Commit Graph

34113 Commits

Author SHA1 Message Date
Petar Jovanovic e2bfcd6394 Correct dwarf unwind information in function epilogue
This patch aims to provide correct dwarf unwind information in function
epilogue for X86.
It consists of two parts. The first part inserts CFI instructions that set
appropriate cfa offset and cfa register in emitEpilogue() in
X86FrameLowering. This part is X86 specific.

The second part is platform independent and ensures that:

* CFI instructions do not affect code generation (they are not counted as
  instructions when tail duplicating or tail merging)
* Unwind information remains correct when a function is modified by
  different passes. This is done in a late pass by analyzing information
  about cfa offset and cfa register in BBs and inserting additional CFI
  directives where necessary.

Added CFIInstrInserter pass:

* analyzes each basic block to determine cfa offset and register are valid
  at its entry and exit
* verifies that outgoing cfa offset and register of predecessor blocks match
  incoming values of their successors
* inserts additional CFI directives at basic block beginning to correct the
  rule for calculating CFA

Having CFI instructions in function epilogue can cause incorrect CFA
calculation rule for some basic blocks. This can happen if, due to basic
block reordering, or the existence of multiple epilogue blocks, some of the
blocks have wrong cfa offset and register values set by the epilogue block
above them.
CFIInstrInserter is currently run only on X86, but can be used by any target
that implements support for adding CFI instructions in epilogue.

Patch by Violeta Vukobrat.

Differential Revision: https://reviews.llvm.org/D42848

llvm-svn: 330706
2018-04-24 10:32:08 +00:00
Florian Hahn f3561ffa87 [LoopInfo] Verify BBMap tracks innermost loops for BBs.
By checking that none of the child loops contain a BB we make sure BBMap
contains the innermost loop defining BB. This invariant was violated in
LoopInterchange and got caught by this assertion.

Reviewers: chandlerc, mzolotukhin, sanjoy, mehdi_amini, efriedma

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D45971

llvm-svn: 330698
2018-04-24 09:10:05 +00:00
David Blaikie a27771b62f InstCombine: Fix layering by not including Scalar.h in InstCombine
(notionally Scalar.h is part of libLLVMScalarOpts, so it shouldn't be
included by InstCombine which doesn't/shouldn't need to depend on
ScalarOpts)

llvm-svn: 330669
2018-04-24 00:48:59 +00:00
Craig Topper 1bcb258ba3 [AggressiveInstCombine] Add aggressive inst combiner to the LLVM C API.
I just tried to copy what was done for regular InstCombine. Hopefully I didn't miss anything.

llvm-svn: 330668
2018-04-24 00:39:29 +00:00
Craig Topper ab7578460b [AggressiveInstCombine] Add createAggressiveInstCombinerPass to LinkAllPasses.h.
llvm-svn: 330664
2018-04-24 00:11:04 +00:00
Craig Topper d4eb2073b7 [AggressiveInstCombine] Add library initializer routine for AggressiveInstCombine library. Use it in bugpoint and llvm-opt-fuzzer to match regular InstCombine.
This should make aggressive instcombine usable with these tools.

llvm-svn: 330663
2018-04-24 00:05:21 +00:00
Robert Widmann 21fc15d553 [LLVM-C] DIBuilder Bindings For Variable Expressions
Summary: Add DIBuilder bindings for (global) variable expressions, variable value expressions, and debug value intrinsic insertion.

Reviewers: harlanhaskins, deadalnix, whitequark

Reviewed By: whitequark

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45979

llvm-svn: 330661
2018-04-23 22:31:49 +00:00
Roman Tereshin 3c6ea7e28c [GlobalISel][Legalizer] Look thro copies while combining G_UNMERGE's
As we're becoming stricter w/ respect to not allowing vregs having LLTs
and regclasses assigned both mid-globalisel pipeline, the number of
extra copies grows, some of which separate G_UNMERGE's from their
corresponding G_MERGE's, becoming a performance concern.

It's worth mentioning that we're already looking through copies while
combining legalization artifacts for every kind of artifact but
G_UNMERGE.

Reviewed By: aditya_nandakumar

Reviewers: ab, t.p.northover, volkan, javed.absar

Subscribers: rovka, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45644

llvm-svn: 330660
2018-04-23 22:28:36 +00:00
Gabor Buella 1a2ce572bf [X86] Revert r330638 - accidental commit
llvm-svn: 330640
2018-04-23 20:05:51 +00:00
George Burgess IV 851e3a1792 Fix a broken typedef; NFCI
Richard Smith noted that `typedef typename iplist::iplist_impl_type
iplist_impl_type` is incorrect, per
http://eel.is/c++draft/basic.scope#class-2

It seems that neither clang nor gcc get too angry about this, but a
newer version of msvc does.

Thanks to jcmac on IRC for pointing this out!

llvm-svn: 330639
2018-04-23 20:03:00 +00:00
Gabor Buella 213a7cda1f [X86] movdiri and movdir64b instructions
Reviewers: craig.topper
llvm-svn: 330638
2018-04-23 20:00:59 +00:00
Daniel Neilson cc45e923c5 [DSE] Teach the pass that atomic memory intrinsics are stores.
Summary:
This change teaches DSE that the atomic memory intrinsics are stores
that can be eliminated, and can allow other stores to be eliminated.
This change specifically does not teach DSE that these intrinsics
can be partially eliminated (i.e. length reduced, and dest/src changed);
that will be handled in another change.

Reviewers: mkazantsev, skatkov, apilipenko, efriedma, rsmith

Reviewed By: efriedma

Subscribers: dmgreen, llvm-commits

Differential Revision: https://reviews.llvm.org/D45535

llvm-svn: 330629
2018-04-23 19:06:49 +00:00
Simon Pilgrim 7f31119fb0 [MC] Remove MachineInstr reference in MC layer (PR37160)
Only add support for getSchedInfoStr(const MachineInstr &MI) at the TargetSubtargetInfo level.

