Commit Graph

253 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
Mehdi Amini 59ae854503 Do not modify a cl::opt programmatically, global mutable state is evil.
Found by TSAN on ThinLTO.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266514
2016-04-16 04:58:30 +00:00
Geoff Berry 6381713b37 [ScheduleDAGInstrs] Re-factor for based on review feedback. NFC.
Summary:
Re-factor some code to improve clarity and style based on review
comments from http://reviews.llvm.org/D18093.

Reviewers: MatzeB, mcrosier

Subscribers: MatzeB, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19128

llvm-svn: 266372
2016-04-14 21:31:07 +00:00
Geoff Berry c0739d8305 [ScheduleDAGInstrs] Handle instructions with multiple MMOs
Summary:
In getUnderlyingObjectsForInstr(): Don't give up on instructions with
multiple MMOs, instead look through all the MMOs and if they all meet
the conservative criteria previously used for single MMO instructions,
then return all of the underlying objects derived from the MMOs.

The change to ScheduleDAGInstrs::buildSchedGraph() is needed to avoid
the case where multiple underlying objects are present and are related
in such a way that successive iterations of the loop end up adding a
dependency from an instruction to itself.

Reviewers: atrick, hfinkel

Subscribers: MatzeB, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18093

llvm-svn: 266084
2016-04-12 15:50:19 +00:00
Chandler Carruth b472856a73 Fix PR26940 where compiles times regressed massively.
Patch by Jonas Paulsson. Original description:
Bugfix in buildSchedGraph() to make -dag-maps-huge-region work properly

I found that the reduction of the maps did in fact never happen in this
test case. This was because *all* the stores / loads were made with
addresses from arguments and they thus became "unknown" stores / loads.
Fixed by removing continue statements and making sure that the test for
reduction always takes place.

Differential Revision: http://reviews.llvm.org/D18673

llvm-svn: 265063
2016-03-31 21:55:58 +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
Duncan P. N. Exon Smith c5b668deb8 Revert "CodeGen: MachineInstr::getIterator() => getInstrIterator(), NFC"
This reverts commit r261504, since it's not obvious the new name is
better:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160222/334298.html

I'll recommit if we get consensus that it's the right direction.

llvm-svn: 261567
2016-02-22 20:49:58 +00:00
Duncan P. N. Exon Smith dc0848c029 CodeGen: MachineInstr::getIterator() => getInstrIterator(), NFC
Delete MachineInstr::getIterator(), since the term "iterator" is
overloaded when talking about MachineInstr.

- Downcast to ilist_node in iplist::getNextNode() and getPrevNode() so
  that ilist_node::getIterator() is still available.
- Add it back as MachineInstr::getInstrIterator().  This matches the
  naming in MachineBasicBlock.
- Add MachineInstr::getBundleIterator().  This is explicitly called
  "bundle" (not matching MachineBasicBlock) to disintinguish it clearly
  from ilist_node::getIterator().
- Update all calls.  Some of these I switched to `auto` to remove
  boiler-plate, since the new name is clear about the type.

There was one call I updated that looked fishy, but it wasn't clear what
the right answer was.  This was in X86FrameLowering::inlineStackProbe(),
added in r252578 in lib/Target/X86/X86FrameLowering.cpp.  I opted to
leave the behaviour unchanged, but I'll reply to the original commit on
the list in a moment.

llvm-svn: 261504
2016-02-21 22:58:35 +00:00
Jonas Paulsson 98963fec41 [ScheduleDAGInstrs] isUnsafeMemoryObject() removed
This function was basically useless, since volatile memacesses or MIs with
unmodelled sideffects become global memory objects, and the other little
checks are also done elsewhere.

Reviewed by Andy Trick
http://reviews.llvm.org/D16881

llvm-svn: 260899
2016-02-15 16:43:15 +00:00
Jonas Paulsson 2293685731 [ScheduleDagInstrs] Improved comments
llvm-svn: 259783
2016-02-04 13:08:48 +00:00
Jonas Paulsson ac29f01788 [ScheduleDAGInstrs::buildSchedGraph()] Handling of memory dependecies rewritten.
Recommited, after some fixing with test cases.

