Commit Graph

2895 Commits

Author SHA1 Message Date
Andrea Di Biagio 517e3fc34c [SampleProfile] Don't assert when printing the DebugLoc of a branch. NFC.
llvm-svn: 300544
2017-04-18 11:27:58 +00:00
Andrea Di Biagio e3edef0977 [SampleProfile] Skip intrinsic calls when visiting callsites in InlineHotFunctions.
Before this patch, we always called method 'findCalleeFunctionSamples()' on
intrinsic calls. However, intrinsic calls like llvm.dbg.value() are not viable
candidates for obvious reasons.

No functional change intended.

Differential Revision: https://reviews.llvm.org/D32008

llvm-svn: 300541
2017-04-18 10:08:53 +00:00
Dehao Chen 1ea8bd8109 Build SymbolMap in SampleProfileLoader to help matchin function names with suffix.
Summary: If there is suffix added in the function name (e.g. module hash added by thinLTO), we will not be able to find a match in profile as the suffix does not exist in profile. This patch build a map from function name to Function *. The map includes the entry for the stripped function name so that inlineHotFunctions can find the corresponding function to promote/inline.

Reviewers: davidxl, dnovillo, tejohnson

Reviewed By: davidxl

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D31952

llvm-svn: 300507
2017-04-17 22:23:05 +00:00
Peter Collingbourne a0f371a106 Bitcode: Add a string table to the bitcode format.
Add a top-level STRTAB block containing a string table blob, and start storing
strings for module codes FUNCTION, GLOBALVAR, ALIAS, IFUNC and COMDAT in
the string table.

This change allows us to share names between globals and comdats as well
as between modules, and improves the efficiency of loading bitcode files by
no longer using a bit encoding for symbol names. Once we start writing the
irsymtab to the bitcode file we will also be able to share strings between
it and the module.

On my machine, link time for Chromium for Linux with ThinLTO decreases by
about 7% for no-op incremental builds or about 1% for full builds. Total
bitcode file size decreases by about 3%.

As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2017-April/111732.html

Differential Revision: https://reviews.llvm.org/D31838

llvm-svn: 300464
2017-04-17 17:51:36 +00:00
Reid Kleckner fb502d2f5e [IR] Make paramHasAttr to use arg indices instead of attr indices
This avoids the confusing 'CS.paramHasAttr(ArgNo + 1, Foo)' pattern.

Previously we were testing return value attributes with index 0, so I
introduced hasReturnAttr() for that use case.

llvm-svn: 300367
2017-04-14 20:19:02 +00:00
Davide Italiano 91239088a1 [FunctionImport] assert(false) -> llvm_unreachable(). NFCI.
llvm-svn: 300344
2017-04-14 17:22:02 +00:00
Reid Kleckner f021fab2af [IR] Make getParamAttributes take argument numbers, not ArgNo+1
Add hasParamAttribute() and use it instead of hasAttribute(ArgNo+1,
Kind) everywhere.

The fact that the AttributeList index for an argument is ArgNo+1 should
be a hidden implementation detail.

NFC

llvm-svn: 300272
2017-04-13 23:12:13 +00:00
Dehao Chen 2c7ca9b5df SamplePGO: convert callsite samples map key from callsite_location to callsite_location+callee_name
Summary: For iterative SamplePGO, an indirect call can be speculatively promoted to multiple direct calls and get inlined. All these promoted direct calls will share the same callsite location (offset+discriminator). With the current implementation, we cannot distinguish between different promotion candidates and its inlined instance. This patch adds callee_name to the key of the callsite sample map. And added helper functions to get all inlined callee samples for a given callsite location. This helps the profile annotator promote correct targets and inline it before annotation, and ensures all indirect call targets to be annotated correctly.

Reviewers: davidxl, dnovillo

Reviewed By: davidxl

Subscribers: andreadb, llvm-commits

Differential Revision: https://reviews.llvm.org/D31950

llvm-svn: 300240
2017-04-13 19:52:10 +00:00
Reid Kleckner aea2a28098 [DAE] Simplify call site replacement code with CallSite NFC
llvm-svn: 300235
2017-04-13 18:42:03 +00:00
Reid Kleckner 3a1150352d [ArgPromotion] Don't drop !prof metadata on promoted calls
Noticed by inspection while doing attribute work. DAE, InstCombineCalls,
and ArgPromotion have a fair amount of duplicated code for hacking on
call sites, and you can find bugs by comparing them.