Really, the getSchedInfoStr calls need to be removed entirely, we should just return a latency/rthroughput through the subtarget and keep a string creation helper function somewhere else.

llvm-svn: 330615
2018-04-23 16:59:06 +00:00
Daniel Neilson 9863b48d4e [SelectionDAG] Refactor lowering of atomic memory intrinsics.
Summary:
This just refactors the lowering of the atomic memory intrinsics to more
closely match the code patterns used in the lowering of the non-atomic
memory intrinsics. Specifically, we encapsulate the lowering in
SelectionDAG::getAtomicMem*() functions rather than embedding
the code directly in the SelectionDAGBuilder code.

llvm-svn: 330603
2018-04-23 15:40:37 +00:00
Robert Widmann 6978db7800 [LLVM-C] DIBuilderBindings for Subrange and Arrays
Summary: Move Go bindings for subranges and DINode arrays.

Reviewers: harlanhaskins, whitequark, deadalnix

Reviewed By: whitequark

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45933

llvm-svn: 330594
2018-04-23 14:29:33 +00:00
Robert Widmann b02fe644d4 [LLVM-C] Finish Up Scope Bindings
Summary: Adds bindings for Module and NameSpace scopes and LLVMDIBuilderCreateForwardDecl, a counterpart to LLVMDIBuilderCreateReplaceableCompositeType.

Reviewers: harlanhaskins, whitequark, deadalnix

Reviewed By: whitequark

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45934

llvm-svn: 330591
2018-04-23 13:51:43 +00:00
Max Kazantsev b1137c42fa [LoopSimplify] Fix incorrect SCEV invalidation
In the function `simplifyOneLoop` we optimistically assume that changes in the
inner loop only affect this very loop and have no impact on its parents. In fact,
after rL329047 has been merged, we can now calculate exit counts for outer
loops which may depend on inner loops. Thus, we need to invalidate all parents
when we do something to a loop.

There is an evidence of incorrect behavior of `simplifyOneLoop`: when we insert
`SE->verify()` check in the end of this funciton, it fails on a bunch of existing
test, in particular:

    LLVM :: Transforms/LoopUnroll/peel-loop-not-forced.ll
    LLVM :: Transforms/LoopUnroll/peel-loop-pgo.ll
    LLVM :: Transforms/LoopUnroll/peel-loop.ll
    LLVM :: Transforms/LoopUnroll/peel-loop2.ll

Note that previously we have fixed issues of this variety, see rL328483.
This patch makes this function invalidate the outermost loop properly.

Differential Revision: https://reviews.llvm.org/D45937
Reviewed By: chandlerc

llvm-svn: 330576
2018-04-23 10:32:37 +00:00
Robert Widmann 12e367b6db [LLVM-C] Add DIBuilder Bindings For Variable Creation
Summary: Wrap LLVMDIBuilderCreateAutoVariable, LLVMDIBuilderCreateParameterVariable, LLVMDIBuilderCreateExpression, and move and correct LLVMDIBuilderInsertDeclareBefore and LLVMDIBuilderInsertDeclareAtEnd from the Go bindings to the C bindings.

Reviewers: harlanhaskins, whitequark, deadalnix

Reviewed By: harlanhaskins, whitequark

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45928

llvm-svn: 330555
2018-04-22 19:24:44 +00:00
Andres Freund d7489a44de Test commit access.
Remove trailing whitespace.

llvm-svn: 330551
2018-04-22 17:53:34 +00:00
Sanjay Patel 30be665e82 [PatternMatch] allow undef elements when matching a vector zero
This is the last step in getting constant pattern matchers to allow
undef elements in constant vectors.

I'm adding a dedicated m_ZeroInt() function and building m_Zero() from
that. In most cases, calling code can be updated to use m_ZeroInt()
directly when there's no need to match pointers, but I'm leaving that
efficiency optimization as a follow-up step because it's not always
clear when that's ok.

There are just enough icmp folds in InstSimplify that can be used for 
integer or pointer types, that we probably still want a generic m_Zero()
for those cases. Otherwise, we could eliminate it (and possibly add a
m_NullPtr() as an alias for isa<ConstantPointerNull>()).

We're conservatively returning a full zero vector (zeroinitializer) in
InstSimplify/InstCombine on some of these folds (see diffs in InstSimplify),
but I'm not sure if that's actually necessary in all cases. We may be 
able to propagate an undef lane instead. One test where this happens is 
marked with 'TODO'.
 

llvm-svn: 330550
2018-04-22 17:07:44 +00:00
Jonas Devlieghere 0c1b29540c [Support] Add optional prefix to convenience helpers in WithColor.
Several tools prefix the error/warning/note output with the name of the
tool. One such tool is LLD for example. This commit adds as an optional
'Prefix' argument to the convenience helpers.

llvm-svn: 330526
2018-04-21 21:36:11 +00:00
Eric Christopher aadbabc070 Remove unused argument from emitModuleMetadata.
NFCI.

llvm-svn: 330470
2018-04-20 19:07:57 +00:00
Gabor Buella 31fa8025ba [X86] WaitPKG instructions
Three new instructions:

umonitor - Sets up a linear address range to be
monitored by hardware and activates the monitor.
The address range should be a writeback memory
caching type.

umwait - A hint that allows the processor to
stop instruction execution and enter an
implementation-dependent optimized state
until occurrence of a class of events.

tpause - Directs the processor to enter an
implementation-dependent optimized state
until the TSC reaches the value in EDX:EAX.

Also modifying the description of the mfence
instruction, as the rep prefix (0xF3) was allowed
before, which would conflict with umonitor during
disassembly.

Before:
$ echo 0xf3,0x0f,0xae,0xf0 | llvm-mc -disassemble
.text
mfence

After:
$ echo 0xf3,0x0f,0xae,0xf0 | llvm-mc -disassemble
.text
umonitor        %rax

Reviewers: craig.topper, zvi

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D45253

llvm-svn: 330462
2018-04-20 18:42:47 +00:00
Zachary Turner 194be871b9 [LLD/PDB] Emit first section contribution for DBI Module Descriptor.
Part of the DBI stream is a list of variable length structures
describing each module that contributes to the final executable.

One member of this structure is a section contribution entry that
describes the first section contribution in the output file for
the given module.