Updated test cases:
test/CodeGen/AArch64/arm64-misched-memdep-bug.ll
test/CodeGen/AArch64/tailcall_misched_graph.ll

Temporarily disabled test cases:
test/CodeGen/AMDGPU/split-vector-memoperand-offsets.ll
test/CodeGen/PowerPC/ppc64-fastcc.ll (partially updated)
test/CodeGen/PowerPC/vsx-fma-m.ll
test/CodeGen/PowerPC/vsx-fma-sp.ll

http://reviews.llvm.org/D8705
Reviewers: Hal Finkel, Andy Trick.

llvm-svn: 259673
2016-02-03 17:52:29 +00:00
Jonas Paulsson 8c738635b1 Temporarily revert "[ScheduleDAGInstrs::buildSchedGraph()] Handling of memory dependecies rewritten."
Some buildbot failures needs to be debugged.

llvm-svn: 259213
2016-01-29 17:22:43 +00:00
Jonas Paulsson 23f12e5c02 [ScheduleDAGInstrs::buildSchedGraph()] Handling of memory dependecies rewritten.
The buildSchedGraph() was in need of reworking as the AA features had been
added on top of earlier code. It was very difficult to understand, and buggy.
There had been found cases where scheduling dependencies had actually been
missed (see r228686).

AliasChain, RejectMemNodes, adjustChainDeps() and iterateChainSucc() have
been removed. There are instead now just the four maps from Value to SUs, which
have been renamed to Stores, Loads, NonAliasStores and NonAliasLoads.

An unknown store used to become the AliasChain, but now becomes a store mapped
to 'unknownValue' (in Stores). What used to be PendingLoads is instead the
list of SUs mapped to 'unknownValue' in Loads.

RejectMemNodes and adjustChainDeps() used to be a safety-net for everything.
The SU maps were sometimes cleared and SUs were put in RejectMemNodes, where
adjustChainDeps() would look. Instead of this, a more straight forward approach
is used in maintaining the SU maps without clearing them and simply letting
them grow over time. Instead of the cutt-off in adjustChainDeps() search, a
reduction of maps will be done if needed (see below).

Each SUnit either becomes the BarrierChain, or is put into one of the maps. For
each SUnit encountered, all the information about previous ones are still
available until a new BarrierChain is set, at which point the maps are cleared.

For huge regions, the algorithm becomes slow, therefore the maps will get
reduced at a threshold (current default is 1000 nodes), by a fraction (default 1/2).
These values can be tuned by use of CL options in case some test case shows that
they need to be changed (-dag-maps-huge-region and -dag-maps-reduction-size).

There has not been any considerable change observed in output quality or compile
time. There may now be more DAG edges inserted than before (i.e. if A->B->C,
then A->C is not needed). However, in a comparison run there were fewer total
calls to AA, and a somewhat improved compile time, which means this seems to
be not a problem.

http://reviews.llvm.org/D8705
Reviewers: Hal Finkel, Andy Trick.

llvm-svn: 259201
2016-01-29 16:11:18 +00:00
Chad Rosier b46d0f9a71 [ScheduleDAGInstrs] Simplify logic to improve readability. NFC.
The call to isInvariantLoad() already returns false for non-load instructions.

llvm-svn: 258841
2016-01-26 19:33:57 +00:00
Matthias Braun d4f6409dff MachineScheduler: Allow independent scheduling of sub register defs
Note that this is disabled by default and still requires a patch to
handleMove() which is not upstreamed yet.

If the TrackLaneMasks policy/strategy is enabled the MachineScheduler
will build a schedule graph where definitions of independent
subregisters are no longer serialised.

Implementation comments:
- Without lane mask tracking a sub register def also counts as a use
  (except for the first one with the read-undef flag set), with lane
  mask tracking enabled this is no longer the case.
- Pressure Diffs where previously maintained per definition of a
  vreg with the help of the SSA information contained in the
  LiveIntervals.  With lanemask tracking enabled we cannot do this
  anymore and instead change the pressure diffs for all uses of the vreg
  as it becomes live/dead.  For this changed style to work correctly we
  ignore uses of instructions that define the same register again: They
  won't affect register pressure.
- With lanemask tracking we remove all read-undef flags from
  sub register defs when building the graph and re-add them later when
  all vreg lanes have become dead.

Differential Revision: http://reviews.llvm.org/D14969

llvm-svn: 258259
2016-01-20 00:23:32 +00:00
Matthias Braun 5d458617aa RegisterPressure: Make liveness tracking subregister aware
Differential Revision: http://reviews.llvm.org/D14968

llvm-svn: 258258
2016-01-20 00:23:26 +00:00
Matthias Braun b505c76c9a RegisterPressure: Expose RegisterOperands API
Previously the RegisterOperands have only been used internally in
RegisterPressure.cpp. However this datastructure can be useful for other
tasks as well and allows refactoring of PDiff initialisation out of
RPTracker::recede().