Add a test case for this.

llvm-svn: 300229
2017-04-13 18:10:30 +00:00
Geoff Berry 85a530fb59 Re-apply "[GVNHoist] Move GVNHoist to function simplification part of pipeline."
This reverts commit r296872 now that PR32153 has been fixed.

llvm-svn: 300200
2017-04-13 15:36:25 +00:00
Reid Kleckner 7f72033e1c [IR] Take func, ret, and arg attrs separately in AttributeList::get
This seems like a much more natural API, based on Derek Schuff's
comments on r300015. It further hides the implementation detail of
AttributeList that function attributes come last and appear at index
~0U, which is easy for the user to screw up. git diff says it saves code
as well: 97 insertions(+), 137 deletions(-)

This also makes it easier to change the implementation, which I want to
do next.

llvm-svn: 300153
2017-04-13 00:58:09 +00:00
Bob Haarman 4075ccc717 ThinLTOBitcodeWriter: keep comdats together, rename if leader is renamed
Summary:
COFF requires that every comdat contain a symbol with the same name as
the comdat. ThinLTOBitcodeWriter renames symbols, which may cause this
requirement to be violated. This change avoids such violations by
renaming comdats if their leaders are renamed. It also keeps comdats
together when splitting modules.

Reviewers: pcc, mehdi_amini, tejohnson

Reviewed By: pcc

Subscribers: rnk, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D31963

llvm-svn: 300019
2017-04-12 01:43:07 +00:00
Reid Kleckner c2cb560045 [IR] Add AttributeSet to hide AttributeSetNode* again, NFC
Summary:
For now, it just wraps AttributeSetNode*. Eventually, it will hold
AvailableAttrs as an inline bitset, and adding and removing enum
attributes will be super cheap.

This sinks AttributeSetNode back down to lib/IR/AttributeImpl.h.

Reviewers: pete, chandlerc

Subscribers: llvm-commits, jfb

Differential Revision: https://reviews.llvm.org/D31940

llvm-svn: 300014
2017-04-12 00:38:00 +00:00
Serge Guelton 59a2d7b909 Module::getOrInsertFunction is using C-style vararg instead of variadic templates.
From a user prospective, it forces the use of an annoying nullptr to mark the end of the vararg, and there's not type checking on the arguments.
The variadic template is an obvious solution to both issues.

Differential Revision: https://reviews.llvm.org/D31070

llvm-svn: 299949
2017-04-11 15:01:18 +00:00
Geoff Berry 9d597adde4 [GVNHoist] Re-enable GVNHoist by default
Turn GVNHoist back on by default now that PR32153 has been fixed.

llvm-svn: 299944
2017-04-11 14:36:30 +00:00
Keno Fischer 30779772cf [StripDeadDebug/DIFinder] Track inlined SPs
Summary:
In rL299692 I improved strip-dead-debug-info's ability to drop CUs that are not
referenced from the current module. However, in doing so I neglected to realize
that some SPs could be referenced entirely from inlined functions. It appears
I was not the only one to make this mistake, because DebugInfoFinder, doesn't
find those SPs either. Fix this in DebugInfoFinder and then use that to make
sure not to drop those CUs in strip-dead-debug-info.

Reviewers: aprantl

Reviewed By: aprantl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31904

llvm-svn: 299936
2017-04-11 13:32:11 +00:00
Diana Picus b050c7fbe0 Revert "Turn some C-style vararg into variadic templates"
This reverts commit r299925 because it broke the buildbots. See e.g.
http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/6008

llvm-svn: 299928
2017-04-11 10:07:12 +00:00
Serge Guelton 5fd75fb72e Turn some C-style vararg into variadic templates
Module::getOrInsertFunction is using C-style vararg instead of
variadic templates.

From a user prospective, it forces the use of an annoying nullptr
to mark the end of the vararg, and there's not type checking on the
arguments. The variadic template is an obvious solution to both
issues.

llvm-svn: 299925
2017-04-11 08:36:52 +00:00
Reid Kleckner eb9dd5b87f Reland "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies"
This re-lands r299875.

