[ThinLTO] Create AliasSummary when building index

Summary:
Previously we were creating the alias summary on the fly while writing
the summary to bitcode. This moves the creation of these summaries t

[ThinLTO] Create AliasSummary when building index

Summary:
Previously we were creating the alias summary on the fly while writing
the summary to bitcode. This moves the creation of these summaries to
the module summary index builder where we build the rest of the summary
index.

This is going to be necessary for setting the NoRename flag for values
possibly used in inline asm or module level asm.

Reviewers: mehdi_amini

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26049

llvm-svn: 285379

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[ThinLTO] Rename HasSection to NoRename (NFC)

Summary:
This is in preparation for a change to utilize this flag for symbols
referenced/defined in either inline or module level assembly.

Reviewers:

[ThinLTO] Rename HasSection to NoRename (NFC)

Summary:
This is in preparation for a change to utilize this flag for symbols
referenced/defined in either inline or module level assembly.

Reviewers: mehdi_amini

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26048

llvm-svn: 285376

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Fix spelling mistake in comment.

llvm-svn: 284714

Fix MSVC bool -> uint64_t promotion warning

llvm-svn: 284713

DebugInfo: preparation to implement DW_AT_alignment

- Add alignment attribute to DIVariable family
- Modify bitcode format to match new DIVariable representation
- Update tests to match these cha

DebugInfo: preparation to implement DW_AT_alignment

- Add alignment attribute to DIVariable family
- Modify bitcode format to match new DIVariable representation
- Update tests to match these changes (also add bitcode upgrade test)
- Expect that frontend passes non-zero align value only when it is not default
(was forcibly aligned by alignas()/_Alignas()/__atribute__(aligned())

Differential Revision: https://reviews.llvm.org/D25073

llvm-svn: 284678

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[thinlto] Basic thinlto fdo heuristic

Summary:
This patch improves thinlto importer
by importing 3x larger functions that are called from hot block.

I compared performance with the trunk on spec, a

[thinlto] Basic thinlto fdo heuristic

Summary:
This patch improves thinlto importer
by importing 3x larger functions that are called from hot block.

I compared performance with the trunk on spec, and there
were about 2% on povray and 3.33% on milc. These results seems
to be consistant and match the results Teresa got with her simple
heuristic. Some benchmarks got slower but I think they are just
noisy (mcf, xalancbmki, omnetpp)- running the benchmarks again with
more iterations to confirm. Geomean of all benchmarks including the noisy ones
were about +0.02%.

I see much better improvement on google branch with Easwaran patch
for pgo callsite inlining (the inliner actually inline those big functions)
Over all I see +0.5% improvement, and I get +8.65% on povray.
So I guess we will see much bigger change when Easwaran patch will land
(it depends on new pass manager), but it is still worth putting this to trunk
before it.

Implementation details changes:
- Removed CallsiteCount.
- ProfileCount got replaced by Hotness
- hot-import-multiplier is set to 3.0 for now,
didn't have time to tune it up, but I see that we get most of the interesting
functions with 3, so there is no much performance difference with higher, and
binary size doesn't grow as much as with 10.0.

Reviewers: eraman, mehdi_amini, tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24638

llvm-svn: 282437

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[ThinLTO] Always emit a summary when compiling in ThinLTO mode

Summary:
Emit an empty summary section, instead of no summary section, when
there are no global variables in the index. This ensures th

[ThinLTO] Always emit a summary when compiling in ThinLTO mode

Summary:
Emit an empty summary section, instead of no summary section, when
there are no global variables in the index. This ensures that LTO
will treat these files as ThinLTO inputs, instead of as regular
LTO inputs.

In addition to not being what the user likely intended when
compiling with -flto=thin, the current behavior is problematic for
distributed build systems that expect to get ThinLTO index and imports
files back for each input compiled with -flto=thin. Combining into
a single regular LTO module also reduces the backend parallelism.
And in the case where the index was suppressed due to uses in
inline assembly, combining into a single LTO module could provoke
renaming of duplicates that we were trying to prevent by suppressing
the index.

This change required a couple of fixes to handle the empty summary
section.

