This is intended to be shared by the ThinLTOCodeGenerator.
Note that there is a change in the way the verifier is run, previously
it was ran as a Pass on the merged module during internalization.
While now the verifier is called explicitely on the merged module
outside of the internalize "pass pipeline".
What remains strange in the API is the fact that `DisableVerify` in
the API does not disable this initial verifier.
Differential Revision: http://reviews.llvm.org/D19000
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266047
This allows the linker to instruct ThinLTO to perform only the
optimization part or only the codegen part of the process.
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265113
(Resubmitting after fixing missing file issue)
With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.
A companion clang patch will immediately succeed this patch to reflect
this renaming.
llvm-svn: 263513
With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.
A companion clang patch will immediately succeed this patch to reflect
this renaming.
llvm-svn: 263490
This is intended to provide a parallel (threaded) ThinLTO scheme
for linker plugin use through the libLTO C API.
The intent of this patch is to provide a first implementation as a
proof-of-concept and allows linker to start supporting ThinLTO by
definiing the libLTO C API. Some part of the libLTO API are left
unimplemented yet. Following patches will add support for these.
The current implementation can link all clang/llvm binaries.
Differential Revision: http://reviews.llvm.org/D17066
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 262977
Function lto_module_create_in_local_context() would previously
rely on the default LLVMContext being created for it by
LTOModule::makeLTOModule(). This context exits the program on
error and is not arranged to update sLastStringError in
tools/lto/lto.cpp.
Function lto_module_create_in_local_context() now creates an
LLVMContext by itself, sets it up correctly to its needs and then
passes it to LTOModule::createInLocalContext() which takes
ownership of the context and keeps it present for the lifetime of
the returned LTOModule.
Function LTOModule::makeLTOModule() is modified to take a
reference to LLVMContext (instead of a pointer) and no longer
creates a default context when nullptr is passed to it. Method
LTOModule::createInContext() that takes a pointer to LLVMContext
is removed because it allows to pass a nullptr to it. Instead
LTOModule::createFromBuffer() (that takes a reference to
LLVMContext) should be used.
Differential Revision: http://reviews.llvm.org/D17715
llvm-svn: 262330
Summary:
This is a companion patch for http://reviews.llvm.org/D16124.
Internalized symbols increase the size of strongly-connected components in
SCC-based module splitting and thus reduce the amount of parallelism. This
patch records the original linkage of non-local symbols prior to
internalization and then restores it just before splitting/CodeGen. This is
also useful for cases where the linker requires symbols to remain external, for
instance, so they can be placed according to linker script rules.
It's currently under its own flag (-restore-globals) but should eventually
share a common flag with D16124.
Reviewers: joker.eph, pcc
Subscribers: slarin, llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D16229
llvm-svn: 258100
Renamed variables to be more reflective of whether they are
an instance of Linker, IRLinker or ModuleLinker. Also fix a stale
comment.
llvm-svn: 256011
Summary:
The order of destructors in LTOCodeGenerator gets changed in r254696.
It is possible for LTOCodeGenerator to have a MergedModule created in
the OwnedContext, in which case the module must be destructed before
the context.
Reviewers: rafael, dexonsmith
Subscribers: llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D15346
llvm-svn: 255092
This is a continuation of r253367.
These functions return is owned by the caller, so they return
std::unique_ptr now.
The call can fail, so the return is wrapped in ErrorOr.
They have a context where to report diagnostics, so they don't need to
take a string out parameter.
With this there are no call to getGlobalContext in lib/LTO.
llvm-svn: 254721
It was only used from LTO for a debug feature, and LTO can just create
another linker.
It is pretty odd to have a method to reset the module in the middle of a
link. It would make IdentifiedStructTypes inconsistent with the Module
for example.
llvm-svn: 254434
This adds a new API, LTOCodeGenerator::setFileType, to choose the output file
format for LTO CodeGen. A corresponding change to use this new API from
llvm-lto and a test case is coming in a separate commit.
