Commit Graph

35720 Commits

Author SHA1 Message Date
Jessica Paquette
962b3ae659 [MachineOutliner] Outline functions by order of benefit
Mostly NFC, only change is the order of outlined function names.

Loop over the outlined functions instead of walking the candidate list.

This is a bit easier to understand. It's far more natural to create a function,
then replace all of its occurrences with calls than the other way around.

The functions outlined after this do not change, but their names will be
decided by their benefit. E.g, OUTLINED_FUNCTION_0 will now always be the
most beneficial function, rather than the first one seen.

This makes it easier to enforce an ordering on the outlined functions. So,
this also adds a test to make sure that the ordering works as expected.

llvm-svn: 348414
2018-12-05 21:36:04 +00:00
Krzysztof Parzyszek
8eb394d764 [Hexagon] Add intrinsics for Hexagon V66
llvm-svn: 348413
2018-12-05 21:14:51 +00:00
Krzysztof Parzyszek
13a9cf28a1 [Hexagon] Foundation of support for Hexagon V66
llvm-svn: 348407
2018-12-05 20:18:09 +00:00
Aditya Nandakumar
f75d4f329c [GISel]: Provide standard interface to observe changes in GISel passes
https://reviews.llvm.org/D54980

This provides a standard API across GISel passes to observe and notify
passes about changes (insertions/deletions/mutations) to MachineInstrs.
This patch also removes the recordInsertion method in MachineIRBuilder
and instead provides method to setObserver.

Reviewed by: vkeles.

llvm-svn: 348406
2018-12-05 20:14:52 +00:00
Jessica Paquette
4532b1f1e8 [MachineOutliner][NFC] Use getOccurrenceCount() in getNotOutlinedCost()
Some more gardening.

llvm-svn: 348392
2018-12-05 18:17:40 +00:00
Jessica Paquette
430ca90d7e [MachineOutliner][NFC] Make getters in MachineOutliner.h const
Just some refactoring. A few of the getters in OutlinedFunction weren't const.

llvm-svn: 348391
2018-12-05 18:12:52 +00:00
Jessica Paquette
34b618bf7e [MachineOutliner][NFC] Don't create outlined sequence from integer mapping
Some gardening/refactoring.

It's cleaner to copy the instructions into the MachineFunction using the first
candidate instead of going to the mapper.

Also, by doing this we can remove the Seq member from OutlinedFunction entirely.

llvm-svn: 348390
2018-12-05 17:57:33 +00:00
Brian Gesiak
f240c4d42a Revert "[IR] Add NODISCARD to attribute functions"
Revert https://reviews.llvm.org/D55217 due to warnings-turned-into-errors in
AMGPU targets. I'll fix the warnings first, then re-commit this patch.

llvm-svn: 348375
2018-12-05 15:56:09 +00:00
Brian Gesiak
df843bddfb [IR] Add NODISCARD to attribute functions
Summary:
Many functions on `llvm::AttributeList` and `llvm::AttributeSet` are
documented with "returns a new {list,set} because attribute
{lists,sets} are immutable." This documentation can be aided by the
addition of an attribute, `LLVM_NODISCARD`. Adding this prevents
unsuspecting users of the API from expecting
`AttributeList::setAttributes` from modifying the underlying list.

At the very least, it would have saved me a few hours of debugging, since I
had been doing just that! I had a bug in my program where I was calling
`setAttributes` but then passing in the unmutated `AttributeList`.
I tried adding LLVM_NODISCARD and confirmed that it would have made my bug
immediately obvious.

Reviewers: rnk, javed.absar

Reviewed By: rnk

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D55217

llvm-svn: 348372
2018-12-05 15:33:55 +00:00
Simon Pilgrim
b97393fae5 [DAG] Add fshl/fshr tblgen opcodes
Missed off from https://reviews.llvm.org/D54698

llvm-svn: 348358
2018-12-05 11:55:33 +00:00
Simon Pilgrim
180639afe5 [SelectionDAG] Initial support for FSHL/FSHR funnel shift opcodes (PR39467)
This is an initial patch to add a minimum level of support for funnel shifts to the SelectionDAG and to begin wiring it up to the X86 SHLD/SHRD instructions.

