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* [ThinLTO/WPD] Remove an overly-aggressive assertTeresa Johnson2020-01-141-8/+3
| | | | | | | | | | | | | | | | | | | | Summary: An assert added to the index-based WPD was trying to verify that we only have multiple vtables for a given guid when they are all non-external linkage. This is too conservative because we may have multiple external vtable with the same guid when they are in comdat. Remove the assert, as we don't have comdat information in the index, the linker should issue an error in this case. See discussion on D71040 for more information. Reviewers: evgeny777, aganea Subscribers: mehdi_amini, inglorion, hiraditya, steven_wu, dexonsmith, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D72648
* [ThinLTO/WPD] Fix index-based WPD for alias vtablesTeresa Johnson2020-01-131-1/+1
| | | | | | | | | | | | | | | | | Summary: A recent fix in D69452 fixed index based WPD in the presence of available_externally vtables. It added a cast of the vtable def summary to a GlobalVarSummary. However, in some cases one def may be an alias, in which case we need to get the base object before casting, otherwise we will crash. Reviewers: evgeny777, steven_wu, aganea Subscribers: mehdi_amini, inglorion, hiraditya, dexonsmith, arphaman, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D71040
* Add Triple::isX86()Fangrui Song2020-01-061-2/+1
| | | | | | Reviewed By: craig.topper, skan Differential Revision: https://reviews.llvm.org/D72247
* [Transforms] Fixes -Wrange-loop-analysis warningsMark de Wever2019-12-221-1/+1
| | | | | | This avoids new warnings due to D68912 adds -Wrange-loop-analysis to -Wall. Differential Revision: https://reviews.llvm.org/D71810
* [WPD] Remove unused parameter (NFC)Teresa Johnson2019-12-061-4/+3
| | | | Remove unused parameter.
* Recommit "[ThinLTO] Add correctness check for RO/WO variable import"evgeny2019-11-151-2/+2
| | | | | | ValueInfo has user-defined 'operator bool' which allows incorrect implicit conversion to GlobalValue::GUID (which is unsigned long). This causes bugs which are hard to track and should be removed in future.
* 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
* Revert "[ThinLTO] Add correctness check for RO/WO variable import"Benjamin Kramer2019-11-141-2/+2
| | | | | This reverts commit a2292cc537b561416c21e8d4017715d652c144cc. Breaks clang selfhost w/ThinLTO.
* WholeProgramDevirt - fix uninitialized variable warnings. NFCI.Simon Pilgrim2019-11-141-2/+2
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* [ThinLTO] Add correctness check for RO/WO variable importevgeny2019-11-141-2/+2
| | | | | | | | | | | This patch adds an assertion check for exported read/write-only variables to be also in import list for module. If they aren't we may face linker errors, because read/write-only variables are internalized in their source modules. The patch also changes export lists to store ValueInfo instead of GUID for performance considerations. Differential revision: https://reviews.llvm.org/D70128
* 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
* [ThinLTO/WPD] Fix index-based WPD for available_externally vtablesTeresa Johnson2019-10-301-8/+26
| | | | | | | | | | | | | | | | | | | | | | Summary: Clang does not add type metadata to available_externally vtables. When choosing a summary to look at for virtual function definitions, make sure we skip summaries for any available externally vtables as they will not describe any virtual function functions, which are only summarized in the presence of type metadata on the vtable def. Simply look for the corresponding strong def's summary. Also add handling for same-named local vtables with the same GUID because of same-named files without enough distinguishing path. In that case we return a conservative result with no devirtualization. Reviewers: pcc, davidxl, evgeny777 Subscribers: mehdi_amini, inglorion, hiraditya, steven_wu, dexonsmith, arphaman, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D69452
* Reland: Dead Virtual Function EliminationOliver Stannard2019-10-171-34/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* [ThinLTO] Import virtual method with single implementation in hybrid modeEugene Leviant2019-10-171-34/+43
| | | | | | Differential revision: https://reviews.llvm.org/D68782 llvm-svn: 375083
* [Alignment][NFC] Remove dependency on GlobalObject::setAlignment(unsigned)Guillaume Chatelet2019-10-151-5/+6
