LLVM  9.0.0svn
SimplifyCFG.h
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1 //===- SimplifyCFG.h - Simplify and canonicalize the CFG --------*- C++ -*-===//
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 /// \file
9 /// This file provides the interface for the pass responsible for both
10 /// simplifying and canonicalizing the CFG.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_TRANSFORMS_SCALAR_SIMPLIFYCFG_H
15 #define LLVM_TRANSFORMS_SCALAR_SIMPLIFYCFG_H
16 
18 #include "llvm/IR/Function.h"
19 #include "llvm/IR/PassManager.h"
20 
21 namespace llvm {
22 
23 /// A pass to simplify and canonicalize the CFG of a function.
24 ///
25 /// This pass iteratively simplifies the entire CFG of a function. It may change
26 /// or remove control flow to put the CFG into a canonical form expected by
27 /// other passes of the mid-level optimizer. Depending on the specified options,
28 /// it may further optimize control-flow to create non-canonical forms.
29 class SimplifyCFGPass : public PassInfoMixin<SimplifyCFGPass> {
30  SimplifyCFGOptions Options;
31 
32 public:
33  /// The default constructor sets the pass options to create canonical IR,
34  /// rather than optimal IR. That is, by default we bypass transformations that
35  /// are likely to improve performance but make analysis for other passes more
36  /// difficult.
39  .forwardSwitchCondToPhi(false)
40  .convertSwitchToLookupTable(false)
41  .needCanonicalLoops(true)
42  .sinkCommonInsts(false)) {}
43 
44 
45  /// Construct a pass with optional optimizations.
46  SimplifyCFGPass(const SimplifyCFGOptions &PassOptions);
47 
48  /// Run the pass over the function.
50 };
51 
52 }
53 
54 #endif
SimplifyCFGPass()
The default constructor sets the pass options to create canonical IR, rather than optimal IR...
Definition: SimplifyCFG.h:37
This class represents lattice values for constants.
Definition: AllocatorList.h:23
F(f)
block Block Frequency true
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
A pass to simplify and canonicalize the CFG of a function.
Definition: SimplifyCFG.h:29
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
Run the pass over the function.
A container for analyses that lazily runs them and caches their results.
A set of parameters used to control the transforms in the SimplifyCFG pass.
Definition: Local.h:63
This header defines various interfaces for pass management in LLVM.