Commit Graph

698 Commits

Author SHA1 Message Date
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
Matthias Braun e6a2485e1a TargetRegisterInfo: Add typedef unsigned LaneBitmask and use it where apropriate; NFC
llvm-svn: 248623
2015-09-25 21:51:14 +00:00
Matthias Braun 73e4221e6c LiveIntervalAnalysis: Avoid multiple connected liveness components
We may have subregister defs which are unused but not discovered and
cleaned up prior to liveness analysis. This creates multiple connected
components in the resulting live range which are forbidden in the
MachineVerifier because they would unnecesarily constrain the register
allocator. Rewrite those dead definitions to define a newly created
virtual register.

Differential Revision: http://reviews.llvm.org/D13035

llvm-svn: 248335
2015-09-22 22:37:44 +00:00
Matthias Braun d3dd1354a4 LiveIntervalAnalysis: Factor common code into splitSeparateComponents; NFC
llvm-svn: 248241
2015-09-22 03:44:41 +00:00
Matthias Braun d9da162789 Save LaneMask with livein registers
With subregister liveness enabled we can detect the case where only
parts of a register are live in, this is expressed as a 32bit lanemask.
The current code only keeps registers in the live-in list and therefore
enumerated all subregisters affected by the lanemask. This turned out to
be too conservative as the subregister may also cover additional parts
of the lanemask which are not live. Expressing a given lanemask by
enumerating a minimum set of subregisters is computationally expensive
so the best solution is to simply change the live-in list to store the
lanemasks as well. This will reduce memory usage for targets using
subregister liveness and slightly increase it for other targets

Differential Revision: http://reviews.llvm.org/D12442

llvm-svn: 247171
2015-09-09 18:08:03 +00:00
Chandler Carruth 7b560d40bd [PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatible
with the new pass manager, and no longer relying on analysis groups.

This builds essentially a ground-up new AA infrastructure stack for
LLVM. The core ideas are the same that are used throughout the new pass
manager: type erased polymorphism and direct composition. The design is
as follows:

- FunctionAAResults is a type-erasing alias analysis results aggregation
  interface to walk a single query across a range of results from
  different alias analyses. Currently this is function-specific as we
  always assume that aliasing queries are *within* a function.

- AAResultBase is a CRTP utility providing stub implementations of
  various parts of the alias analysis result concept, notably in several
  cases in terms of other more general parts of the interface. This can
  be used to implement only a narrow part of the interface rather than
  the entire interface. This isn't really ideal, this logic should be
  hoisted into FunctionAAResults as currently it will cause
  a significant amount of redundant work, but it faithfully models the
  behavior of the prior infrastructure.

- All the alias analysis passes are ported to be wrapper passes for the
  legacy PM and new-style analysis passes for the new PM with a shared
  result object. In some cases (most notably CFL), this is an extremely
  naive approach that we should revisit when we can specialize for the
  new pass manager.

- BasicAA has been restructured to reflect that it is much more
  fundamentally a function analysis because it uses dominator trees and
  loop info that need to be constructed for each function.

All of the references to getting alias analysis results have been
updated to use the new aggregation interface. All the preservation and
other pass management code has been updated accordingly.

The way the FunctionAAResultsWrapperPass works is to detect the
available alias analyses when run, and add them to the results object.
This means that we should be able to continue to respect when various
passes are added to the pipeline, for example adding CFL or adding TBAA
passes should just cause their results to be available and to get folded
into this. The exception to this rule is BasicAA which really needs to
be a function pass due to using dominator trees and loop info. As
a consequence, the FunctionAAResultsWrapperPass directly depends on
BasicAA and always includes it in the aggregation.

This has significant implications for preserving analyses. Generally,
most passes shouldn't bother preserving FunctionAAResultsWrapperPass
because rebuilding the results just updates the set of known AA passes.
The exception to this rule are LoopPass instances which need to preserve
all the function analyses that the loop pass manager will end up
needing. This means preserving both BasicAAWrapperPass and the
aggregating FunctionAAResultsWrapperPass.

Now, when preserving an alias analysis, you do so by directly preserving
that analysis. This is only necessary for non-immutable-pass-provided
alias analyses though, and there are only three of interest: BasicAA,
GlobalsAA (formerly GlobalsModRef), and SCEVAA. Usually BasicAA is
preserved when needed because it (like DominatorTree and LoopInfo) is
marked as a CFG-only pass. I've expanded GlobalsAA into the preserved
set everywhere we previously were preserving all of AliasAnalysis, and
I've added SCEVAA in the intersection of that with where we preserve
SCEV itself.

One significant challenge to all of this is that the CGSCC passes were
actually using the alias analysis implementations by taking advantage of
a pretty amazing set of loop holes in the old pass manager's analysis
management code which allowed analysis groups to slide through in many
cases. Moving away from analysis groups makes this problem much more
obvious. To fix it, I've leveraged the flexibility the design of the new
PM components provides to just directly construct the relevant alias
analyses for the relevant functions in the IPO passes that need them.
This is a bit hacky, but should go away with the new pass manager, and
is already in many ways cleaner than the prior state.

