forked from OSchip/llvm-project
96ab8726a3
Summary: Implements PR889 Removing the virtual table pointer from Value saves 1% of RSS when doing LTO of llc on Linux. The impact on time was positive, but too noisy to conclusively say that performance improved. Here is a link to the spreadsheet with the original data: https://docs.google.com/spreadsheets/d/1F4FHir0qYnV0MEp2sYYp_BuvnJgWlWPhWOwZ6LbW7W4/edit?usp=sharing This change makes it invalid to directly delete a Value, User, or Instruction pointer. Instead, such code can be rewritten to a null check and a call Value::deleteValue(). Value objects tend to have their lifetimes managed through iplist, so for the most part, this isn't a big deal. However, there are some places where LLVM deletes values, and those places had to be migrated to deleteValue. I have also created llvm::unique_value, which has a custom deleter, so it can be used in place of std::unique_ptr<Value>. I had to add the "DerivedUser" Deleter escape hatch for MemorySSA, which derives from User outside of lib/IR. Code in IR cannot include MemorySSA headers or call the MemoryAccess object destructors without introducing a circular dependency, so we need some level of indirection. Unfortunately, no class derived from User may have any virtual methods, because adding a virtual method would break User::getHungOffOperands(), which assumes that it can find the use list immediately prior to the User object. I've added a static_assert to the appropriate OperandTraits templates to help people avoid this trap. Reviewers: chandlerc, mehdi_amini, pete, dberlin, george.burgess.iv Reviewed By: chandlerc Subscribers: krytarowski, eraman, george.burgess.iv, mzolotukhin, Prazek, nlewycky, hans, inglorion, pcc, tejohnson, dberlin, llvm-commits Differential Revision: https://reviews.llvm.org/D31261 llvm-svn: 303362 |
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| .. | ||
| AsmWriter.cpp | ||
| AttributeImpl.h | ||
| Attributes.cpp | ||
| AttributesCompatFunc.td | ||
| AutoUpgrade.cpp | ||
| BasicBlock.cpp | ||
| CMakeLists.txt | ||
| Comdat.cpp | ||
| ConstantFold.cpp | ||
| ConstantFold.h | ||
| ConstantRange.cpp | ||
| Constants.cpp | ||
| ConstantsContext.h | ||
| Core.cpp | ||
| DIBuilder.cpp | ||
| DataLayout.cpp | ||
| DebugInfo.cpp | ||
| DebugInfoMetadata.cpp | ||
| DebugLoc.cpp | ||
| DiagnosticInfo.cpp | ||
| DiagnosticPrinter.cpp | ||
| Dominators.cpp | ||
| Function.cpp | ||
| GCOV.cpp | ||
| GVMaterializer.cpp | ||
| Globals.cpp | ||
| IRBuilder.cpp | ||
| IRPrintingPasses.cpp | ||
| InlineAsm.cpp | ||
| Instruction.cpp | ||
| Instructions.cpp | ||
| IntrinsicInst.cpp | ||
| LLVMBuild.txt | ||
| LLVMContext.cpp | ||
| LLVMContextImpl.cpp | ||
| LLVMContextImpl.h | ||
| LegacyPassManager.cpp | ||
| MDBuilder.cpp | ||
| Mangler.cpp | ||
| Metadata.cpp | ||
| MetadataImpl.h | ||
| Module.cpp | ||
| ModuleSummaryIndex.cpp | ||
| Operator.cpp | ||
| OptBisect.cpp | ||
| Pass.cpp | ||
| PassManager.cpp | ||
| PassRegistry.cpp | ||
| ProfileSummary.cpp | ||
| Statepoint.cpp | ||
| SymbolTableListTraitsImpl.h | ||
| Type.cpp | ||
| TypeFinder.cpp | ||
| Use.cpp | ||
| User.cpp | ||
| Value.cpp | ||
| ValueSymbolTable.cpp | ||
| ValueTypes.cpp | ||
| Verifier.cpp | ||