| 1 | //===-- UnreachableBlockElim.h - Remove unreachable blocks for codegen --===// |
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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 | // This pass is an extremely simple version of the SimplifyCFG pass. Its sole |
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| 10 | // job is to delete LLVM basic blocks that are not reachable from the entry |
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| 11 | // node. To do this, it performs a simple depth first traversal of the CFG, |
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| 12 | // then deletes any unvisited nodes. |
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| 13 | // |
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| 14 | // Note that this pass is really a hack. In particular, the instruction |
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| 15 | // selectors for various targets should just not generate code for unreachable |
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| 16 | // blocks. Until LLVM has a more systematic way of defining instruction |
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| 17 | // selectors, however, we cannot really expect them to handle additional |
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| 18 | // complexity. |
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| 19 | // |
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| 20 | //===----------------------------------------------------------------------===// |
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| 21 | |
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| 22 | #ifndef LLVM_CODEGEN_UNREACHABLEBLOCKELIM_H |
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| 23 | #define LLVM_CODEGEN_UNREACHABLEBLOCKELIM_H |
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| 24 | |
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| 25 | #include "llvm/IR/PassManager.h" |
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| 26 | |
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| 27 | namespace llvm { |
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| 28 | |
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| 29 | class UnreachableBlockElimPass |
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| 30 | : public PassInfoMixin<UnreachableBlockElimPass> { |
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| 31 | public: |
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| 32 | PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM); |
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| 33 | }; |
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| 34 | } // end namespace llvm |
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| 35 | |
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| 36 | #endif // LLVM_CODEGEN_UNREACHABLEBLOCKELIM_H |
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| 37 | |
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