1//=== lib/CodeGen/GlobalISel/AArch64O0PreLegalizerCombiner.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// This pass does combining of machine instructions at the generic MI level,
10// before the legalizer.
11//
12//===----------------------------------------------------------------------===//
13
14#include "AArch64GlobalISelUtils.h"
15#include "AArch64TargetMachine.h"
16#include "llvm/CodeGen/GlobalISel/Combiner.h"
17#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
18#include "llvm/CodeGen/GlobalISel/CombinerInfo.h"
19#include "llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h"
20#include "llvm/CodeGen/GlobalISel/GISelKnownBits.h"
21#include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
22#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
23#include "llvm/CodeGen/MachineDominators.h"
24#include "llvm/CodeGen/MachineFunction.h"
25#include "llvm/CodeGen/MachineFunctionPass.h"
26#include "llvm/CodeGen/MachineRegisterInfo.h"
27#include "llvm/CodeGen/TargetPassConfig.h"
28#include "llvm/IR/Instructions.h"
29#include "llvm/Support/Debug.h"
30
31#define GET_GICOMBINER_DEPS
32#include "AArch64GenO0PreLegalizeGICombiner.inc"
33#undef GET_GICOMBINER_DEPS
34
35#define DEBUG_TYPE "aarch64-O0-prelegalizer-combiner"
36
37using namespace llvm;
38using namespace MIPatternMatch;
39namespace {
40#define GET_GICOMBINER_TYPES
41#include "AArch64GenO0PreLegalizeGICombiner.inc"
42#undef GET_GICOMBINER_TYPES
43
44class AArch64O0PreLegalizerCombinerImpl : public Combiner {
45protected:
46  // TODO: Make CombinerHelper methods const.
47  mutable CombinerHelper Helper;
48  const AArch64O0PreLegalizerCombinerImplRuleConfig &RuleConfig;
49  const AArch64Subtarget &STI;
50
51public:
52  AArch64O0PreLegalizerCombinerImpl(
53      MachineFunction &MF, CombinerInfo &CInfo, const TargetPassConfig *TPC,
54      GISelKnownBits &KB, GISelCSEInfo *CSEInfo,
55      const AArch64O0PreLegalizerCombinerImplRuleConfig &RuleConfig,
56      const AArch64Subtarget &STI);
57
58  static const char *getName() { return "AArch64O0PreLegalizerCombiner"; }
59
60  bool tryCombineAll(MachineInstr &I) const override;
61
62  bool tryCombineAllImpl(MachineInstr &I) const;
63
64private:
65#define GET_GICOMBINER_CLASS_MEMBERS
66#include "AArch64GenO0PreLegalizeGICombiner.inc"
67#undef GET_GICOMBINER_CLASS_MEMBERS
68};
69
70#define GET_GICOMBINER_IMPL
71#include "AArch64GenO0PreLegalizeGICombiner.inc"
72#undef GET_GICOMBINER_IMPL
73
74AArch64O0PreLegalizerCombinerImpl::AArch64O0PreLegalizerCombinerImpl(
75    MachineFunction &MF, CombinerInfo &CInfo, const TargetPassConfig *TPC,
76    GISelKnownBits &KB, GISelCSEInfo *CSEInfo,
77    const AArch64O0PreLegalizerCombinerImplRuleConfig &RuleConfig,
78    const AArch64Subtarget &STI)
79    : Combiner(MF, CInfo, TPC, &KB, CSEInfo),
80      Helper(Observer, B, /*IsPreLegalize*/ true, &KB), RuleConfig(RuleConfig),
81      STI(STI),
82#define GET_GICOMBINER_CONSTRUCTOR_INITS
83#include "AArch64GenO0PreLegalizeGICombiner.inc"
84#undef GET_GICOMBINER_CONSTRUCTOR_INITS
85{
86}
87
88bool AArch64O0PreLegalizerCombinerImpl::tryCombineAll(MachineInstr &MI) const {
89  if (tryCombineAllImpl(MI))
90    return true;
91
92  unsigned Opc = MI.getOpcode();
93  switch (Opc) {
94  case TargetOpcode::G_CONCAT_VECTORS:
95    return Helper.tryCombineConcatVectors(MI);
96  case TargetOpcode::G_SHUFFLE_VECTOR:
97    return Helper.tryCombineShuffleVector(MI);
98  case TargetOpcode::G_MEMCPY_INLINE:
99    return Helper.tryEmitMemcpyInline(MI);
100  case TargetOpcode::G_MEMCPY:
101  case TargetOpcode::G_MEMMOVE:
102  case TargetOpcode::G_MEMSET: {
103    // At -O0 set a maxlen of 32 to inline;
104    unsigned MaxLen = 32;
105    // Try to inline memcpy type calls if optimizations are enabled.
