Summary:
When we have an aliasee that is linkonce, while we can't convert
the non-prevailing copies to available_externally, we still need to
convert the prevailing copy to weak. If a reference to the aliasee
is exported, not converting a copy to weak will result in undefined
references when the linkonce is removed in its original module.
Add a new test and update existing tests.
Reviewers: mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26076
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285512 91177308-0d34-0410-b5e6-96231b3b80d8
In an IR symbol table I would expect the comdats to be represented as:
- A table of strings, one for each comdat name.
- Each symbol has an optional index into that table.
The natural api for accessing that would be
InputFile:
ArrayRef<StringRef> getComdatTable() const;
Symbol:
int getComdatIndex() const;
This patch implements an API as close to that as possible. The
implementation on top of the current IRObjectFile is a bit hackish,
but should map just fine over a symbol table and is very convenient to
use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285061 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This is a follow-up to D25416. It removes all usages of TimeValue from
llvm/Support library (except for the actual TimeValue declaration), and replaces
them with appropriate usages of std::chrono. To facilitate this, I have added
small utility functions for converting time points and durations into appropriate
OS-specific types (FILETIME, struct timespec, ...).
Reviewers: zturner, mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25730
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284966 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Changes default backend parallelism from thread::hardware_concurrency to
the new llvm::heavyweight_hardware_concurrency, which for X86 Linux
defaults to the number of physical cores (and will fall back to
thread::hardware_concurrency otherwise). This avoid oversubscribing
the physical cores using hyperthreading.
Reviewers: mehdi_amini, pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25775
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284618 91177308-0d34-0410-b5e6-96231b3b80d8
Declare the LLVM_CMAKE_PATH to the source directory location of CMake
files, in order to make it possible to easily use them in subprojects.
Such a variable is already declared in most of LLVM projects
(and inconsistently mixed with direct source tree references), including
Clang, LLDB, compiler-rt, libcxx... Declaring it inside main LLVM tree
makes it possible to avoid having to declare fallback values or use
conditionals in those projects.
It should be noted that in some of the subprojects LLVM_CMAKE_PATH is
used to reference generated LLVMConfig.cmake file. However, these
references are conditional to stand-alone builds and explicitly
including this file is unnecessary in combined builds.
Differential Revision: https://reviews.llvm.org/D25724
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284581 91177308-0d34-0410-b5e6-96231b3b80d8
Module inline asm was always being linked/concatenated
when running the IRLinker. This is correct for full LTO but not when
we are importing for ThinLTO, as it can result in multiply defined
symbols when the module asm defines a global symbol.
In order to test with llvm-lto2, I had to work around PR30396,
where a symbol that is defined in module assembly but defined in the
LLVM IR appears twice. Added workaround to llvm-lto2 with a FIXME.
Fixes PR30610.
Reviewers: mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25359
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284030 91177308-0d34-0410-b5e6-96231b3b80d8
We need to add an entry in the combined-index for modules that have
a hash but otherwise empty summary, this is needed so that we can
get the hash for the module.
Also, if no entry is present in the combined index for a module, we
need to skip it when trying to compute a cache entry.
Differential Revision: https://reviews.llvm.org/D25300
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283654 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282437 91177308-0d34-0410-b5e6-96231b3b80d8
The NativeObjectOutput class has a design problem: it mixes up the caching
policy with the interface for output streams, which makes the client-side
code hard to follow and would for example make it harder to replace the
cache implementation in an arbitrary client.
This change separates the two aspects by moving the caching policy
to a separate field in Config, replacing NativeObjectOutput with a
NativeObjectStream class which only deals with streams and does not need to
be overridden by most clients and introducing an AddFile callback for adding
files (e.g. from the cache) to the link.
Differential Revision: https://reviews.llvm.org/D24622
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282299 91177308-0d34-0410-b5e6-96231b3b80d8
With the new LTO API in r278338, we stopped emitting the individual
index files and imports files for some modules in the distributed backend
case (thinlto-index-only plugin option).
Specifically, this is when the linker decides not to include a module in the
link, because it was in an archive library and did not have a strong
reference to it. Not creating the expected output files makes the
distributed build system implementation more difficult, in terms of
checking for the expected outputs of the thin link, and scheduling the
backend jobs. To address this, the gold-plugin will write dummy empty
.thinlto.bc and .imports files for modules not included in the link
(which LTO never sees).
Augmented a gold v1.12+ test, since that version of gold has the handling
for notifying on modules not being included in the link.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282100 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282037 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
In runThinLTO we start the task numbering for ThinLTO backend
tasks depending on whether there was also a regular LTO object
(CombinedModule). However, the CombinedModule is moved at
the end of runRegularLTO, so we need to save this information and
pass it into runThinLTO. Otherwise the AddOutput callback to the client
will use the same task number for both the regular LTO object
and the first ThinLTO object, which in gold-plugin caused only
one to be end up in the output filename array and therefore passed
back to gold for the final native link.
Reviewers: pcc, mehdi_amini
Subscribers: mehdi_amini, kromanova
Differential Revision: https://reviews.llvm.org/D24643
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281725 91177308-0d34-0410-b5e6-96231b3b80d8
Previously the prevailing information was not honored, and commons
symbols could override a strong definition. This patch fixes it and
propose the following semantic for commons: the client should mark
as prevailing the commons that it expects the LTO implementation to
merge (i.e. take the maximum size and alignment).
It implies that commons are allowed to have multiple prevailing
definitions.
Differential Revision: https://reviews.llvm.org/D24545
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281538 91177308-0d34-0410-b5e6-96231b3b80d8
This is in preparation for adding an option
to run a custom pipeline with the new PM. It's
currently used in lld.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280258 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This addresses a regression in common handling from the new LTO
API in r278338. Only create a new common if the size is different.
The type comparison against an array type fails when the size is
different but not an array. GlobalMerge does not handle the
array types as well and we lose some global merging opportunities.
Reviewers: mehdi_amini
Subscribers: junbuml, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23955
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279911 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Have the cache pass back the path to the cache entry when it
is ready to be loaded, instead of a buffer.
For gold-plugin we can simply pass this file back to gold directly,
which avoids expensive writing of a separate tmp file. Ensure
the cache entry is not deleted on cleanup by adjusting the setting
of the IsTemporary flags.
Moved the loading of the buffer into llvm-lto2 to maintain current
behavior.
Reviewers: mehdi_amini
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23946
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279883 91177308-0d34-0410-b5e6-96231b3b80d8
Add the ability to plug a cache on the LTO API.
I tried to write such that a linker implementation can
control the cache backend. This is intrusive and I'm
not totally happy with it, but I can't figure out a
better design right now.
Differential Revision: https://reviews.llvm.org/D23599
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279576 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
I assume there was a use case, so maybe this strawman patch will help
clarifying if it is legit.
In any case the current situation is not legit: a ThinLTO compilation
should not trigger an unexpected full LTO compilation.
Right now, adding a --save-temps option triggers this and makes the
number of output differs.
Reviewers: tejohnson
Subscribers: pcc, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23600
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279550 91177308-0d34-0410-b5e6-96231b3b80d8
An important performance setting on the LLVMContext for LTO is
enableDebugTypeODRUniquing(), this adds an automatic merging of
debug information in the context based on type ids.
Also, the lto::Config includes a diagnostic handler that needs to
be set on the Context, as well as the setDiscardValueNames() setting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279532 91177308-0d34-0410-b5e6-96231b3b80d8
It use to be non-const for the sole purpose of custom handling of
commons symbol. This is moved now in the regular LTO handling now
and such we can constify the callback.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279438 91177308-0d34-0410-b5e6-96231b3b80d8