Differential Revision: http://reviews.llvm.org/D14554
llvm-svn: 253622
This patch removes the std::string& argument from a number of C++ LTO API calls
and instead makes them use the installed diagnostic handler. This would also
improve consistency of diagnostic handling infrastructure: if an LTO client used
lto_codegen_set_diagnostic_handler() to install a custom error handler, we do
not want some error messages to go through the custom error handler, and some
other error messages to go into sLastErrorString.
llvm-svn: 253367
Summary: Mimic parseTriple(); and exposes it to LTOModule.cpp
Reviewers: dexonsmith, rafael
Subscribers: llvm-commits
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 252442
The verifier currently runs three times in LTO: (1) after parsing, (2)
at the beginning of the optimization pipeline, and (3) at the end of it.
The first run is important, since we're not sure where the bitcode comes
from and it's nice to validate it, but in release builds the extra runs
aren't appropriate.
This commit:
- Allows these runs to be disabled in LTOCodeGenerator.
- Adds command-line options to llvm-lto.
- Adds command-line options to libLTO.dylib, and disables the verifier
by default in release builds (based on NDEBUG).
This shaves about 3.5% off the runtime of ld64 when linking
verify-uselistorder with -flto -g.
rdar://22509081
llvm-svn: 247729
Follow LLVM style for the parameter names (`CamelCase` not `camelCase`),
and surface the header docs in doxygen. No functionality change
intended.
llvm-svn: 246509
llvm::splitCodeGen is a function that implements the core of parallel LTO
code generation. It uses llvm::SplitModule to split the module into linkable
partitions and spawning one code generation thread per partition. The function
produces multiple object files which can be linked in the usual way.
This has been threaded through to LTOCodeGenerator (and llvm-lto for testing
purposes). Separate patches will add parallel LTO support to the gold plugin
and lld.
Differential Revision: http://reviews.llvm.org/D12260
llvm-svn: 246236
This change moves LTOCodeGenerator's ownership of the merged module to a
field of type std::unique_ptr<Module>. This helps simplify parts of the code
and clears the way for the module to be consumed by LLVM CodeGen (see D12132
review comments).
Differential Revision: http://reviews.llvm.org/D12205
llvm-svn: 245891
This allows us to remove a bunch of code in LTOCodeGenerator and llvm-lto
and has the side effect of improving error handling in the libLTO C API.
llvm-svn: 245756
This change unifies how LTOModule and the backend obtain linker flags
for globals: via a new TargetLoweringObjectFile member function named
emitLinkerFlagsForGlobal. A new function LTOModule::getLinkerOpts() returns
the list of linker flags as a single concatenated string.
This change affects the C libLTO API: the function lto_module_get_*deplibs now
exposes an empty list, and lto_module_get_*linkeropts exposes a single element
which combines the contents of all observed flags. libLTO should never have
tried to parse the linker flags; it is the linker's job to do so. Because
linkers will need to be able to parse flags in regular object files, it
makes little sense for libLTO to have a redundant mechanism for doing so.
The new API is compatible with the old one. It is valid for a user to specify
multiple linker flags in a single pragma directive like this:
#pragma comment(linker, "/defaultlib:foo /defaultlib:bar")
The previous implementation would not have exposed
either flag via lto_module_get_*deplibs (as the test in
TargetLoweringObjectFileCOFF::getDepLibFromLinkerOpt was case sensitive)
and would have exposed "/defaultlib:foo /defaultlib:bar" as a single flag via
lto_module_get_*linkeropts. This may have been a bug in the implementation,
but it does give us a chance to fix the interface.
Differential Revision: http://reviews.llvm.org/D10548
llvm-svn: 241010
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
llvm-svn: 240137
Start using C++ types such as StringRef and MemoryBuffer in the C++ LTO
API. In doing so, clarify the ownership of the native object file: the caller
now owns it, not the LTOCodeGenerator. The C libLTO library has been modified
to use a derived class of LTOCodeGenerator that owns the object file.