I introduced a bug in Clang code responsible for replacing K&R, no
prototype declarations with a real function definition with a prototype.
The bug was here:

       // Collect any return attributes from the call.
  -    if (oldAttrs.hasAttributes(llvm::AttributeList::ReturnIndex))
  -      newAttrs.push_back(llvm::AttributeList::get(newFn->getContext(),
  -                                                  oldAttrs.getRetAttributes()));
  +    newAttrs.push_back(oldAttrs.getRetAttributes());

Previously getRetAttributes() carried AttributeList::ReturnIndex in its
AttributeList. Now that we return the AttributeSetNode* directly, it no
longer carries that index, and we call this overload with a single node:
  AttributeList::get(LLVMContext&, ArrayRef<AttributeSetNode*>)

That aborted with an assertion on x86_32 targets. I added an explicit
triple to the test and added CHECKs to help find issues like this in the
future sooner.

llvm-svn: 299899
2017-04-10 23:31:05 +00:00
Matt Arsenault 3c1fc768ed Allow DataLayout to specify addrspace for allocas.
LLVM makes several assumptions about address space 0. However,
alloca is presently constrained to always return this address space.
There's no real way to avoid using alloca, so without this
there is no way to opt out of these assumptions.

The problematic assumptions include:
- That the pointer size used for the stack is the same size as
  the code size pointer, which is also the maximum sized pointer.

- That 0 is an invalid, non-dereferencable pointer value.

These are problems for AMDGPU because alloca is used to
implement the private address space, which uses a 32-bit
index as the pointer value. Other pointers are 64-bit
and behave more like LLVM's notion of generic address
space. By changing the address space used for allocas,
we can change our generic pointer type to be LLVM's generic
pointer type which does have similar properties.

llvm-svn: 299888
2017-04-10 22:27:50 +00:00
Dehao Chen d4a3397861 Emit less compiler optimization remarks in samplepgo to reduce a call to findCalleeFunctionSamples which is going to be refactored.
Summary: Now the SamplePGO support is more stable, we do not need so many verbose optimization remarks emitted.

Reviewers: dnovillo, davidxl

Reviewed By: davidxl

Subscribers: fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D31826

llvm-svn: 299883
2017-04-10 20:49:16 +00:00
Evgeniy Stepanov ba7c2e9661 Revert "[asan] Fix dead stripping of globals on Linux."
This reverts commit r299697, which caused a big increase in object file size.

llvm-svn: 299879
2017-04-10 20:36:30 +00:00
Reid Kleckner 211b1f324f Revert "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies"
This reverts r299875. A Linux bot came back with a test failure:
http://bb.pgr.jp/builders/test-clang-i686-linux-RA/builds/741/steps/test_clang/logs/Clang%20%3A%3A%20CodeGen__2006-05-19-SingleEltReturn.c

llvm-svn: 299878
2017-04-10 20:34:19 +00:00
Reid Kleckner 324c99dee5 [IR] Make AttributeSetNode public, avoid temporary AttributeList copies
Summary:
AttributeList::get(Fn|Ret|Param)Attributes no longer creates a temporary
AttributeList just to hide the AttributeSetNode type.

I've also added a factory method to create AttributeLists from a
parallel array of AttributeSetNodes. I think this simplifies
construction of AttributeLists when rewriting function prototypes.
Previously we would test if a particular index had attributes, and
conditionally add a temporary attribute list to a vector. Now the
attribute set vector is parallel to the argument vector already that
these passes already construct.

My long term vision is to wrap AttributeSetNode* inside an AttributeSet
type that holds the enum attributes, but that will come in a follow up
change.

I haven't done any performance measurements for this change because
profiling hasn't shown that any of the affected code is hot.

Reviewers: pete, chandlerc, sanjoy, hfinkel

Reviewed By: pete

Subscribers: jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D31198

llvm-svn: 299875
2017-04-10 20:18:10 +00:00
Evgeniy Stepanov 349adbacca [cfi] Take over existing __cfi_check in CrossDSOCFI.
https://reviews.llvm.org/D31796 will emit a dummy __cfi_check in the
frontend.

llvm-svn: 299805
2017-04-07 23:00:20 +00:00
Mehdi Amini db11fdfda5 Revert "Turn some C-style vararg into variadic templates"
This reverts commit r299699, the examples needs to be updated.

llvm-svn: 299702
2017-04-06 20:23:57 +00:00
Mehdi Amini 579540a8f7 Turn some C-style vararg into variadic templates
Module::getOrInsertFunction is using C-style vararg instead of
variadic templates.