We have been leaving this structure unpopulated until now, so with
this patch it is now filled out correctly.

Differential Revision: https://reviews.llvm.org/D45832

llvm-svn: 330457
2018-04-20 18:00:46 +00:00
Nicholas Wilson ef90ff36da [WebAssembly] Distinguish debug/symbol names in the Wasm structs. NFC
Differential Revision: https://reviews.llvm.org/D45021

llvm-svn: 330448
2018-04-20 17:07:24 +00:00
Sanjay Patel 3d453ad711 [DAGCombine] (float)((int) f) --> ftrunc (PR36617)
This was originally committed at rL328921 and reverted at rL329920 to
investigate failures in Chrome. This time I've added to the ReleaseNotes
to warn users of the potential of exposing UB and let me repeat that
here for more exposure:

  Optimization of floating-point casts is improved. This may cause surprising
  results for code that is relying on undefined behavior. Code sanitizers can
  be used to detect affected patterns such as this:

    int main() {
      float x = 4294967296.0f;
      x = (float)((int)x);
      printf("junk in the ftrunc: %f\n", x);
      return 0;
    }

    $ clang -O1 ftrunc.c -fsanitize=undefined ; ./a.out
    ftrunc.c:5:15: runtime error: 4.29497e+09 is outside the range of 
                   representable values of type 'int'
    junk in the ftrunc: 0.000000


Original commit message:

fptosi / fptoui round towards zero, and that's the same behavior as ISD::FTRUNC,
so replace a pair of casts with the equivalent node. We don't have to account for
special cases (NaN, INF) because out-of-range casts are undefined.

Differential Revision: https://reviews.llvm.org/D44909

llvm-svn: 330437
2018-04-20 15:07:55 +00:00
Michael Zolotukhin a2c9af0209 Revert "Revert r330403 and r330413."
Reapply the patches with a fix. Thanks Ilya and Hans for the reproducer!
This reverts commit r330416.

The issue was that removing predecessors invalidated uses that we stored
for rewrite. The fix is to finish manipulating with CFG before we select
uses for rewrite.

llvm-svn: 330431
2018-04-20 13:34:32 +00:00
Jonas Devlieghere 5c709eda07 [ObjectYAML] Add ability for DWARFYAML to calculate DIE lengths
This patch adds the ability for the ObjectYAML DWARFEmitter to calculate
the lengths of DIEs. This is accomplished by creating a DIEFixupVisitor
class which traverses the DWARF DIEs to calculate and fix up the lengths
in the Compile Unit header.

The DIEFixupVisitor can be extended in the future to enable more complex
fix ups which will enable simplified YAML string representations.

This is also very useful when using the YAML format in unit tests
because you no longer need to know the length of the compile unit when
writing the YAML string.

Differential commandeered from Chris Bieneman (beanz)

Differential revision: https://reviews.llvm.org/D30666

llvm-svn: 330421
2018-04-20 12:33:49 +00:00
Ilya Biryukov afe822bd6d Revert r330403 and r330413.
Revert r330413: "[SSAUpdaterBulk] Use SmallVector instead of DenseMap for storing rewrites."
Revert r330403 "Reapply "[PR16756] Use SSAUpdaterBulk in JumpThreading." one more time."

r330403 commit seems to crash clang during our integrate while doing PGO build with the following stacktrace:
      #2 llvm::SSAUpdaterBulk::RewriteAllUses(llvm::DominatorTree*, llvm::SmallVectorImpl<llvm::PHINode*>*)
      #3 llvm::JumpThreadingPass::ThreadEdge(llvm::BasicBlock*, llvm::SmallVectorImpl<llvm::BasicBlock*> const&, llvm::BasicBlock*)
      #4 llvm::JumpThreadingPass::ProcessThreadableEdges(llvm::Value*, llvm::BasicBlock*, llvm::jumpthreading::ConstantPreference, llvm::Instruction*)
      #5 llvm::JumpThreadingPass::ProcessBlock(llvm::BasicBlock*)
The crash happens while compiling 'lib/Analysis/CallGraph.cpp'.

r3340413 is reverted due to conflicting changes.

llvm-svn: 330416
2018-04-20 10:52:54 +00:00
Michael Zolotukhin 9dea079315 [SSAUpdaterBulk] Use SmallVector instead of DenseMap for storing rewrites.
llvm-svn: 330413
2018-04-20 10:31:06 +00:00
Florian Hahn d4332eb3b7 [LTO] Add stats-file option to LTO/Config.h.
This patch adds a StatsFile option to LTO/Config.h and updates both
LLVMGold and llvm-lto2 to set it.

Reviewers: MatzeB, tejohnson, espindola

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D45531

llvm-svn: 330411
2018-04-20 10:18:36 +00:00
Michael Zolotukhin 79cb54b2d9 [SSAUpdaterBulk] Use SmallVector instead of SmallPtrSet for uses.
llvm-svn: 330398
2018-04-20 07:56:00 +00:00
Vlad Tsyrklevich 230b256783 LowerTypeTests: Propagate symver directives
Summary:
This change fixes https://crbug.com/834474, a build failure caused by
LowerTypeTests not preserving .symver symbol versioning directives for
exported functions. Emit symver information to ThinLTO summary data and
then propagate symver directives for exported functions to the merged
module.

Emitting symver information to the summaries increases the size of
intermediate build artifacts for a Chromium build by less than 0.2%.

Reviewers: pcc

Reviewed By: pcc

Subscribers: tejohnson, mehdi_amini, eraman, llvm-commits, eugenis, kcc

Differential Revision: https://reviews.llvm.org/D45798

llvm-svn: 330387
2018-04-20 01:36:48 +00:00
Amara Emerson 6aacbf4d7c Move a dump() implementation out of line.
Fixes some link issues.

llvm-svn: 330384
2018-04-20 00:42:46 +00:00
Jessica Paquette 1eca23bdd8 [MachineOutliner] NFC: Move EnableLinkOnceODROutlining into MachineOutliner.cpp
This moves the EnableLinkOnceODROutlining flag from TargetPassConfig.cpp into
MachineOutliner.cpp. It also removes OutlineFromLinkOnceODRs from the
MachineOutliner constructor. This is now handled by the moved command-line
flag.

llvm-svn: 330373
2018-04-19 22:17:07 +00:00
Jin Lin 585f2699cf Refine the loop rotation's API
Summary:
The following changes addresses the following two issues.

