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/GISelKnownBits.h"
20 #include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
21 #include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
22 #include "llvm/CodeGen/MachineDominators.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineFunctionPass.h"
25 #include "llvm/CodeGen/MachineRegisterInfo.h"
26 #include "llvm/CodeGen/TargetPassConfig.h"
27 #include "llvm/IR/Instructions.h"
28 #include "llvm/Support/Debug.h"
29
30 #define DEBUG_TYPE "aarch64-O0-prelegalizer-combiner"
31
32 using namespace llvm;
33 using namespace MIPatternMatch;
34
35 class AArch64O0PreLegalizerCombinerHelperState {
36 protected:
37 CombinerHelper &Helper;
38
39 public:
AArch64O0PreLegalizerCombinerHelperState(CombinerHelper & Helper)40 AArch64O0PreLegalizerCombinerHelperState(CombinerHelper &Helper)
41 : Helper(Helper) {}
42 };
43
44 #define AARCH64O0PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_DEPS
45 #include "AArch64GenO0PreLegalizeGICombiner.inc"
46 #undef AARCH64O0PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_DEPS
47
48 namespace {
49 #define AARCH64O0PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_H
50 #include "AArch64GenO0PreLegalizeGICombiner.inc"
51 #undef AARCH64O0PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_H
52
53 class AArch64O0PreLegalizerCombinerInfo : public CombinerInfo {
54 GISelKnownBits *KB;
55 MachineDominatorTree *MDT;
56 AArch64GenO0PreLegalizerCombinerHelperRuleConfig GeneratedRuleCfg;
57
58 public:
AArch64O0PreLegalizerCombinerInfo(bool EnableOpt,bool OptSize,bool MinSize,GISelKnownBits * KB,MachineDominatorTree * MDT)59 AArch64O0PreLegalizerCombinerInfo(bool EnableOpt, bool OptSize, bool MinSize,
60 GISelKnownBits *KB,
61 MachineDominatorTree *MDT)
62 : CombinerInfo(/*AllowIllegalOps*/ true, /*ShouldLegalizeIllegal*/ false,
63 /*LegalizerInfo*/ nullptr, EnableOpt, OptSize, MinSize),
64 KB(KB), MDT(MDT) {
65 if (!GeneratedRuleCfg.parseCommandLineOption())
66 report_fatal_error("Invalid rule identifier");
67 }
68
69 virtual bool combine(GISelChangeObserver &Observer, MachineInstr &MI,
70 MachineIRBuilder &B) const override;
71 };
72
combine(GISelChangeObserver & Observer,MachineInstr & MI,MachineIRBuilder & B) const73 bool AArch64O0PreLegalizerCombinerInfo::combine(GISelChangeObserver &Observer,
74 MachineInstr &MI,
75 MachineIRBuilder &B) const {
76 CombinerHelper Helper(Observer, B, KB, MDT);
77 AArch64GenO0PreLegalizerCombinerHelper Generated(GeneratedRuleCfg, Helper);
78
79 if (Generated.tryCombineAll(Observer, MI, B))
80 return true;
81
82 unsigned Opc = MI.getOpcode();
83 switch (Opc) {
84 case TargetOpcode::G_CONCAT_VECTORS:
85 return Helper.tryCombineConcatVectors(MI);
86 case TargetOpcode::G_SHUFFLE_VECTOR:
87 return Helper.tryCombineShuffleVector(MI);
88 case TargetOpcode::G_MEMCPY:
89 case TargetOpcode::G_MEMMOVE:
90 case TargetOpcode::G_MEMSET: {
91 // At -O0 set a maxlen of 32 to inline;
92 unsigned MaxLen = 32;
93 // Try to inline memcpy type calls if optimizations are enabled.
94 if (Helper.tryCombineMemCpyFamily(MI, MaxLen))
95 return true;
96 if (Opc == TargetOpcode::G_MEMSET)
97 return llvm::AArch64GISelUtils::tryEmitBZero(MI, B, EnableMinSize);
98 return false;
99 }
100 }
101
102 return false;
103 }
104
105 #define AARCH64O0PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_CPP
106 #include "AArch64GenO0PreLegalizeGICombiner.inc"
107 #undef AARCH64O0PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_CPP
108
109 // Pass boilerplate
110 // ================
111
112 class AArch64O0PreLegalizerCombiner : public MachineFunctionPass {
113 public:
114 static char ID;
115
116 AArch64O0PreLegalizerCombiner();
117
getPassName() const118 StringRef getPassName() const override {
119 return "AArch64O0PreLegalizerCombiner";
120 }
121
122 bool runOnMachineFunction(MachineFunction &MF) override;
123
124 void getAnalysisUsage(AnalysisUsage &AU) const override;
125 };
126 } // end anonymous namespace
127
getAnalysisUsage(AnalysisUsage & AU) const128 void AArch64O0PreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
129 AU.addRequired<TargetPassConfig>();
130 AU.setPreservesCFG();
131 getSelectionDAGFallbackAnalysisUsage(AU);
132 AU.addRequired<GISelKnownBitsAnalysis>();
133 AU.addPreserved<GISelKnownBitsAnalysis>();
134 MachineFunctionPass::getAnalysisUsage(AU);
135 }
136
AArch64O0PreLegalizerCombiner()137 AArch64O0PreLegalizerCombiner::AArch64O0PreLegalizerCombiner()
138 : MachineFunctionPass(ID) {
139 initializeAArch64O0PreLegalizerCombinerPass(*PassRegistry::getPassRegistry());
140 }
141
runOnMachineFunction(MachineFunction & MF)142 bool AArch64O0PreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) {
143 if (MF.getProperties().hasProperty(
144 MachineFunctionProperties::Property::FailedISel))
145 return false;
146 auto &TPC = getAnalysis<TargetPassConfig>();
147
148 const Function &F = MF.getFunction();
149 GISelKnownBits *KB = &getAnalysis<GISelKnownBitsAnalysis>().get(MF);
150 AArch64O0PreLegalizerCombinerInfo PCInfo(
151 false, F.hasOptSize(), F.hasMinSize(), KB, nullptr /* MDT */);
152 Combiner C(PCInfo, &TPC);
153 return C.combineMachineInstrs(MF, nullptr /* CSEInfo */);
154 }
155
156 char AArch64O0PreLegalizerCombiner::ID = 0;
157 INITIALIZE_PASS_BEGIN(AArch64O0PreLegalizerCombiner, DEBUG_TYPE,
158 "Combine AArch64 machine instrs before legalization",
159 false, false)
160 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
161 INITIALIZE_PASS_DEPENDENCY(GISelKnownBitsAnalysis)
162 INITIALIZE_PASS_DEPENDENCY(GISelCSEAnalysisWrapperPass)
163 INITIALIZE_PASS_END(AArch64O0PreLegalizerCombiner, DEBUG_TYPE,
164 "Combine AArch64 machine instrs before legalization", false,
165 false)
166
167 namespace llvm {
createAArch64O0PreLegalizerCombiner()168 FunctionPass *createAArch64O0PreLegalizerCombiner() {
169 return new AArch64O0PreLegalizerCombiner();
170 }
171 } // end namespace llvm
172