Commit Graph

275 Commits

Author SHA1 Message Date
Mehdi Amini
732afdd09a Turn cl::values() (for enum) from a vararg function to using C++ variadic template
The core of the change is supposed to be NFC, however it also fixes
what I believe was an undefined behavior when calling:

 va_start(ValueArgs, Desc);

with Desc being a StringRef.

Differential Revision: https://reviews.llvm.org/D25342

llvm-svn: 283671
2016-10-08 19:41:06 +00:00
Teresa Johnson
fbb431b292 [ThinLTO] Ensure anonymous globals renamed even at -O0
Summary:
This fixes an issue when files are compiled with -flto=thin
at default -O0. We need to rename anonymous globals before attempting
to write the module summary because all values need names for
the summary. This was happening at -O1 and above, but not before
the early exit when constructing the pipeline for -O0.

Also add an internal -prepare-for-thinlto option to enable this
to be tested via opt.

Fixes PR30419.

Reviewers: mehdi_amini

Subscribers: probinson, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D24701

llvm-svn: 281840
2016-09-17 20:40:16 +00:00
Mehdi Amini
27d2379b4e Rename NameAnonFunctions to NameAnonGlobals to match what it is doing (NFC)
llvm-svn: 281745
2016-09-16 16:56:30 +00:00
Teresa Johnson
8c1bc986b5 [ThinLTO] Indirect call promotion fixes for promoted local functions
Summary:
Fix a couple issues limiting the application of indirect call promotion
in ThinLTO mode:
- Invoke indirect call promotion before globalopt, since it may
  eliminate imported functions which appear unreferenced.
- Invoke indirect call promotion with InLTO=true so that the PGOFuncName
  metadata is used to get the name for locals which would have been
  renamed during promotion.

Reviewers: davidxl, mehdi_amini

Subscribers: Prazek, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D24004

llvm-svn: 280024
2016-08-29 22:46:56 +00:00
Easwaran Raman
61edc107bb Add a new method to create SimpleInliner instance and make pre-inliner use this.
This adds a createFunctionInliningPass pass that takes an InlineParams object and use this to create the pre-inliner pass. This prevents the regular inliner's threshold flag from influencing the preinliner.

Differential revision: https://reviews.llvm.org/D23377

llvm-svn: 278377
2016-08-11 18:24:08 +00:00
Sebastian Pop
bfb96c5bfd GVN-hoist: enable by default
llvm-svn: 278010
2016-08-08 14:46:15 +00:00
Matthias Braun
9a0035d8d2 Revert "(refs/bisect/bad) GVN-hoist: enable by default"
GVN-Hoist appears to miscompile llvm-testsuite
SingleSource/Benchmarks/Misc/fbench.c at the moment.

I filed http://llvm.org/PR28880

This reverts commit r277786.

llvm-svn: 277909
2016-08-06 02:23:15 +00:00
Sebastian Pop
c33f0e25c9 GVN-hoist: enable by default
llvm-svn: 277786
2016-08-04 23:49:07 +00:00
Bruno Cardoso Lopes
bd887581fc Revert "GVN-hoist: enable by default" & "Make GVN Hoisting obey optnone/bisect."
This reverts commits r277685 & r277688. r277685 broke compiler-rt
compilation http://lab.llvm.org:8080/green/job/clang-stage1-configure-RA_build/23335
and r277685 is a followup from it.

llvm-svn: 277690
2016-08-04 04:16:24 +00:00
Sebastian Pop
70ffe6523f GVN-hoist: enable by default
As we addressed all compilation time problems with GVN-hoist
https://llvm.org/bugs/show_bug.cgi?id=28670
this patch turns GVN-hoist back by default.

Differential Revision: https://reviews.llvm.org/D23136

llvm-svn: 277685
2016-08-04 01:59:42 +00:00
David Majnemer
6e9b47bc8a Add EP_CGSCCOptimizerLate extension point to PassManagerBuilder
The EP_CGSCCOptimizerLate extension point allows adding CallGraphSCC
passes at the end of the main CallGraphSCC passes and before any
function simplification passes run by CGPassManager.