1) The existing loop rotation pass contains both loop latch simplification and loop rotation. So one flag RotationOnly is added to be passed to the loop rotation pass.
2) The threshold value is initialized with MAX_UINT since the loop rotation utility should not have threshold limit.

Reviewers: dmgreen, efriedma

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D45582

llvm-svn: 330362
2018-04-19 20:29:43 +00:00
Lang Hames 9bbd653084 [ORC] Make VSO symbol resolution/finalization operations private.
This forces these operations to be carried out via a
MaterializationResponsibility instance, ensuring responsibility is explicitly
tracked.

llvm-svn: 330356
2018-04-19 18:42:49 +00:00
Alexander Ivchenko e8fed1546e Lowering x86 adds/addus/subs/subus intrinsics (llvm part)
This is the patch that lowers x86 intrinsics to native IR
in order to enable optimizations. The patch also includes folding
of previously missing saturation patterns so that IR emits the same
machine instructions as the intrinsics.

Patch by tkrupa

Differential Revision: https://reviews.llvm.org/D44785

llvm-svn: 330322
2018-04-19 12:13:30 +00:00
Florian Hahn 147fc016e3 [BasicBlock] Add instructionsWithoutDebug methods to skip debug insts.
Reviewers: aprantl, vsk, mattd, chandlerc

Reviewed By: aprantl, vsk

Differential Revision: https://reviews.llvm.org/D45657

llvm-svn: 330316
2018-04-19 09:48:07 +00:00
Artem Belevich 0ae8590354 [NVPTX, CUDA] Added support for m8n32k16 and m32n8k16 variants of wmma instructions.
The new instructions were added added for sm_70+ GPUs in CUDA-9.1.

Differential Revision: https://reviews.llvm.org/D45068

llvm-svn: 330296
2018-04-18 21:51:48 +00:00
Sanjay Patel b2ab3f28d5 [SimplifyLibcalls] Realloc(null, N) -> Malloc(N)
Patch by Dávid Bolvanský!

Differential Revision: https://reviews.llvm.org/D45413

llvm-svn: 330259
2018-04-18 14:21:31 +00:00
Matt Davis 6ae0b1fe2b [NFC] Remove doxygen brief tag from BasicBlock.h
Summary: Documentation is built using the AutoBrief configuration option in docs/doxygen.cfg.in.  This change removes the redundant brief tags from BasicBlock.h.   I'm happy to write a sed script and remove all \brief tags as a separate commit later.

Reviewers: aprantl

Reviewed By: aprantl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45708

llvm-svn: 330242
2018-04-18 07:58:45 +00:00
Keith Wyss 3d86823f3d [XRay] Typed event logging intrinsic
Summary:
Add an LLVM intrinsic for type discriminated event logging with XRay.
Similar to the existing intrinsic for custom events, but also accepts
a type tag argument to allow plugins to be aware of different types
and semantically interpret logged events they know about without
choking on those they don't.

Relies on a symbol defined in compiler-rt patch D43668. I may wait
to submit before I can see demo everything working together including
a still to come clang patch.

Reviewers: dberris, pelikan, eizan, rSerge, timshen

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45633

llvm-svn: 330219
2018-04-17 21:30:29 +00:00
Rui Ueyama e6ac9f5ec3 Rename sys::Process::GetArgumentVector -> sys::windows::GetCommandLineArguments
GetArgumentVector (or GetCommandLineArguments) is very Windows-specific.
I think it doesn't make much sense to provide that function from sys::Process.

I also made a change so that the function takes a BumpPtrAllocator
instead of a SpecificBumpPtrAllocator. The latter is the class to call
dtors, but since char * is trivially destructible, we should use the
former class.

Differential Revision: https://reviews.llvm.org/D45641

llvm-svn: 330216
2018-04-17 21:09:16 +00:00
Zachary Turner bee6c22414 [llvm-pdbutil] Dump first section contribution for each module.
The DBI stream contains a list of module descriptors.  At the
beginning of each descriptor is a structure representing the first
section contribution in the output file for that module.  LLD
currently doesn't fill out this structure at all, but link.exe
does.  So as a precursor to emitting this data in LLD, we first
need a way to dump it so that it can be checked.

This patch adds support for the dumping, and verifies via a test
that LLD emits bogus information.

llvm-svn: 330208
2018-04-17 20:06:43 +00:00
Nemanja Ivanovic a9a6dd826a [PowerPC] Mark the BDNZ intrinsic as NoDuplicate
Duplicating this intrinsic is not generally valid because it has the side-effect
of decrementing the CTR. Any passes that duplicate it would need to be taught to
keep the regions formed completely disjoint.
This patch should be NFC for typical uses as CTRLoops runs after the remaining
loop passes. It only affects situations where the loop passes are scheduled on
the IR after the codegen passes (as is the case with some JIT pipelines).

Fixes https://bugs.llvm.org/show_bug.cgi?id=37050

llvm-svn: 330186
2018-04-17 13:07:01 +00:00
Gerolf Hoflehner 1c3a07834e [IR] Upgrade comment token in objc retain release marker for asm call
Older compiler issued '#' instead of ';'

llvm-svn: 330173
2018-04-17 04:02:24 +00:00
Peter Collingbourne 2f6d00612d COFF: Make SectionChunk::Relocs field an ArrayRef. NFCI.
Differential Revision: https://reviews.llvm.org/D45714

llvm-svn: 330172
2018-04-17 01:54:34 +00:00
Zachary Turner d8d97de514 [PDB] Correctly use the target machine when writing DBI stream.
Using Config->is64() will treat ARM64 as Amd64, which is incorrect.
Furthermore, there are more esoteric architectures that could
theoretically be encountered.  Just set it directly to the machine
type, which we already know anyway.

llvm-svn: 330157
2018-04-16 20:42:06 +00:00
Zachary Turner e3fe669855 Resubmit "Fix some incorrect fields in our generated PDBs."
This fixes the failing tests.  They simply hadn't been updated
to match the new output resulting from this patch.

llvm-svn: 330145
2018-04-16 18:17:13 +00:00
Lang Hames 67feadb2c7 [ORC] Add a MaterializationResponsibility class to track responsibility for
materializing function definitions.

