Commit Graph

239 Commits

Author SHA1 Message Date
Evgeniy Stepanov
d8c5d5c30e [gold] Save bitcode for module partitions (save-temps + split codegen).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265583 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-06 18:32:13 +00:00
Teresa Johnson
ee68481a50 Clean up calls to WriteBitcodeToFile (NFC)
Remove a default parameter value being passed unnecessarily, which
also reduces the changes required when this parameter is changed in
D18763.

Document the remaining non-default bool value passed for another
parameter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265348 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-04 21:19:31 +00:00
Mehdi Amini
b659366e9e Revert "ThinLTO: add module caching handling."
This reverts commit r265214, unintentionally commited.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265216 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-02 05:08:18 +00:00
Mehdi Amini
4ac4b88b38 ThinLTO: add module caching handling.
Reviewers: tejohnson

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18494

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265214 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-02 05:07:08 +00:00
Hans Wennborg
88fbbb352c Fix -Wpedantic warning about extra semi-colon
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265204 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-02 01:03:41 +00:00
Mehdi Amini
03669a56fb ThinLTO: special handling for LinkOnce functions
These function can be dropped by the compiler if they are no longer
referenced in the current module. However there is a change that
another module is still referencing them because of the import.

Multiple solutions can be used:

- Always import LinkOnce when a caller is imported. This ensure that
  every module with a call to a LinkOnce has the definition and will
  be able to emit it if it emits the call.
- Turn the LinkOnce into Weak, so that it is always emitted.
- Turn all LinkOnce into available_externally and come back after all
  modules are codegen'ed to emit only one copy of the linkonce, when
  there is still a reference to it.

This patch implement the second option, with am optimization that
only *one* module will turn the LinkOnce into Weak, while the others
will turn it into available_externally, so that there is exactly one
copy emitted for the whole compilation.

http://reviews.llvm.org/D18346

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265190 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-01 21:53:50 +00:00
Mehdi Amini
03b2cf694d ThinLTO: move ObjCARCContractPass in the CodeGen pipeline
This is to be coherent with Full LTO.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265118 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-01 08:22:59 +00:00
Mehdi Amini
51f5548e2a Add a libLTO API to stop/restart ThinLTO between optimizations and CodeGen
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>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265113 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-01 06:47:02 +00:00
Mehdi Amini
5e8cf48d61 ThinLTO: use the callgraph from the combined index to drive the FunctionImporter
Summary:
Now that the summary contains the full reference/call graph, we can
replace the existing function importer that loads and inspect the IR
to iteratively walk the call graph by a traversal based purely on the
summary information. Decouple the actual importing decision from any
IR manipulation.

Reviewers: tejohnson

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18343

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264503 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-26 05:40:34 +00:00
Teresa Johnson
f2403fe5b5 [ThinLTO] Renaming of function index to module summary index (NFC)
(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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263513 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-15 00:04:37 +00:00
Teresa Johnson
c37b05528e Revert "[ThinLTO] Renaming of function index to module summary index (NFC)"
This reverts commit r263490. Missed a file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263493 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-14 21:18:10 +00:00
Teresa Johnson
256128f217 [ThinLTO] Renaming of function index to module summary index (NFC)
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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263490 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-14 21:05:56 +00:00
Teresa Johnson
dc6615addb [ThinLTO] Support for reference graph in per-module and combined summary.
Summary:
This patch adds support for including a full reference graph including
call graph edges and other GV references in the summary.

The reference graph edges can be used to make importing decisions
without materializing any source modules, can be used in the plugin
to make file staging decisions for distributed build systems, and is
expected to have other uses.

The call graph edges are recorded in each function summary in the
bitcode via a list of <CalleeValueIds, StaticCount> tuples when no PGO
data exists, or <CalleeValueId, StaticCount, ProfileCount> pairs when
there is PGO, where the ValueId can be mapped to the function GUID via
the ValueSymbolTable. In the function index in memory, the call graph
edges reference the target via the CalleeGUID instead of the
CalleeValueId.

The reference graph edges are recorded in each summary record with a
list of referenced value IDs, which can be mapped to value GUID via the
ValueSymbolTable.

Addtionally, a new summary record type is added to record references
from global variable initializers. A number of bitcode records and data
structures have been renamed to reflect the newly expanded scope of the
summary beyond functions. More cleanup will follow.

Reviewers: joker.eph, davidxl

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D17212

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263275 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-11 18:52:24 +00:00
Chandler Carruth
dd15ed0335 [PM] Port GVN to the new pass manager, wire it up, and teach a couple of
tests to run GVN in both modes.