Patch by Gor Nishanov!

Differential Revision: https://reviews.llvm.org/D22897

llvm-svn: 276953
2016-07-28 03:28:43 +00:00
Xinliang David Li
9239245401 [Profile] Use explicit flag to enable IR PGO
Patch by Jake VanAdrighem

Differential Revision: http://reviews.llvm.org/D22607

llvm-svn: 276516
2016-07-23 04:28:52 +00:00
Alina Sbirlea
ba21ffebff Add flag to PassManagerBuilder to disable GVN Hoist Pass.
Summary:
Adding a flag to diable GVN Hoisting by default.
Note: The GVN Hoist Pass causes some Halide tests to hang. Halide will disable the pass while investigating.

Reviewers: llvm-commits, chandlerc, spop, dberlin

Subscribers: mehdi_amini

Differential Revision: https://reviews.llvm.org/D22639

llvm-svn: 276479
2016-07-22 22:02:19 +00:00
George Burgess IV
f84bb6fa67 Make help text more consistent. NFC.
llvm-svn: 276205
2016-07-20 23:14:29 +00:00
Teresa Johnson
cd21a646f6 [ThinLTO] Perform profile-guided indirect call promotion
Summary:
To enable profile-guided indirect call promotion in ThinLTO mode, we
simply add call graph edges for each profitable target from the profile
to the summaries, then the summary-guided importing will consider the
callee for importing as usual.

Also we need to enable the indirect call promotion pass creation in the
PassManagerBuilder when PerformThinLTO=true (we are in the ThinLTO
backend), so that the newly imported functions are considered for
promotion in the backends.

The IC promotion profiles refer to callees by GUID, which required
adding GUIDs to the per-module VST in bitcode (and assigning them
valueIds similar to how they are assigned valueIds in the combined
index).

Reviewers: mehdi_amini, xur

Subscribers: mehdi_amini, davidxl, llvm-commits

Differential Revision: http://reviews.llvm.org/D21932

llvm-svn: 275707
2016-07-17 14:47:01 +00:00
Rong Xu
96a19d35ae [PGO] IRPGO pre-cleanup pass changes
This patch adds a selected set of cleanup passes including a pre-inline pass
before LLVM IR PGO instrumentation. The inline is only intended to apply those
obvious/trivial ones before instrumentation so that much less instrumentation
is needed to get better profiling information. This will drastically improve
the instrumented code performance for large C++ applications. Another benefit
is the context sensitive counts that can potentially improve the PGO
optimization.

Differential Revision: http://reviews.llvm.org/D21405

llvm-svn: 275588
2016-07-15 18:10:49 +00:00
Sebastian Pop
4177480aad code hoisting pass based on GVN
This pass hoists duplicated computations in the program. The primary goal of
gvn-hoist is to reduce the size of functions before inline heuristics to reduce
the total cost of function inlining.

Pass written by Sebastian Pop, Aditya Kumar, Xiaoyu Hu, and Brian Rzycki.
Important algorithmic contributions by Daniel Berlin under the form of reviews.

Differential Revision: http://reviews.llvm.org/D19338

llvm-svn: 275561
2016-07-15 13:45:20 +00:00
Nico Weber
755cd760cd Revert r275401, it caused PR28551.
llvm-svn: 275420
2016-07-14 14:41:25 +00:00
Sebastian Pop
63847d04e7 code hoisting pass based on GVN
This pass hoists duplicated computations in the program. The primary goal of
gvn-hoist is to reduce the size of functions before inline heuristics to reduce
the total cost of function inlining.

Pass written by Sebastian Pop, Aditya Kumar, Xiaoyu Hu, and Brian Rzycki.
Important algorithmic contributions by Daniel Berlin under the form of reviews.

Differential Revision: http://reviews.llvm.org/D19338

llvm-svn: 275401
2016-07-14 12:18:53 +00:00
George Burgess IV
bfa401e5ad [CFLAA] Split into Anders+Steens analysis.
StratifiedSets (as implemented) is very fast, but its accuracy is also
limited. If we take a more aggressive andersens-like approach, we can be
way more accurate, but we'll also end up being slower.

