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
28namespace llvm {
29
30class UnreachableBlockElimPass
31    : public PassInfoMixin<UnreachableBlockElimPass> {
32public:
33  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
34};
35} // end namespace llvm
36
37#endif // LLVM_LIB_CODEGEN_UNREACHABLEBLOCKELIM_H
38