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| Rev | Author | Line No. | Line |
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| 14 | pmbaty | 1 | //===- FunctionAttrs.h - Compute function attributes ------------*- C++ -*-===// |
| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | /// \file |
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| 10 | /// Provides passes for computing function attributes based on interprocedural |
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| 11 | /// analyses. |
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| 12 | // |
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| 13 | //===----------------------------------------------------------------------===// |
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| 14 | |||
| 15 | #ifndef LLVM_TRANSFORMS_IPO_FUNCTIONATTRS_H |
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| 16 | #define LLVM_TRANSFORMS_IPO_FUNCTIONATTRS_H |
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| 17 | |||
| 18 | #include "llvm/Analysis/AliasAnalysis.h" |
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| 19 | #include "llvm/Analysis/CGSCCPassManager.h" |
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| 20 | #include "llvm/Analysis/LazyCallGraph.h" |
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| 21 | #include "llvm/IR/PassManager.h" |
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| 22 | |||
| 23 | namespace llvm { |
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| 24 | |||
| 25 | class GlobalValueSummary; |
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| 26 | class ModuleSummaryIndex; |
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| 27 | class Function; |
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| 28 | class Module; |
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| 29 | class Pass; |
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| 30 | |||
| 31 | /// Returns the memory access properties of this copy of the function. |
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| 32 | MemoryEffects computeFunctionBodyMemoryAccess(Function &F, AAResults &AAR); |
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| 33 | |||
| 34 | /// Propagate function attributes for function summaries along the index's |
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| 35 | /// callgraph during thinlink |
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| 36 | bool thinLTOPropagateFunctionAttrs( |
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| 37 | ModuleSummaryIndex &Index, |
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| 38 | function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)> |
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| 39 | isPrevailing); |
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| 40 | |||
| 41 | /// Computes function attributes in post-order over the call graph. |
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| 42 | /// |
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| 43 | /// By operating in post-order, this pass computes precise attributes for |
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| 44 | /// called functions prior to processsing their callers. This "bottom-up" |
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| 45 | /// approach allows powerful interprocedural inference of function attributes |
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| 46 | /// like memory access patterns, etc. It can discover functions that do not |
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| 47 | /// access memory, or only read memory, and give them the readnone/readonly |
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| 48 | /// attribute. It also discovers function arguments that are not captured by |
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| 49 | /// the function and marks them with the nocapture attribute. |
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| 50 | struct PostOrderFunctionAttrsPass : PassInfoMixin<PostOrderFunctionAttrsPass> { |
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| 51 | PreservedAnalyses run(LazyCallGraph::SCC &C, CGSCCAnalysisManager &AM, |
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| 52 | LazyCallGraph &CG, CGSCCUpdateResult &UR); |
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| 53 | }; |
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| 54 | |||
| 55 | /// Create a legacy pass manager instance of a pass to compute function attrs |
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| 56 | /// in post-order. |
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| 57 | Pass *createPostOrderFunctionAttrsLegacyPass(); |
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| 58 | |||
| 59 | /// A pass to do RPO deduction and propagation of function attributes. |
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| 60 | /// |
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| 61 | /// This pass provides a general RPO or "top down" propagation of |
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| 62 | /// function attributes. For a few (rare) cases, we can deduce significantly |
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| 63 | /// more about function attributes by working in RPO, so this pass |
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| 64 | /// provides the complement to the post-order pass above where the majority of |
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| 65 | /// deduction is performed. |
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| 66 | // FIXME: Currently there is no RPO CGSCC pass structure to slide into and so |
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| 67 | // this is a boring module pass, but eventually it should be an RPO CGSCC pass |
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| 68 | // when such infrastructure is available. |
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| 69 | class ReversePostOrderFunctionAttrsPass |
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| 70 | : public PassInfoMixin<ReversePostOrderFunctionAttrsPass> { |
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| 71 | public: |
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| 72 | PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM); |
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| 73 | }; |
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| 74 | |||
| 75 | } // end namespace llvm |
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| 76 | |||
| 77 | #endif // LLVM_TRANSFORMS_IPO_FUNCTIONATTRS_H |