So, we've decided to split CFLAA into CFLSteensAA and CFLAndersAA.

Long-term, we want to end up in a place where CFLSteens is queried
first; if it can provide an answer, great (since queries are basically
map lookups). Otherwise, we'll fall back to CFLAnders, BasicAA, etc.

This patch splits everything out so we can try to do something like
that when we get a reasonable CFLAnders implementation.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21910

llvm-svn: 274589
2016-07-06 00:26:41 +00:00
Duncan P. N. Exon Smith
9d1f156418 Revert "code hoisting pass based on GVN"
This reverts commit r274305, since it breaks self-hosting:
  http://lab.llvm.org:8080/green/job/clang-stage1-configure-RA_build/22349/
  http://lab.llvm.org:8011/builders/clang-x86_64-linux-selfhost-modules/builds/17232

Note that the blamelist on lab.llvm.org:8011 is incorrect.  The previous
build was r274299, but somehow r274305 wasn't included in the blamelist:
  http://lab.llvm.org:8011/builders/clang-x86_64-linux-selfhost-modules

llvm-svn: 274320
2016-07-01 01:51:40 +00:00
Sebastian Pop
5c5798c57c code hoisting pass based on GVN
This pass hoists duplicated computations in the program. The primary goal of
gvn-hoist is to reduce the size of functions before inline heuristics to reduce
the total cost of function inlining.

Pass written by Sebastian Pop, Aditya Kumar, Xiaoyu Hu, and Brian Rzycki.
Important algorithmic contributions by Daniel Berlin under the form of reviews.

Differential Revision: http://reviews.llvm.org/D19338

llvm-svn: 274305
2016-07-01 00:24:31 +00:00
Peter Collingbourne
7efd750607 IR: New representation for CFI and virtual call optimization pass metadata.
The bitset metadata currently used in LLVM has a few problems:

1. It has the wrong name. The name "bitset" refers to an implementation
   detail of one use of the metadata (i.e. its original use case, CFI).
   This makes it harder to understand, as the name makes no sense in the
   context of virtual call optimization.

2. It is represented using a global named metadata node, rather than
   being directly associated with a global. This makes it harder to
   manipulate the metadata when rebuilding global variables, summarise it
   as part of ThinLTO and drop unused metadata when associated globals are
   dropped. For this reason, CFI does not currently work correctly when
   both CFI and vcall opt are enabled, as vcall opt needs to rebuild vtable
   globals, and fails to associate metadata with the rebuilt globals. As I
   understand it, the same problem could also affect ASan, which rebuilds
   globals with a red zone.

This patch solves both of those problems in the following way:

1. Rename the metadata to "type metadata". This new name reflects how
   the metadata is currently being used (i.e. to represent type information
   for CFI and vtable opt). The new name is reflected in the name for the
   associated intrinsic (llvm.type.test) and pass (LowerTypeTests).

2. Attach metadata directly to the globals that it pertains to, rather
   than using the "llvm.bitsets" global metadata node as we are doing now.
   This is done using the newly introduced capability to attach
   metadata to global variables (r271348 and r271358).

See also: http://lists.llvm.org/pipermail/llvm-dev/2016-June/100462.html

Differential Revision: http://reviews.llvm.org/D21053

llvm-svn: 273729
2016-06-24 21:21:32 +00:00
David Majnemer
cbf614a93b Remove the ScalarReplAggregates pass
Nearly all the changes to this pass have been done while maintaining and
updating other parts of LLVM.  LLVM has had another pass, SROA, which
has superseded ScalarReplAggregates for quite some time.

Differential Revision: http://reviews.llvm.org/D21316

llvm-svn: 272737
2016-06-15 00:19:09 +00:00
Manuel Jacob
a485984c0c [PM] Schedule InstSimplify after late LICM run, to clean up LCSSA nodes.
Summary:
The module pass pipeline includes a late LICM run after loop
unrolling.  LCSSA is implicitly run as a pass dependency of LICM.  However no
cleanup pass was run after this, so the LCSSA nodes ended in the optimized output.

