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* Add missing includes needed to prune LLVMContext.h include, NFCReid Kleckner2019-11-141-0/+1
| | | | | These are a pre-requisite to removing #include "llvm/Support/Options.h" from LLVMContext.h: https://reviews.llvm.org/D70280
* Sink all InitializePasses.h includesReid Kleckner2019-11-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This file lists every pass in LLVM, and is included by Pass.h, which is very popular. Every time we add, remove, or rename a pass in LLVM, it caused lots of recompilation. I found this fact by looking at this table, which is sorted by the number of times a file was changed over the last 100,000 git commits multiplied by the number of object files that depend on it in the current checkout: recompiles touches affected_files header 342380 95 3604 llvm/include/llvm/ADT/STLExtras.h 314730 234 1345 llvm/include/llvm/InitializePasses.h 307036 118 2602 llvm/include/llvm/ADT/APInt.h 213049 59 3611 llvm/include/llvm/Support/MathExtras.h 170422 47 3626 llvm/include/llvm/Support/Compiler.h 162225 45 3605 llvm/include/llvm/ADT/Optional.h 158319 63 2513 llvm/include/llvm/ADT/Triple.h 140322 39 3598 llvm/include/llvm/ADT/StringRef.h 137647 59 2333 llvm/include/llvm/Support/Error.h 131619 73 1803 llvm/include/llvm/Support/FileSystem.h Before this change, touching InitializePasses.h would cause 1345 files to recompile. After this change, touching it only causes 550 compiles in an incremental rebuild. Reviewers: bkramer, asbirlea, bollu, jdoerfert Differential Revision: https://reviews.llvm.org/D70211
* Reland: Dead Virtual Function EliminationOliver Stannard2019-10-171-2/+154
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove dead virtual functions from vtables with replaceNonMetadataUsesWith, so that CGProfile metadata gets cleaned up correctly. Original commit message: Currently, it is hard for the compiler to remove unused C++ virtual functions, because they are all referenced from vtables, which are referenced by constructors. This means that if the constructor is called from any live code, then we keep every virtual function in the final link, even if there are no call sites which can use it. This patch allows unused virtual functions to be removed during LTO (and regular compilation in limited circumstances) by using type metadata to match virtual function call sites to the vtable slots they might load from. This information can then be used in the global dead code elimination pass instead of the references from vtables to virtual functions, to more accurately determine which functions are reachable. To make this transformation safe, I have changed clang's code-generation to always load virtual function pointers using the llvm.type.checked.load intrinsic, instead of regular load instructions. I originally tried writing this using clang's existing code-generation, which uses the llvm.type.test and llvm.assume intrinsics after doing a normal load. However, it is possible for optimisations to obscure the relationship between the GEP, load and llvm.type.test, causing GlobalDCE to fail to find virtual function call sites. The existing linkage and visibility types don't accurately describe the scope in which a virtual call could be made which uses a given vtable. This is wider than the visibility of the type itself, because a virtual function call could be made using a more-visible base class. I've added a new !vcall_visibility metadata type to represent this, described in TypeMetadata.rst. The internalization pass and libLTO have been updated to change this metadata when linking is performed. This doesn't currently work with ThinLTO, because it needs to see every call to llvm.type.checked.load in the linkage unit. It might be possible to extend this optimisation to be able to use the ThinLTO summary, as was done for devirtualization, but until then that combination is rejected in the clang driver. To test this, I've written a fuzzer which generates random C++ programs with complex class inheritance graphs, and virtual functions called through object and function pointers of different types. The programs are spread across multiple translation units and DSOs to test the different visibility restrictions. I've also tried doing bootstrap builds of LLVM to test this. This isn't ideal, because only classes in anonymous namespaces can be optimised with -fvisibility=default, and some parts of LLVM (plugins and bugpoint) do not work correctly with -fvisibility=hidden. However, there are only 12 test failures when building with -fvisibility=hidden (and an unmodified compiler), and this change does not cause any new failures for either value of -fvisibility. On the 7 C++ sub-benchmarks of SPEC2006, this