This is mostly the boring refactoring just like SROA and other complex
transformation passes. There is some trickiness in that GVN's
ValueNumber class requires hand holding to get to compile cleanly. I'm
open to suggestions about a better pattern there, but I tried several
before settling on this. I was trying to balance my desire to sink as
much implementation detail into the source file as possible without
introducing overly many layers of abstraction.

Much like with SROA, the design of this system is made somewhat more
cumbersome by the need to support both pass managers without duplicating
the significant state and logic of the pass. The same compromise is
struck here.

I've also left a FIXME in a doxygen comment as the GVN pass seems to
have pretty woeful documentation within it. I'd like to submit this with
the FIXME and let those more deeply familiar backfill the information
here now that we have a nice place in an interface to put that kind of
documentaiton.

Differential Revision: http://reviews.llvm.org/D18019

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263208 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-11 08:50:55 +00:00
Mehdi Amini
fffed50461 Rename -discard-value-names into -lto-discard-value-names in libLLVMLTO
This is avoiding a naming conflict with opt and llc.
While opt and llc don't link to LTO usually, users that are building a
monolithic libLLVM.dylib and linking the tools to it would have a
runtime error because of the duplicate cl::opt registration.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263127 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-10 17:06:52 +00:00
Mehdi Amini
2de9927963 Add a flag to the LLVMContext to disable name for Value other than GlobalValue
Summary:
This is intended to be a performance flag, on the same level as clang
cc1 option "--disable-free". LLVM will never initialize it by default,
it will be up to the client creating the LLVMContext to request this
behavior. Clang will do it by default in Release build (just like
--disable-free).

"opt" and "llc" can opt-in using -disable-named-value command line
option.

When performing LTO on llvm-tblgen, the initial merging of IR peaks
at 92MB without this patch, and 86MB after this patch,setNameImpl()
drops from 6.5MB to 0.5MB.
The total link time goes from ~29.5s to ~27.8s.

Compared to a compile-time flag (like the IRBuilder one), it performs
very close. I profiled on SROA and obtain these results:

 420ms with IRBuilder that preserve name
 372ms with IRBuilder that strip name
 375ms with IRBuilder that preserve name, and a runtime flag to strip

Reviewers: chandlerc, dexonsmith, bogner

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D17946

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263086 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-10 01:28:54 +00:00
Mehdi Amini
73cf01b193 libLTO: add a ThinLTOCodeGenerator on the model of LTOCodeGenerator.
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>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262977 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-09 01:37:22 +00:00
David Blaikie
d93c63989b Fix some warnings a bit harder/different
This is an alternate fix to 262378 and a fix to a pessimizing-move
warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262390 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-01 20:41:17 +00:00
Petr Pavlu
3a3e8ddebb [LTO] Fix error reporting from lto_module_create_in_local_context()
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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262330 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-01 13:13:49 +00:00
Chandler Carruth
e9afeb0bd1 [PM] Port the PostOrderFunctionAttrs pass to the new pass manager and
convert one test to use this.

This is a particularly significant milestone because it required
a working per-function AA framework which can be queried over each
function from within a CGSCC transform pass (and additionally a module
analysis to be accessible). This is essentially *the* point of the
entire pass manager rewrite. A CGSCC transform is able to query for
multiple different function's analysis results. It works. The whole
thing appears to actually work and accomplish the original goal. While
we were able to hack function attrs and basic-aa to "work" in the old
pass manager, this port doesn't use any of that, it directly leverages
the new fundamental functionality.

For this to work, the CGSCC framework also has to support SCC-based
behavior analysis, etc. The only part of the CGSCC pass infrastructure
not sorted out at this point are the updates in the face of inlining and
running function passes that mutate the call graph.

The changes are pretty boring and boiler-plate. Most of the work was
factored into more focused preperatory patches. But this is what wires
it all together.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261203 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-18 11:03:11 +00:00
Adam Nemet
6df4a6f175 [LTO] Support Statistics
Summary:
I thought -Xlinker -mllvm -Xlinker -stats worked at some point but maybe
it never did.

For clang, I believe that stats are printed from cc1_main.  This patch
also prints them for LTO, specifically right after codegen happens.

I only looked at the C API for LTO briefly to see if this is a good
place.  Probably there are still cases where this wouldn't be printed
but it seems to be working for the common case.  I also experimented
putting this in the LTOCodeGenerator destructor but that didn't trigger
for me because ld64 does not destroy the LTOCodeGenerator.