Reviewers: mehdi_amini

Subscribers: mehdi_amini, llvm-commits, pcc

Differential Revision: https://reviews.llvm.org/D24779

llvm-svn: 282037

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BitcodeWriter: fix emission of invoke when calling a var-arg function with operand bundles

llvm-svn: 281940

Don't create a SymbolTable in Function when the LLVMContext discards value names (NFC)

The ValueSymbolTable is used to detect name conflict and rename
instructions automatically. This is not needed

Don't create a SymbolTable in Function when the LLVMContext discards value names (NFC)

The ValueSymbolTable is used to detect name conflict and rename
instructions automatically. This is not needed when the value
names are automatically discarded by the LLVMContext.
No functional change intended, just saving a little bit of memory.

This is a recommit of r281806 after fixing the accessor to return
a pointer instead of a reference and updating all the call-sites.

llvm-svn: 281813

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DebugInfo: New metadata representation for global variables.

This patch reverses the edge from DIGlobalVariable to GlobalVariable.
This will allow us to more easily preserve debug info metadata when

DebugInfo: New metadata representation for global variables.

This patch reverses the edge from DIGlobalVariable to GlobalVariable.
This will allow us to more easily preserve debug info metadata when
manipulating global variables.

Fixes PR30362. A program for upgrading test cases is attached to that
bug.

Differential Revision: http://reviews.llvm.org/D20147

llvm-svn: 281284

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DebugInfo: Add flag to CU to disable emission of inline debug info into the skeleton CU

In cases where .dwo/.dwp files are guaranteed to be available, skipping
the extra online (in the .o file) inli

DebugInfo: Add flag to CU to disable emission of inline debug info into the skeleton CU

In cases where .dwo/.dwp files are guaranteed to be available, skipping
the extra online (in the .o file) inline info can save a substantial
amount of space - see the original r221306 for more details there.

llvm-svn: 279650

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Constify some path in the bitcode writer (NFC)

llvm-svn: 279211

Don't import variadic functions

Summary:
This patch adds IsVariadicFunction bit to summary in order
to not import variadic functions. Inliner doesn't inline
variadic functions because it is hard to

Don't import variadic functions

Summary:
This patch adds IsVariadicFunction bit to summary in order
to not import variadic functions. Inliner doesn't inline
variadic functions because it is hard to reason about it.

This one small fix improves Importer by about 16%
(going from 86% to 100% of imported functions that are
inlined anywhere)
on some spec benchmarks like 'int' and others.

Reviewers: eraman, mehdi_amini, tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23339

llvm-svn: 278432

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[ThinLTO] Address review comments from PGO indirect call promotion (NFC)

Address a couple of post-commit review comments from r275707.

llvm-svn: 275867

[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

[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

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Add writeonly IR attribute

Summary:
This complements the earlier addition of IntrWriteMem and IntrWriteArgMem
LLVM intrinsic properties, see D18291.

Also start using the attribute for memset, memcp

Add writeonly IR attribute

Summary:
This complements the earlier addition of IntrWriteMem and IntrWriteArgMem
LLVM intrinsic properties, see D18291.

Also start using the attribute for memset, memcpy, and memmove intrinsics,
and remove their special-casing in BasicAliasAnalysis.

Reviewers: reames, joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18714

llvm-svn: 274485

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[codeview] Add DISubprogram::ThisAdjustment

Summary:
This represents the adjustment applied to the implicit 'this' parameter
in the prologue of a virtual method in the MS C++ ABI. The adjustment is

[codeview] Add DISubprogram::ThisAdjustment

Summary:
This represents the adjustment applied to the implicit 'this' parameter
in the prologue of a virtual method in the MS C++ ABI. The adjustment is
always zero unless multiple inheritance is involved.

This increases the size of DISubprogram by 8 bytes, unfortunately. The
adjustment really is a signed 32-bit integer. If this size increase is
too much, we could probably win it back by splitting out a subclass with
info specific to virtual methods (virtuality, vindex, thisadjustment,
containingType).

Reviewers: aprantl, dexonsmith

Subscribers: aaboud, amccarth, llvm-commits

Differential Revision: http://reviews.llvm.org/D21614

llvm-svn: 274325

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BitcodeWriter: Remove redundant (and incorrect) check for whether to emit module summary.

The function name Module::empty() is slightly misleading in that it
only tests for the presence of functions

BitcodeWriter: Remove redundant (and incorrect) check for whether to emit module summary.

