1 //===-- UnreachableBlockElim.h - Remove unreachable blocks for codegen --===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This pass is an extremely simple version of the SimplifyCFG pass. Its sole 11 // job is to delete LLVM basic blocks that are not reachable from the entry 12 // node. To do this, it performs a simple depth first traversal of the CFG, 13 // then deletes any unvisited nodes. 14 // 15 // Note that this pass is really a hack. In particular, the instruction 16 // selectors for various targets should just not generate code for unreachable 17 // blocks. Until LLVM has a more systematic way of defining instruction 18 // selectors, however, we cannot really expect them to handle additional 19 // complexity. 20 // 21 //===----------------------------------------------------------------------===// 22 23 #ifndef LLVM_LIB_CODEGEN_UNREACHABLEBLOCKELIM_H 24 #define LLVM_LIB_CODEGEN_UNREACHABLEBLOCKELIM_H 25 26 #include "llvm/IR/PassManager.h" 27 28 namespace llvm { 29 30 class UnreachableBlockElimPass 31 : public PassInfoMixin<UnreachableBlockElimPass> { 32 public: 33 PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM); 34 }; 35 } // end namespace llvm 36 37 #endif // LLVM_LIB_CODEGEN_UNREACHABLEBLOCKELIM_H 38