gives a geomean code-size reduction of ~6%, over a baseline compiled with "-O2 -flto -fvisibility=hidden -fwhole-program-vtables". The best cases are reductions of ~14% in 450.soplex and 483.xalancbmk, and there are no code size increases. I've also run this on a set of 8 mbed-os examples compiled for Armv7M, which show a geomean size reduction of ~3%, again with no size increases. I had hoped that this would have no effect on performance, which would allow it to awlays be enabled (when using -fwhole-program-vtables). However, the changes in clang to use the llvm.type.checked.load intrinsic are causing ~1% performance regression in the C++ parts of SPEC2006. It should be possible to recover some of this perf loss by teaching optimisations about the llvm.type.checked.load intrinsic, which would make it worth turning this on by default (though it's still dependent on -fwhole-program-vtables). Differential revision: https://reviews.llvm.org/D63932 llvm-svn: 375094
* Revert "Dead Virtual Function Elimination"Jorge Gorbe Moya2019-10-141-154/+2
| | | | | | This reverts commit 9f6a873268e1ad9855873d9d8007086c0d01cf4f. llvm-svn: 374844
* Fix compilation warnings. NFC.Michael Liao2019-10-111-1/+1
| | | | llvm-svn: 374554
* Dead Virtual Function EliminationOliver Stannard2019-10-111-2/+154
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, it is hard for the compiler to remove unused C++ virtual functions, because they are all referenced from vtables, which are referenced by constructors. This means that if the constructor is called from any live code, then we keep every virtual function in the final link, even if there are no call sites which can use it. This patch allows unused virtual functions to be removed during LTO (and regular compilation in limited circumstances) by using type metadata to match virtual function call sites to the vtable slots they might load from. This information can then be used in the global dead code elimination pass instead of the references from vtables to virtual functions, to more accurately determine which functions are reachable. To make this transformation safe, I have changed clang's code-generation to always load virtual function pointers using the llvm.type.checked.load intrinsic, instead of regular load instructions. I originally tried writing this using clang's existing code-generation, which uses the llvm.type.test and llvm.assume intrinsics after doing a normal load. However, it is possible for optimisations to obscure the relationship between the GEP, load and llvm.type.test, causing GlobalDCE to fail to find virtual function call sites. The existing linkage and visibility types don't accurately describe the scope in which a virtual call could be made which uses a given vtable. This is wider than the visibility of the type itself, because a virtual function call could be made using a more-visible base class. I've added a new !vcall_visibility metadata type to represent this, described in TypeMetadata.rst. The internalization pass and libLTO have been updated to change this metadata when linking is performed. This doesn't currently work with ThinLTO, because it needs to see every call to llvm.type.checked.load in the linkage unit. It might be possible to extend this optimisation to be able to use the ThinLTO summary, as was done for devirtualization, but until then that combination is rejected in the clang driver. To test this, I've written a fuzzer which generates random C++ programs with complex class inheritance graphs, and virtual functions called through object and function pointers of different types. The programs are spread across multiple translation units and DSOs to test the different visibility restrictions. I've also tried doing bootstrap builds of LLVM to test this. This isn't ideal, because only classes in anonymous namespaces can be optimised with -fvisibility=default, and some parts of LLVM (plugins and bugpoint) do not work correctly with -fvisibility=hidden. However, there are only 12 test failures when building with -fvisibility=hidden (and an unmodified compiler), and this change does not cause any new failures for either value of -fvisibility. On the 7 C++ sub-benchmarks of SPEC2006, this gives a geomean code-size reduction of ~6%, over a baseline compiled with "-O2 -flto -fvisibility=hidden -fwhole-program-vtables". The best cases are reductions of ~14% in 450.soplex and 483.xalancbmk, and there are no code size increases. I've also run this on a set of 8 mbed-os examples compiled for Armv7M, which show a geomean size reduction of ~3%, again with no size increases. I had hoped that this would have no effect on performance, which would allow it to awlays be enabled (when using -fwhole-program-vtables). However, the changes in clang to use the llvm.type.checked.load intrinsic are causing ~1% performance regression in the C++ parts of SPEC2006. It should be possible to recover some of this perf loss by teaching optimisations about the llvm.type.checked.load intrinsic, which would make it worth turning this on by default (though it's still dependent on -fwhole-program-vtables). Differential revision: https://reviews.llvm.org/D63932 llvm-svn: 374539