This patch:
- Exposes RegisterOperands as public API
- Splits RPTracker::recede() into a part that skips DebugValues and
  maintains the region borders, and the core that changes register
  pressure when given a set of RegisterOperands.
- This allows to move the PDiff initialisation out recede() into a
  method of the PressureDiffs class.
- The upcoming subregister scheduling code will also use
  RegisterOperands to avoid pushing more unrelated functionality into
  recede()/advance().

Differential Revision: http://reviews.llvm.org/D15473

llvm-svn: 257535
2016-01-12 22:57:35 +00:00
Geoff Berry 12fe2279f3 ScheduleDAGInstrs: Bug fix for missed memory dependency.
Summary:
In buildSchedGraph(), when adding memory dependencies for loads, move
the call to adjustChainDeps() after the call to
addChainDependency(AliasChain) to handle the case where
addChainDependency(AliasChain) ends up not adding a dependency and
instead putting the SU on the RejectMemNodes list.  The call to
adjustChainDeps() must be done after the call to addChainDependency() in
order to process the SU added to the RejectMemNodes list to create
memory dependencies for it.

Reviewers: hfinkel, atrick, jonpa, resistor

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D15927

llvm-svn: 256950
2016-01-06 18:14:26 +00:00
Matthias Braun b17e8b1c1d ScheduleDAGInstrs: Move LiveIntervals field to ScheduleDAGMI
Now that ScheduleDAGInstrs doesn't need it anymore we can move the field
down the class hierarcy to ScheduleDAGMI.

llvm-svn: 254759
2015-12-04 19:54:24 +00:00
Matthias Braun 97d0ffbe06 ScheduleDAGInstrs: Rework schedule graph builder.
Re-comitting with a change that avoids undefined uses getting put into
the VRegUses list.

The new algorithm remembers the uses encountered while walking backwards
until a matching def is found. Contrary to the previous version this:
- Works without LiveIntervals being available
- Allows to increase the precision to subregisters/lanemasks
  (not used for now)

The changes in the AMDGPU tests are necessary because the R600 scheduler
is not stable with respect to the order of nodes in the ready queues.

Differential Revision: http://reviews.llvm.org/D9068

llvm-svn: 254683
2015-12-04 01:51:19 +00:00
Matthias Braun 2fd672a221 Revert "ScheduleDAGInstrs: Rework schedule graph builder."
This works mostly fine but breaks some stage 1 builders when compiling
compiler-rt on i386. Revert for further investigation as I can't see an
obvious cause/fix.

This reverts commit r254577.

llvm-svn: 254586
2015-12-03 03:01:10 +00:00
Matthias Braun d35fe3d984 ScheduleDAGInstrs: Rework schedule graph builder.
The new algorithm remembers the uses encountered while walking backwards
until a matching def is found. Contrary to the previous version this:
- Works without LiveIntervals being available
- Allows to increase the precision to subregisters/lanemasks
  (not used for now)

The changes in the AMDGPU tests are necessary because the R600 scheduler
is not stable with respect to the order of nodes in the ready queues.

Differential Revision: http://reviews.llvm.org/D9068

llvm-svn: 254577
2015-12-03 02:05:27 +00:00
Matthias Braun 93563e7032 ScheduleDAGInstrs: Remove IsPostRA flag; NFC
ScheduleDAGInstrs doesn't behave differently before or after register
allocation. It was only used in a method of MachineSchedulerBase which
behaved differently in MachineScheduler/PostMachineScheduler. Change
this to let MachineScheduler/PostMachineScheduler just pass in a
parameter to that function.

The order of the LiveIntervals* and bool RemoveKillFlags paramters have
been switched to make out-of-tree code fail instead of unintentionally
passing a value intended for the IsPostRA flag to the (previously
following and default initialized) RemoveKillFlags.

Differential Revision: http://reviews.llvm.org/D14245

llvm-svn: 251883
2015-11-03 01:53:29 +00:00
Matthias Braun f2f194455f Revert "ScheduleDAGInstrs: Remove IsPostRA flag"
It broke 3 arm testcases.

