Commit Graph

28576 Commits

Author SHA1 Message Date
Chandler Carruth b8824a5d3f [PM] Revert r279227 and r279228 until I can find someone to help me
solve completely opaque MSVC build errors. It complains about lots of
stuff with this change without givin nearly enough information to even
try to fix.

llvm-svn: 279231
2016-08-19 10:51:55 +00:00
Chandler Carruth db1759ace1 [PM] Make the the new pass manager support fully generic extra arguments
to run methods, both for transform passes and analysis passes.

This also allows the analysis manager to use a different set of extra
arguments from the pass manager where useful. Consider passes over
analysis produced units of IR like SCCs of the call graph or loops.
Passes of this nature will often want to refer to the analysis result
that was used to compute their IR units (the call graph or LoopInfo).
And for transformations, they may want to communicate special update
information to the outer pass manager. With this change, it becomes
possible to have a run method for a loop pass that looks more like:

  PreservedAnalyses run(Loop &L, AnalysisManager<Loop, LoopInfo> &AM,
                        LoopInfo &LI, LoopUpdateRecord &UR);

And to query the analysis manager like:

    AM.getResult<MyLoopAnalysis>(L, LI);

This makes accessing the known-available analyses convenient and clear,
and it makes passing customized data structures around easy.

My initial use case is going to be in updating the pass manager layers
when the analysis units of IR change. But there are more use cases here
such as having a layer that lets inner passes signal whether certain
additional passes should be run because of particular simplifications
made. Two desires for this have come up in the past: triggering
additional optimization after successfully unrolling loops, and
triggering additional inlining after collapsing indirect calls to direct
calls.

Despite adding this layer of generic extensibility, the *only* change to
existing, simple usage are for places where we forward declare the
AnalysisManager template. We really shouldn't be doing this because of
the fragility exposed here, but currently it makes coping with the
legacy PM code easier.

Differential Revision: http://reviews.llvm.org/D21462

llvm-svn: 279227
2016-08-19 09:45:16 +00:00
Chandler Carruth 6b6375b1d0 [PM] Try to work-around what appears to be an MSVC SFINAE issue with
r279217 where it fails to select the path that other compilers select.

The workaround won't be as careful to produce an error when an analysis
result is incorrect, but we can rely on non-MSVC builds to catch such
errors it seems and MSVC doesn't seem to support the alternative
techniques.

Hoping this brings the windows bots back to life. If not, will have to
revert all of this.

llvm-svn: 279225
2016-08-19 09:26:00 +00:00
Chandler Carruth 6d6310dd4a [PM] NFC refactoring: remove the AnalysisManagerBase class, folding it
into the AnalysisManager class template.

Back when I first added this base class there were separate analysis
managers and some plausible reason why it would be a useful factoring of
common code between them. However, after a lot of refactoring cleaning,
we now have *entirely* shared code. The base class was just an arbitrary
division between code in one class template and a separate class
template. It didn't add anything and forced lots of indirection through
"derived_this" for no real gain.

We can always factor a base CRTP class out with common code if there is
ever some *other* analysis manager that wants to share a subset of
logic. But for now, folding things into the primary template is
a non-trivial simplification with no down sides I see. It shortens the
code considerably, removes an unhelpful abstraction, and will make
subsequent patches *dramatically* less complex which enhance the
analysis manager infrastructure to effectively cope with invalidation.

llvm-svn: 279221
2016-08-19 08:31:47 +00:00
Vassil Vassilev 8fa30f2829 [modules] Add missing include.
llvm-svn: 279219
2016-08-19 08:30:42 +00:00
Chandler Carruth 92d3c7e8e2 [PM] Redesign how the new PM detects whether an analysis result provides
its own invalidate method.

Previously, the technique would assume that if a result didn't have an
invalidate method that didn't exactly match the expected signature it
didn't have one at all. This is in fact not the case. And we had
analyses with incorrect signatures for the invalidate method in the
tree that would be erroneously invalidated in certain cases! Yikes.

Moreover a result might legitimately want to have multiple overloads for
the invalidate method, and if one changes or a new one is needed we
again really want a compiler error. For example in the tree we had not
added the overload for a *function* IR unit to the invalidate routine
for TLI. Doh.