| | | | | | | | | | | | | | | | | Summary: This is patch is part of a series to introduce an Alignment type. See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html See this patch for the introduction of the type: https://reviews.llvm.org/D64790 Reviewers: courbet Subscribers: arsenm, mehdi_amini, jvesely, nhaehnle, hiraditya, steven_wu, dexonsmith, dang, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68944 llvm-svn: 374880
* Revert "Dead Virtual Function Elimination"Jorge Gorbe Moya2019-10-141-7/+34
| | | | | | This reverts commit 9f6a873268e1ad9855873d9d8007086c0d01cf4f. llvm-svn: 374844
* Dead Virtual Function EliminationOliver Stannard2019-10-111-34/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* [ThinLTO/WPD] Ensure devirtualized targets use promoted symbol when necessaryTeresa Johnson2019-10-021-4/+2
| | | | | | | | | | | | | | | | | | | | Summary: This fixes a hole in the handling of devirtualized targets that were local but need promoting due to devirtualization in another module. We were not correctly referencing the promoted symbol in some cases. Make sure the code that updates the name also looks at the ExportedGUIDs set by utilizing a callback that checks all conditions (the callback utilized by the internalization/promotion code). Reviewers: pcc, davidxl, hiraditya Subscribers: mehdi_amini, Prazek, inglorion, steven_wu, dexonsmith, dang, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68159 llvm-svn: 373485
* [llvm] Migrate llvm::make_unique to std::make_uniqueJonas Devlieghere2019-08-151-1/+1
| | | | | | | | Now that we've moved to C++14, we no longer need the llvm::make_unique implementation from STLExtras.h. This patch is a mechanical replacement of (hopefully) all the llvm::make_unique instances across the monorepo. llvm-svn: 369013
* Rename F_{None,Text,Append} to OF_{None,Text,Append}. NFCFangrui Song2019-08-051-1/+1
| | | | | | F_{None,Text,Append} are kept for compatibility since r334221. llvm-svn: 367800
* [ThinLTO] Implement index-based WPDTeresa Johnson2019-08-021-5/+298
| | | | | | | | | | | | | | | | | | | This patch adds support to the WholeProgramDevirt pass to perform index-based WPD, which is invoked from ThinLTO during the thin link. The ThinLTO backend (WPD import phase) behaves the same regardless of whether the WPD decisions were made with the index-based or (the existing) IR-based analysis. Depends on D54815. Reviewers: pcc Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, arphaman, dang, llvm-commits Differential Revision: https://reviews.llvm.org/D55153 llvm-svn: 367679
* WholeProgramDevirt: Teach the pass to respect the global's alignment.Peter Collingbourne2019-07-221-4/+7
| | | | | | | | | | | | | | | | | | | The bytes inserted before an overaligned global need to be padded according to the alignment set on the original global in order for the initializer to meet the global's alignment requirements. The previous implementation that padded to the pointer width happened to be correct for vtables on most platforms but may do the wrong thing if the vtable has a larger alignment. This issue is visible with a prototype implementation of HWASAN for globals, which will overalign all globals including vtables to 16 bytes. There is also no padding requirement for the bytes inserted after the global because they are never read from nor are they significant for alignment purposes, so stop inserting padding there. Differential Revision: https://reviews.llvm.org/D65031 llvm-svn: 366725
* [ThinLTO] Detect partially split modules during the thin linkTeresa Johnson2019-02-141-11/+8
| | | | | | | | | | | | | | | | | | | | | | | | Summary: The changes to disable LTO unit splitting by default (r350949) and detect inconsistently split LTO units (r350948) are causing some crashes when the inconsistency is detected in multiple threads simultaneously. Fix that by having the code always look for the inconsistently split LTO units during the thin link, by checking for the presence of type tests recorded in the summaries. Modify test added in r350948 to remove single threading required to fix a bot failure due to this issue (and some debugging options added in the process of diagnosing it). Reviewers: pcc Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D57561 llvm-svn: 354062
* [opaque pointer types] Pass value type to LoadInst creation.James Y Knight2019-02-011-1/+1