Some partial legalization code has been added to handle the case for 'SlowSHLD' where we want to expand instead and I've added a few DAG combines so we don't get regressions from the existing DAG builder expansion code.

Differential Revision: https://reviews.llvm.org/D54698

llvm-svn: 348353
2018-12-05 11:12:12 +00:00
Vitaly Buka
8076c57fd2 [asan] Add clang flag -fsanitize-address-use-odr-indicator
Reviewers: eugenis, m.ostapenko, ygribov

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D55157

llvm-svn: 348327
2018-12-05 01:44:31 +00:00
Michael Kruse
f57bfd3d9f [ADT] Add zip_longest iterators.
Like the already existing zip_shortest/zip_first iterators, zip_longest
iterates over multiple iterators at once, but has as many iterations as
the longest sequence.

This means some iterators may reach the end before others do.
zip_longest uses llvm::Optional's None value to mark a
past-the-end value.

zip_longest is not reverse-iteratable because the tuples iterated over
would be different for different length sequences (IMHO for the same
reason neither zip_shortest nor zip_first should be reverse-iteratable;
one can still reverse the ranges individually if that's the expected
behavior).

In contrast to zip_shortest/zip_first, zip_longest tuples contain
rvalues instead of references. This is because llvm::Optional cannot
contain reference types and the value-initialized default does not have
a memory location a reference could point to.

The motivation for these iterators is to use C++ foreach to compare two
lists of ordered attributes in D48100 (SemaOverload.cpp and
ASTReaderDecl.cpp).

Idea by @hfinkel.

This re-commits r348301 which was reverted by r348303.
The compilation error by gcc 5.4 was resolved using make_tuple in the in
the initializer_list.
The compileration error by msvc14 was resolved by splitting
ZipLongestValueType (which already was a workaround for msvc15) into
ZipLongestItemType and ZipLongestTupleType.

Differential Revision: https://reviews.llvm.org/D48348

llvm-svn: 348323
2018-12-05 00:31:54 +00:00
Zachary Turner
68b6a46fed Remove the hash code from CVRecord.
This is no longer used and is just taking up space in the structure.
Heap allocation of this structure is on the critical path, so space
actually matters.

llvm-svn: 348318
2018-12-04 23:56:07 +00:00
Zachary Turner
7c6b19f49b [PDB] Emit S_UDT records in LLD.
Previously these were dropped.  We now understand them sufficiently
well to start emitting them.  From the debugger's perspective, this
now enables us to have debug info about typedefs (both global and
function-locally scoped)

Differential Revision: https://reviews.llvm.org/D55228

llvm-svn: 348306
2018-12-04 21:48:46 +00:00
Michael Kruse
4db904b3bb Revert "[ADT] Add zip_longest iterators"
This reverts commit r348301.

Compilation fails on buildbots with older versions of gcc and msvc.

llvm-svn: 348303
2018-12-04 21:38:55 +00:00
Michael Kruse
e6899bf002 [ADT] Add zip_longest iterators
Like the already existing zip_shortest/zip_first iterators, zip_longest
iterates over multiple iterators at once, but has as many iterations as
the longest sequence.

This means some iterators may reach the end before others do.
zip_longest uses llvm::Optional's None value to mark a
past-the-end value.

zip_longest is not reverse-iteratable because the tuples iterated over
would be different for different length sequences (IMHO for the same
reason neither zip_shortest nor zip_first should be reverse-iteratable;
one can still reverse the ranges individually if that's the expected
behavior).

In contrast to zip_shortest/zip_first, zip_longest tuples contain
rvalues instead of references. This is because llvm::Optional cannot
contain reference types and the value-initialized default does not have
a memory location a reference could point to.