So a new techique for the SFINAE detection here: if the result has *any*
member spelled "invalidate" we turn off the synthesis of a default
version. We don't care if it is a member function or a member variable
or how many overloads there are. Once a result has something by that
name it must provide suitable overloads for the contexts in which it is
used. This seems much more resilient and durable.

Huge props to Richard Smith who helped me figure out how on earth we
could even do this in C++. It took quite some doing. The technique is
remarkably clean however, and merely requires that the analysis results
are not *final* classes. I think that's a requirement we can live with
even if it is a bit odd.

I've fixed the two bad in-tree analysis results. And this will make my
next change which changes the API for invalidate much easier to
validate as correct.

llvm-svn: 279217
2016-08-19 07:49:23 +00:00
Chandler Carruth b7be5b6479 [PM] Rework the new PM support for building the ModuleSummaryIndex to
directly produce the index as the value type result.

This requires making the index movable which is straightforward. It
greatly simplifies things by allowing us to completely avoid the builder
API and the layers of abstraction inherent there. Instead both pass
managers can directly construct these when run by value. They still
won't be constructed truly eagerly thanks to the optional in the legacy
PM. The code that directly builds the index can also just share a direct
function.

A notable change here is that the result type of the analysis for the
new PM is no longer a reference type. This was really problematic when
making changes to how we handle result types to make our interface
requirements *much* more strict and precise. But I think this is an
overall improvement.

Differential Revision: https://reviews.llvm.org/D23701

llvm-svn: 279216
2016-08-19 07:49:19 +00:00
Mehdi Amini cc1fe9b9d6 Constify some path in the bitcode writer (NFC)
llvm-svn: 279211
2016-08-19 06:06:18 +00:00
Matthias Braun fdc4c6b426 Revert "RegScavenging: Add scavengeRegisterBackwards()"
The ppc64 multistage bot fails on this.

This reverts commit r279124.

Also Revert "CodeGen: Add/Factor out LiveRegUnits class; NFCI" because it depends on the previous change
This reverts commit r279171.

llvm-svn: 279199
2016-08-19 03:03:24 +00:00
Chandler Carruth e8529c28f1 [ADT] Add the worlds simplest STL extra. Or at least close to it.
This is a little class template that just builds an inheritance chain of
empty classes. Despite how simple this is, it can be used to really
nicely create ranked overload sets. I've added a unittest as much to
document this as test it. You can pass an object of this type as an
argument to a function overload set an it will call the first viable and
enabled candidate at or below the rank of the object.

I'm planning to use this in a subsequent commit to more clearly rank
overload candidates used for SFINAE. All credit for this technique and
both lines of code here to Richard Smith who was helping me rewrite the
SFINAE check in question to much more effectively capture the intended
set of checks.

llvm-svn: 279197
2016-08-19 02:07:51 +00:00
Vitaly Buka aa654292bd [asan] Optimize store size in FunctionStackPoisoner::poisonRedZones
Summary: Reduce store size to avoid leading and trailing zeros.

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23648

llvm-svn: 279178
2016-08-18 23:51:15 +00:00
Matthias Braun 91f95f0201 CodeGen: Add/Factor out LiveRegUnits class; NFCI
This is a set of register units intended to track register liveness, it
is similar in spirit to LivePhysRegs.
You can also think of this as the liveness tracking parts of the
RegisterScavenger factored out into an own class.

This was proposed in http://llvm.org/PR27609

Differential Revision: http://reviews.llvm.org/D21916

llvm-svn: 279171
2016-08-18 22:11:28 +00:00
Hemant Kulkarni e77a0a9a3b llvm-objdump: Add Hexagon printer changes for -S/-l options
Differential Revision: https://reviews.llvm.org/D23521

llvm-svn: 279161
2016-08-18 21:50:13 +00:00
Tim Shen 36bde4f81d [Analysis] Change several Analysis pieces to use NodeRef. NFC.
Reviewers: dblaikie, grosser

Subscribers: mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D23625

llvm-svn: 279156
2016-08-18 21:41:24 +00:00
Michael Kuperstein 2bc3d4d46c [SelectionDAG] Rename fextend -> fpextend, fround -> fpround, frnd -> fround
The names of the tablegen defs now match the names of the ISD nodes.
This makes the world a slightly saner place, as previously "fround" matched
ISD::FP_ROUND and not ISD::FROUND.