* Update the file headers across all of the LLVM projects in the monorepoChandler Carruth2019-01-191-4/+3
| | | | | | | | | | | | | | | | | to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
* GlobalDCE: Teach isEmptyFunction() to ignore debug intrinsics.Adrian Prantl2018-11-161-5/+10
| | | | | | | This fixes PR39669. https://bugs.llvm.org/show_bug.cgi?id=39669 llvm-svn: 347065
* [GlobalDCE] AvailableExternal linkage is checked in isDiscardableIfUnused [NFC].Xin Tong2018-09-201-1/+1
| | | | | | | | | | | | | | | | Summary: AvailableExternal was not handled in isDiscardableIfUnused when isDiscardableIfUnused was added in r158476. Till it was handled in r247044. This is a NFC. Reviewers: pcc, tejohnson Reviewed By: tejohnson Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D52319 llvm-svn: 342684
* Remove redundant includes from lib/Transforms.Michael Zolotukhin2017-12-131-1/+0
| | | | llvm-svn: 320628
* [GlobalDCE] Use DenseMap instead of unordered_multimap for GVDependencies.Michael Zolotukhin2017-10-171-3/+3
| | | | | | | | | | | | | | | Summary: std::unordered_multimap happens to be very slow when the number of elements grows large. On one of our internal applications we observed a 17x compile time improvement from changing it to DenseMap. Reviewers: mehdi_amini, serge-sans-paille, davide Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D38916 llvm-svn: 316045
* Global DCE performance improvementMehdi Amini2017-01-271-60/+83
| | | | | | | | | | | | | | | | | | | Change the original algorithm so that it scales better when meeting very large bitcode where every instruction does not implies a global. The target query is "how to you get all the globals referenced by another global"? Before this patch, it was doing this by walking the body (or the initializer) and collecting the references. What this patch is doing, it precomputing the answer to this query for the whole module by walking the use-list of every global instead. Patch by: Serge Guelton <serge.guelton@telecom-bretagne.eu> Differential Revision: https://reviews.llvm.org/D28549 llvm-svn: 293328
* [PH] Replace uses of AssertingVH from members of analysis results withChandler Carruth2017-01-241-17/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | a lazy-asserting PoisoningVH. AssertVH is fundamentally incompatible with cache-invalidation of analysis results. The invaliadtion happens after the AssertingVH has already fired. Instead, use a PoisoningVH that will assert if the dangling handle is ever used rather than merely be assigned or destroyed. This patch also removes all of the (numerous) doomed attempts to work around this fundamental incompatibility. It is a pretty significant simplification IMO. The most interesting change is in the Inliner where we still do some clearing because we don't want to rely on the coarse grained invalidation strategy of the containing pass manager. However, I prefer the approach that contains this logic to the cleanup phase of the Inliner, and I think we could enhance the CGSCC analysis management layer to make this even better in the future if desired. The rest is straight cleanup. I've also added a test for one of the harder cases to work around: when a *module analysis* contains many AssertingVHes pointing at functions. Differential Revision: https://reviews.llvm.org/D29006 llvm-svn: 292928
* [PM] Replace the hard invalidate in JumpThreading for LVI with correctChandler Carruth2017-01-231-2/+25
| | | | | | | | | | | | | | | | | | | | | invalidation of deleted functions in GlobalDCE. This was always testing a bug really triggered in GlobalDCE. Right now we have analyses with asserting value handles into IR. As long as those remain, when *deleting* an IR unit, we cannot wait for the normal invalidation scheme to kick in even though it was designed to work correctly in the face of these kinds of deletions. Instead, the pass needs to directly handle invalidating the analysis results pointing at that IR unit. I've tought the Inliner about this and this patch teaches GlobalDCE. This will handle the asserting VH case in the existing test as well as other issues of the same fundamental variety. I've moved the test into the GlobalDCE directory and added a comment explaining what is going on. Note that we cannot simply require LVI here because LVI is too lazy. llvm-svn: 292773
