[IR] Allow attributes with global variables

This patch extends llvm-ir to allow attributes to be set on global variables.
An RFC was sent out earlier by my colleague James Molloy: http://lists.llvm.

[IR] Allow attributes with global variables

This patch extends llvm-ir to allow attributes to be set on global variables.
An RFC was sent out earlier by my colleague James Molloy: http://lists.llvm.org/pipermail/cfe-dev/2017-March/053100.html
A key part of that proposal was to extend LLVM-IR to carry attributes on global variables.
This generic feature could be useful for multiple purposes.
In our present context, it would be useful to carry user specified sections for bss/rodata/data.

Reviewed by: Jonathan Roelofs, Reid Kleckner
Differential Revision: https://reviews.llvm.org/D32009

llvm-svn: 302794

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Re-apply r302108, "IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI."
with a fix for the clang backend.

llvm-svn: 302176

Revert "IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI."

This reverts commit r302108. This causes crash in clang bootstrap with LTO.

Contacted the auther in the or

Revert "IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI."

This reverts commit r302108. This causes crash in clang bootstrap with LTO.

Contacted the auther in the original commit.

llvm-svn: 302140

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IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI.

When profiling a no-op incremental link of Chromium I found that the functions
computeImportForFunction and computeD

IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI.

When profiling a no-op incremental link of Chromium I found that the functions
computeImportForFunction and computeDeadSymbols were consuming roughly 10% of
the profile. The goal of this change is to improve the performance of those
functions by changing the map lookups that they were previously doing into
pointer dereferences.

This is achieved by changing the ValueInfo data structure to be a pointer to
an element of the global value map owned by ModuleSummaryIndex, and changing
reference lists in the GlobalValueSummary to hold ValueInfos instead of GUIDs.
This means that a ValueInfo will take a client directly to the summary list
for a given GUID.

Differential Revision: https://reviews.llvm.org/D32471

llvm-svn: 302108

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Fix a pessimising move warning.

llvm-svn: 301852

Bitcode: Make the summary reader responsible for merging. NFCI.

This is to prepare for an upcoming change which uses pointers instead of
GUIDs to represent references.

Differential Revision: https:

Bitcode: Make the summary reader responsible for merging. NFCI.

This is to prepare for an upcoming change which uses pointers instead of
GUIDs to represent references.

Differential Revision: https://reviews.llvm.org/D32469

llvm-svn: 301843

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Object: Remove ModuleSummaryIndexObjectFile class.

Differential Revision: https://reviews.llvm.org/D32195

llvm-svn: 301832

Remove set but unused variable in BitcodeReader.cpp. NFC.

llvm-svn: 301713

Add speculatable function attribute

This attribute tells the optimizer that the function may be speculated.

Patch by Tom Stellard

llvm-svn: 301680

Bitcode: Do not remove empty summary entries when reading a per-module summary.

This became no longer necessary after D19462 landed, and will be incompatible
with an upcoming change to the summary d

Bitcode: Do not remove empty summary entries when reading a per-module summary.

This became no longer necessary after D19462 landed, and will be incompatible
with an upcoming change to the summary data structures that changes how we
represent references.

llvm-svn: 301660

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PR32382: Fix emitting complex DWARF expressions.

The DWARF specification knows 3 kinds of non-empty simple location
descriptions:
1. Register location descriptions
- describe a variable in a regis

PR32382: Fix emitting complex DWARF expressions.

The DWARF specification knows 3 kinds of non-empty simple location
descriptions:
1. Register location descriptions
- describe a variable in a register
- consist of only a DW_OP_reg
2. Memory location descriptions
- describe the address of a variable
3. Implicit location descriptions
- describe the value of a variable
- end with DW_OP_stack_value & friends

The existing DwarfExpression code is pretty much ignorant of these
restrictions. This used to not matter because we only emitted very
short expressions that we happened to get right by accident. This
patch makes DwarfExpression aware of the rules defined by the DWARF
standard and now chooses the right kind of location description for
each expression being emitted.

This would have been an NFC commit (for the existing testsuite) if not
for the way that clang describes captured block variables. Based on
how the previous code in LLVM emitted locations, DW_OP_deref
operations that should have come at the end of the expression are put
at its beginning. Fixing this means changing the semantics of
DIExpression, so this patch bumps the version number of DIExpression
and implements a bitcode upgrade.