Reviewers: hfinkel, mehdi_amini

Subscribers: majnemer, bruno, mzolotukhin, mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D20606

llvm-svn: 271602
2016-06-02 22:14:26 +00:00
Peter Collingbourne
fad596aa81 Move whole-program virtual call optimization pass after function attribute inference in LTO pipeline.
As a result of D18634 we no longer infer certain attributes on linkonce_odr
functions at compile time, and may only infer them at LTO time. The readnone
attribute in particular is required for virtual constant propagation (part
of whole-program virtual call optimization) to work correctly.

This change moves the whole-program virtual call optimization pass after
the function attribute inference passes, and enables the attribute inference
passes at opt level 1, so that virtual constant propagation has a chance to
work correctly for linkonce_odr functions.

Differential Revision: http://reviews.llvm.org/D20643

llvm-svn: 270765
2016-05-25 21:26:14 +00:00
Xinliang David Li
72616180df Rename pass name to prepare to new PM porting /NFC
llvm-svn: 269586
2016-05-15 01:04:24 +00:00
Xinliang David Li
d55827f7b2 [PM] code refactoring -- preparation for new PM porting /NFC
llvm-svn: 268851
2016-05-07 05:39:12 +00:00
Mehdi Amini
31407ba009 Tweak the ThinLTO pass pipeline
Summary:
The original ThinLTO pipeline was derived from some
work I did tuning FullLTO on the test suite and SPEC. This
patch reduces the amount of work done in the "linker phase" of
the build, and extend the function simplifications passes
performed during the "compile phase". This helps the build time
by reducing the IR as much as possible during the compile phase
and limiting the work to be performed during the "link phase",
while keeping the performance "on par" with the existing pipeline.

Reviewers: tejohnson

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D19773

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268769
2016-05-06 18:17:03 +00:00
Xinliang David Li
8aebf44c97 [PM] port IR based PGO prof-gen pass to new pass manager
llvm-svn: 268710
2016-05-06 05:49:19 +00:00
Mehdi Amini
7f7d8be518 Move "Eliminate Available Externally" immediately after the inliner
This pass is supposed to reduce the size of the IR for compile time
purpose. We should run it ASAP, except when we prepare for LTO or
ThinLTO, and we want to keep them available for link-time inline.

Differential Revision: http://reviews.llvm.org/D19813

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268394
2016-05-03 15:46:00 +00:00
Mehdi Amini
45c7b3ecb5 Move createReversePostOrderFunctionAttrsPass right after the inliner is done
This is where it was originally, until LoopVersioningLICM was
inserted before in r259986, I don't believe it was on purpose.

Differential Revision: http://reviews.llvm.org/D19809

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268252
2016-05-02 16:53:16 +00:00
Rong Xu
6e34c490ff [PGO] Promote indirect calls to conditional direct calls with value-profile
This patch implements the transformation that promotes indirect calls to
conditional direct calls when the indirect-call value profile meta-data is
available.

Differential Revision: http://reviews.llvm.org/D17864

llvm-svn: 267815
2016-04-27 23:20:27 +00:00
Adam Nemet
d2fa414718 [LoopDist] Add llvm.loop.distribute.enable loop metadata
Summary:
D19403 adds a new pragma for loop distribution.  This change adds
support for the corresponding metadata that the pragma is translated to
by the FE.

As part of this I had to rethink the flag -enable-loop-distribute.  My
goal was to be backward compatible with the existing behavior:

  A1. pass is off by default from the optimization pipeline
  unless -enable-loop-distribute is specified

  A2. pass is on when invoked directly from opt (e.g. for unit-testing)

The new pragma/metadata overrides these defaults so the new behavior is:

  B1. A1 + enable distribution for individual loop with the pragma/metadata

  B2. A2 + disable distribution for individual loop with the pragma/metadata

The default value whether the pass is on or off comes from the initiator
of the pass.  From the PassManagerBuilder the default is off, from opt
it's on.

I moved -enable-loop-distribute under the pass.  If the flag is
specified it overrides the default from above.