* GlobalDCE: Restore a statement accidentally removed in r285048.Peter Collingbourne2016-10-251-0/+1
| | | | llvm-svn: 285052
* GlobalDCE: Deduplicate code. NFCI.Peter Collingbourne2016-10-251-35/+18
| | | | llvm-svn: 285048
* IR: Introduce Module::global_objects().Peter Collingbourne2016-06-221-13/+6
| | | | | | | | | | | | This is a convenience iterator that allows clients to enumerate the GlobalObjects within a Module. Also start using it in a few places where it is obviously the right thing to use. Differential Revision: http://reviews.llvm.org/D21580 llvm-svn: 273470
* [PM] Remove support for omitting the AnalysisManager argument to newChandler Carruth2016-06-171-2/+3
| | | | | | | | | | | | | | | | | | | | pass manager passes' `run` methods. This removes a bunch of SFINAE goop from the pass manager and just requires pass authors to accept `AnalysisManager<IRUnitT> &` as a dead argument. This is a small price to pay for the simplicity of the system as a whole, despite the noise that changing it causes at this stage. This will also helpfull allow us to make the signature of the run methods much more flexible for different kinds af passes to support things like intelligently updating the pass's progression over IR units. While this touches many, many, files, the changes are really boring. Mostly made with the help of my trusty perl one liners. Thanks to Sean and Hal for bouncing ideas for this with me in IRC. llvm-svn: 272978
* [GlobalDCE, Misc] Don't remove functions referenced by ifuncsDavid Majnemer2016-05-041-0/+26
| | | | | | | | | | | | We forgot to consider the target of ifuncs when considering if a function was alive or dead. N.B. Also update a few auxiliary tools like bugpoint and verify-uselistorder. This fixes PR27593. llvm-svn: 268468
* [IPO/GlobalDCE] Port to the new pass manager.Davide Italiano2016-05-031-27/+28
| | | | | | Differential Revision: http://reviews.llvm.org/D19782 llvm-svn: 268425
* Re-commit optimization bisect support (r267022) without new pass manager ↵Andrew Kaylor2016-04-221-0/+3
| | | | | | | | | | support. The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling). Differential Revision: http://reviews.llvm.org/D19172 llvm-svn: 267231
* Revert "Initial implementation of optimization bisect support."Vedant Kumar2016-04-221-3/+0
| | | | | | | | This reverts commit r267022, due to an ASan failure: http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/1549 llvm-svn: 267115
* Initial implementation of optimization bisect support.Andrew Kaylor2016-04-211-0/+3
| | | | | | | | | | | | This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations. The bisection is enabled using a new command line option (-opt-bisect-limit). Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit. A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used. The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check. Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute. A new function call has been added for module and SCC passes that behaves in a similar way. Differential Revision: http://reviews.llvm.org/D19172 llvm-svn: 267022
* [NFC] Header cleanupMehdi Amini2016-04-181-2/+2
| | | | | | | | | | | | | | Removed some unused headers, replaced some headers with forward class declarations. Found using simple scripts like this one: clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap' Patch by Eugene Kosov <claprix@yandex.ru> Differential Revision: http://reviews.llvm.org/D19219 From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 266595
* [IFUNC] Use GlobalIndirectSymbol when aliases and ifuncs have something similarDmitry Polukhin2016-04-051-3/+3
| | | | | | | | | | | Second part extracted from http://reviews.llvm.org/D15525 Use GlobalIndirectSymbol in all cases when aliases and ifuncs have something in common. Differential Revision: http://reviews.llvm.org/D18754 llvm-svn: 265382
* Re-reapply "[IR] Move optional data in llvm::Function into a hungoff uselist"Vedant Kumar2015-12-191-8/+2
| | | | | | | | | | | | | | | | | Make personality functions, prefix data, and prologue data hungoff operands of Function. This is based on the email thread "[RFC] Clean up the way we store optional Function data" on llvm-dev. Thanks to sanjoyd, majnemer, rnk, loladiro, and dexonsmith for feedback! Includes a fix to scrub value subclass data in dropAllReferences. Does not use binary literals. Differential Revision: http://reviews.llvm.org/D13829 llvm-svn: 256095
* Revert "Reapply "[IR] Move optional data in llvm::Function into a hungoff ↵Vedant Kumar2015-12-191-2/+8
| | | | | | | | | | uselist"" This reverts commit r256093. This broke lld-x86_64-win7 because of -Werror,-Wc++1y-extensions. llvm-svn: 256094