The motivation for these iterators is to use C++ foreach to compare two
lists of ordered attributes in D48100 (SemaOverload.cpp and
ASTReaderDecl.cpp).

Idea by @hfinkel.

Differential Revision: https://reviews.llvm.org/D48348

llvm-svn: 348301
2018-12-04 21:06:16 +00:00
Sanjay Patel
3d5bb15a1d [CmpInstAnalysis] fix function signature for ICmp code to predicate; NFC
The old function underspecified the return type, took an unused parameter,
and had a misleading name.

llvm-svn: 348292
2018-12-04 18:53:27 +00:00
Matt Arsenault
43153024ab MIR: Add method to stop after specific runs of passes
Currently if you use -{start,stop}-{before,after}, it picks
the first instance with the matching pass name. If you run
the same pass multiple times, there's no way to distinguish them.

Allow specifying a run index wih ,N to specify which you mean.

llvm-svn: 348285
2018-12-04 17:45:12 +00:00
Ilya Biryukov
449a7f0dbb Revert "Adapt gcov to changes in CFE."
This reverts commit r348203.
Reason: this produces absolute paths in .gcno files, breaking us
internally as we rely on them being consistent with the filenames passed
in the command line.

Also reverts r348157 and r348155 to account for revert of r348154 in
clang repository.

llvm-svn: 348279
2018-12-04 16:30:31 +00:00
Simon Pilgrim
0add090e24 [TargetLowering] expandFP_TO_UINT - avoid FPE due to out of range conversion (PR17686)
PR17686 demonstrates that for some targets FP exceptions can fire in cases where the FP_TO_UINT is expanded using a FP_TO_SINT instruction.

The existing code converts both the inrange and outofrange cases using FP_TO_SINT and then selects the result, this patch changes this for 'strict' cases to pre-select the FP_TO_SINT input and the offset adjustment.

The X87 cases don't need the strict flag but generates much nicer code with it....

Differential Revision: https://reviews.llvm.org/D53794

llvm-svn: 348251
2018-12-04 11:21:30 +00:00
Lang Hames
eca6d4b638 [ExecutionEngine] Change NotifyObjectEmitted/NotifyObjectFreed API.
This patch renames both methods (NotifyObjectEmitted -> notifyObjectLoaded, and
NotifyObjectFreed -> notifyObjectFreed), adds an abstract "ObjectKey" (uint64_t)
parameter to notifyObjectLoaded, and replaces the ObjectFile parameter for
notifyObjectFreed with an ObjectKey. Using an ObjectKey to track identify
events, rather than a reference to the ObjectFile, allows us to free the
ObjectFile after notifyObjectLoaded is called, saving memory.

https://reviews.llvm.org/D53773

llvm-svn: 348223
2018-12-04 00:55:15 +00:00
Krzysztof Parzyszek
44c1f81b27 [Hexagon] Switch to auto-generated intrinsic definitions and patterns
llvm-svn: 348206
2018-12-03 22:40:36 +00:00
Vedant Kumar
d129569e34 [CodeExtractor] Split PHI nodes with incoming values from outlined region (PR39433)
If a PHI node out of extracted region has multiple incoming values from it,
split this PHI on two parts. First PHI has incomings only from region and
extracts with it (they are placed to the separate basic block that added to the
list of outlined), and incoming values in original PHI are replaced by first
PHI. Similar solution is already used in CodeExtractor for PHIs in entry block
(severSplitPHINodes method). It covers PR39433 bug.

Patch by Sergei Kachkov!

Differential Revision: https://reviews.llvm.org/D55018

llvm-svn: 348205
2018-12-03 22:40:21 +00:00
Artem Dergachev
18de5e4657 BumpPtrAllocator: Add a couple of convenient wrappers around identifyObject().
This allows obtaining smaller, more readable identifiers
in a more comfortable way.