MaterializationUnit instances are responsible for resolving and finalizing
symbol definitions when their materialize method is called. By contract, the
MaterializationUnit must materialize all definitions it is responsible for and
no others. If it can not materialize all definitions (because of some error)
then it must notify the associated VSO about each definition that could not be
materialized. The MaterializationResponsibility class tracks this
responsibility, asserting that all required symbols are resolved and finalized,
and that no extraneous symbols are resolved or finalized. In the event of an
error it provides a convenience method for notifying the VSO about each
definition that could not be materialized.

llvm-svn: 330142
2018-04-16 18:05:24 +00:00
Lang Hames ffeacb7b1a [ORC] Merge VSO notifyResolutionFailed and notifyFinalizationFailed in to
notifyMaterializationFailed.

The notifyMaterializationFailed method can determine which error to raise by
looking at which queue the pending queries are in (resolution or finalization).

llvm-svn: 330141
2018-04-16 18:05:22 +00:00
Zachary Turner 52c80e3860 Revert "Fix some incorrect fields in our generated PDBs."
There are a couple of failing tests which slipped under my radar
so I'm reverting this while I attempt to fix.

llvm-svn: 330133
2018-04-16 16:55:41 +00:00
Brock Wyma 94ece8fbc9 [CodeView] Initial support for emitting S_THUNK32 symbols for compiler...
When emitting CodeView debug information, compiler-generated thunk routines
should be emitted using S_THUNK32 symbols instead of S_GPROC32_ID symbols so
Visual Studio can properly step into the user code.  This initial support only
handles standard thunk ordinals.

Differential Revision: https://reviews.llvm.org/D43838

llvm-svn: 330132
2018-04-16 16:53:57 +00:00
Zachary Turner 1b06cc7817 Fix some incorrect fields in our generated PDBs.
Most of these are pretty trivial and obvious. Setting the toolchain
version to 14.11 is perhaps a little questionable, but we've been bitten
in the past where one of our version fields sidn't match MSVC's, and I
definitely don't want to go through that diagnosis again as it was
pretty time consuming and hard to track down.

I found all of these by using llvm-pdbutil export to dump the dbi and
pdb streams to a file, then using fc followed by llvm-pdbutil explain to
explain the mismatched bytes.

There are still some more, these are just the low hanging fruit.

Differential Revision: https://reviews.llvm.org/D45276

llvm-svn: 330130
2018-04-16 16:27:49 +00:00
David Blaikie c3d6e991f8 SmallVectorMemoryBuffer: Fix some comments
llvm-svn: 330128
2018-04-16 14:23:15 +00:00
Roman Lebedev 9f6d02dcf1 [LatencyPriorityQueue] Fix build: missing override
[10/260] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/PostRASchedulerList.cpp.o
FAILED: lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/PostRASchedulerList.cpp.o
/usr/local/bin/clang++  -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Ilib/CodeGen -I/build/llvm/lib/CodeGen -I/usr/include/libxml2 -Iinclude -I/build/llvm/include -g0 -fPIC -fvisibility-inlines-hidden -Werror -Werror=date-time -Werror=unguarded-availability-new -std=c++11 -Wall -W -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wcovered-switch-default -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wstring-conversion -fcolor-diagnostics -ffunction-sections -fdata-sections -O3 -g0  -fPIC   -UNDEBUG  -fno-exceptions -fno-rtti -MD -MT lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/PostRASchedulerList.cpp.o -MF lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/PostRASchedulerList.cpp.o.d -o lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/PostRASchedulerList.cpp.o -c /build/llvm/lib/CodeGen/PostRASchedulerList.cpp
In file included from /build/llvm/lib/CodeGen/PostRASchedulerList.cpp:26:
/build/llvm/include/llvm/CodeGen/LatencyPriorityQueue.h:87:27: error: 'dump' overrides a member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
    LLVM_DUMP_METHOD void dump(ScheduleDAG *DAG) const {
                          ^
/build/llvm/include/llvm/CodeGen/ScheduleDAG.h:547:18: note: overridden virtual function is here
    virtual void dump(ScheduleDAG *) const {}
                 ^
1 error generated.

llvm-svn: 330119
2018-04-16 10:40:56 +00:00
Stefan Pintilie 2bee2022fb [LatencyPriorityQueue] The LatencyPriorityQueue class is missing the implementation for the dump function
Added implementation of the dump function for LatencyPriorityQueue.

llvm-svn: 330117
2018-04-16 10:20:56 +00:00
Gabor Buella 8f1646b579 [X86] Introduce archs: goldmont-plus & tremont
Using Goldmont's cost tables for these two upcoming
atom archs.

Reviewers: craig.topper

Reviewed By: craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45612

llvm-svn: 330109
2018-04-16 07:47:35 +00:00
Weiming Zhao 79f2d093dd Rename ObjectMemoryBuffer to SmallVectorMemoryBuffer; NFCI
Summary: As discussed in https://reviews.llvm.org/D45606, it makes more sense to name the class as SmallVectorMemoryBuffer

Reviewers: bkramer, dblaikie

Reviewed By: dblaikie

Subscribers: mehdi_amini, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D45661

llvm-svn: 330107
2018-04-16 03:44:03 +00:00
Andrea Di Biagio b9acf13907 [MC] Moved all the remaining logic that computed instruction latency and reciprocal throughput from TargetSchedModel to MCSchedModel.
TargetSchedModel now always delegates to MCSchedModel the computation of
instruction latency and reciprocal throughput.
No functional change intended.

llvm-svn: 330099
2018-04-15 17:32:17 +00:00
Jonas Devlieghere 6be1f01935 [Support] Extend WithColor helpers
Although printing warnings and errors to stderr is by far the most
common case, this patch makes it possible to specify any stream.

