LLVM  9.0.0svn
UnreachableBlockElim.h
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1 //===-- UnreachableBlockElim.h - Remove unreachable blocks for codegen --===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This pass is an extremely simple version of the SimplifyCFG pass. Its sole
10 // job is to delete LLVM basic blocks that are not reachable from the entry
11 // node. To do this, it performs a simple depth first traversal of the CFG,
12 // then deletes any unvisited nodes.
13 //
14 // Note that this pass is really a hack. In particular, the instruction
15 // selectors for various targets should just not generate code for unreachable
16 // blocks. Until LLVM has a more systematic way of defining instruction
17 // selectors, however, we cannot really expect them to handle additional
18 // complexity.
19 //
20 //===----------------------------------------------------------------------===//
21 
22 #ifndef LLVM_LIB_CODEGEN_UNREACHABLEBLOCKELIM_H
23 #define LLVM_LIB_CODEGEN_UNREACHABLEBLOCKELIM_H
24 
25 #include "llvm/IR/PassManager.h"
26 
27 namespace llvm {
28 
30  : public PassInfoMixin<UnreachableBlockElimPass> {
31 public:
33 };
34 } // end namespace llvm
35 
36 #endif // LLVM_LIB_CODEGEN_UNREACHABLEBLOCKELIM_H
This class represents lattice values for constants.
Definition: AllocatorList.h:23
F(f)
A CRTP mix-in to automatically provide informational APIs needed for passes.
Definition: PassManager.h:372
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:153
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
A container for analyses that lazily runs them and caches their results.
This header defines various interfaces for pass management in LLVM.