Another significant challenge is that various facilities of the old
alias analysis infrastructure just don't fit any more. The most
significant of these is the alias analysis 'counter' pass. That pass
relied on the ability to snoop on AA queries at different points in the
analysis group chain. Instead, I'm planning to build printing
functionality directly into the aggregation layer. I've not included
that in this patch merely to keep it smaller.

Note that all of this needs a nearly complete rewrite of the AA
documentation. I'm planning to do that, but I'd like to make sure the
new design settles, and to flesh out a bit more of what it looks like in
the new pass manager first.

Differential Revision: http://reviews.llvm.org/D12080

llvm-svn: 247167
2015-09-09 17:55:00 +00:00
Reid Kleckner 0e2882345d [WinEH] Add some support for code generating catchpad
We can now run 32-bit programs with empty catch bodies.  The next step
is to change PEI so that we get funclet prologues and epilogues.

llvm-svn: 246235
2015-08-27 23:27:47 +00:00
Matthias Braun b2b7ef1de8 MachineBasicBlock: Add liveins() method returning an iterator_range
llvm-svn: 245895
2015-08-24 22:59:52 +00:00
Matthias Braun 0d4cebd434 LiveInterval: Document and enforce rules about empty subranges.
Empty subranges are not allowed in a LiveInterval and must be removed
instead: Check this in the verifiers, put a reminder for this in the
comment of the shrinkToUses variant for a single lane and make it
automatic for the shrinkToUses variant for a LiveInterval.

llvm-svn: 242431
2015-07-16 18:55:35 +00:00
Matthias Braun 7f5ae19e80 Do not duplicate method name in comment, remove duplicate comment
llvm-svn: 242430
2015-07-16 18:55:32 +00:00
Matthias Braun e41e146c16 CodeGen: Use mop_iterator instead of MIOperands/ConstMIOperands
MIOperands/ConstMIOperands are classes iterating over the MachineOperand
of a MachineInstr, however MachineInstr::mop_iterator does the same
thing.

I assume these two iterators exist to have a uniform interface to
iterate over the operands of a machine instruction bundle and a single
machine instruction. However in practice I find it more confusing to have 2
different iterator classes, so this patch transforms (nearly all) the
code to use mop_iterators.

The only exception being MIOperands::anlayzePhysReg() and
MIOperands::analyzeVirtReg() still needing an equivalent, I leave that
as an exercise for the next patch.

Differential Revision: http://reviews.llvm.org/D9932

This version is slightly modified from the proposed revision in that it
introduces MachineInstr::getOperandNo to avoid the extra counting
variable in the few loops that previously used MIOperands::getOperandNo.

llvm-svn: 238539
2015-05-29 02:56:46 +00:00
Matthias Braun a25e13aaf1 Do not track subregister liveness when it brings no benefits
Some subregisters are only to indicate different access sizes, while not
providing any way to actually divide the register up into multiple
disjunct parts. Avoid tracking subregister liveness in these cases as it
is not beneficial.

Differential Revision: http://reviews.llvm.org/D8429

llvm-svn: 232695
2015-03-19 00:21:58 +00:00
Quentin Colombet a8cb36ea43 [LiveIntervalAnalysis] Speed up creation of live ranges for physical registers
by using a segment set.

The patch addresses a compile-time performance regression in the LiveIntervals
analysis pass (see http://llvm.org/bugs/show_bug.cgi?id=18580). This regression
is especially critical when compiling long functions. Our analysis had shown
that the most of time is taken for generation of live intervals for physical
registers. Insertions in the middle of the array of live ranges cause quadratic
algorithmic complexity, which is apparently the main reason for the slow-down. 

Overview of changes:
- The patch introduces an additional std::set<Segment>* member in LiveRange for
  storing segments in the phase of initial creation. The set is used if this
  member is not NULL, otherwise everything works the old way. 
- The set of operations on LiveRange used during initial creation (i.e. used by
  createDeadDefs and extendToUses) have been reimplemented to use the segment
  set if it is available.
- After a live range is created the contents of the set are flushed to the
  segment vector, because the set is not as efficient as the vector for the
  later uses of the live range. After the flushing, the set is deleted and
  cannot be used again.
- The set is only for live ranges computed in
  LiveIntervalAnalysis::computeLiveInRegUnits() and getRegUnit() but not in
  computeVirtRegs(), because I did not bring any performance benefits to
  computeVirtRegs() and for some examples even brought a slow down.

Patch by Vaidas Gasiunas <vaidas.gasiunas@sap.com>

Differential Revision: http://reviews.llvm.org/D6013

llvm-svn: 228421
2015-02-06 18:42:41 +00:00
Matthias Braun c1988f384c LiveIntervalAnalysis: Mark subregister defs as undef when we determined they are only reading a dead superregister value
This was not necessary before as this case can only be detected when the
liveness analysis is at subregister level.

llvm-svn: 226733
2015-01-21 22:55:13 +00:00
Matthias Braun 311730ac78 LiveIntervalAnalysis: Factor out code to update liveness on vreg def removal
This cleans up code and is more in line with the general philosophy of
modifying LiveIntervals through LiveIntervalAnalysis instead of changing
them directly.