* Reapply "[IR] Move optional data in llvm::Function into a hungoff uselist"Vedant Kumar2015-12-191-8/+2
| | | | | | | | | | | | | | | | Make personality functions, prefix data, and prologue data hungoff operands of Function. This is based on the email thread "[RFC] Clean up the way we store optional Function data" on llvm-dev. Thanks to sanjoyd, majnemer, rnk, loladiro, and dexonsmith for feedback! Includes a fix to scrub value subclass data in dropAllReferences. Differential Revision: http://reviews.llvm.org/D13829 llvm-svn: 256093
* Revert "[IR] Move optional data in llvm::Function into a hungoff uselist"Vedant Kumar2015-12-191-2/+8
| | | | | | | | This reverts commit r256090. This broke llvm-clang-lld-x86_64-debian-fast. llvm-svn: 256091
* [IR] Move optional data in llvm::Function into a hungoff uselistVedant Kumar2015-12-191-8/+2
| | | | | | | | | | | | | | Make personality functions, prefix data, and prologue data hungoff operands of Function. This is based on the email thread "[RFC] Clean up the way we store optional Function data" on llvm-dev. Thanks to sanjoyd, majnemer, rnk, loladiro, and dexonsmith for feedback! Differential Revision: http://reviews.llvm.org/D13829 llvm-svn: 256090
* Rangify for loops in GlobalDCE, NFC.Yaron Keren2015-07-181-55/+49
| | | | llvm-svn: 242619
* Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)Alexander Kornienko2015-06-231-1/+1
| | | | | | Apparently, the style needs to be agreed upon first. llvm-svn: 240390
* Fixed/added namespace ending comments using clang-tidy. NFCAlexander Kornienko2015-06-191-1/+1
| | | | | | | | | | | | | 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
* Move the personality function from LandingPadInst to FunctionDavid Majnemer2015-06-171-0/+3
| | | | | | | | | | | | | | | | | | | The personality routine currently lives in the LandingPadInst. This isn't desirable because: - All LandingPadInsts in the same function must have the same personality routine. This means that each LandingPadInst beyond the first has an operand which produces no additional information. - There is ongoing work to introduce EH IR constructs other than LandingPadInst. Moving the personality routine off of any one particular Instruction and onto the parent function seems a lot better than have N different places a personality function can sneak onto an exceptional function. Differential Revision: http://reviews.llvm.org/D10429 llvm-svn: 239940
* GlobalDCE: Improve performance for large modules containing comdats.Peter Collingbourne2015-03-191-10/+16
| | | | | | | | | | | | | | | | When we encounter a global with a comdat, rather than iterating over every global in the module to find globals in the same comdat, store the members in a multimap. This effectively lowers the complexity to O(N log N), improving performance significantly for large modules such as might be encountered during LTO. It looks like we used to do something like this until r219191. No functional change. Differential Revision: http://reviews.llvm.org/D8431 llvm-svn: 232743
* Prologue supportPeter Collingbourne2014-12-031-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch by Ben Gamari! This redefines the `prefix` attribute introduced previously and introduces a `prologue` attribute. There are a two primary usecases that these attributes aim to serve, 1. Function prologue sigils 2. Function hot-patching: Enable the user to insert `nop` operations at the beginning of the function which can later be safely replaced with a call to some instrumentation facility 3. Runtime metadata: Allow a compiler to insert data for use by the runtime during execution. GHC is one example of a compiler that needs this functionality for its tables-next-to-code functionality. Previously `prefix` served cases (1) and (2) quite well by allowing the user to introduce arbitrary data at the entrypoint but before the function body. Case (3), however, was poorly handled by this approach as it required that prefix data was valid executable code. Here we redefine the notion of prefix data to instead be data which occurs immediately before the function entrypoint (i.e. the symbol address). Since prefix data now occurs before the function entrypoint, there is no need for the data to be valid code. The previous notion of prefix data now goes under the name "prologue data" to emphasize its duality with the function epilogue. The intention here is to handle cases (1) and (2) with prologue data and case (3) with prefix data. References ---------- This idea arose out of discussions[1] with Reid Kleckner in response to a proposal to introduce the notion of symbol offsets to enable handling of case (3). [1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-May/073235.html Test Plan: testsuite Differential Revision: http://reviews.llvm.org/D6454 llvm-svn: 223189