From a user prospective, it forces the use of an annoying nullptr
to mark the end of the vararg, and there's not type checking on the
arguments. The variadic template is an obvious solution to both
issues.

Patch by: Serge Guelton <serge.guelton@telecom-bretagne.eu>

Differential Revision: https://reviews.llvm.org/D31070

llvm-svn: 299699
2017-04-06 20:09:31 +00:00
Evgeniy Stepanov 6c3a8cbc4d [asan] Fix dead stripping of globals on Linux.
Use a combination of !associated, comdat, @llvm.compiler.used and
custom sections to allow dead stripping of globals and their asan
metadata. Sometimes.

Currently this works on LLD, which supports SHF_LINK_ORDER with
sh_link pointing to the associated section.

This also works on BFD, which seems to treat comdats as
all-or-nothing with respect to linker GC. There is a weird quirk
where the "first" global in each link is never GC-ed because of the
section symbols.

At this moment it does not work on Gold (as in the globals are never
stripped).

This is a re-land of r298158 rebased on D31358. This time,
asan.module_ctor is put in a comdat as well to avoid quadratic
behavior in Gold.

llvm-svn: 299697
2017-04-06 19:55:17 +00:00
Keno Fischer bacc64b5fa [StripDeadDebugInfo] Drop dead CUs entirely
Summary:
Prior to this while it would delete the dead DIGlobalVariables, it would
leave dead DICompileUnits and everything referenced therefrom. For a bit
bitcode file with thousands of compile units those dead nodes easily
outnumbered the real ones. Clean that up.

Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D31720

llvm-svn: 299692
2017-04-06 19:26:22 +00:00
Bob Haarman 6de8134784 ThinLTOBitcodeWriter: handle aliases first in filterModule
Summary: This change fixes a "local linkage requires default visibility" assert when attempting to build LLVM with ThinLTO on Windows.

Reviewers: pcc, tejohnson, mehdi_amini

Reviewed By: pcc

Subscribers: llvm-commits, Prazek

Differential Revision: https://reviews.llvm.org/D31632

llvm-svn: 299491
2017-04-05 00:42:07 +00:00
Rong Xu 48596b6f7a [PGO] Memory intrinsic calls optimization based on profiled size
This patch optimizes two memory intrinsic operations: memset and memcpy based
on the profiled size of the operation. The high level transformation is like:
  mem_op(..., size)
  ==>
  switch (size) {
    case s1:
       mem_op(..., s1);
       goto merge_bb;
    case s2:
       mem_op(..., s2);
       goto merge_bb;
    ...
    default:
       mem_op(..., size);
       goto merge_bb;
    }
  merge_bb:

Differential Revision: http://reviews.llvm.org/D28966

llvm-svn: 299446
2017-04-04 16:42:20 +00:00
Peter Collingbourne 6b193966ac ThinLTOBitcodeWriter: Use Module::global_values(). NFCI.
llvm-svn: 299132
2017-03-30 23:43:08 +00:00
Joerg Sonnenberger fa7367428a Split the SimplifyCFG pass into two variants.
The first variant contains all current transformations except
transforming switches into lookup tables. The second variant
contains all current transformations.

The switch-to-lookup-table conversion results in code that is more
difficult to analyze and optimize by other passes. Most importantly,
it can inhibit Dead Code Elimination. As such it is often beneficial to
only apply this transformation very late. A common example is inlining,
which can often result in range restrictions for the switch expression.

Changes in execution time according to LNT:
SingleSource/Benchmarks/Misc/fp-convert +3.03%
MultiSource/Benchmarks/ASC_Sequoia/CrystalMk/CrystalMk -11.20%
MultiSource/Benchmarks/Olden/perimeter/perimeter -10.43%
and a couple of smaller changes. For perimeter it also results 2.6%
a smaller binary.

Differential Revision: https://reviews.llvm.org/D30333

llvm-svn: 298799
2017-03-26 06:44:08 +00:00
Dehao Chen 722e94061b Set the prof weight correctly for call instructions in DeadArgumentElimination.
Summary: In DeadArgumentElimination, the call instructions will be replaced. We also need to set the prof weights so that function inlining can find the correct profile.

