| 1 | //===- llvm/CodeGen/GlobalMerge.h -------------------------------*- C++ -*-===// |
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| 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 | #ifndef LLVM_CODEGEN_GLOBALMERGE_H |
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| 10 | #define LLVM_CODEGEN_GLOBALMERGE_H |
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| 11 | |
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| 12 | #include "llvm/IR/PassManager.h" |
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| 13 | |
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| 14 | namespace llvm { |
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| 15 | |
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| 16 | class TargetMachine; |
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| 17 | |
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| 18 | struct GlobalMergeOptions { |
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| 19 | // FIXME: Infer the maximum possible offset depending on the actual users |
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| 20 | // (these max offsets are different for the users inside Thumb or ARM |
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| 21 | // functions), see the code that passes in the offset in the ARM backend |
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| 22 | // for more information. |
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| 23 | unsigned MaxOffset = 0; |
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| 24 | bool GroupByUse = true; |
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| 25 | bool IgnoreSingleUse = true; |
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| 26 | bool MergeConst = false; |
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| 27 | /// Whether we should merge global variables that have external linkage. |
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| 28 | bool MergeExternal = true; |
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| 29 | /// Whether we should try to optimize for size only. |
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| 30 | /// Currently, this applies a dead simple heuristic: only consider globals |
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| 31 | /// used in minsize functions for merging. |
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| 32 | /// FIXME: This could learn about optsize, and be used in the cost model. |
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| 33 | bool SizeOnly = false; |
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| 34 | }; |
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| 35 | |
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| 36 | // FIXME: This pass must run before AsmPrinterPass::doInitialization! |
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| 37 | class GlobalMergePass : public PassInfoMixin<GlobalMergePass> { |
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| 38 | const TargetMachine *TM; |
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| 39 | GlobalMergeOptions Options; |
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| 40 | |
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| 41 | public: |
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| 42 | GlobalMergePass(const TargetMachine *TM, GlobalMergeOptions Options) |
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| 43 | : TM(TM), Options(Options) {} |
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| 44 | |
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| 45 | PreservedAnalyses run(Module &M, ModuleAnalysisManager &MAM); |
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| 46 | }; |
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| 47 | |
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| 48 | } // namespace llvm |
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| 49 | |
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| 50 | #endif // LLVM_CODEGEN_GLOBALMERGE_H |
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| 51 | |
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