106    if (Helper.tryCombineMemCpyFamily(MI, MaxLen))
107      return true;
108    if (Opc == TargetOpcode::G_MEMSET)
109      return llvm::AArch64GISelUtils::tryEmitBZero(MI, B, CInfo.EnableMinSize);
110    return false;
111  }
112  }
113
114  return false;
115}
116
117// Pass boilerplate
118// ================
119
120class AArch64O0PreLegalizerCombiner : public MachineFunctionPass {
121public:
122  static char ID;
123
124  AArch64O0PreLegalizerCombiner();
125
126  StringRef getPassName() const override {
127    return "AArch64O0PreLegalizerCombiner";
128  }
129
130  bool runOnMachineFunction(MachineFunction &MF) override;
131
132  void getAnalysisUsage(AnalysisUsage &AU) const override;
133
134private:
135  AArch64O0PreLegalizerCombinerImplRuleConfig RuleConfig;
136};
137} // end anonymous namespace
138
139void AArch64O0PreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
140  AU.addRequired<TargetPassConfig>();
141  AU.setPreservesCFG();
142  getSelectionDAGFallbackAnalysisUsage(AU);
143  AU.addRequired<GISelKnownBitsAnalysis>();
144  AU.addPreserved<GISelKnownBitsAnalysis>();
145  MachineFunctionPass::getAnalysisUsage(AU);
146}
147
148AArch64O0PreLegalizerCombiner::AArch64O0PreLegalizerCombiner()
149    : MachineFunctionPass(ID) {
150  initializeAArch64O0PreLegalizerCombinerPass(*PassRegistry::getPassRegistry());
151
152  if (!RuleConfig.parseCommandLineOption())
153    report_fatal_error("Invalid rule identifier");
154}
155
156bool AArch64O0PreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) {
157  if (MF.getProperties().hasProperty(
158          MachineFunctionProperties::Property::FailedISel))
159    return false;
160  auto &TPC = getAnalysis<TargetPassConfig>();
161
162  const Function &F = MF.getFunction();
163  GISelKnownBits *KB = &getAnalysis<GISelKnownBitsAnalysis>().get(MF);
164
165  const AArch64Subtarget &ST = MF.getSubtarget<AArch64Subtarget>();
166
167  CombinerInfo CInfo(/*AllowIllegalOps*/ true, /*ShouldLegalizeIllegal*/ false,
168                     /*LegalizerInfo*/ nullptr, /*EnableOpt*/ false,
169                     F.hasOptSize(), F.hasMinSize());
170  AArch64O0PreLegalizerCombinerImpl Impl(MF, CInfo, &TPC, *KB,
171                                         /*CSEInfo*/ nullptr, RuleConfig, ST);
172  return Impl.combineMachineInstrs();
173}
174
175char AArch64O0PreLegalizerCombiner::ID = 0;
176INITIALIZE_PASS_BEGIN(AArch64O0PreLegalizerCombiner, DEBUG_TYPE,
177                      "Combine AArch64 machine instrs before legalization",
178                      false, false)
179INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
180INITIALIZE_PASS_DEPENDENCY(GISelKnownBitsAnalysis)
181INITIALIZE_PASS_DEPENDENCY(GISelCSEAnalysisWrapperPass)
182INITIALIZE_PASS_END(AArch64O0PreLegalizerCombiner, DEBUG_TYPE,
183                    "Combine AArch64 machine instrs before legalization", false,
184                    false)
185
186namespace llvm {
187FunctionPass *createAArch64O0PreLegalizerCombiner() {
188  return new AArch64O0PreLegalizerCombiner();
189}
190} // end namespace llvm
191