1//===- llvm/CodeGen/GlobalISel/CombinerInfo.h ------*- 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//
9/// Interface for Targets to specify which operations are combined how and when.
10///
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CODEGEN_GLOBALISEL_COMBINER_INFO_H
14#define LLVM_CODEGEN_GLOBALISEL_COMBINER_INFO_H
15
16#include <cassert>
17namespace llvm {
18
19class GISelChangeObserver;
20class LegalizerInfo;
21class MachineInstr;
22class MachineIRBuilder;
23class MachineRegisterInfo;
24
25// Contains information relevant to enabling/disabling various combines for a
26// pass.
27class CombinerInfo {
28public:
29  CombinerInfo(bool AllowIllegalOps, bool ShouldLegalizeIllegal,
30               LegalizerInfo *LInfo, bool OptEnabled, bool OptSize,
31               bool MinSize)
32      : IllegalOpsAllowed(AllowIllegalOps),
33        LegalizeIllegalOps(ShouldLegalizeIllegal), LInfo(LInfo),
34        EnableOpt(OptEnabled), EnableOptSize(OptSize), EnableMinSize(MinSize) {
35    assert(((AllowIllegalOps || !LegalizeIllegalOps) || LInfo) &&
36           "Expecting legalizerInfo when illegalops not allowed");
37  }
38  virtual ~CombinerInfo() = default;
39  /// If \p IllegalOpsAllowed is false, the CombinerHelper will make use of
40  /// the legalizerInfo to check for legality before each transformation.
41  bool IllegalOpsAllowed; // TODO: Make use of this.
42
43  /// If \p LegalizeIllegalOps is true, the Combiner will also legalize the
44  /// illegal ops that are created.
45  bool LegalizeIllegalOps; // TODO: Make use of this.
46  const LegalizerInfo *LInfo;
47
48  /// Whether optimizations should be enabled. This is to distinguish between
49  /// uses of the combiner unconditionally and only when optimizations are
50  /// specifically enabled/
51  bool EnableOpt;
52  /// Whether we're optimizing for size.
53  bool EnableOptSize;
54  /// Whether we're optimizing for minsize (-Oz).
55  bool EnableMinSize;
56
57  /// Attempt to combine instructions using MI as the root.
58  ///
59  /// Use Observer to report the creation, modification, and erasure of
60  /// instructions. GISelChangeObserver will automatically report certain
61  /// kinds of operations. These operations are:
62  /// * Instructions that are newly inserted into the MachineFunction
63  /// * Instructions that are erased from the MachineFunction.
64  ///
65  /// However, it is important to report instruction modification and this is
66  /// not automatic.
67  virtual bool combine(GISelChangeObserver &Observer, MachineInstr &MI,
68                       MachineIRBuilder &B) const = 0;
69};
70} // namespace llvm
71
72#endif
73