LLVM  14.0.0git
UnreachableBlockElim.h
Go to the documentation of this file.
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_CODEGEN_UNREACHABLEBLOCKELIM_H
23 #define LLVM_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_CODEGEN_UNREACHABLEBLOCKELIM_H
llvm::PreservedAnalyses
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:155
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AllocatorList.h:23
llvm::PassInfoMixin
A CRTP mix-in to automatically provide informational APIs needed for passes.
Definition: PassManager.h:374
llvm::Function
Definition: Function.h:62
F
#define F(x, y, z)
Definition: MD5.cpp:56
llvm::UnreachableBlockElimPass::run
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
Definition: UnreachableBlockElim.cpp:70
llvm::UnreachableBlockElimPass
Definition: UnreachableBlockElim.h:29
PassManager.h
llvm::AnalysisManager
A container for analyses that lazily runs them and caches their results.
Definition: InstructionSimplify.h:44