llvm-svn: 330094
2018-04-15 08:44:15 +00:00
Weiming Zhao 7c16977a8f NFC: Move ObjectMemoryBuffer to support
Summary:
Since the class is used by both MCJIT and LTO, it makes more sense to move it to Support lib.
This is a follow up patch to r329929 and https://reviews.llvm.org/D45244

Reviewers: bkramer, dblaikie

Reviewed By: bkramer

Subscribers: mehdi_amini, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D45606

llvm-svn: 330093
2018-04-15 05:17:14 +00:00
Jonas Devlieghere 3072b130b2 [Support] Add convenience functions to WithColor. NFC.
Create convenience functions for printing error, warning and note to
stdout. Previously we had similar functions being used in dsymutil, but
given that this pattern is so common it makes sense to make it available
globally.

llvm-svn: 330091
2018-04-14 21:36:42 +00:00
Roman Tereshin dab10b5468 [DebugInfo][OPT] NFC follow-up on "Fixing a couple of DI duplication bugs of CloneModule"
llvm-svn: 330070
2018-04-13 21:23:11 +00:00
Roman Tereshin d769eb36ab [DebugInfo][OPT] Fixing a couple of DI duplication bugs of CloneModule
As demonstrated by the regression tests added in this patch, the
following cases are valid cases:

1. A Function with no DISubprogram attached, but various debug info
  related to its instructions, coming, for instance, from an inlined
  function, also defined somewhere else in the same module;
2. ... or coming exclusively from the functions inlined and eliminated
  from the module entirely.

The ValueMap shared between CloneFunctionInto calls within CloneModule
needs to contain identity mappings for all of the DISubprogram's to
prevent them from being duplicated by MapMetadata / RemapInstruction
calls, this is achieved via DebugInfoFinder collecting all the
DISubprogram's. However, CloneFunctionInto was missing calls into
DebugInfoFinder for functions w/o DISubprogram's attached, but still
referring DISubprogram's from within (case 1). This patch fixes that.

The fix above, however, exposes another issue: if a module contains a
DISubprogram referenced only indirectly from other debug info
metadata, but not attached to any Function defined within the module
(case 2), cloning such a module causes a DICompileUnit duplication: it
will be moved in indirecty via a DISubprogram by DebugInfoFinder first
(because of the first bug fix described above), without being
self-mapped within the shared ValueMap, and then will be copied during
named metadata cloning. So this patch makes sure DebugInfoFinder
visits DICompileUnit's referenced from DISubprogram's as it goes w/o
re-processing llvm.dbg.cu list over and over again for every function
cloned, and makes sure that CloneFunctionInto self-maps
DICompileUnit's referenced from the entire function, not just its own
DISubprogram attached that may also be missing.

The most convenient way of tesing CloneModule I found is to rely on
CloneModule call from `opt -run-twice`, instead of writing tedious
unit tests. That feature has a couple of properties that makes it hard
to use for this purpose though:

1. CloneModule doesn't copy source filename, making `opt -run-twice`
  report it as a difference.
2. `opt -run-twice` does the second run on the original module, not
  its clone, making the result of cloning completely invisible in opt's
  actual output with and without `-run-twice` both, which directly
  contradicts `opt -run-twice`s own error message.

This patch fixes this as well.

Reviewed By: aprantl

Reviewers: loladiro, GorNishanov, espindola, echristo, dexonsmith

Subscribers: vsk, debug-info, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D45593

llvm-svn: 330069
2018-04-13 21:22:24 +00:00
Krzysztof Parzyszek dfed941eec [LV] Introduce TTI::getMinimumVF
The function getMinimumVF(ElemWidth) will return the minimum VF for
a vector with elements of size ElemWidth bits. This value will only
apply to targets for which TTI::shouldMaximizeVectorBandwidth returns
true. The value of 0 indicates that there is no minimum VF.

Differential Revision: https://reviews.llvm.org/D45271

llvm-svn: 330062
2018-04-13 20:16:32 +00:00
Rui Ueyama 197194b6c9 Define InitLLVM to do common initialization all at once.
We have a few functions that virtually all command wants to run on
process startup/shutdown. This patch adds InitLLVM class to do that
all at once, so that we don't need to copy-n-paste boilerplate code
to each llvm command's main() function.

Differential Revision: https://reviews.llvm.org/D45602

llvm-svn: 330046
2018-04-13 18:26:06 +00:00
Andrey Konovalov 1ba9d9c6ca hwasan: add -fsanitize=kernel-hwaddress flag
This patch adds -fsanitize=kernel-hwaddress flag, that essentially enables
-hwasan-kernel=1 -hwasan-recover=1 -hwasan-match-all-tag=0xff.

Differential Revision: https://reviews.llvm.org/D45046

llvm-svn: 330044
2018-04-13 18:05:21 +00:00
Sean Fertile eaa1607b48 Add PPC64_GLINK dynamic tag.
Add support for the PPC64_GLINK dynamic tag which is used in the ElfV2 abi.

Differential Revision: https://reviews.llvm.org/D45574

llvm-svn: 330038
2018-04-13 16:42:48 +00:00
Ivan A. Kosarev f533a6e5aa [NEON] Support intrinsic for scalar and vector versions of the VRINTN instruction
Differential Revision: https://reviews.llvm.org/D45514

llvm-svn: 330011
2018-04-13 12:45:12 +00:00
Hiroshi Inoue 372ffa15cb [NFC] fix trivial typos in comments
"the the" -> "the", "we we" -> "we", etc

llvm-svn: 330006
2018-04-13 11:37:06 +00:00
Gabor Buella 604be4424b [X86] Introduce cldemote instruction
Hint to hardware to move the cache line containing the
address to a more distant level of the cache without
writing back to memory.

Reviewers: craig.topper, zvi

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D45256

llvm-svn: 329992
2018-04-13 07:35:08 +00:00
Craig Topper 254ed028a4 [X86] Remove the pmuldq/pmuldq intrinsics and replace with native IR.
This completes the work started in r329604 and r329605 when we changed clang to no longer use the intrinsics.