Differential Revision: https://reviews.llvm.org/D23597

llvm-svn: 279129
2016-08-18 20:08:15 +00:00
Wei Ding 52bb661dec AMDGPU : Fix QSAD and MQSAD instructions' incorrect data type.
Differential Revision: http://reviews.llvm.org/D23689

llvm-svn: 279126
2016-08-18 19:51:14 +00:00
Matthias Braun 075d0c23d5 RegScavenging: Add scavengeRegisterBackwards()
Re-apply r276044 with off-by-1 instruction fix for the reload placement.

This is a variant of scavengeRegister() that works for
enterBasicBlockEnd()/backward(). The benefit of the backward mode is
that it is not affected by incomplete kill flags.

This patch also changes
PrologEpilogInserter::doScavengeFrameVirtualRegs() to use the register
scavenger in backwards mode.

Differential Revision: http://reviews.llvm.org/D21885

llvm-svn: 279124
2016-08-18 19:47:59 +00:00
Pete Cooper a8db71e840 Add a version of Intrinsic::getName which is more efficient when there are no overloads.
When running 'opt -O2 verify-uselistorder-nodbg.lto.bc', there are 33m allocations.  8.2m
come from std::string allocations in Intrinsic::getName().  Turns out this method only
returns a std::string because it needs to handle overloads, but that is not the common case.

This adds an overload of getName which just returns a StringRef when there are no overloads
and so saves on the allocations.

llvm-svn: 279113
2016-08-18 18:30:54 +00:00
Valery Pykhtin 609c2f8137 [AMDGPU] add s_incperflevel/s_decperflevel intrinsics.
Differential revision: https://reviews.llvm.org/D23666

llvm-svn: 279106
2016-08-18 18:06:20 +00:00
Eugene Zelenko 61a72d8850 [LLVM] Fix some Clang-tidy modernize-use-using and Include What You Use warnings
Differential revision: https://reviews.llvm.org/D23675

llvm-svn: 279102
2016-08-18 17:56:27 +00:00
Duncan P. N. Exon Smith 9d748f9499 Reapply "ADT: Remove references in has_rbegin for reverse()"
This reverts commit r279086, reapplying r279084.  I'm not sure what I
ran before, because the compile failure for ADTTests reproduced locally.

The problem is that TestRev is calling BidirectionalVector::rbegin()
when the BidirectionalVector is const, but rbegin() is always non-const.
I've updated BidirectionalVector::rbegin() to be callable from const.

Original commit message follows.

--

As a follow-up to r278991, add some tests that check that
decltype(reverse(R).begin()) == decltype(R.rbegin()), and get them
passing by adding std::remove_reference to has_rbegin.

I'm using static_assert instead of EXPECT_TRUE (and updated the other
has_rbegin check from r278991 in the same way) since I figure that's
more helpful.

llvm-svn: 279091
2016-08-18 17:15:25 +00:00
Zachary Turner ac5763eca4 Resubmit "Write the TPI stream from a PDB to Yaml."
The original patch was breaking some buildbots due to an
incorrect ordering of function definitions which caused some
compilers to recognize a definition but others to not.

llvm-svn: 279089
2016-08-18 16:49:29 +00:00
Duncan P. N. Exon Smith 5195d3fc0e Revert "ADT: Remove references in has_rbegin for reverse()"
This reverts commit r279084, since it failed on a bot:
  http://bb.pgr.jp/builders/cmake-llvm-x86_64-linux/builds/41733

llvm-svn: 279086
2016-08-18 16:27:41 +00:00
Duncan P. N. Exon Smith b28eb332d9 ADT: Remove references in has_rbegin for reverse()
As a follow-up to r278991, add some tests that check that
decltype(reverse(R).begin()) == decltype(R.rbegin()), and get them
passing by adding std::remove_reference to has_rbegin.