Differential Revision: http://reviews.llvm.org/D10114
llvm-svn: 238776
Reverse libLTO's default behaviour for preserving use-list order in
bitcode, and add API for controlling it. The default setting is now
`false` (don't preserve them), which is consistent with `clang`'s
default behaviour.
Users of libLTO should call `lto_codegen_should_embed_uselists(CG,true)`
prior to calling `lto_codegen_write_merged_modules()` whenever the
output file isn't part of the production workflow in order to reproduce
results with subsequent calls to `llc`.
(I haven't added tests since `llvm-lto` (the test tool for LTO) doesn't
support bitcode output, and even if it did: there isn't actually a good
way to test whether a tool has passed the flag. If the order is already
"natural" (if the order will already round-trip) then no use-list
directives are emitted at all. At some point I'll circle back to add
tests to `llvm-as` (etc.) that they actually respect the flag, at which
point I can somehow add a test here as well.)
llvm-svn: 235943
When debugging LTO issues with ld64, we use -save-temps to save the merged
optimized bitcode file, then invoke ld64 again on the single bitcode file.
The saved bitcode file is already internalized, so we can call
lto_codegen_set_should_internalize and skip running internalization again.
rdar://20227235
llvm-svn: 235211
This change also introduces a link-time optimization level of 1. This
optimization level runs only the globaldce pass as well as cleanup passes for
passes that run at -O0, specifically simplifycfg which cleans up lowerbitsets.
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150316/266951.html
llvm-svn: 232769
When debugging LTO issues with ld64, we use -save-temps to save the merged
optimized bitcode file, then invoke ld64 again on the single bitcode file to
speed up debugging code generation passes and ld64 stuff after code generation.
llvm linking a single bitcode file via lto_codegen_add_module will generate a
different bitcode file from the single input. With the newly-added
lto_codegen_set_module, we can make sure the destination module is the same as
the input.
lto_codegen_set_module will transfer the ownship of the module to code
generator.
rdar://19024554
llvm-svn: 230290
lto_codegen_compile_optimized. Also add lto_api_version.
Before this commit, we can only dump the optimized bitcode after running
lto_codegen_compile, but it includes some impacts of running codegen passes,
one example is StackProtector pass. We will get assertion failure when running
llc on the optimized bitcode, because StackProtector is effectively run twice.
After splitting lto_codegen_compile, the linker can choose to dump the bitcode
before running lto_codegen_compile_optimized.
lto_api_version is added so ld64 can check for runtime-availability of the new
API.
rdar://19565500
llvm-svn: 228000
Having two ways to do this doesn't seem terribly helpful and
consistently using the insert version (which we already has) seems like
it'll make the code easier to understand to anyone working with standard
data structures. (I also updated many references to the Entry's
key and value to use first() and second instead of getKey{Data,Length,}
and get/setValue - for similar consistency)
Also removes the GetOrCreateValue functions so there's less surface area
to StringMap to fix/improve/change/accommodate move semantics, etc.
llvm-svn: 222319
We used to always vectorize (slp and loop vectorize) in the LTO pass pipeline.
r220345 changed it so that we used the PassManager's fields 'LoopVectorize' and
'SLPVectorize' out of the desire to be able to disable vectorization using the
cl::opt flags 'vectorize-loops'/'slp-vectorize' which the before mentioned
fields default to.
Unfortunately, this turns off vectorization because those fields
default to false.
This commit adds flags to the LTO library to disable lto vectorization which
reconciles the desire to optionally disable vectorization during LTO and
the desired behavior of defaulting to enabled vectorization.
We really want tools to set PassManager flags directly to enable/disable
vectorization and not go the route via cl::opt flags *in*
PassManagerBuilder.cpp.
llvm-svn: 220652