Differential Revision: https://reviews.llvm.org/D54486

llvm-svn: 348197
2018-12-03 22:05:24 +00:00
Jake Ehrlich
8ad7779071 [llvm-objcopy] Add --build-id-link-dir flag
This flag does not exist in GNU objcopy but has a major use case.
Debugging tools support the .build-id directory structure to find
debug binaries. There is no easy way to build this structure up
however. One way to do it is by using llvm-readelf and some crazy
shell magic. This implements the feature directly. It is most often
the case that you'll want to strip a file and send the original to
the .build-id directory but if you just want to send a file to the
.build-id directory you can copy to /dev/null instead.

Differential Revision: https://reviews.llvm.org/D54384

llvm-svn: 348174
2018-12-03 19:49:23 +00:00
Armando Montanez
1e4b3709bb [llvm-tapi] initial commit, supports ELF text stubs
http://lists.llvm.org/pipermail/llvm-dev/2018-September/126472.html

TextAPI is a library and accompanying tool that allows conversion between binary shared object stubs and textual counterparts. The motivations and uses cases for this are explained thoroughly in the llvm-dev proposal [1]. This initial commit proposes a potential structure for the TAPI library, also including support for reading/writing text-based ELF stubs (.tbe) in addition to preliminary support for reading binary ELF files. The goal for this patch is to ensure the project architecture appropriately welcomes integration of Mach-O stubbing from Apple's TAPI [2].

Added:

 - TextAPI library
 - .tbe read support
 - .tbe write (to raw_ostream) support

[1] http://lists.llvm.org/pipermail/llvm-dev/2018-September/126472.html
[2] https://github.com/ributzka/tapi

Differential Revision: https://reviews.llvm.org/D53051

llvm-svn: 348170
2018-12-03 19:30:52 +00:00
Craig Topper
dd953631fa [X86] Fix bad formatting. NFC
llvm-svn: 348164
2018-12-03 18:58:57 +00:00
Adrian Prantl
ff90e627ba Fix non-modular build.
llvm-svn: 348157
2018-12-03 18:07:03 +00:00
Adrian Prantl
0f873eb80a Update Diagnostic handling for changes in CFE.
The clang frontend no longer emits the current working directory for
DIFiles containing an absolute path in the filename: and will move the
common prefix between current working directory and the file into the
directory: component.

https://reviews.llvm.org/D55085

llvm-svn: 348155
2018-12-03 17:55:29 +00:00
Sanjay Patel
472652ef68 [CmpInstAnalysis] fix formatting; NFC
There are potential improvements to the structure of this API
raised by D54994, but remove some cosmetic blemishes before
making any functional changes.

llvm-svn: 348149
2018-12-03 15:48:30 +00:00
Pablo Barrio
a17f855698 [AArch64] Add command-line option for SSBS
Summary:
SSBS (Speculative Store Bypass Safe) is only mandatory from 8.5
onwards but is optional from Armv8.0-A. This patch adds a command
line option to enable SSBS, as it was previously only possible to
enable by selecting -march=armv8.5-a.

Similar patch upstream in GNU binutils:
https://sourceware.org/ml/binutils/2018-09/msg00274.html

Reviewers: olista01, samparker, aemerson

Reviewed By: samparker

Subscribers: javed.absar, kristof.beyls, kristina, llvm-commits

Differential Revision: https://reviews.llvm.org/D54629

llvm-svn: 348137
2018-12-03 14:00:47 +00:00
Oliver Stannard
4cf35b4ab0 [ARM][MC] Move information about variadic register defs into tablegen
Currently, variadic operands on an MCInst are assumed to be uses,
because they come after the defs. However, this is not always the case,
for example the Arm/Thumb LDM instructions write to a variable number of
registers.

This adds a property of instruction definitions which can be used to
mark variadic operands as defs. This only affects MCInst, because
MachineInstruction already tracks use/def per operand in each instance
of the instruction, so can already represent this.

This property can then be checked in MCInstrDesc, allowing us to remove
some special cases in ARMAsmParser::isITBlockTerminator.