I'm using static_assert instead of EXPECT_TRUE (and updated the other
has_rbegin check from r278991 in the same way) since I figure that's
more helpful.

llvm-svn: 279084
2016-08-18 16:22:54 +00:00
Ahmed Bougacha 71d033a17f [GlobalISel] Add floating-point binary ops.
llvm-svn: 279080
2016-08-18 16:05:06 +00:00
Richard Barton 5808bd656a [ARM] Correct ARMv8*-A optional extension definitions in TargetParser
The ARMv8*-A descriptions in the ARM and AArch64 TargetParsers are incorrect
architecturally and mismatched to the backend descriptions.

RAS is an optional extension to ARMv8-A and ARMv8.1-A and mandatory in
ARMv8.2-A. Correct the ARMTargetParser descriptions which had this as enabled
by default in the earlier versions.

The FP16 and SPE extensions are optional in ARMv8.2-A and the backend defaults
them as off. They are not available as extensions to earlier ARMv8-A versions.
Correct the AArch64TargetParser which had these as enabled by default in all
ARMv8-A definitions.

These macros are only used to define preprocessor macros. There are no macros
yet as ACLE has not caught up with ARMv8.2-A so not possible to add a test.

Differential Revision: https://reviews.llvm.org/D23500

llvm-svn: 279078
2016-08-18 15:50:11 +00:00
Ahmed Bougacha 13db94540c [GlobalISel] Add support for DIV/REM.
llvm-svn: 279073
2016-08-18 15:17:01 +00:00
Diana Picus 9405ae704b Revert "ADT: Remove UB in ilist (and use a circular linked list)"
This reverts commit r278974 which broke some of our bots (e.g.
clang-cmake-aarch64-42vma, clang-cmake-aarch64-full).

llvm-svn: 279053
2016-08-18 11:17:53 +00:00
Diana Picus fa1a4b36f1 Revert "ADT: Tidy up ilist_traits static asserts, NFC"
This reverts commit r279012.
r278974 broke some bots, I have to revert this to get to it.

llvm-svn: 279052
2016-08-18 11:17:47 +00:00
Teresa Johnson f2b5ec6ef4 [ThinLTO] Keep common symbols in ThinLTO modules
Summary:
Skip the merging of common symbols for ThinLTO modules, they will be
merged by the final native object link. Trying to merge the symbols and
add to a combined module will incorrectly enable the common symbol to be
internalized in the ThinLTO module. Additionally, we will not want to
create a combined module for ThinLTO distributed builds.

This fixes failures in 7 cpu2006 benchmarks from the new LTO API in
ThinLTO mode.

Reviewers: mehdi_amini

Subscribers: pcc, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23637

llvm-svn: 279023
2016-08-18 01:08:50 +00:00
Vitaly Buka d5ec14989d [asan] Add support of lifetime poisoning into ComputeASanStackFrameLayout
Summary:
We are going to combine poisoning of red zones and scope poisoning.

PR27453

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23623

llvm-svn: 279020
2016-08-18 00:56:58 +00:00
Duncan P. N. Exon Smith 56ee4f1fb7 ADT: Tidy up ilist_traits static asserts, NFC
Change the ilist traits to use decltype instead of sizeof, and add
HasObsoleteCustomization so that additions to this list don't need to be
added in two places.

I suspect this will now work with MSVC, since the trait tested in
r278991 seems to work.  If for some reason it continues to fail on
Windows I'll follow up by adding back the #ifndef _MSC_VER.

llvm-svn: 279012
2016-08-17 23:47:56 +00:00
Tim Shen 5c0c063ad5 [LV] Move LoopBodyTraits to a better place, and add comment for simplifying LoopBlocksTraversal. NFC.
Summary: I later (after r278573) found that LoopIterator.h has some overlapping with LoopBodyTraits. It's good to use LoopBodyTraits because a *Traits struct is algorithm independent.

Reviewers: anemet, nadav, mkuper

Subscribers: mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D23529

llvm-svn: 278996
2016-08-17 22:20:07 +00:00
Tim Shen a96b05e62a [RegionIterator] clang-format some pieces. NFC.
llvm-svn: 278992
2016-08-17 22:12:49 +00:00
Pete Cooper 0041888aea Fix reverse to work on const rbegin()/rend().
Duncan found that reverse worked on mutable rbegin(), but the has_rbegin
trait didn't work with a const method.  See http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160815/382890.html
for more details.