We lost some InstCombine SimplifyDemandedBit optimizations through this change as we aren't able to fold 'and', bitcast, shuffle very well.

llvm-svn: 329990
2018-04-13 06:07:18 +00:00
Yunlian Jiang bd200b9ff6 Enable debug fission for thinLTO linked via gold-plugin
Summary: This enables debug fission on implicit ThinLTO when linked with gold. It will put the .dwo files in a directory specified by user. 

Reviewers: tejohnson, pcc, dblaikie

Reviewed By: pcc

Subscribers: JDevlieghere, mehdi_amini, inglorion

Differential Revision: https://reviews.llvm.org/D44792

llvm-svn: 329988
2018-04-13 05:03:28 +00:00
Fangrui Song 6cf69128a1 [CachePruning] Clarify the per-directory entry limit on Linux ext4.
Summary:
508   root node entries (root_limit)
510   internal node entries (node_limit)

For a filename with 40 bytes, its sizeof(ext4_dir_entry_2) = 48, a linear directory can contain at most floor(4096/48)=85 of them.
The real per-directory entry limit should be 508*510*85 = 22021800
The limit varies with the average length of filenames.

However, the Linux ext4 code does not try rebalancing the htree, so we will not be able to create filenames in a full leaf node. This is demonstrated with the following example, certain filenames cannot be used while others can:

  % touch d/0000000000000000000000000000000000816a6f
  touch: cannot touch 'd/0000000000000000000000000000000000816a6f': No
  space left on device
  % touch d/0000000000000000000000000000000000816a70
  # succeeded

Reviewers: pcc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45546

llvm-svn: 329966
2018-04-12 22:27:38 +00:00
Vedant Kumar 65b0d4df20 [DebugInfo] Create merged locations for instructions other than calls
This lifts a restriction on DILocation::getMergedLocation(), allowing it
to create merged locations for instructions other than calls.

Instruction::applyMergedLocation() now defaults to creating merged
locations for all instructions.

The default behavior of getMergedLocation() is unchanged: callers which
invoke it directly are unaffected.

This change will enable a follow-up Mem2Reg fix which improves crash
reporting.

Differential Revision: https://reviews.llvm.org/D45396

llvm-svn: 329955
2018-04-12 20:58:24 +00:00
Erik Pilkington 67d82d6edd [demangler] Add a partial demangling API for LLDB.
This parses a mangled name into an AST (typically an intermediate stage in
itaniumDemangle) and provides some functions to query certain properties or
print certain parts of the demangled name.

Differential revision: https://reviews.llvm.org/D44668

llvm-svn: 329951
2018-04-12 20:41:38 +00:00
Lang Hames e7c4502a87 [ORC] Use insert rather than emplace.
Hopefully this will fix the build failure at
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/9028

llvm-svn: 329944
2018-04-12 19:54:41 +00:00
Gabor Buella 297c138798 [X86] Introduce LLVM wbinvd intrinsic
A previously missing intrinsic for an old instruction.

Reviewers: craig.topper, echristo

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D45312

llvm-svn: 329936
2018-04-12 18:38:18 +00:00
Lang Hames 9d8877baf8 [ORC] Plumb error notifications through the VSO interface.
This allows materializers to notify the VSO that they were unable to
resolve or finalize symbols.

llvm-svn: 329934
2018-04-12 18:35:08 +00:00
Benjamin Kramer 4c5fa6be27 [MCJIT] Remove the anchor from mcjit.
This is a layering violation. LTO shouldn't depend on MCJIT. The right
fix for this is moving the class somewhere else.

llvm-svn: 329929
2018-04-12 17:28:30 +00:00
Sanjay Patel 5ace2b765a revert r328921 - [DAGCombine] (float)((int) f) --> ftrunc (PR36617)
This change is exposing UB in source code - as was warned/predicted. :)
See D44909 for discussion. Reverting while we figure out how to fix things.

llvm-svn: 329920
2018-04-12 15:27:01 +00:00
Jonas Paulsson e8f1ac7063 [MachineScheduler] NFC refactoring
This patch makes tryCandidate() virtual and some utility functions like
tryLess(), tryGreater(), ... externally available (used to be static).

This makes it possible for a target to derive a new MachineSchedStrategy from
GenericScheduler and reuse most parts.

It was necessary to wrap functions with the same names in
AMDGPU/SIMachineScheduler in a local namespace.

Review: Andy Trick, Florian Hahn
https://reviews.llvm.org/D43329

llvm-svn: 329884
2018-04-12 07:21:39 +00:00
Hiroshi Inoue bcadfee2ad [NFC] fix trivial typos in documents and comments
"is is" -> "is", "if if" -> "if", "or or" -> "or"

llvm-svn: 329878
2018-04-12 05:53:20 +00:00
Weiming Zhao 1bd40005ba Add missing vtable anchors
Summary: This patch adds anchor() for MemoryBuffer, raw_fd_ostream, RTDyldMemoryManager, SectionMemoryManager, etc.

Reviewers: jlebar, eli.friedman, dblaikie

Reviewed By: dblaikie

Subscribers: mehdi_amini, mgorny, dblaikie, weimingz, llvm-commits

Differential Revision: https://reviews.llvm.org/D45244

llvm-svn: 329861
2018-04-11 23:09:20 +00:00
whitequark 1ae61a6126 [LLVM-C] Add LLVMGetHostCPU{Name,Features}.
Without these functions it's hard to create a TargetMachine for
Orc JIT that creates efficient native code.

It's not sufficient to just expose LLVMGetHostCPUName(), because
for some CPUs there's fewer features actually available than
the CPU name indicates (e.g. AVX might be missing on some CPUs
identified as Skylake).

Differential Revision: https://reviews.llvm.org/D44861

llvm-svn: 329856
2018-04-11 22:40:42 +00:00
Gabor Buella 2ef36f3571 [X86] Describe wbnoinvd instruction
Similar to the wbinvd instruction, except this
one does not invalidate caches. Ring 0 only.
The encoding matches a wbinvd instruction with
an F3 prefix.