Differential revision: https://reviews.llvm.org/D54853

llvm-svn: 348114
2018-12-03 10:32:42 +00:00
Oliver Stannard
c588110f13 [ARM][Asm] Debug trace for the processInstruction loop
In the Arm assembly parser, we first match an instruction, then call
processInstruction to possibly change it to a different encoding, to
match rules in the architecture manual which can't be expressed by the
table-generated matcher.

This adds debug printing so that this process is visible when using the
-debug option.

To support this, I've added a new overload of MCInst::dump_pretty which
takes the opcode name as a StringRef, since we don't have an InstPrinter
instance in the assembly parser. Instead, we can get the same
information directly from the MCInstrInfo.

Differential revision: https://reviews.llvm.org/D54852

llvm-svn: 348113
2018-12-03 10:21:28 +00:00
Sanjay Patel
7d82d37854 [ValueTracking] add helper function for testing implied condition; NFCI
We were duplicating code around the existing isImpliedCondition() that
checks for a predecessor block/dominating condition, so make that a
wrapper call.

llvm-svn: 348088
2018-12-02 13:26:03 +00:00
Simon Pilgrim
102854f4d4 [TTI] Reduction costs only need to include a single extract element cost (REAPPLIED)
We were adding the entire scalarization extraction cost for reductions, which returns the total cost of extracting every element of a vector type.

For reductions we don't need to do this - we just need to extract the 0'th element after the reduction pattern has completed.

Fixes PR37731

Rebased and reapplied after being reverted in rL347541 due to PR39774 - which was fixed by D54955/rL347759 and D55017/rL347997

Differential Revision: https://reviews.llvm.org/D54585

llvm-svn: 348076
2018-12-01 14:18:31 +00:00
Reid Kleckner
cada498038 [codeview] Remove dead macros for codeview record serialization, NFC
These weren't needed when we went to the yaml IO style of serialization,
which has "mapOptional".

llvm-svn: 348052
2018-11-30 23:32:11 +00:00
Nicolai Haehnle
a9cc92c247 AMDGPU: Fix various issues around the VirtReg2Value mapping
Summary:
The VirtReg2Value mapping is crucial for getting consistently
reliable divergence information into the SelectionDAG. This
patch fixes a bunch of issues that lead to incorrect divergence
info and introduces tight assertions to ensure we don't regress:

1. VirtReg2Value is generated lazily; there were some cases where
   a lookup was performed before all relevant virtual registers were
   created, leading to an out-of-sync mapping. Those cases were:

  - Complex code to lower formal arguments that generated CopyFromReg
    nodes from live-in registers (fixed by never querying the mapping
    for live-in registers).

  - Code that generates CopyToReg for formal arguments that are used
    outside the entry basic block (fixed by never querying the
    mapping for Register nodes, which don't need the divergence info
    anyway).

2. For complex values that are lowered to a sequence of registers,
   all registers must be reflected in the VirtReg2Value mapping.

I am not adding any new tests, since I'm not actually aware of any
bugs that these problems are causing with trunk as-is. However,
I recently added a test case (in r346423) which fails when D53283 is
applied without this change. Also, the new assertions should provide
most of the effective test coverage.

There is one test change in sdwa-peephole.ll. The underlying issue
is that since the divergence info is now correct, the DAGISel will
select V_OR_B32 directly instead of S_OR_B32. This leads to an extra
COPY which affects the behavior of MachineLICM in a way that ends up
with the S_MOV_B32 with the constant in a different basic block than
the V_OR_B32, which is presumably what defeats the peephole.

Reviewers: alex-t, arsenm, rampitec

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D54340

llvm-svn: 348049
2018-11-30 22:55:29 +00:00
Nicolai Haehnle
56d0ed2a50 [DA] GPUDivergenceAnalysis for unstructured GPU kernels
Summary:
This is patch #3 of the new DivergenceAnalysis

  <https://lists.llvm.org/pipermail/llvm-dev/2018-May/123606.html>

The GPUDivergenceAnalysis is intended to eventually supersede the existing
LegacyDivergenceAnalysis. The existing LegacyDivergenceAnalysis produces
incorrect results on unstructured Control-Flow Graphs:

  <https://bugs.llvm.org/show_bug.cgi?id=37185>

This patch adds the option -use-gpu-divergence-analysis to the
LegacyDivergenceAnalysis to turn it into a transparent wrapper for the
GPUDivergenceAnalysis.