Turns out this was already solved in clang with has_getDecl.  Copied that and made it work for rbegin.

This includes the tests Duncan attached to that thread, including the traits test.

llvm-svn: 278991
2016-08-17 22:06:59 +00:00
Chris Bieneman 432ba9d89a [macho2yaml] Don't write empty linkedit data
Since I stopped writing empty export tries it causes LinkEdit to potentially be completely empty which results in invalid yaml being generated.

To prevent this we skip linkedit data if it is empty.

llvm-svn: 278985
2016-08-17 21:46:04 +00:00
Kyle Butt db3391ebe0 Tail Duplication: Accept explicit threshold for duplicating.
This will allow tail duplication and tail merging during layout to have a
shared threshold to make sure that they don't overlap. No observable change
intended.

llvm-svn: 278981
2016-08-17 21:07:35 +00:00
Duncan P. N. Exon Smith 10ae33a906 ADT: Remove UB in ilist (and use a circular linked list)
This removes the undefined behaviour (UB) in ilist/ilist_node/etc.,
mainly by removing (gutting) the ilist_sentinel_traits customization
point and canonicalizing on a single, efficient memory layout.  This
fixes PR26753.

The new ilist is a doubly-linked circular list.
- ilist_node_base has two ilist_node_base*: Next and Prev.  Size-of: two
  pointers.
- ilist_node<T> (size-of: two pointers) is a type-safe wrapper around
  ilist_node_base.
- ilist_iterator<T> (size-of: two pointers) operates on an
  ilist_node<T>*, and downcasts to T* on dereference.
- ilist_sentinel<T> (size-of: two pointers) is a wrapper around
  ilist_node<T> that has some extra API for list management.
- ilist<T> (size-of: two pointers) has an ilist_sentinel<T>, whose
  address is returned for end().

The new memory layout matches ilist_half_embedded_sentinel_traits<T>
exactly.  The Head pointer that previously lived in ilist<T> is
effectively glued to the ilist_half_node<T> that lived in
ilist_half_embedded_sentinel_traits<T>, becoming the Next and Prev in
the ilist_sentinel_node<T>, respectively.  sizeof(ilist<T>) is now the
size of two pointers, and there is never any additional storage for a
sentinel.

This is a much simpler design for a doubly-linked list, removing most of
the corner cases of list manipulation (add, remove, etc.).  In follow-up
commits, I intend to move as many algorithms as possible into a
non-templated base class (ilist_base) to reduce code size.

Moreover, this fixes the UB in ilist_iterator/getNext/getPrev
operations.  Previously, ilist_iterator<T> operated on a T*, even when
the sentinel was not of type T (i.e., ilist_embedded_sentinel_traits and
ilist_half_embedded_sentinel_traits).  This added UB to all operations
involving end().   Now, ilist_iterator<T> operates on an ilist_node<T>*,
and only downcasts when the full type is guaranteed to be T*.

What did we lose?  There used to be a crash (in some configurations) on
++end().  Curiously (via UB), ++end() would return begin() for users of
ilist_half_embedded_sentinel_traits<T>, but otherwise ++end() would
cause a nice dependable nullptr dereference, crashing instead of a
possible infinite loop.  Options:
 1. Lose that behaviour.
 2. Keep it, by stealing a bit from Prev in asserts builds.
 3. Crash on dereference instead, using the same technique.

Hans convinced me (because of the number of problems this and r278532
exposed on Windows) that we really need some assertion here, at least in
the short term.  I've opted for #3 since I think it catches more bugs.

I added only a couple of unit tests to root out specific bugs I hit
during bring-up, but otherwise this is tested implicitly via the
extensive usage throughout LLVM.

Planned follow-ups:
- Remove ilist_*sentinel_traits<T>.  Here I've just gutted them to
  prevent build failures in sub-projects.  Once I stop referring to them
  in sub-projects, I'll come back and delete them.
- Add ilist_base and move algorithms there.
- Check and fix move construction and assignment.