Reviewers: eraman

Reviewed By: eraman

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31143

llvm-svn: 298660
2017-03-23 23:26:00 +00:00
Dehao Chen 8c88671985 Disable loop unrolling and icp in SamplePGO ThinLTO compile phase
Summary:
loop unrolling and icp will make the sample profile annotation much harder in the backend. So disable these 2 optimization in the ThinLTO compile phase.
Will add a test in cfe in a separate patch.

Reviewers: tejohnson

Reviewed By: tejohnson

Subscribers: mehdi_amini, llvm-commits, Prazek

Differential Revision: https://reviews.llvm.org/D31217

llvm-svn: 298646
2017-03-23 21:20:05 +00:00
Teresa Johnson 0c6a4ff8dc [ThinLTO] Add support for emitting minimized bitcode for thin link
Summary:
The cumulative size of the bitcode files for a very large application
can be huge, particularly with -g. In a distributed build environment,
all of these files must be sent to the remote build node that performs
the thin link step, and this can exceed size limits.

The thin link actually only needs the summary along with a bitcode
symbol table. Until we have a proper bitcode symbol table, simply
stripping the debug metadata results in significant size reduction.

Add support for an option to additionally emit minimized bitcode
modules, just for use in the thin link step, which for now just strips
all debug metadata. I plan to add a cc1 option so this can be invoked
easily during the compile step.

However, care must be taken to ensure that these minimized thin link
bitcode files produce the same index as with the original bitcode files,
as these original bitcode files will be used in the backends.

Specifically:
1) The module hash used for caching is typically produced by hashing the
written bitcode, and we want to include the hash that would correspond
to the original bitcode file. This is because we want to ensure that
changes in the stripped portions affect caching. Added plumbing to emit
the same module hash in the minimized thin link bitcode file.
2) The module paths in the index are constructed from the module ID of
each thin linked bitcode, and typically is automatically generated from
the input file path. This is the path used for finding the modules to
import from, and obviously we need this to point to the original bitcode
files. Added gold-plugin support to take a suffix replacement during the
thin link that is used to override the identifier on the MemoryBufferRef
constructed from the loaded thin link bitcode file. The assumption is
that the build system can specify that the minimized bitcode file has a
name that is similar but uses a different suffix (e.g. out.thinlink.bc
instead of out.o).

Added various tests to ensure that we get identical index files out of
the thin link step.

Reviewers: mehdi_amini, pcc

Subscribers: Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D31027

llvm-svn: 298638
2017-03-23 19:47:39 +00:00
Dehao Chen 53a0c082d2 Do not set branch weight if the branch weight annotation is present.
Summary: ThinLTO will annotate the CFG twice. If the branch weight is set by the first annotation, we should not set the branch weight again in the second annotation because the first annotation is more accurate as there is less optimization that could affect debug info accuracy.

Reviewers: tejohnson, davidxl

Reviewed By: tejohnson

Subscribers: mehdi_amini, aprantl, llvm-commits

Differential Revision: https://reviews.llvm.org/D31228

llvm-svn: 298602
2017-03-23 14:43:10 +00:00
Peter Collingbourne f7691d8b41 IPO: Const correctness for summaries passed into passes.
Pass const qualified summaries into importers and unqualified summaries into
exporters. This lets us const-qualify the summary argument to thinBackend.

Differential Revision: https://reviews.llvm.org/D31230

llvm-svn: 298534
2017-03-22 18:22:59 +00:00
Peter Collingbourne 9a3f97977f IR: Fix a race condition in type id clients of ModuleSummaryIndex.
Add a const version of the getTypeIdSummary accessor that avoids
mutating the TypeIdMap.

Differential Revision: https://reviews.llvm.org/D31226

llvm-svn: 298531
2017-03-22 18:04:39 +00:00
Evgeny Astigeevich 7823c66e05 r286814 resulted that CallPenalty can be subtracted twice:
- First time, during calculation of the cost in InlineCost.cpp
- Second time, during calculation of the cost in Inliner.cpp

This patches fixes this.

Differential Revision: https://reviews.llvm.org/D31137

llvm-svn: 298496
2017-03-22 12:01:57 +00:00
Dehao Chen 9907e9d860 Do not inline hot callsites for samplepgo in thinlto compile phase.
Summary: Because SamplePGO passes will be invoked twice in ThinLTO build: once at compile phase, the other at backend. We want to make sure the IR at the 2nd phase matches the hot part in profile, thus we do not want to inline hot callsites in the first phase.