This also fixes a case where SplitEditor::removeBackCopies() would miss
the subregister ranges.

llvm-svn: 226690
2015-01-21 19:02:30 +00:00
Matthias Braun cfb8ad29b5 LiveIntervalAnalysis: Factor out code to update liveness on physreg def removal
This cleans up code and is more in line with the general philosophy of
modifying LiveIntervals through LiveIntervalAnalysis instead of changing
them directly.

llvm-svn: 226687
2015-01-21 18:50:21 +00:00
Matthias Braun 1002baf7b9 LiveIntervalAnalysis: Remove unused pruneValue() variant.
llvm-svn: 226686
2015-01-21 18:45:57 +00:00
Matthias Braun f603c88d13 LiveIntervalAnalysis: Fix performance bug that I introduced in r224663.
Without a reference the code did not remember when moving the iterators
of the subranges/registerunit ranges forward and instead would scan from
the beginning again at the next position.

llvm-svn: 224803
2014-12-24 02:11:43 +00:00
Matthias Braun 714c494ca1 LiveIntervalAnalysis: No kill flags for partially undefined uses.
We must not add kill flags when reading a vreg with some undefined
subregisters, if subreg liveness tracking is enabled.  This is because
the register allocator may reuse these undefined subregisters for other
values which are not killed.

llvm-svn: 224664
2014-12-20 01:54:50 +00:00
Matthias Braun 7f8dece1d7 LiveIntervalAnalysis: cleanup addKills(), NFC
- Use more const modifiers
- Use references for things that can't be nullptr
- Improve some variable names

llvm-svn: 224663
2014-12-20 01:54:48 +00:00
Matthias Braun 15abf3743c LiveIntervalAnalysis: Cleanup computeDeadValues
- This also fixes a bug introduced in r223880 where values were not
  correctly marked as Dead anymore.
- Cleanup computeDeadValues(): split up SubRange code variant, simplify
  arguments.

llvm-svn: 224538
2014-12-18 19:58:52 +00:00
Matthias Braun 1aed6ffa35 LiveRangeCalc: Rewrite subrange calculation
This changes subrange calculation to calculate subranges sequentially
instead of in parallel. The code is easier to understand that way and
addresses the code review issues raised about LiveOutData being
hard to understand/needing more comments by removing them :)

llvm-svn: 224313
2014-12-16 04:03:38 +00:00
Matthias Braun c3a72c2e5f Revert "LiveRangeCalc: Rewrite subrange calculation"
Revert until I find out why non-subreg enabled targets break.

This reverts commit 6097277eefb9c5fb35a7f493c783ee1fd1b9d6a7.

llvm-svn: 224278
2014-12-15 21:36:35 +00:00
Matthias Braun 0352201e15 LiveRangeCalc: Rewrite subrange calculation
This changes subrange calculation to calculate subranges sequentially
instead of in parallel. The code is easier to understand that way and
addresses the code review issues raised about LiveOutData being
hard to understand/needing more comments by removing them :)

llvm-svn: 224272
2014-12-15 21:16:21 +00:00
Matthias Braun 09afa1ea74 LiveInterval: Use range based for loops for subregister ranges.
llvm-svn: 223991
2014-12-11 00:59:06 +00:00
Matthias Braun 96761959d4 LiveInterval: Use more range based for loops for value numbers and segments.
llvm-svn: 223978
2014-12-10 23:07:54 +00:00
Matthias Braun d70caaf5a5 VirtRegMap: No implicit defs/uses for super registers with subreg liveness tracking.
Adding the implicit defs/uses to the superregisters is semantically questionable
but was not dangerous before as the register allocator never assigned the same
register to two overlapping LiveIntervals even when the actually live
subregisters do not overlap. With subregister liveness tracking enabled this
does actually happen and leads to subsequent bugs if we don't stop adding
the superregister defs/uses.

llvm-svn: 223892
2014-12-10 01:13:04 +00:00
Matthias Braun 8970d847c4 LiveIntervalAnalysis: Add subregister aware variants pruneValue().
llvm-svn: 223886
2014-12-10 01:12:36 +00:00
Matthias Braun e3d3b88cb9 Add a flag to enable/disable subregister liveness.
llvm-svn: 223884
2014-12-10 01:12:30 +00:00
Matthias Braun e5f861b781 LiveIntervalAnalysis: Adapt repairIntervalsInRange() to subregister liveness.
llvm-svn: 223883
2014-12-10 01:12:26 +00:00
Matthias Braun 7044d69e87 LiveIntervalAnalysis: Adapt handleMove() to subregister ranges.
llvm-svn: 223881
2014-12-10 01:12:20 +00:00
Matthias Braun 20e1f38a41 LiveIntervalAnalysis: Update SubRanges in shrinkToUses().
llvm-svn: 223880
2014-12-10 01:12:18 +00:00