Eventually, there are other interesting directions:
- Rewrite reverse iterators, so that rbegin().getNodePtr()==&*rbegin().
  This allows much simpler logic when erasing elements during a reverse
  traversal.
- Remove ilist_traits::createNode, by deleting the remaining API that
  creates nodes.  Intrusive lists shouldn't be creating nodes
  themselves.
- Remove ilist_traits::deleteNode, by (1) asserting that lists are empty
  on destruction and (2) changing API that calls it to take a Deleter
  functor (intrusive lists shouldn't be in the memory management
  business).
- Reconfigure the remaining callback traits (addNodeToList, etc.) to be
  higher-level, pulling out a simple_ilist<T> that is much easier to
  read and understand.
- Allow tags (e.g., ilist_node<T,tag1> and ilist_node<T,tag2>) so that T
  can be a member of multiple intrusive lists.

llvm-svn: 278974
2016-08-17 20:44:33 +00:00
Tim Northover de3aea0412 GlobalISel: support irtranslation of icmp instructions.
llvm-svn: 278969
2016-08-17 20:25:25 +00:00
Tim Shen eb3958fafd [GraphWriter] Change GraphWriter to use NodeRef in GraphTraits
Summary:
This is part of the "NodeType* -> NodeRef" migration. Notice that since
GraphWriter prints object address as identity, I added a static_assert on
NodeRef to be a pointer type.

Reviewers: dblaikie

Subscribers: llvm-commits, MatzeB

Differential Revision: https://reviews.llvm.org/D23580

llvm-svn: 278966
2016-08-17 20:07:29 +00:00
Tim Shen 8b58bdfe6f [GenericDomTree] Change GenericDomTree to use NodeRef in GraphTraits. NFC.
Summary:
Looking at the implementation, GenericDomTree has more specific
requirements on NodeRef, e.g. NodeRefObject->getParent() should compile,
and NodeRef should be a pointer. We can remove the pointer requirement,
but it seems to have little gain, given the limited use cases.

Also changed GraphTraits<Inverse<Inverse<T>> to be more accurate.

Reviewers: dblaikie, chandlerc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23593

llvm-svn: 278961
2016-08-17 20:01:58 +00:00
Adrian Prantl c19dee734f Support the DW_AT_noreturn DWARF flag.
This is used to mark functions with the C++11 [[ noreturn ]] or C11 _Noreturn
attributes.

Patch by Victor Leschuk!

https://reviews.llvm.org/D23167

llvm-svn: 278940
2016-08-17 16:02:43 +00:00
Chad Rosier ea7e4647db Revert "Reassociate: Reprocess RedoInsts after each inst".
This reverts commit r258830, which introduced a bug described in PR28367.

PR28367

llvm-svn: 278938
2016-08-17 15:54:39 +00:00
Jonas Paulsson 7a79422536 [LoopStrenghtReduce] Refactoring and addition of a new target cost function.
Refactored so that a LSRUse owns its fixups, as oppsed to letting the
LSRInstance own them. This makes it easier to rate formulas for
LSRUses, since the fixups are available directly. The Offsets vector
has been removed since it was no longer necessary.

New target hook isFoldableMemAccessOffset(), which is used during formula
rating.

For SystemZ, this is useful to express that loads and stores with
float or vector types with a big/negative offset should be avoided in
loops. Without this, LSR will generate a lot of negative offsets that
would require extra instructions for loading the address.

Updated tests:
test/CodeGen/SystemZ/loop-01.ll

Reviewed by: Quentin Colombet and Ulrich Weigand.
https://reviews.llvm.org/D19152

llvm-svn: 278927
2016-08-17 13:24:19 +00:00
Marina Yatsina 4b22642e6f Fixing bug committed in rev. 278321
In theory the indices of RC (and thus the index used for LiveRegs) may differ from the indices of OpRC.
Fixed the code to extract the correct RC index.
OpRC contains the first X consecutive elements of RC, and thus their indices are currently de facto the same, therefore a test cannot be added at this point.

