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
17#include "llvm/Transforms/Utils/Local.h"
18#include "llvm/IR/Function.h"
19#include "llvm/IR/PassManager.h"
20
21namespace 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.
29class SimplifyCFGPass : public PassInfoMixin<SimplifyCFGPass> {
30  SimplifyCFGOptions Options;
31
32public:
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.
37  SimplifyCFGPass()
38      : SimplifyCFGPass(SimplifyCFGOptions()
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.
49  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
50};
51
52}
53
54#endif
55