There are two major changes in this patch:

I had to fix the semantics of dbg.declare for describing function
arguments. After this patch a dbg.declare always takes the *address*
of a variable as the first argument, even if the argument is not an
alloca.

When lowering a DBG_VALUE, the decision of whether to emit a register
location description or a memory location description depends on the
MachineLocation — register machine locations may get promoted to
memory locations based on their DIExpression. (Future) optimization
passes that want to salvage implicit debug location for variables may
do so by appending a DW_OP_stack_value. For example:
DBG_VALUE, [RBP-8] --> DW_OP_fbreg -8
DBG_VALUE, RAX --> DW_OP_reg0 +0
DBG_VALUE, RAX, DIExpression(DW_OP_deref) --> DW_OP_reg0 +0

All testcases that were modified were regenerated from clang. I also
added source-based testcases for each of these to the debuginfo-tests
repository over the last week to make sure that no synchronized bugs
slip in. The debuginfo-tests compile from source and run the debugger.

https://bugs.llvm.org/show_bug.cgi?id=32382
<rdar://problem/31205000>

Differential Revision: https://reviews.llvm.org/D31439

llvm-svn: 300522

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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 COMDA

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

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Bitcode: Move version and global value module code parsers to separate functions. NFCI.

This will make it easier to teach this code about the string table.

Differential Revision: https://reviews.ll

Bitcode: Move version and global value module code parsers to separate functions. NFCI.

This will make it easier to teach this code about the string table.

Differential Revision: https://reviews.llvm.org/D31828

llvm-svn: 300099

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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

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

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Bitcode: Merge the code for parsing global value module codes in the summary bitcode reader. NFCI.

This code will need to be taught to handle string tables and it's better if
there is only one copy

Bitcode: Merge the code for parsing global value module codes in the summary bitcode reader. NFCI.

This code will need to be taught to handle string tables and it's better if
there is only one copy of it.

Differential Revision: https://reviews.llvm.org/D31829

llvm-svn: 299886

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Bitcode: Do not create FNENTRYs for aliases of functions.

There doesn't seem to be any point in doing this.

Differential Revision: https://reviews.llvm.org/D31691

llvm-svn: 299694

Bitcode: Remove reader support for MODULE_CODE_PURGEVALS.

Support for writing this module code was removed in r73220, which was well
before the LLVM 3.0 release, so we do not need to be able to unde

Bitcode: Remove reader support for MODULE_CODE_PURGEVALS.

Support for writing this module code was removed in r73220, which was well
before the LLVM 3.0 release, so we do not need to be able to understand it
for backwards compatibility.

Differential Revision: https://reviews.llvm.org/D31563

llvm-svn: 299370

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[IR] Add AllowContract to FastMathFlags

-ffp-contract=fast does not currently work with LTO because it's passed as a
TargetOption to the backend rather than in the IR. This adds it to
FastMathFlags.

[IR] Add AllowContract to FastMathFlags

-ffp-contract=fast does not currently work with LTO because it's passed as a
TargetOption to the backend rather than in the IR. This adds it to
FastMathFlags.

This is toward fixing PR25721

Differential Revision: https://reviews.llvm.org/D31164

llvm-svn: 298939

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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 ParamAttr

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

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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

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

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Address Mehdi's post-commit review comments on r294795.

llvm-svn: 294822

IR: Function summary extensions for whole-program devirtualization pass.

The summary information includes all uses of llvm.type.test and
llvm.type.checked.load intrinsics that can be used to devirtu

IR: Function summary extensions for whole-program devirtualization pass.

The summary information includes all uses of llvm.type.test and
llvm.type.checked.load intrinsics that can be used to devirtualize calls,
including any constant arguments for virtual constant propagation.

Differential Revision: https://reviews.llvm.org/D29734

llvm-svn: 294795

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Revert "[ThinLTO] Add an auto-hide feature"

This reverts commit r293970.

After more discussion, this belongs to the linker side and
there is no added value to do it at this level.

llvm-svn: 293993

[ThinLTO] Add an auto-hide feature

When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instan

[ThinLTO] Add an auto-hide feature

When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.

This is a recommit of r293912 after fixing build failures,
and a recommit of r293918 after fixing LLD tests.

Differential Revision: https://reviews.llvm.org/D28978

llvm-svn: 293970

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Revert "[ThinLTO] Add an auto-hide feature"

This reverts commit r293918, one lld test does not pass.

llvm-svn: 293961