| | | | | | | | | This cleans up all LoadInst creation in LLVM to explicitly pass the value type rather than deriving it from the pointer's element-type. Differential Revision: https://reviews.llvm.org/D57172 llvm-svn: 352911
* [opaque pointer types] Pass function types to InvokeInst creation.James Y Knight2019-02-011-1/+1
| | | | | | | | | This cleans up all InvokeInst creation in LLVM to explicitly pass a function type rather than deriving it from the pointer's element-type. Differential Revision: https://reviews.llvm.org/D57171 llvm-svn: 352910
* [opaque pointer types] Pass function types to CallInst creation.James Y Knight2019-02-011-5/+6
| | | | | | | | | This cleans up all CallInst creation in LLVM to explicitly pass a function type rather than deriving it from the pointer's element-type. Differential Revision: https://reviews.llvm.org/D57170 llvm-svn: 352909
* [opaque pointer types] Add a FunctionCallee wrapper type, and use it.James Y Knight2019-02-011-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recommit r352791 after tweaking DerivedTypes.h slightly, so that gcc doesn't choke on it, hopefully. Original Message: The FunctionCallee type is effectively a {FunctionType*,Value*} pair, and is a useful convenience to enable code to continue passing the result of getOrInsertFunction() through to EmitCall, even once pointer types lose their pointee-type. Then: - update the CallInst/InvokeInst instruction creation functions to take a Callee, - modify getOrInsertFunction to return FunctionCallee, and - update all callers appropriately. One area of particular note is the change to the sanitizer code. Previously, they had been casting the result of `getOrInsertFunction` to a `Function*` via `checkSanitizerInterfaceFunction`, and storing that. That would report an error if someone had already inserted a function declaraction with a mismatching signature. However, in general, LLVM allows for such mismatches, as `getOrInsertFunction` will automatically insert a bitcast if needed. As part of this cleanup, cause the sanitizer code to do the same. (It will call its functions using the expected signature, however they may have been declared.) Finally, in a small number of locations, callers of `getOrInsertFunction` actually were expecting/requiring that a brand new function was being created. In such cases, I've switched them to Function::Create instead. Differential Revision: https://reviews.llvm.org/D57315 llvm-svn: 352827
* Revert "[opaque pointer types] Add a FunctionCallee wrapper type, and use it."James Y Knight2019-01-311-10/+4
| | | | | | | | | This reverts commit f47d6b38c7a61d50db4566b02719de05492dcef1 (r352791). Seems to run into compilation failures with GCC (but not clang, where I tested it). Reverting while I investigate. llvm-svn: 352800
* [opaque pointer types] Add a FunctionCallee wrapper type, and use it.James Y Knight2019-01-311-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The FunctionCallee type is effectively a {FunctionType*,Value*} pair, and is a useful convenience to enable code to continue passing the result of getOrInsertFunction() through to EmitCall, even once pointer types lose their pointee-type. Then: - update the CallInst/InvokeInst instruction creation functions to take a Callee, - modify getOrInsertFunction to return FunctionCallee, and - update all callers appropriately. One area of particular note is the change to the sanitizer code. Previously, they had been casting the result of `getOrInsertFunction` to a `Function*` via `checkSanitizerInterfaceFunction`, and storing that. That would report an error if someone had already inserted a function declaraction with a mismatching signature. However, in general, LLVM allows for such mismatches, as `getOrInsertFunction` will automatically insert a bitcast if needed. As part of this cleanup, cause the sanitizer code to do the same. (It will call its functions using the expected signature, however they may have been declared.) Finally, in a small number of locations, callers of `getOrInsertFunction` actually were expecting/requiring that a brand new function was being created. In such cases, I've switched them to Function::Create instead. Differential Revision: https://reviews.llvm.org/D57315 llvm-svn: 352791
* 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