Reviewers: nhaehnle

Reviewed By: nhaehnle

Subscribers: jholewinski, jvesely, jfb, llvm-commits, alex-t, sameerds, arsenm, nhaehnle

Differential Revision: https://reviews.llvm.org/D53493

llvm-svn: 348048
2018-11-30 22:55:20 +00:00
Saleem Abdulrasool
5842df93dd Support: use std::is_trivially_copyable on MSVC
MSVC 2015 and newer have std::is_trivially_copyable available for use.
We should prefer that over the std::is_class to get this check be
correct.

llvm-svn: 348042
2018-11-30 22:13:42 +00:00
Yonghong Song
f487334622 Revert "[BTF] Add BTF DebugInfo"
This reverts commit 9c6b970db8bc63b28ce58a129bb1580a6a3c6caf.

llvm-svn: 348004
2018-11-30 16:54:43 +00:00
Yonghong Song
81b77e9159 [BTF] Add BTF DebugInfo
This patch adds BPF Debug Format (BTF) as a standalone
LLVM debuginfo. The BTF related sections are directly
generated from IR. The BTF debuginfo is generated
only when the compilation target is BPF.

What is BTF?
============

First, the BPF is a linux kernel virtual machine
and widely used for tracing, networking and security.
  https://www.kernel.org/doc/Documentation/networking/filter.txt
  https://cilium.readthedocs.io/en/v1.2/bpf/

BTF is the debug info format for BPF, introduced in the below
linux patch
  69b693f0ae (diff-06fb1c8825f653d7e539058b72c83332)
in the patch set mentioned in the below lwn article.
  https://lwn.net/Articles/752047/

The BTF format is specified in the above github commit.
In summary, its layout looks like
  struct btf_header
  type subsection (a list of types)
  string subsection (a list of strings)

With such information, the kernel and the user space is able to
pretty print a particular bpf map key/value. One possible example below:
  Withtout BTF:
    key: [ 0x01, 0x01, 0x00, 0x00 ]
  With BTF:
    key: struct t { a : 1; b : 1; c : 0}
  where struct is defined as
    struct t { char a; char b; short c; };

How BTF is generated?
=====================

Currently, the BTF is generated through pahole.
  https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=68645f7facc2eb69d0aeb2dd7d2f0cac0feb4d69
and available in pahole v1.12
  https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=4a21c5c8db0fcd2a279d067ecfb731596de822d4

Basically, the bpf program needs to be compiled with -g with
dwarf sections generated. The pahole is enhanced such that
a .BTF section can be generated based on dwarf. This format
of the .BTF section matches the format expected by
the kernel, so a bpf loader can just take the .BTF section
and load it into the kernel.
  8a138aed4a

The .BTF section layout is also specified in this patch:
with file include/llvm/BinaryFormat/BTF.h.

What use cases this patch tries to address?
===========================================

Currently, only the bpf instruction stream is required to
pass to the kernel. The kernel verifies it, jits it if configured
to do so, attaches it to a particular kernel attachment point,
and later executes when a particular event happens.

This patch tries to expand BTF to support two more use cases below:
  (1). BPF supports subroutine calls.
       During performance analysis, it would be good to
       differentiate which call is hot instead of just
       providing a virtual address. This would require to
       pass a unique identifier for each subroutine to
       the kernel, the subroutine name is a natual choice.
  (2). If a particular jitted instruction is hot, we want
       user to know which source line this jitted instruction
       belongs to. This would require the source information
       is available to various profiling tools.