Reviewers: tejohnson, eraman

Reviewed By: tejohnson

Subscribers: mehdi_amini, llvm-commits, Prazek

Differential Revision: https://reviews.llvm.org/D31201

llvm-svn: 298428
2017-03-21 19:55:36 +00:00
Reid Kleckner b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
Evgeniy Stepanov c440572715 Revert r298158.
Revert "[asan] Fix dead stripping of globals on Linux."

OOM in gold linker.

llvm-svn: 298288
2017-03-20 18:45:34 +00:00
Evgeniy Stepanov c5aa6b9411 [asan] Fix dead stripping of globals on Linux.
Use a combination of !associated, comdat, @llvm.compiler.used and
custom sections to allow dead stripping of globals and their asan
metadata. Sometimes.

Currently this works on LLD, which supports SHF_LINK_ORDER with
sh_link pointing to the associated section.

This also works on BFD, which seems to treat comdats as
all-or-nothing with respect to linker GC. There is a weird quirk
where the "first" global in each link is never GC-ed because of the
section symbols.

At this moment it does not work on Gold (as in the globals are never
stripped).

Differential Revision: https://reviews.llvm.org/D30121

llvm-svn: 298158
2017-03-17 22:17:29 +00:00
Stanislav Mekhanoshin ee2dd785f6 Only unswitch loops with uniform conditions
Loop unswitching can be extremely harmful for a SIMT target. In case
if hoisted condition is not uniform a SIMT machine will execute both
clones of a loop sequentially. Therefor LoopUnswitch checks if the
condition is non-divergent.

Since DivergenceAnalysis adds an expensive PostDominatorTree analysis
not needed for non-SIMT targets a new option is added to avoid unneded
analysis initialization. The method getAnalysisUsage is called when
TargetTransformInfo is not yet available and we cannot use it here.
For that reason a new field DivergentTarget is added to PassManagerBuilder
to control the behavior and set this field from a target.

Differential Revision: https://reviews.llvm.org/D30796

llvm-svn: 298104
2017-03-17 17:13:41 +00:00
Chandler Carruth 814e0df1c5 [PM/Inliner] Fix a bug in r297374 where we would leave stale calls in
the work queue and crash when trying to visit them after deleting the
function containing those calls.

llvm-svn: 297940
2017-03-16 10:45:42 +00:00
Dehao Chen 4a435e0896 SamplePGO ThinLTO ICP fix for local functions.
Summary:
In SamplePGO, if the profile is collected from non-LTO binary, and used to drive ThinLTO, the indirect call promotion may fail because ThinLTO adjusts local function names to avoid conflicts. There are two places of where the mismatch can happen:

1. thin-link prepends SourceFileName to front of FuncName to build the GUID (GlobalValue::getGlobalIdentifier). Unlike instrumentation FDO, SamplePGO does not use the PGOFuncName scheme and therefore the indirect call target profile data contains a hash of the OriginalName.
2. backend compiler promotes some local functions to global and appends .llvm.{$ModuleHash} to the end of the FuncName to derive PromotedFunctionName

This patch tries at the best effort to find the GUID from the original local function name (in profile), and use that in ICP promotion, and in SamplePGO matching that happens in the backend after importing/inlining:

1. in thin-link, it builds the map from OriginalName to GUID so that when thin-link reads in indirect call target profile (represented by OriginalName), it knows which GUID to import.
2. in backend compiler, if sample profile reader cannot find a profile match for PromotedFunctionName, it will try to find if there is a match for OriginalFunctionName.
3. in backend compiler, we build symbol table entry for OriginalFunctionName and pointer to the same symbol of PromotedFunctionName, so that ICP can find the correct target to promote.

Reviewers: mehdi_amini, tejohnson

Reviewed By: tejohnson

Subscribers: llvm-commits, Prazek

Differential Revision: https://reviews.llvm.org/D30754

llvm-svn: 297757
2017-03-14 17:33:01 +00:00
Peter Collingbourne 14dcf02fcb WholeProgramDevirt: Implement export/import support for VCP.
Differential Revision: https://reviews.llvm.org/D30017

llvm-svn: 297503
2017-03-10 20:13:58 +00:00
Peter Collingbourne 59675ba0f8 WholeProgramDevirt: Implement export/import support for unique ret val opt.
Differential Revision: https://reviews.llvm.org/D29917

llvm-svn: 297502
2017-03-10 20:09:11 +00:00