Reviewers: dexonsmith, joker.eph

Subscribers: rafael, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D17302

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261013 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-16 21:41:51 +00:00
Benjamin Kramer
030c9dc308 Move MCTargetAsmParser.h to llvm/MC/MCParser where it belongs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258917 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-27 10:01:28 +00:00
Chris Bieneman
caeade4234 Remove autoconf support
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html

"I felt a great disturbance in the [build system], as if millions of [makefiles] suddenly cried out in terror and were suddenly silenced. I fear something [amazing] has happened."
- Obi Wan Kenobi

Reviewers: chandlerc, grosbach, bob.wilson, tstellarAMD, echristo, whitequark

Subscribers: chfast, simoncook, emaste, jholewinski, tberghammer, jfb, danalbert, srhines, arsenm, dschuff, jyknight, dsanders, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D16471

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258861 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-26 21:29:08 +00:00
Petr Pavlu
616e99df64 [LTO] Fix error reporting when a file passed to libLTO is invalid or non-existent
This addresses PR26060 where function lto_module_create() could return nullptr
but lto_get_error_message() returned an empty string.

The error() call after LTOModule::createFromFile() in llvm-lto is then removed
because any error from this function should go through the diagnostic handler in
llvm-lto which will exit the program. The error() call was added because this
previously did not happen when the file was non-existent. This is fixed by the
patch. (The situation that llvm-lto reports an error when the input file does
not exist is tested by llvm/tools/llvm-lto/error.ll).

Differential Revision: http://reviews.llvm.org/D16106


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258298 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-20 09:03:42 +00:00
Tobias Edler von Koch
5ffce2cd5d [LTO] Restore original linkage of externals prior to splitting
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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258100 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-18 23:24:54 +00:00
Chandler Carruth
e96fb9ab15 [attrs] Split the late-revisit pattern for deducing norecurse in
a top-down manner into a true top-down or RPO pass over the call graph.

There are specific patterns of function attributes, notably the
norecurse attribute, which are most effectively propagated top-down
because all they us caller information.

Walk in RPO over the call graph SCCs takes the form of a module pass run
immediately after the CGSCC pass managers postorder walk of the SCCs,
trying again to deduce norerucrse for each singular SCC in the call
graph.

This removes a very legacy pass manager specific trick of using a lazy
revisit list traversed during finalization of the CGSCC pass. There is
no analogous finalization step in the new pass manager, and a lazy
revisit list is just trying to produce an RPO iteration of the call
graph. We can do that more directly if more expensively. It seems
unlikely that this will be the expensive part of any compilation though
as we never examine the function bodies here. Even in an LTO run over
a very large module, this should be a reasonable fast set of operations
over a reasonably small working set -- the function call graph itself.

In the future, if this really is a compile time performance issue, we
can look at building support for both post order and RPO traversals
directly into a pass manager that builds and maintains the PO list of
SCCs.

Differential Revision: http://reviews.llvm.org/D15785

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257163 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-08 10:55:52 +00:00
Teresa Johnson
18f59c52f2 Rename variables to reflect linker split (NFC)
Renamed variables to be more reflective of whether they are
an instance of Linker, IRLinker or ModuleLinker. Also fix a stale
comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256011 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-18 19:28:59 +00:00
Rafael Espindola
d912be98f8 Change linkInModule to take a std::unique_ptr.
Passing in a std::unique_ptr should help find errors when the module
is used after being linked into another module.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255842 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-16 23:16:33 +00:00
Rafael Espindola
7a1fc2d33e Use diagnostic handler in the LLVMContext
This patch converts code that has access to a LLVMContext to not take a
diagnostic handler.

This has a few advantages

* It is easier to use a consistent diagnostic handler in a single program.
* Less clutter since we are not passing a handler around.

It does make it a bit awkward to implement some C APIs that return a
diagnostic string. I will propose new versions of these APIs and
deprecate the current ones.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255571 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-14 23:17:03 +00:00
Rafael Espindola
f8e0f06f7c MSVC complains about this being ambiguous.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254782 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-04 22:26:21 +00:00
Rafael Espindola
c55f4fb805 Always pass a diagnostic handler to the linker.
Before this patch the diagnostic handler was optional. If it was not
passed, the one in the LLVMContext was used.

That is probably not a pattern we want to follow. If each area has an
optional callback, there is a sea of callbacks and it is hard to follow
which one is called.

Doing this also found cases where the callback is a nice addition, like
testing that no errors or warnings are reported.

The other option is to always use the diagnostic handler in the
LLVMContext. That has a few problems

* To implement the C API we would have to set the diag handler and then
  set it back to the original value.
* Code that creates the context might be far away from code that wants
  the diagnostics.