Then the pragma/metadata can further modifies this per loop.

As a side-effect, we can now also use -enable-loop-distribute=0 from opt
to emulate the default from the optimization pipeline.  So to be precise
this is the new behavior:

  C1. pass is off by default from the optimization pipeline
  unless -enable-loop-distribute or the pragma/metadata enables it

  C2. pass is on when invoked directly from opt
  unless -enable-loop-distribute=0 or the pragma/metadata disables it

Reviewers: hfinkel

Subscribers: joker.eph, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D19431

llvm-svn: 267672
2016-04-27 05:28:18 +00:00
Mehdi Amini
bf4513b9aa Run GlobalOpt before emitting the bitcode for ThinLTO
This is motivated by reducing the size of the IR and thus reduce
compile time.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267385
2016-04-25 08:47:49 +00:00
Mehdi Amini
f72ca86b71 ThinLTO: Move createNameAnonFunctionPass insertion in PassManagerBuilder (NFC)
It is just code motion, but makes more sense this way.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267384
2016-04-25 08:47:37 +00:00
Xinliang David Li
e6b892940f Port InstrProfiling pass to the new pass manager
Differential Revision: http://reviews.llvm.org/D18126

llvm-svn: 266637
2016-04-18 17:47:38 +00:00
Justin Lebar
cf63b64fc6 [PM] Add a SpeculativeExecution pass for targets with divergent branches.
Summary:
This IR pass is helpful for GPUs, and other targets with divergent
branches.  It's a nop on targets without divergent branches.

Reviewers: chandlerc

Subscribers: llvm-commits, jingyue, rnk, joker.eph, tra

Differential Revision: http://reviews.llvm.org/D18626

llvm-svn: 266399
2016-04-15 00:32:12 +00:00
Mehdi Amini
d5faa267c4 Add a pass to name anonymous/nameless function
Summary:
For correct handling of alias to nameless
function, we need to be able to refer them through a GUID in the summary.
Here we name them using a hash of the non-private global names in the module.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18883

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266132
2016-04-12 21:35:28 +00:00
Justin Lebar
2fe1323112 [PassManager] Make PassManagerBuilder::addExtension take an std::function, rather than a function pointer.
Summary:
This gives callers flexibility to pass lambdas with captures, which lets
callers avoid the C-style void*-ptr closure style.  (Currently, callers
in clang store state in the PassManagerBuilderBase arg.)

No functional change, and the new API is backwards-compatible.

Reviewers: chandlerc

Subscribers: joker.eph, cfe-commits

Differential Revision: http://reviews.llvm.org/D18613

llvm-svn: 264918
2016-03-30 20:39:29 +00:00
Adam Nemet
c979c6e123 Turn LoopLoadElimination on again
The latent bug that LLE exposed in the LoopVectorizer was resolved
(PR26952).

The pass can be disabled with -mllvm -enable-loop-load-elim=0

llvm-svn: 263595
2016-03-15 22:26:12 +00:00
Teresa Johnson
26ab5772b0 [ThinLTO] Renaming of function index to module summary index (NFC)
(Resubmitting after fixing missing file issue)

With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.

A companion clang patch will immediately succeed this patch to reflect
this renaming.

llvm-svn: 263513
2016-03-15 00:04:37 +00:00
Teresa Johnson
cec0cae313 Revert "[ThinLTO] Renaming of function index to module summary index (NFC)"
This reverts commit r263490. Missed a file.

llvm-svn: 263493
2016-03-14 21:18:10 +00:00
Teresa Johnson
892920b358 [ThinLTO] Renaming of function index to module summary index (NFC)
With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.

A companion clang patch will immediately succeed this patch to reflect
this renaming.

llvm-svn: 263490
2016-03-14 21:05:56 +00:00
Adam Nemet
bb45810e4f Revert "Turn LoopLoadElimination on again"
This reverts commit r263472.

There is an LNT failure on clang-ppc64be-linux-lnt.  Turn this off,
while I am investigating.

llvm-svn: 263485
2016-03-14 20:38:55 +00:00
Adam Nemet
5a19ae917b Turn LoopLoadElimination on again
The two issues that were discovered got fixed (r263058, r263173).

