis: Fix handleMove() extending liverange for undef inputs
Fix handleMove() incorrectly extending liveranges when an undef input of
a vreg was moved past the (current) end of the liverange.

llvm-svn: 268805
2016-05-06 21:47:41 +00:00
Matthias Braun f84547c6e0 LiveIntervalAnalysis: Remove LiveVariables requirement
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.

llvm-svn: 267954
2016-04-28 23:42:51 +00:00
Matthias Braun e9631f166e LiveIntervalAnalysis: No need to deal with dead subregister defs anymore.
The DetectDeadLaneMask already ensures that we have no dead subregister
definitions making the special handling in LiveIntervalAnalysis
unnecessary. This reverts most of r248335.

llvm-svn: 267937
2016-04-28 20:35:26 +00:00
Matthias Braun c9e759acff LiveIntervalAnalysis: Fix handleMove() using wrong value numbers
handleMove() was incorrectly swapping two value numbers. This was missed
before because the problem only occured when moving subregister definitions
and needed -verify-machineinstrs to be detected.

I cannot add a testcase as long as I cannot reapply r260905/r260806.

llvm-svn: 267840
2016-04-28 02:11:49 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Duncan P. N. Exon Smith be8f8c4478 CodeGen: Update LiveIntervalAnalysis API to use MachineInstr&, NFC
These parameters aren't expected to be null, so take them by reference.

llvm-svn: 262151
2016-02-27 20:14:29 +00:00
Duncan P. N. Exon Smith f9ab416d70 WIP: CodeGen: Use MachineInstr& in MachineInstrBundle.h, NFC
Update APIs in MachineInstrBundle.h to take and return MachineInstr&
instead of MachineInstr* when the instruction cannot be null.  Besides
being a nice cleanup, this is tacking toward a fix for PR26753.

llvm-svn: 262141
2016-02-27 17:05:33 +00:00
Duncan P. N. Exon Smith 3ac9cc6156 CodeGen: Take MachineInstr& in SlotIndexes and LiveIntervals, NFC
Take MachineInstr by reference instead of by pointer in SlotIndexes and
the SlotIndex wrappers in LiveIntervals.  The MachineInstrs here are
never null, so this cleans up the API a bit.  It also incidentally
removes a few implicit conversions from MachineInstrBundleIterator to
MachineInstr* (see PR26753).

At a couple of call sites it was convenient to convert to a range-based
for loop over MachineBasicBlock::instr_begin/instr_end, so I added
MachineBasicBlock::instrs.

llvm-svn: 262115
2016-02-27 06:40:41 +00:00
Reid Kleckner 70c9bc71d4 [WinEH] Fix funclet return block clobber mask placement
MBB slot index intervals are half open, not closed. getMBBEndIndex()
returns the slot index of the start of the next block in layout order.
Placing a register mask there is incorrect if the successor of the
funclet return is not laid out after the return. Clang generates IR for
catch bodies before generating the following normal code, so we never
noticed this issue until the D frontend authors filed a bug about it.

Instead, we can put the clobber mask on the last instruction of the
funclet return block. We still aren't using a register mask operand on
the CATCHRET instruction because it would cause PEI to spill all CSRs,
including XMM regs, in the prologue.

Fixes PR26679.

llvm-svn: 262035
2016-02-26 16:53:19 +00:00
Matthias Braun ac697c5d8e Revert "LiveIntervalAnalysis: Remove LiveVariables requirement" and LiveIntervalTest
The commit breaks stage2 compilation on PowerPC. Reverting for now while
this is analyzed. I also have to revert the LiveIntervalTest for now as
that depends on this commit.

Revert "LiveIntervalAnalysis: Remove LiveVariables requirement"
This reverts commit r260806.
Revert "Remove an unnecessary std::move to fix -Wpessimizing-move warning."
This reverts commit r260931.
Revert "Fix typo in LiveIntervalTest"
This reverts commit r260907.
Revert "Add unittest for LiveIntervalAnalysis::handleMove()"
This reverts commit r260905.

llvm-svn: 261189
2016-02-18 05:21:43 +00:00
Matthias Braun 4a6c728cc0 LiveIntervalAnalysis: Support moving of subregister defs in handleMove
This is an updated version which fixes a bug that happened with
uses tied to an earlyclobber operand which end at an unusual slotindex.

If two definitions write to independent subregisters then they can be
put in any order. LiveIntervalAnalysis::handleMove() did not support
this previously because it looks like moving a definition of a vreg past
another one.

This is a modified version of a patch proposed (two years ago) by
Vincent Lejeune! This version does not touch the read-undef flags and is
extended for the case of moving a subregister def behind all uses - this
can happen for subregister defs that are completely unused.