* [LTO] Record whether LTOUnit splitting is enabled in indexTeresa Johnson2019-01-111-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Records in the module summary index whether the bitcode was compiled with the option necessary to enable splitting the LTO unit (e.g. -fsanitize=cfi, -fwhole-program-vtables, or -fsplit-lto-unit). The information is passed down to the ModuleSummaryIndex builder via a new module flag "EnableSplitLTOUnit", which is propagated onto a flag on the summary index. This is then used during the LTO link to check whether all linked summaries were built with the same value of this flag. If not, an error is issued when we detect a situation requiring whole program visibility of the class hierarchy. This is the case when both of the following conditions are met: 1) We are performing LowerTypeTests or Whole Program Devirtualization. 2) There are type tests or type checked loads in the code. Note I have also changed the ThinLTOBitcodeWriter to also gate the module splitting on the value of this flag. Reviewers: pcc Subscribers: ormris, mehdi_amini, Prazek, inglorion, eraman, steven_wu, dexonsmith, arphaman, dang, llvm-commits Differential Revision: https://reviews.llvm.org/D53890 llvm-svn: 350948
* [IPO][AVR] Create new Functions in the default address space specified in ↵Dylan McKay2018-12-181-1/+4
| | | | | | | | | | | | | | | | | | | | | the data layout This modifies the IPO pass so that it respects any explicit function address space specified in the data layout. In targets with nonzero program address spaces, all functions should, by default, be placed into the default program address space. This is required for Harvard architectures like AVR. Without this, the functions will be marked as residing in data space, and thus not be callable. This has no effect to any in-tree official backends, as none use an explicit program address space in their data layouts. Patch by Tim Neumann. llvm-svn: 349469
* [WPD] Fix incorrect devirtualization after indirect call promotionTeresa Johnson2018-09-271-20/+41
| | | | | | | | | | | | | | | | | | | | | | | | | Summary: Add a dominance check to ensure that the possible devirtualizable call is actually dominated by the type test/checked load intrinsic being analyzed. With PGO, after indirect call promotion is performed during the compile step, followed by inlining, we may have a type test in the promoted and inlined sequence that allows an indirect call in that sequence to be devirtualized. That indirect call (inserted by inlining after promotion) will share the same vtable pointer as the fallback indirect call that cannot be devirtualized. Before this patch the code was incorrectly devirtualizing the fallback indirect call. See the new test and the example described there for more details. Reviewers: pcc, vitalybuka Subscribers: mehdi_amini, Prazek, eraman, steven_wu, dexonsmith, llvm-commits Differential Revision: https://reviews.llvm.org/D52514 llvm-svn: 343226
* [WholeProgramDevirt] Don't process declarations when building type id mapEugene Leviant2018-09-231-1/+1
| | | | | | Differential revision: https://reviews.llvm.org/D52175 llvm-svn: 342836
* [LTO] Make detection of WPD remark enablement more robustTeresa Johnson2018-09-181-9/+8
| | | | | | | | | | | | | | | | Summary: Currently only the first function in the module is checked to see if it has remarks enabled. If that first function is a declaration, remarks will be incorrectly skipped. Change to look for the first non-empty function. Reviewers: pcc Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits Differential Revision: https://reviews.llvm.org/D51556 llvm-svn: 342477
* [ThinLTO] Fix printing of WPD remarksTeresa Johnson2018-08-141-2/+4
| | | | | | | | | | | | | | | | | Summary: When WPD is performed in a ThinLTO backend, the function may be created if it isn't already in that module. Module::getOrInsertFunction may add a bitcast, in which case the returned Constant is not a Function and doesn't have a name. Invoke stripPointerCasts() on the returned value where we access its name. Reviewers: pcc Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits Differential Revision: https://reviews.llvm.org/D49959 llvm-svn: 339640
* [ThinLTO] Enable ThinLTO WholeProgramDevirt and LowerTypeTests in new PMTeresa Johnson2018-07-191-1/+2
| | | | | | | | | | | | | | | | Summary: Enable these passes for CFI and WPD in ThinLTO and LTO with the new pass manager. Add a couple of tests for both PMs based on the clang tests tools/clang/test/CodeGen/thinlto-distributed-cfi*.ll, but just test through llvm-lto2 and not with distributed ThinLTO. Reviewers: pcc Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits Differential Revision: https://reviews.llvm.org/D49429 llvm-svn: 337461