The pass can be disabled with -mllvm -enable-loop-load-elim=0

llvm-svn: 263472
2016-03-14 19:40:25 +00:00
Chandler Carruth
89c45a162f [PM] Port GVN to the new pass manager, wire it up, and teach a couple of
tests to run GVN in both modes.

This is mostly the boring refactoring just like SROA and other complex
transformation passes. There is some trickiness in that GVN's
ValueNumber class requires hand holding to get to compile cleanly. I'm
open to suggestions about a better pattern there, but I tried several
before settling on this. I was trying to balance my desire to sink as
much implementation detail into the source file as possible without
introducing overly many layers of abstraction.

Much like with SROA, the design of this system is made somewhat more
cumbersome by the need to support both pass managers without duplicating
the significant state and logic of the pass. The same compromise is
struck here.

I've also left a FIXME in a doxygen comment as the GVN pass seems to
have pretty woeful documentation within it. I'd like to submit this with
the FIXME and let those more deeply familiar backfill the information
here now that we have a nice place in an interface to put that kind of
documentaiton.

Differential Revision: http://reviews.llvm.org/D18019

llvm-svn: 263208
2016-03-11 08:50:55 +00:00
Matthias Braun
c31032d607 InstCombine: Restrict computeKnownBits() on all Values to OptLevel > 2
As part of r251146 InstCombine was extended to call computeKnownBits on
every value in the function to determine whether it happens to be
constant. This increases typical compiletime by 1-3% (5% in irgen+opt
time) in my measurements. On the other hand this case did not trigger
once in the whole llvm-testsuite.

This patch introduces the notion of ExpensiveCombines which are only
enabled for OptLevel > 2. I removed the check in InstructionSimplify as
that is called from various places where the OptLevel is not known but
given the rarity of the situation I think a check in InstCombine is
enough.

Differential Revision: http://reviews.llvm.org/D16835

llvm-svn: 263047
2016-03-09 18:47:11 +00:00
Adam Nemet
81113ef68c Revert "Enable LoopLoadElimination by default"
This reverts commit r262250.

It causes SPEC2006/gcc to generate wrong result (166.s) in AArch64 when
running with *ref* data set.  The error happens with
"-Ofast -flto -fuse-ld=gold" or "-O3 -fno-strict-aliasing".

llvm-svn: 262839
2016-03-07 17:38:02 +00:00
Adam Nemet
dd9e637aca Enable LoopLoadElimination by default
Summary:
I re-benchmarked this and results are similar to original results in
D13259:

On ARM64:
  SingleSource/Benchmarks/Polybench/linear-algebra/solvers/dynprog -59.27%
  SingleSource/Benchmarks/Polybench/stencils/adi                   -19.78%

On x86:
  SingleSource/Benchmarks/Polybench/linear-algebra/solvers/dynprog  -27.14%

And of course the original ~20% gain on SPECint_2006/456.hmmer with Loop
Distribution.

In terms of compile time, there is ~5% increase on both
SingleSource/Benchmarks/Misc/oourafft and
SingleSource/Benchmarks/Linkpack/linkpack-pc.  These are both very tiny
loop-intensive programs where SCEV computations dominates compile time.

The reason that time spent in SCEV increases has to do with the design
of the old pass manager.  If a transform pass does not preserve an
analysis we *invalidate* the analysis even if there was *no*
modification made by the transform pass.

This means that currently we don't take advantage of LLE and LV sharing
the same analysis (LAA) and unfortunately we recompute LAA *and* SCEV
for LLE.

(There should be a way to work around this limitation in the case of
SCEV and LAA since both compute things on demand and internally cache
their result.  Thus we could pretend that transform passes preserve
these analyses and manually invalidate them upon actual modification.
On the other hand the new pass manager is supposed to solve so I am not
sure if this is worthwhile.)

Reviewers: hfinkel, dberlin

Subscribers: dberlin, reames, mssimpso, aemerson, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D16300

llvm-svn: 262250
2016-02-29 20:35:11 +00:00