Differential Revision: https://reviews.llvm.org/D23491

llvm-svn: 278923
2016-08-17 11:40:21 +00:00
Nicolai Haehnle 1cdd6ca6ca LiveIntervals: add removeRegUnit
Summary:
See D22198 for the motivation: We have a pass that uses LiveIntervals anyway,
and there is now a requirement to track a physical register that is not
usually tracked at this point of the compilation. The pass also introduces
instructions that affect this physical register, but we want to preserve
LiveIntervals.

Rather than add brittle and rarely exercised code to keep the tracking of
the physical register intact, we want to just remove the corresponding
LiveRange -- it didn't exist before anyway, and subsequent passes don't
expect it to be there.

Reviewers: MatzeB, arsenm

Subscribers: llvm-commits, MatzeB

Differential Revision: https://reviews.llvm.org/D22801

llvm-svn: 278920
2016-08-17 09:34:55 +00:00
Chandler Carruth bd5ad0df51 Restrict the use of the C++17 attribute to C++17 (at least as best we
can given the current __cplusplus definitions).

Without this, Clang triggers TONS of warnings about using a C++17
extension. I tried using LLVM_EXTENSION to turn these off and it doesn't
work.

Suggestions on a better approach are welcome, but at least this makes
the build usable for me again.

llvm-svn: 278909
2016-08-17 07:18:44 +00:00
Mehdi Amini 970800e0c8 [LTO] Introduce an Output class to wrap the output stream creation (NFC)
Summary:
While NFC for now, this will allow more flexibility on the client side
to hold state necessary to back up the stream.
Also when adding caching, this class will grow in complexity.

Note I blindly modified the gold-plugin as I can't compile it.

Reviewers: tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23542

llvm-svn: 278907
2016-08-17 06:23:09 +00:00
Chandler Carruth 67fc52f067 [PM] Port the always inliner to the new pass manager in a much more
minimal and boring form than the old pass manager's version.

This pass does the very minimal amount of work necessary to inline
functions declared as always-inline. It doesn't support a wide array of
things that the legacy pass manager did support, but is alse ... about
20 lines of code. So it has that going for it. Notably things this
doesn't support:

- Array alloca merging
  - To support the above, bottom-up inlining with careful history
    tracking and call graph updates
- DCE of the functions that become dead after this inlining.
- Inlining through call instructions with the always_inline attribute.
  Instead, it focuses on inlining functions with that attribute.

The first I've omitted because I'm hoping to just turn it off for the
primary pass manager. If that doesn't pan out, I can add it here but it
will be reasonably expensive to do so.

The second should really be handled by running global-dce after the
inliner. I don't want to re-implement the non-trivial logic necessary to
do comdat-correct DCE of functions. This means the -O0 pipeline will
have to be at least 'always-inline,global-dce', but that seems
reasonable to me. If others are seriously worried about this I'd like to
hear about it and understand why. Again, this is all solveable by
factoring that logic into a utility and calling it here, but I'd like to
wait to do that until there is a clear reason why the existing
pass-based factoring won't work.

The final point is a serious one. I can fairly easily add support for
this, but it seems both costly and a confusing construct for the use
case of the always inliner running at -O0. This attribute can of course
still impact the normal inliner easily (although I find that
a questionable re-use of the same attribute). I've started a discussion
to sort out what semantics we want here and based on that can figure out
if it makes sense ta have this complexity at O0 or not.

One other advantage of this design is that it should be quite a bit
faster due to checking for whether the function is a viable candidate
for inlining exactly once per function instead of doing it for each call
site.

Anyways, hopefully a reasonable starting point for this pass.

Differential Revision: https://reviews.llvm.org/D23299

llvm-svn: 278896
2016-08-17 02:56:20 +00:00
Duncan P. N. Exon Smith 362d120488 Scalar: Avoid dereferencing end() in IndVarSimplify
IndVarSimplify::sinkUnusedInvariants calls
BasicBlock::getFirstInsertionPt on the ExitBlock and moves instructions
before it.  This can return end(), so it's not safe to dereference.  Add
an iterator-based overload to Instruction::moveBefore to avoid the UB.

llvm-svn: 278886
2016-08-17 01:54:41 +00:00