The function name Module::empty() is slightly misleading in that it
only tests for the presence of functions in the module. However we
still want to emit the module summary if the module contains only
global variables or aliases. The presence of such entities can be
determined simply by checking the summary directly, as we are doing
below.

Differential Revision: http://reviews.llvm.org/D21669

llvm-svn: 273638

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IR: Allow metadata attachments on declarations, and fix lazy loaded metadata issue with globals.

This change is motivated by an upcoming change to the metadata representation
used for CFI. The indir

IR: Allow metadata attachments on declarations, and fix lazy loaded metadata issue with globals.

This change is motivated by an upcoming change to the metadata representation
used for CFI. The indirect function call checker needs type information for
external function declarations in order to correctly generate jump table
entries for such declarations. We currently associate such type information
with declarations using a global metadata node, but I plan [1] to move all
such metadata to global object attachments.

In bitcode, metadata attachments for function declarations appear in the
global metadata block. This seems reasonable to me because I expect metadata
attachments on declarations to be uncommon. In the long term I'd also expect
this to be the case for CFI, because we'd want to use some specialized bitcode
format for this metadata that could be read as part of the ThinLTO thin-link
phase, which would mean that it would not appear in the global metadata block.

To solve the lazy loaded metadata issue I was seeing with D20147, I use the
same bitcode representation for metadata attachments for global variables as I
do for function declarations. Since there's a use case for metadata attachments
in the global metadata block, we might as well use that representation for
global variables as well, at least until we have a mechanism for lazy loading
global variables.

In the assembly format, the metadata attachments appear after the "declare"
keyword in order to avoid a parsing ambiguity.

[1] http://lists.llvm.org/pipermail/llvm-dev/2016-June/100462.html

Differential Revision: http://reviews.llvm.org/D21052

llvm-svn: 273336

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IR: Introduce local_unnamed_addr attribute.

If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing un

IR: Introduce local_unnamed_addr attribute.

If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
the normal rule that the global must have a unique address can be broken without
being observable by the program by performing comparisons against the global's
address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
its own copy of the global if it requires one, and the copy in each linkage unit
must be the same)
- It is a constant or a function (which means that the program cannot observe that
the unique-address rule has been broken by writing to the global)

Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.

See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.html
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.

Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20348

llvm-svn: 272709

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[DebugInfo] Add calling convention support for DWARF and CodeView

Summary:
Now DISubroutineType has a 'cc' field which should be a DW_CC_ enum. If
it is present and non-zero, the backend will emit

[DebugInfo] Add calling convention support for DWARF and CodeView

Summary:
Now DISubroutineType has a 'cc' field which should be a DW_CC_ enum. If
it is present and non-zero, the backend will emit it as a
DW_AT_calling_convention attribute. On the CodeView side, we translate
it to the appropriate enum for the LF_PROCEDURE record.

I added a new LLVM vendor specific enum to the list of DWARF calling
conventions. DWARF does not appear to attempt to standardize these, so I
assume it's OK to do this until we coordinate with GCC on how to emit
vectorcall convention functions.

Reviewers: dexonsmith, majnemer, aaboud, amccarth

Subscribers: mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D21114

llvm-svn: 272197

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Add support for metadata attachments for global variables.

This patch adds an IR, assembly and bitcode representation for metadata
attachments for globals. Future patches will port existing features

Add support for metadata attachments for global variables.

This patch adds an IR, assembly and bitcode representation for metadata
attachments for globals. Future patches will port existing features to use
these new attachments.

Differential Revision: http://reviews.llvm.org/D20074

llvm-svn: 271348

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Avoid temporary vector for sorting in BitcodeWriter

As suggested by Duncan, fixup for r269634 and r269635

From: Mehdi Amini <[email protected]>
llvm-svn: 269715

ThinLTO: fix non-determinism in bitcode writing

Calls are initialized from a DenseMap. We can sort them using the
value id to recover some determinism during serialization.

From: mehdi_amini <mehdi

ThinLTO: fix non-determinism in bitcode writing

Calls are initialized from a DenseMap. We can sort them using the
value id to recover some determinism during serialization.

From: mehdi_amini <mehdi_amini@91177308-0d34-0410-b5e6-96231b3b80d8>
llvm-svn: 269638

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Revert "ThinLTO: fix non-determinism in bitcode writing"

This reverts commit r269634, bots are broken.

From: Mehdi Amini <[email protected]>
llvm-svn: 269637