* Update SetVector to rely on the underlying set's insert to return a ↵David Blaikie2014-11-191-2/+2
| | | | | | | | | | | | | pair<iterator, bool> This is to be consistent with StringSet and ultimately with the standard library's associative container insert function. This lead to updating SmallSet::insert to return pair<iterator, bool>, and then to update SmallPtrSet::insert to return pair<iterator, bool>, and then to update all the existing users of those functions... llvm-svn: 222334
* GlobalDCE: Don't drop any COMDAT membersDavid Majnemer2014-10-071-25/+14
| | | | | | | | | If we require a single member of a comdat, require all of the other members as well. This fixes PR20981. llvm-svn: 219191
* Remove dangling initializers in GlobalDCEBruno Cardoso Lopes2014-08-251-1/+7
| | | | | | | | | | | | | | GlobalDCE deletes global vars and updates their initializers to nullptr while leaving underlying constants to be cleaned up later by its uses. The clean up may never happen, fix this by forcing it every time it's safe to destroy constants. Final patch by Rafael Espindola http://reviews.llvm.org/D4931 <rdar://problem/17523868> llvm-svn: 216390
* Revert "GlobalDCE: Delete available_externally initializers if it allows ↵Pete Cooper2014-07-081-40/+3
| | | | | | | | | | removing the value the initializer is referring to." This reverts commit 5b55a47e94e28fbb56d0cd5d72c3db9105c15b4c. A test case was found to crash after this was applied. I'll file a bug to track fixing this with the test case needed. llvm-svn: 212550
* GlobalDCE: Delete available_externally initializers if it allows removing ↵Benjamin Kramer2014-07-041-3/+40
| | | | | | | | | | | | the value the initializer is referring to. This is useful for functions that are not actually available externally but referenced by a vtable of some kind. Clang emits functions like this for the MS ABI. PR20182. llvm-svn: 212337
* IR: Add COMDATs to the IRDavid Majnemer2014-06-271-7/+34
| | | | | | | | | | | | | | | | This new IR facility allows us to represent the object-file semantic of a COMDAT group. COMDATs allow us to tie together sections and make the inclusion of one dependent on another. This is required to implement features like MS ABI VFTables and optimizing away certain kinds of initialization in C++. This functionality is only representable in COFF and ELF, Mach-O has no similar mechanism. Differential Revision: http://reviews.llvm.org/D4178 llvm-svn: 211920
* [C++11] Use 'nullptr'.Craig Topper2014-06-081-1/+1
| | | | llvm-svn: 210442
* Re-commit r208025, reverted in r208030, with a fix for a conformance issueRichard Smith2014-05-061-3/+3
| | | | | | which GCC detects and Clang does not! llvm-svn: 208033
* Revert r208025, which made buildbots unhappy for unknown reasons.Richard Smith2014-05-061-3/+3
| | | | llvm-svn: 208030
* Add llvm::function_ref (and a couple of uses of it), representing a ↵Richard Smith2014-05-061-3/+3
| | | | | | type-erased reference to a callable object. llvm-svn: 208025
* Teach GlobalDCE how to remove empty global_ctor entries.Nico Weber2014-05-021-1/+15
| | | | | | | | | | | | | | | | | This moves most of GlobalOpt's constructor optimization code out of GlobalOpt into Transforms/Utils/CDtorUtils.{h,cpp}. The public interface is a single function OptimizeGlobalCtorsList() that takes a predicate returning which constructors to remove. GlobalOpt calls this with a function that statically evaluates all constructors, just like it did before. This part of the change is behavior-preserving. Also add a call to this from GlobalDCE with a filter that removes global constructors that contain a "ret" instruction and nothing else – this fixes PR19590. llvm-svn: 207856
* [C++] Use 'nullptr'. Transforms edition.Craig Topper2014-04-251-2/+2
| | | | llvm-svn: 207196
* [Modules] Fix potential ODR violations by sinking the DEBUG_TYPEChandler Carruth2014-04-221-1/+2
| | | | | | | | | | | | | | | | | definition below all of the header #include lines, lib/Transforms/... edition. This one is tricky for two reasons. We again have a couple of passes that define something else before the includes as well. I've sunk their name macros with the DEBUG_TYPE. Also, InstCombine contains headers that need DEBUG_TYPE, so now those headers #define and #undef DEBUG_TYPE around their code, leaving them well formed modular headers. Fixing these headers was a large motivation for all of these changes, as "leaky" macros of this form are hard on the modules implementation. llvm-svn: 206844
* [C++11] Add 'override' keyword to virtual methods that override their base ↵Craig Topper2014-03-051-1/+1
| | | | | | class. llvm-svn: 202953
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