Note that in a single ELF file,
  . there may be multiple loadable bpf programs,
  . for a particular to-be-loaded bpf instruction stream,
    its instructions may come from multiple PROGBITS sections,
    the bpf loader needs to merge them together to a single
    consecutive insn stream before loading to the kernel.
For example:
  section .text: subroutines funcFoo
  section _progA: calling funcFoo
  section _progB: calling funcFoo
The bpf loader could construct two loadable bpf instruction
streams and load them into the kernel:
  . _progA funcFoo
  . _progB funcFoo
So per ELF section function offset and instruction offset
will need to be adjusted before passing to the kernel, and
the kernel essentially expect only one code section regardless
of how many in the ELF file.

What do we propose and Why?
===========================

To support the above two use cases, we propose to
add an additional section, .BTF.ext, to the ELF file
which is the input of the bpf loader. A different section
is preferred since loader may need to manipulate it before
loading part of its data to the kernel.

The .BTF.ext section has a similar header to the .BTF section
and it contains two subsections for func_info and line_info.
  . the func_info maps the func insn byte offset to a func
    type in the .BTF type subsection.
  . the line_info maps the insn byte offset to a line info.
  . both func_info and line_info subsections are organized
    by ELF PROGBITS AX sections.

pahole is not a good place to implement .BTF.ext as
pahole is mostly for structure hole information and more
importantly, we want to pass the actual code to the kernel.
  . bpf program typically is small so storage overhead
    should be small.
  . in bpf land, it is totally possible that
    an application loads the bpf program into the
    kernel and then that application quits, so
    holding debug info by the user space application
    is not practical as you may not even know who
    loads this bpf program.
  . having source codes directly kept by kernel
    would ease deployment since the original source
    code does not need ship on every hosts and
    kernel-devel package does not need to be
    deployed even if kernel headers are used.

LLVM is a good place to implement.
  . The only reliable time to get the source code is
    during compilation time. This will result in both more
    accurate information and easier deployment as
    stated in the above.
  . Another consideration is for JIT. The project like bcc
    (https://github.com/iovisor/bcc)
    use MCJIT to compile a C program into bpf insns and
    load them to the kernel. The llvm generated BTF sections
    will be readily available for such cases as well.

Design and implementation of emiting .BTF/.BTF.ext sections
===========================================================

The BTF debuginfo format is defined. Both .BTF and .BTF.ext
sections are generated directly from IR when both
"-target bpf" and "-g" are specified. Note that
dwarf sections are still generated as dwarf is used
by user space tools like llvm-objdump etc. for BPF target.

This patch also contains tests to verify generated
.BTF and .BTF.ext sections for all supported types, func_info
and line_info subsections. The patch is also tested
against linux kernel bpf sample tests and selftests.

Signed-off-by: Yonghong Song <yhs@fb.com>

Differential Revision: https://reviews.llvm.org/D53736

llvm-svn: 347999
2018-11-30 16:22:59 +00:00
Nicolai Haehnle
445b0b6260 TableGen/ISel: Allow PatFrag predicate code to access captured operands
Summary:
This simplifies writing predicates for pattern fragments that are
automatically re-associated or commuted.

For example, a followup patch adds patterns for fragments of the form
(add (shl $x, $y), $z) to the AMDGPU backend. Such patterns are
automatically commuted to (add $z, (shl $x, $y)), which makes it basically
impossible to refer to $x, $y, and $z generically in the PredicateCode.

With this change, the PredicateCode can refer to $x, $y, and $z simply
as `Operands[i]`.

Test confirmed that there are no changes to any of the generated files
when building all (non-experimental) targets.

Change-Id: I61c00ace7eed42c1d4edc4c5351174b56b77a79c

Reviewers: arsenm, rampitec, RKSimon, craig.topper, hfinkel, uweigand

Subscribers: wdng, tpr, llvm-commits

Differential Revision: https://reviews.llvm.org/D51994

llvm-svn: 347992
2018-11-30 14:15:13 +00:00
Renato Golin
135e72e1b9 Add a new reduction pattern match
Adding a new reduction pattern match for vectorizing code similar
to TSVC s3111:

for (int i = 0; i < N; i++)
  if (a[i] > b)
    sum += a[i];

This patch adds support for fadd, fsub and fmull, as well as multiple
branches and different (but compatible) instructions (ex. add+sub) in
different branches.