I do have a patch that implements the second option and will send that as
an RFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254777 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-04 22:08:53 +00:00
Rafael Espindola
608d7b4f4a Modernize the C++ APIs for creating LTO modules.
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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254721 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-04 16:14:31 +00:00
Rafael Espindola
c6a202e859 Move a call to getGlobalContext out of lib/LTO.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254696 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-04 02:42:28 +00:00
Rafael Espindola
34254063b5 Simplify since this function never fails.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254667 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-03 23:56:42 +00:00
Rafael Espindola
76c60c37de Use references now that it is natural to do so.
The linker never takes ownership of a module or changes which module it
is refering to, making it natural to use references.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254449 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-01 19:50:54 +00:00
Rafael Espindola
1d06f0bf4e Delete the setModule method from the Linker.
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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254434 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-01 18:41:30 +00:00
Tobias Edler von Koch
5b01c01496 [LTO] Add option to emit assembly from LTOCodeGenerator
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



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253622 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-19 23:59:24 +00:00
Yunzhong Gao
576772b030 Switch lto codegen to using diagnostic handlers.
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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253367 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-17 19:48:12 +00:00
Yunzhong Gao
8de34ad8f7 Add a libLTO diagnostic handler that supports lto_get_error_message API
This is a follow-up from the previous discussion on the thread:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151019/307763.html

The LibLTO lto_get_error_message() API reads error messages from a std::string
sLastErrorString. Instead of passing this string around as an argument, this
patch creates a diagnostic handler and then sends this handler to the
constructor of LTOCodeGenerator.

Differential Revision: http://reviews.llvm.org/D14313



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252791 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-11 19:59:08 +00:00
Mehdi Amini
dd77c4496e Add a method to the BitcodeReader to parse only the identification block
Summary: Mimic parseTriple(); and exposes it to LTOModule.cpp

Reviewers: dexonsmith, rafael

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252442 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-09 02:46:41 +00:00
Duncan P. N. Exon Smith
5e60a68a2d Reapply "LTO: Disable extra verify runs in release builds"
This reverts commit r247730, effectively reapplying r247729.  This time
I have an lld commit ready to follow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247735 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-15 23:05:59 +00:00
Duncan P. N. Exon Smith
c567bd6ca2 Revert "LTO: Disable extra verify runs in release builds"
This temporarily reverts commit r247729, as it caused lld build
failures.  I'll recommit once I have an lld patch ready-to-go.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247730 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-15 22:47:38 +00:00
Duncan P. N. Exon Smith
b0d872aece LTO: Disable extra verify runs in release builds
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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247729 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-15 22:26:11 +00:00
Chandler Carruth
e73e5b49f9 [PM] Port SROA to the new pass manager.
In some ways this is a very boring port to the new pass manager as there
are no interesting analyses or dependencies or other oddities.

However, this does introduce the first good example of a transformation
pass with non-trivial state porting to the new pass manager. I've tried
to carve out patterns here to replicate elsewhere, and would appreciate
comments on whether folks like these patterns:

- A common need in the new pass manager is to effectively lift the pass
  class and some of its state into a public header file. Prior to this,
  LLVM used anonymous namespaces to provide "module private" types and
  utilities, but that doesn't scale to cases where a public header file
  is needed and the new pass manager will exacerbate that. The pattern
  I've adopted here is to use the namespace-cased-name of the core pass
  (what would be a module if we had them) as a module-private namespace.
  Then utility and other code can be declared and defined in this
  namespace. At some point in the future, we could even have
  (conditionally compiled) code that used modules features when
  available to do the same basic thing.

- I've split the actual pass run method in two in order to expose
  a private method usable by the old pass manager to wrap the new class
  with a minimum of duplicated code. I actually looked at a bunch of
  ways to automate or generate these, but they are all quite terrible
  IMO. The fundamental need is to extract the set of analyses which need
  to cross this interface boundary, and that will end up being too
  unpredictable to effectively encapsulate IMO. This is also
  a relatively small amount of boiler plate that will live a relatively
  short time, so I'm not too worried about the fact that it is boiler
  plate.

The rest of the patch is totally boring but results in a massive diff
(sorry). It just moves code around and removes or adds qualifiers to
reflect the new name and nesting structure.

Differential Revision: http://reviews.llvm.org/D12773

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247501 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-12 09:09:14 +00:00
Yunzhong Gao
7ba3323aff Add a non-exiting diagnostic handler for LTO.
This is in order to give LTO clients a chance to do some clean-up before
terminating the process.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247461 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-11 20:01:53 +00:00
Chandler Carruth
9146833fa3 [PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatible
with the new pass manager, and no longer relying on analysis groups.