This reverts commit r251608.

llvm-svn: 251615
2015-10-29 05:06:41 +00:00
Matthias Braun 7ffadd0087 ScheduleDAGInstrs: Remove IsPostRA flag
This was a layering violation in ScheduleDAGInstrs (and
MachineSchedulerBase) they both shouldn't know directly whether they are
used by the PostMachineScheduler or the MachineScheduler.

llvm-svn: 251608
2015-10-29 03:57:24 +00:00
Rafael Espindola 84921b9860 Refactor: Simplify boolean conditional return statements in lib/CodeGen.
Patch by Richard.

llvm-svn: 251213
2015-10-24 23:11:13 +00:00
Duncan P. N. Exon Smith 6e98cd32dc CodeGen: Avoid more ilist iterator implicit conversions, NFC
llvm-svn: 249903
2015-10-09 21:08:19 +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
Matthias Braun b2b7ef1de8 MachineBasicBlock: Add liveins() method returning an iterator_range
llvm-svn: 245895
2015-08-24 22:59:52 +00:00
Benjamin Kramer df005cbe19 Fix some comment typos.
llvm-svn: 244402
2015-08-08 18:27:36 +00:00
Mehdi Amini bd7287ebe5 Move most user of TargetMachine::getDataLayout to the Module one
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

This patch is quite boring overall, except for some uglyness in
ASMPrinter which has a getDataLayout function but has some clients
that use it without a Module (llmv-dsymutil, llvm-dwarfdump), so
some methods are taking a DataLayout as parameter.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11090

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 242386
2015-07-16 06:11:10 +00:00
Alexander Kornienko f00654e31b Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
2015-06-23 09:49:53 +00:00
Chandler Carruth c3f49eb451 [PM/AA] Hoist the AliasResult enum out of the AliasAnalysis class.
This will allow classes to implement the AA interface without deriving
from the class or referencing an internal enum of some other class as
their return types.

Also, to a pretty fundamental extent, concepts such as 'NoAlias',
'MayAlias', and 'MustAlias' are first class concepts in LLVM and we
aren't saving anything by scoping them heavily.

My mild preference would have been to use a scoped enum, but that
feature is essentially completely broken AFAICT. I'm extremely
disappointed. For example, we cannot through any reasonable[1] means
construct an enum class (or analog) which has scoped names but converts
to a boolean in order to test for the possibility of aliasing.

[1]: Richard Smith came up with a "solution", but it requires class
templates, and lots of boilerplate setting up the enumeration multiple
times. Something like Boost.PP could potentially bundle this up, but
even that would be quite painful and it doesn't seem realistically worth
it. The enum class solution would probably work without the need for
a bool conversion.

Differential Revision: http://reviews.llvm.org/D10495

llvm-svn: 240255
2015-06-22 02:16:51 +00:00
Alexander Kornienko 70bc5f1398 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
Chandler Carruth ac80dc7532 [PM/AA] Remove the Location typedef from the AliasAnalysis class now
that it is its own entity in the form of MemoryLocation, and update all
the callers.

This is an entirely mechanical change. References to "Location" within
AA subclases become "MemoryLocation", and elsewhere
"AliasAnalysis::Location" becomes "MemoryLocation". Hope that helps
out-of-tree folks update.

llvm-svn: 239885
2015-06-17 07:18:54 +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
Sanjay Patel f8c028c0b0 use range-based for-loop
llvm-svn: 237914
2015-05-21 17:04:17 +00:00
Sanjay Patel 490aca92be use range-based for-loop; NFCI
llvm-svn: 237908
2015-05-21 16:00:50 +00:00
Matthias Braun bff3a7eb3d Remove MCInstrItineraries includes in parts that don't use them anymore
llvm-svn: 237375
2015-05-14 18:01:11 +00:00
Saleem Abdulrasool ee13fbe848 CodeGen: ignore DEBUG_VALUE nodes in KILL tagging
DEBUG_VALUE nodes do not take part in code generation.  Ignore them when
performing KILL updates.  Addresses PR23486.

llvm-svn: 237211
2015-05-12 23:36:18 +00:00
Arnold Schwaighofer f54b73d681 ScheduleDAGInstrs: In functions with tail calls PseudoSourceValues are not non-aliasing distinct objects
The code that builds the dependence graph assumes that two PseudoSourceValues
don't alias. In a tail calling function two FixedStackObjects might refer to the
same location. Worse 'immutable' fixed stack objects like function arguments are
not immutable and will be clobbered.

Change this so that a load from a FixedStackObject is not invariant in a tail
calling function and don't return a PseudoSourceValue for an instruction in tail
calling functions when building the dependence graph so that we handle function
arguments conservatively.