Differential Revision: http://reviews.llvm.org/D9067

llvm-svn: 260906
2016-02-15 19:25:36 +00:00
Matthias Braun bbb528f189 LiveIntervalAnalysis: Remove LiveVariables requirement
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.

llvm-svn: 260806
2016-02-13 04:35:31 +00:00
Matthias Braun c67f5a6ab1 Revert "LiveIntervalAnalysis: Support moving of subregister defs in handleMove"
This is broke a bot:

http://lab.llvm.org:8011/builders/clang-cmake-aarch64-quick/builds/4703/steps/test-suite/logs/test.log

Reverting while I investigate.

This reverts commit r260565.

llvm-svn: 260586
2016-02-11 21:07:44 +00:00
Matthias Braun 33c641bddf LiveIntervalAnalysis: Support moving of subregister defs in handleMove
If two definitions write to independent subregisters then they can be
put in any order. LiveIntervalAnalysis::handleMove() did not support
this previously because it looks like moving a definition of a vreg past
another one.

This is a modified version of a patch proposed (two years ago) by
Vincent Lejeune! This version does not touch the read-undef flags and is
extended for the case of moving a subregister def behind all uses - this
can happen for subregister defs that are completely unused.

Differential Revision: http://reviews.llvm.org/D9067

llvm-svn: 260565
2016-02-11 19:03:53 +00:00
Matthias Braun db320773e1 LiveIntervalAnalysis: Improve some comments
As recommended by Justin.

llvm-svn: 258771
2016-01-26 01:40:48 +00:00
Matthias Braun 242b8bb58d LiveIntervalAnalysis: Cleanup handleMove{Down|Up}() functions, NFC
These two functions are hard to reason about. This commit makes the code
more comprehensible:

- Use four distinct variables (OldIdxIn, OldIdxOut, NewIdxIn, NewIdxOut)
  with a fixed value instead of a changing iterator I that points to
  different things during the function.
- Remove the early explanation before the function in favor of more
  detailed comments inside the function. Should have more/clearer comments now
  stating which conditions are tested and which invariants hold at
  different points in the functions.

The behaviour of the code was not changed.

I hope that this will make it easier to review the changes in
http://reviews.llvm.org/D9067 which I will adapt next.

Differential Revision: http://reviews.llvm.org/D16379

llvm-svn: 258756
2016-01-26 00:43:50 +00:00
Matthias Braun 3907fded1b LiveInterval: Add utility class to rename independent subregister usage
This renaming is necessary to avoid a subregister aware scheduler
accidentally creating liveness "holes" which are rejected by the
MachineVerifier.

Explanation as found in this patch:

Helper class that can divide MachineOperands of a virtual register into
equivalence classes of connected components.
MachineOperands belong to the same equivalence class when they are part of
the same SubRange segment or adjacent segments (adjacent in control
flow); Different subranges affected by the same MachineOperand belong to
the same equivalence class.

Example:
  vreg0:sub0 = ...
  vreg0:sub1 = ...
  vreg0:sub2 = ...
  ...
  xxx        = op vreg0:sub1
  vreg0:sub1 = ...
  store vreg0:sub0_sub1

The example contains 3 different equivalence classes:
  - One for the (dead) vreg0:sub2 definition
  - One containing the first vreg0:sub1 definition and its use,
    but not the second definition!
  - The remaining class contains all other operands involving vreg0.

We provide a utility function here to rename disjunct classes to different
virtual registers.

Differential Revision: http://reviews.llvm.org/D16126

llvm-svn: 258257
2016-01-20 00:23:21 +00:00
Matthias Braun bf47f63b74 LiveInterval: A LiveRange is enough for ConnectedVNInfoEqClasses::Classify()
llvm-svn: 257129
2016-01-08 01:16:35 +00:00
Matthias Braun 2c98d0f477 MachineInstr: addRegisterDefReadUndef() => setRegisterDefReadUndef()
This way we can not only add but also remove read undef flags.

llvm-svn: 252678
2015-11-11 00:41:58 +00:00
Reid Kleckner b8fd162fc5 [WinEH] Mark funclet entries and exits as clobbering all registers
Summary:
In this implementation, LiveIntervalAnalysis invents a few register
masks on basic block boundaries that preserve no registers. The nice
thing about this is that it prevents the prologue inserter from thinking
it needs to spill all XMM CSRs, because it doesn't see any explicit
physreg defs in the MI.

Reviewers: MatzeB, qcolombet, JosephTremoulet, majnemer

Subscribers: MatzeB, llvm-commits

Differential Revision: http://reviews.llvm.org/D14407

llvm-svn: 252318
2015-11-06 17:06:38 +00:00
Reid Kleckner e535c1f856 Range-for some LiveIntervals code under review
llvm-svn: 252267
2015-11-06 02:01:02 +00:00
Duncan P. N. Exon Smith 5ae5939fa1 CodeGen: Remove more ilist iterator implicit conversions, NFC
llvm-svn: 249879
2015-10-09 19:13:58 +00:00
Matthias Braun c804cdb912 TargetRegisterInfo: Introduce PrintLaneMask.
This makes it more convenient to print lane masks and lead to more
uniform printing.

llvm-svn: 248624
2015-09-25 21:51:24 +00:00