The difference from the previous patch(https://reviews.llvm.org/D49168)
is as follows:
 - Added check of fast-math property of fp-instruction to the
   previous patch
 - Fix/add some pattern for if-reduction.ll


Differential Revision: https://reviews.llvm.org/D54464

Patch by Takahiro Miyoshi <takahiro.miyoshi@linaro.org>
     and Masakazu Ueno <masakazu.ueno@linaro.org>

llvm-svn: 347989
2018-11-30 13:40:10 +00:00
Alex Bradbury
e0e62e97df [TargetLowering][RISCV] Introduce isSExtCheaperThanZExt hook and implement for RISC-V
DAGTypeLegalizer::PromoteSetCCOperands currently prefers to zero-extend 
operands when it is able to do so. For some targets this is more expensive 
than a sign-extension, which is also a valid choice. Introduce the 
isSExtCheaperThanZExt hook and use it in the new SExtOrZExtPromotedInteger 
helper. On RISC-V, we prefer sign-extension for FromTy == MVT::i32 and ToTy == 
MVT::i64, as it can be performed using a single instruction.

Differential Revision: https://reviews.llvm.org/D52978

llvm-svn: 347977
2018-11-30 09:56:54 +00:00
Alex Bradbury
66d9a752b9 [RISCV] Implement codegen for cmpxchg on RV32IA
Utilise a similar ('late') lowering strategy to D47882. The changes to 
AtomicExpandPass allow this strategy to be utilised by other targets which 
implement shouldExpandAtomicCmpXchgInIR.

All cmpxchg are lowered as 'strong' currently and failure ordering is ignored. 
This is conservative but correct.

Differential Revision: https://reviews.llvm.org/D48131

llvm-svn: 347914
2018-11-29 20:43:42 +00:00
David Stuttard
c6603861d8 Revert r347871 "Fix: Add support for TFE/LWE in image intrinsic"
Also revert fix r347876

One of the buildbots was reporting a failure in some relevant tests that I can't
repro or explain at present, so reverting until I can isolate.

llvm-svn: 347911
2018-11-29 20:14:17 +00:00
Artur Pilipenko
eba2365f23 Introduce MaxUsesToExplore argument to capture tracking
Currently CaptureTracker gives up if it encounters a value with more than 20 
uses. The motivation for this cap is to keep it relatively cheap for 
BasicAliasAnalysis use case, where the results can't be cached. Although, other 
clients of CaptureTracker might be ok with higher cost. This patch introduces an 
argument for PointerMayBeCaptured functions to specify the max number of uses to 
explore. The motivation for this change is a downstream user of CaptureTracker, 
but I believe upstream clients of CaptureTracker might also benefit from more 
fine grained cap.

Reviewed By: hfinkel

Differential Revision: https://reviews.llvm.org/D55042

llvm-svn: 347910
2018-11-29 20:08:12 +00:00
Volkan Keles
4fe0080984 [GlobalISel] LegalizationArtifactCombiner: Combine aext([asz]ext x) -> [asz]ext x
Summary:
Replace `aext([asz]ext x)` with `aext/sext/zext x` in order to
reduce the number of instructions generated to clean up some
legalization artifacts.

Reviewers: aditya_nandakumar, dsanders, aemerson, bogner

Reviewed By: aemerson

Subscribers: rovka, kristof.beyls, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D54174

llvm-svn: 347893
2018-11-29 18:19:24 +00:00
Serge Guelton
644aa88235 Avoid redundant reference to isPodLike in SmallVect/Optional implementation
NFC, preparatory work for isPodLike cleaning.

Differential Revision: https://reviews.llvm.org/D55005

llvm-svn: 347890
2018-11-29 17:21:54 +00:00