Reviewers: craig.topper, zvi, ashlykov

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D43816

llvm-svn: 329847
2018-04-11 20:01:57 +00:00
David Blaikie 4333f9700d Rename *CommandFlags.def to *CommandFlags.inc
These aren't the .def style files used in LLVM that require a macro
defined before their inclusion - they're just basic non-modular includes
to stamp out command line flag variables.

llvm-svn: 329840
2018-04-11 18:49:37 +00:00
Craig Topper 9507fa358c [X86] Remove 128/256-bit masked pmaddubsw and pmaddwd intrinsics. Replace 512-bit masked intrinsic with unmasked intrinsic and a select.
The 128/256-bit versions were no longer used by clang. It uses the legacy SSE/AVX2 version and a select. The 512-bit was changed to the same for consistency.

llvm-svn: 329774
2018-04-11 04:55:04 +00:00
Steven Wu d0804aa6dc [MachO] Emit Weak ReadOnlyWithRel to ConstDataSection
Summary:
Darwin dynamic linker can handle weak symbols in ConstDataSection.
ReadonReadOnlyWithRel symbols should be emitted in ConstDataSection
instead of normal DataSection.

rdar://problem/39298457

Reviewers: dexonsmith, kledzik

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45472

llvm-svn: 329752
2018-04-10 20:16:35 +00:00
Daniel Neilson 5eae06f21d [IR] Refactor memset inst classes (NFC)
Summary:
A simple refactor to remove duplicate code in the definitions of
MemSetInst, AtomicMemSetInst, and AnyMemSetInst. Introduce a
templated base class that contains all of the methods unique to
a memset intrinsic, and derive these three classes from that.

llvm-svn: 329747
2018-04-10 19:51:44 +00:00
Daniel Neilson 08a930a9c2 [IR] Refactor memtransfer inst classes (NFC)
Summary:
A simple refactor to remove duplicate code in the definitions of
MemTransferInst, AtomicMemTransferInst, and AnyMemTransferInst.
Introduce a templated base class that contains all of the methods
unique to a memory transfer intrinsic, and derive these three
classes from that.

llvm-svn: 329744
2018-04-10 19:23:11 +00:00
Aaron Smith 3dca0bedbb [DebugInfoPDB] Add DIA implementations of findSymbolByRVA and findSymbolByAddr
llvm-svn: 329724
2018-04-10 17:33:18 +00:00
Krzysztof Parzyszek 71a4c0ca07 [CodeGen] Fix printing bundles in MIR output
Delay printing the newline until after the opening bracket was
printed, e.g.
  BUNDLE implicit-def $r1, implicit-def $r21, implicit $r1 {
    renamable $r1 = S2_asr_i_r renamable $r1, 1
    renamable $r21 = A2_tfrsi 0
  }
instead of
  BUNDLE implicit-def $r1, implicit-def $r21, implicit $r1
 {    renamable $r1 = S2_asr_i_r renamable $r1, 1
    renamable $r21 = A2_tfrsi 0
  }

llvm-svn: 329719
2018-04-10 16:46:13 +00:00
Aaron Smith c0a5c01aeb [PDB] Remove dead code and run clang format; NFC
llvm-svn: 329712
2018-04-10 15:25:04 +00:00
Pavel Labath 397e150ddc [Testing/Support] Make Failed() matcher work with abstract error types
Failed<ErrorInfoBase>() did not compile, because it was attempting to
create a copy of the Error object when passing it to the nested matcher,
which was not possible because ErrorInfoBase is abstract.

This commit fixes the problem by making sure we pass the ErrorInfo
object by reference, which also improves the handling of non-abstract
objects, as we avoid potentially slicing an object during the copy.

llvm-svn: 329703
2018-04-10 14:11:53 +00:00
Clement Courbet b449379eae [MC][TableGen] Add optional libpfm counter names for ProcResUnits.
Summary:
Subtargets can define the libpfm counter names that can be used to
measure cycles and uops issued on ProcResUnits.
This allows making llvm-exegesis available on more targets.
Fixes PR36984.

Reviewers: gchatelet, RKSimon, andreadb, craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45360

llvm-svn: 329675
2018-04-10 08:16:37 +00:00
Chandler Carruth 19618fc639 [x86] Introduce a pass to begin more systematically fixing PR36028 and similar issues.
The key idea is to lower COPY nodes populating EFLAGS by scanning the
uses of EFLAGS and introducing dedicated code to preserve the necessary
state in a GPR. In the vast majority of cases, these uses are cmovCC and
jCC instructions. For such cases, we can very easily save and restore
the necessary information by simply inserting a setCC into a GPR where
the original flags are live, and then testing that GPR directly to feed
the cmov or conditional branch.

However, things are a bit more tricky if arithmetic is using the flags.
This patch handles the vast majority of cases that seem to come up in
practice: adc, adcx, adox, rcl, and rcr; all without taking advantage of
partially preserved EFLAGS as LLVM doesn't currently model that at all.

There are a large number of operations that techinaclly observe EFLAGS
currently but shouldn't in this case -- they typically are using DF.
Currently, they will not be handled by this approach. However, I have
never seen this issue come up in practice. It is already pretty rare to
have these patterns come up in practical code with LLVM. I had to resort
to writing MIR tests to cover most of the logic in this pass already.
I suspect even with its current amount of coverage of arithmetic users
of EFLAGS it will be a significant improvement over the current use of
pushf/popf. It will also produce substantially faster code in most of
the common patterns.

This patch also removes all of the old lowering for EFLAGS copies, and
the hack that forced us to use a frame pointer when EFLAGS copies were
found anywhere in a function so that the dynamic stack adjustment wasn't
a problem. None of this is needed as we now lower all of these copies
directly in MI and without require stack adjustments.

Lots of thanks to Reid who came up with several aspects of this
approach, and Craig who helped me work out a couple of things tripping
me up while working on this.

Differential Revision: https://reviews.llvm.org/D45146

llvm-svn: 329657
2018-04-10 01:41:17 +00:00
Fangrui Song 0b7c424737 [CachePruning] Fix comment about ext4 per-directory file limit. NFC
There is a limit on number of subdirectories if dir_nlinks is not
enabled (31998), but per-directory number of files is not limited.

llvm-svn: 329648
2018-04-10 00:12:28 +00:00