1//===- llvm/CodeGen/GlobalISel/GIMatchTableExecutor.cpp -------------------===//
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/// \file
10/// This file implements the GIMatchTableExecutor class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/CodeGen/GlobalISel/GIMatchTableExecutor.h"
15#include "llvm/CodeGen/GlobalISel/Utils.h"
16#include "llvm/CodeGen/MachineInstr.h"
17#include "llvm/CodeGen/MachineOperand.h"
18#include "llvm/CodeGen/MachineRegisterInfo.h"
19
20#define DEBUG_TYPE "gi-match-table-executor"
21
22using namespace llvm;
23
24GIMatchTableExecutor::MatcherState::MatcherState(unsigned MaxRenderers)
25    : Renderers(MaxRenderers) {}
26
27GIMatchTableExecutor::GIMatchTableExecutor() = default;
28
29bool GIMatchTableExecutor::isOperandImmEqual(const MachineOperand &MO,
30                                             int64_t Value,
31                                             const MachineRegisterInfo &MRI,
32                                             bool Splat) const {
33  if (MO.isReg() && MO.getReg()) {
34    if (auto VRegVal = getIConstantVRegValWithLookThrough(MO.getReg(), MRI))
35      return VRegVal->Value.getSExtValue() == Value;
36
37    if (Splat) {
38      if (auto VRegVal = getIConstantSplatVal(MO.getReg(), MRI))
39        return VRegVal->getSExtValue() == Value;
40    }
41  }
42  return false;
43}
44
45bool GIMatchTableExecutor::isBaseWithConstantOffset(
46    const MachineOperand &Root, const MachineRegisterInfo &MRI) const {
47  if (!Root.isReg())
48    return false;
49
50  MachineInstr *RootI = MRI.getVRegDef(Root.getReg());
51  if (RootI->getOpcode() != TargetOpcode::G_PTR_ADD)
52    return false;
53
54  MachineOperand &RHS = RootI->getOperand(2);
55  MachineInstr *RHSI = MRI.getVRegDef(RHS.getReg());
56  if (RHSI->getOpcode() != TargetOpcode::G_CONSTANT)
57    return false;
58
59  return true;
60}
61
62bool GIMatchTableExecutor::isObviouslySafeToFold(MachineInstr &MI,
63                                                 MachineInstr &IntoMI) const {
64  // Immediate neighbours are already folded.
65  if (MI.getParent() == IntoMI.getParent() &&
66      std::next(MI.getIterator()) == IntoMI.getIterator())
67    return true;
68
69  // Convergent instructions cannot be moved in the CFG.
70  if (MI.isConvergent() && MI.getParent() != IntoMI.getParent())
71    return false;
72
73  return !MI.mayLoadOrStore() && !MI.mayRaiseFPException() &&
74         !MI.hasUnmodeledSideEffects() && MI.implicit_operands().empty();
75}
76