Fix for PR23459.

rdar://20740035

llvm-svn: 236916
2015-05-08 23:52:00 +00:00
Pete Cooper 300069a019 ScheduleDAGInstrs should toggle kill flags on bundled instrs.
ScheduleDAGInstrs wasn't setting or clearing the kill flags on instructions inside bundles.  This led to code such as this

%R3<def> = t2ANDrr %R0
BUNDLE %ITSTATE<imp-def,dead>, %R0<imp-use,kill>
  t2IT 1, 24, %ITSTATE<imp-def>
  R6<def,tied6> = t2ORRrr %R0<kill>, ...

being transformed to

BUNDLE %ITSTATE<imp-def,dead>, %R0<imp-use>
  t2IT 1, 24, %ITSTATE<imp-def>
  R6<def,tied6> = t2ORRrr %R0<kill>, ...
%R3<def> = t2ANDrr %R0<kill>

where the kill flag was removed from the BUNDLE instruction, but not the t2ORRrr inside it.  The verifier then thought that
R0 was undefined when read by the AND.

This change make the toggleKillFlags method also check for bundles and toggle flags on bundled instructions.
Setting the kill flag is special cased as we only want to set the kill flag on the last instruction in the bundle.

llvm-svn: 236428
2015-05-04 16:52:06 +00:00
Mehdi Amini a28d91d81b DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231740
2015-03-10 02:37:25 +00:00
Eric Christopher 1cdefae9c4 Rewrite MachineOperand::print and MachineInstr::print to avoid
uses of TM->getSubtargetImpl and propagate to all calls.

This could be a debugging regression in places where we had a
TargetMachine and/or MachineFunction but don't have it as part
of the MachineInstr. Fixing this would require passing a
MachineFunction/Function down through the print operator, but
none of the existing uses in tree seem to do this.

llvm-svn: 230710
2015-02-27 00:11:34 +00:00
Jonas Paulsson afa6813816 Bugfix for missed dependency from store to load in buildSchedGraph().
Background: When handling underlying objects for a store, the vector
of previous mem uses, mapped to the same Value, is afterwards cleared
(regardless of ThisMayAlias). This means that during handling of the
next store using the same Value, adjustChainDeps() must be called,
otherwise a dependency might be missed.

For example, three spill/reload (NonAliasing) memory accesses using
the same Value 'a', with different offsets:

    SU(2): store  @a
    SU(1): store  @a, Offset:1
    SU(0): load   @a

In this case we have:

* SU(1) does not need a dep against SU(0). Therefore,SU(0) ends up in
  RejectMemNodes and is removed from the mem-uses list (AliasMemUses
  or NonAliasMemUses), as this list is cleared.

* SU(2) needs a dep against SU(0). Therefore, SU(2) must check
  RejectMemNodes by calling adjustChainDeps().

Previously, for store SUs, adjustChainDeps() was only called if
MayAlias was true, missing the S(2) to S(0) dependency in the case
above. The fix is to always call adjustChainDeps(), regardless of
MayAlias, since this applies both for AliasMemUses and
NonAliasMemUses.

No testcase found for any in-tree target.

llvm-svn: 228686
2015-02-10 13:03:32 +00:00
Eric Christopher 2c63549386 Update a few calls to getSubtarget<> to either be getSubtargetImpl
when we didn't need the cast to the base class or the cached version
off of the subtarget.

llvm-svn: 227176
2015-01-27 07:54:39 +00:00
Jonas Paulsson fcf0cba88c New method SDep::isNormalMemoryOrBarrier() in ScheduleDAGInstrs.cpp.
Used to iterate over previously added memory dependencies in
adjustChainDeps() and iterateChainSucc().

SDep::isCtrl() was previously used in these places, that also gave
anti and output edges. The code may be worse if these are followed,
because MisNeedChainEdge() will conservatively return true since a
non-memory instruction has no memory operands, and a false chain dep
will be added. It is also unnecessary since all memory accesses of
interest will be reached by memory dependencies, and there is a budget
limit for the number of edges traversed.

This problem was found on an out-of-tree target with enabled alias
analysis. No test case for an in-tree target has been found.

Reviewed by Hal Finkel.

llvm-svn: 225351
2015-01-07 13:38:29 +00:00
Jonas Paulsson bf408bbe38 Fix typos in comment and option help texts.
For -enable-aa-sched-mi and -use-tbaa-in-sched-mi.

llvm-svn: 225350
2015-01-07 13:20:57 +00:00
Tom Stellard 3e01d47d98 MISched: Fix moving stores across barriers
This fixes an issue with ScheduleDAGInstrs::buildSchedGraph
where stores without an underlying object would not be added
as a predecessor to the current BarrierChain.

llvm-svn: 223717
2014-12-08 23:36:48 +00:00