This builds essentially a ground-up new AA infrastructure stack for
LLVM. The core ideas are the same that are used throughout the new pass
manager: type erased polymorphism and direct composition. The design is
as follows:

- FunctionAAResults is a type-erasing alias analysis results aggregation
  interface to walk a single query across a range of results from
  different alias analyses. Currently this is function-specific as we
  always assume that aliasing queries are *within* a function.

- AAResultBase is a CRTP utility providing stub implementations of
  various parts of the alias analysis result concept, notably in several
  cases in terms of other more general parts of the interface. This can
  be used to implement only a narrow part of the interface rather than
  the entire interface. This isn't really ideal, this logic should be
  hoisted into FunctionAAResults as currently it will cause
  a significant amount of redundant work, but it faithfully models the
  behavior of the prior infrastructure.

- All the alias analysis passes are ported to be wrapper passes for the
  legacy PM and new-style analysis passes for the new PM with a shared
  result object. In some cases (most notably CFL), this is an extremely
  naive approach that we should revisit when we can specialize for the
  new pass manager.

- BasicAA has been restructured to reflect that it is much more
  fundamentally a function analysis because it uses dominator trees and
  loop info that need to be constructed for each function.

All of the references to getting alias analysis results have been
updated to use the new aggregation interface. All the preservation and
other pass management code has been updated accordingly.

The way the FunctionAAResultsWrapperPass works is to detect the
available alias analyses when run, and add them to the results object.
This means that we should be able to continue to respect when various
passes are added to the pipeline, for example adding CFL or adding TBAA
passes should just cause their results to be available and to get folded
into this. The exception to this rule is BasicAA which really needs to
be a function pass due to using dominator trees and loop info. As
a consequence, the FunctionAAResultsWrapperPass directly depends on
BasicAA and always includes it in the aggregation.

This has significant implications for preserving analyses. Generally,
most passes shouldn't bother preserving FunctionAAResultsWrapperPass
because rebuilding the results just updates the set of known AA passes.
The exception to this rule are LoopPass instances which need to preserve
all the function analyses that the loop pass manager will end up
needing. This means preserving both BasicAAWrapperPass and the
aggregating FunctionAAResultsWrapperPass.

Now, when preserving an alias analysis, you do so by directly preserving
that analysis. This is only necessary for non-immutable-pass-provided
alias analyses though, and there are only three of interest: BasicAA,
GlobalsAA (formerly GlobalsModRef), and SCEVAA. Usually BasicAA is
preserved when needed because it (like DominatorTree and LoopInfo) is
marked as a CFG-only pass. I've expanded GlobalsAA into the preserved
set everywhere we previously were preserving all of AliasAnalysis, and
I've added SCEVAA in the intersection of that with where we preserve
SCEV itself.

One significant challenge to all of this is that the CGSCC passes were
actually using the alias analysis implementations by taking advantage of
a pretty amazing set of loop holes in the old pass manager's analysis
management code which allowed analysis groups to slide through in many
cases. Moving away from analysis groups makes this problem much more
obvious. To fix it, I've leveraged the flexibility the design of the new
PM components provides to just directly construct the relevant alias
analyses for the relevant functions in the IPO passes that need them.
This is a bit hacky, but should go away with the new pass manager, and
is already in many ways cleaner than the prior state.

Another significant challenge is that various facilities of the old
alias analysis infrastructure just don't fit any more. The most
significant of these is the alias analysis 'counter' pass. That pass
relied on the ability to snoop on AA queries at different points in the
analysis group chain. Instead, I'm planning to build printing
functionality directly into the aggregation layer. I've not included
that in this patch merely to keep it smaller.

Note that all of this needs a nearly complete rewrite of the AA
documentation. I'm planning to do that, but I'd like to make sure the
new design settles, and to flesh out a bit more of what it looks like in
the new pass manager first.

Differential Revision: http://reviews.llvm.org/D12080

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247167 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-09 17:55:00 +00:00
Yaron Keren
7e374d84bc Fix typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246538 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 10:13:49 +00:00
Duncan P. N. Exon Smith
680ff33b17 LTO: Cleanup parameter names and header docs, NFC
Follow LLVM style for the parameter names (`CamelCase` not `camelCase`),
and surface the header docs in doxygen.  No functionality change
intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246509 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 23:44:06 +00:00
Peter Collingbourne
daf6885fa4 CodeGen: Introduce splitCodeGen and teach LTOCodeGenerator to use it.
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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246236 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-27 23:37:36 +00:00
Peter Collingbourne
8c1602df50 LTO: Simplify merged module ownership.
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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245891 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-24 22:22:53 +00:00