* [ThinLTO] Rename index IsAnalysis flag to HaveGVs (NFC)Teresa Johnson2018-06-061-1/+1
| | | | | | | | | With the upcoming patch to add summary parsing support, IsAnalysis would be true in contexts where we are not performing module summary analysis. Rename to the more specific and approprate HaveGVs, which is essentially what this flag is indicating. llvm-svn: 334140
* Extend the GlobalObject metadata interfaceBenjamin Kramer2018-05-311-1/+1
| | | | | | | | | | | | - Make eraseMetadata return whether it changed something - Wire getMetadata for a single MDNode efficiently into the attachment map - Add hasMetadata, which is less weird than checking getMetadata == nullptr on a multimap. Use it to simplify code. llvm-svn: 333649
* Fix warning by cl::opt<int> -> cl::opt<unsigned>Vitaly Buka2018-04-061-4/+5
| | | | llvm-svn: 329461
* Runtime flag to control branch funnel thresholdVitaly Buka2018-04-061-2/+6
| | | | | | | | | | Reviewers: pcc Subscribers: hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D45193 llvm-svn: 329459
* Use branch funnels for virtual calls when retpoline mitigation is enabled.Peter Collingbourne2018-03-091-22/+189
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The retpoline mitigation for variant 2 of CVE-2017-5715 inhibits the branch predictor, and as a result it can lead to a measurable loss of performance. We can reduce the performance impact of retpolined virtual calls by replacing them with a special construct known as a branch funnel, which is an instruction sequence that implements virtual calls to a set of known targets using a binary tree of direct branches. This allows the processor to speculately execute valid implementations of the virtual function without allowing for speculative execution of of calls to arbitrary addresses. This patch extends the whole-program devirtualization pass to replace certain virtual calls with calls to branch funnels, which are represented using a new llvm.icall.jumptable intrinsic. It also extends the LowerTypeTests pass to recognize the new intrinsic, generate code for the branch funnels (x86_64 only for now) and lay out virtual tables as required for each branch funnel. The implementation supports full LTO as well as ThinLTO, and extends the ThinLTO summary format used for whole-program devirtualization to support branch funnels. For more details see RFC: http://lists.llvm.org/pipermail/llvm-dev/2018-January/120672.html Differential Revision: https://reviews.llvm.org/D42453 llvm-svn: 327163
* [ThinLTO] Re-commit of dot dumper after test fixEugene Leviant2018-01-221-1/+1
| | | | llvm-svn: 323116
* Temporarily revert r323062 to investigate buildbot failuresEugene Leviant2018-01-211-1/+1
| | | | llvm-svn: 323065
* [ThinLTO] Implement summary visualizerEugene Leviant2018-01-211-1/+1
| | | | | | Differential revision: https://reviews.llvm.org/D41297 llvm-svn: 323062
* WholeProgramDevirt: Simplify ORE getter mechanism for old PM. NFCI.Peter Collingbourne2018-01-051-34/+17
| | | | llvm-svn: 321841
* Silence a bunch of implicit fallthrough warningsAdrian Prantl2017-12-191-0/+1
| | | | llvm-svn: 321114
* Remove redundant includes from lib/Transforms.Michael Zolotukhin2017-12-131-1/+0
| | | | llvm-svn: 320628
* Rename OptimizationDiagnosticInfo.* to OptimizationRemarkEmitter.*Adam Nemet2017-10-091-1/+1
| | | | | | | Sync it up with the name of the class actually defined here. This has been bothering me for a while... llvm-svn: 315249
* WholeProgramDevirt: Add import/export support for targets without absolute ↵Peter Collingbourne2017-09-111-16/+57
| | | | | | | | | | | | | | | | | | | symbol constants. Not all targets support the use of absolute symbols to export constants. In particular, ARM has a wide variety of constant encodings that cannot currently be relocated by linkers. So instead of exporting the constants using symbols, export them directly in the summary. The values of the constants are left as zeroes on targets that support symbolic exports. This may result in more cache misses when targeting those architectures as a result of arbitrary changes in constant values, but this seems somewhat unavoidable for now. Differential Revision: https://reviews.llvm.org/D37407 llvm-svn: 312967
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