1 //=== lib/CodeGen/GlobalISel/AArch64PreLegalizerCombiner.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 "AArch64TargetMachine.h"
15 #include "llvm/CodeGen/GlobalISel/Combiner.h"
16 #include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
17 #include "llvm/CodeGen/GlobalISel/CombinerInfo.h"
18 #include "llvm/CodeGen/GlobalISel/GISelKnownBits.h"
19 #include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
20 #include "llvm/CodeGen/MachineDominators.h"
21 #include "llvm/CodeGen/MachineFunctionPass.h"
22 #include "llvm/CodeGen/TargetPassConfig.h"
23 #include "llvm/Support/Debug.h"
24
25 #define DEBUG_TYPE "aarch64-prelegalizer-combiner"
26
27 using namespace llvm;
28 using namespace MIPatternMatch;
29
30 #define AARCH64PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_DEPS
31 #include "AArch64GenGICombiner.inc"
32 #undef AARCH64PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_DEPS
33
34 namespace {
35 #define AARCH64PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_H
36 #include "AArch64GenGICombiner.inc"
37 #undef AARCH64PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_H
38
39 class AArch64PreLegalizerCombinerInfo : public CombinerInfo {
40 GISelKnownBits *KB;
41 MachineDominatorTree *MDT;
42
43 public:
44 AArch64GenPreLegalizerCombinerHelper Generated;
45
AArch64PreLegalizerCombinerInfo(bool EnableOpt,bool OptSize,bool MinSize,GISelKnownBits * KB,MachineDominatorTree * MDT)46 AArch64PreLegalizerCombinerInfo(bool EnableOpt, bool OptSize, bool MinSize,
47 GISelKnownBits *KB, MachineDominatorTree *MDT)
48 : CombinerInfo(/*AllowIllegalOps*/ true, /*ShouldLegalizeIllegal*/ false,
49 /*LegalizerInfo*/ nullptr, EnableOpt, OptSize, MinSize),
50 KB(KB), MDT(MDT) {
51 if (!Generated.parseCommandLineOption())
52 report_fatal_error("Invalid rule identifier");
53 }
54
55 virtual bool combine(GISelChangeObserver &Observer, MachineInstr &MI,
56 MachineIRBuilder &B) const override;
57 };
58
combine(GISelChangeObserver & Observer,MachineInstr & MI,MachineIRBuilder & B) const59 bool AArch64PreLegalizerCombinerInfo::combine(GISelChangeObserver &Observer,
60 MachineInstr &MI,
61 MachineIRBuilder &B) const {
62 CombinerHelper Helper(Observer, B, KB, MDT);
63
64 switch (MI.getOpcode()) {
65 case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS:
66 switch (MI.getIntrinsicID()) {
67 case Intrinsic::memcpy:
68 case Intrinsic::memmove:
69 case Intrinsic::memset: {
70 // If we're at -O0 set a maxlen of 32 to inline, otherwise let the other
71 // heuristics decide.
72 unsigned MaxLen = EnableOpt ? 0 : 32;
73 // Try to inline memcpy type calls if optimizations are enabled.
74 return (!EnableMinSize) ? Helper.tryCombineMemCpyFamily(MI, MaxLen)
75 : false;
76 }
77 default:
78 break;
79 }
80 }
81
82 if (Generated.tryCombineAll(Observer, MI, B, Helper))
83 return true;
84
85 switch (MI.getOpcode()) {
86 case TargetOpcode::G_CONCAT_VECTORS:
87 return Helper.tryCombineConcatVectors(MI);
88 case TargetOpcode::G_SHUFFLE_VECTOR:
89 return Helper.tryCombineShuffleVector(MI);
90 }
91
92 return false;
93 }
94
95 #define AARCH64PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_CPP
96 #include "AArch64GenGICombiner.inc"
97 #undef AARCH64PRELEGALIZERCOMBINERHELPER_GENCOMBINERHELPER_CPP
98
99 // Pass boilerplate
100 // ================
101
102 class AArch64PreLegalizerCombiner : public MachineFunctionPass {
103 public:
104 static char ID;
105
106 AArch64PreLegalizerCombiner(bool IsOptNone = false);
107
getPassName() const108 StringRef getPassName() const override { return "AArch64PreLegalizerCombiner"; }
109
110 bool runOnMachineFunction(MachineFunction &MF) override;
111
112 void getAnalysisUsage(AnalysisUsage &AU) const override;
113 private:
114 bool IsOptNone;
115 };
116 } // end anonymous namespace
117
getAnalysisUsage(AnalysisUsage & AU) const118 void AArch64PreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
119 AU.addRequired<TargetPassConfig>();
120 AU.setPreservesCFG();
121 getSelectionDAGFallbackAnalysisUsage(AU);
122 AU.addRequired<GISelKnownBitsAnalysis>();
123 AU.addPreserved<GISelKnownBitsAnalysis>();
124 if (!IsOptNone) {
125 AU.addRequired<MachineDominatorTree>();
126 AU.addPreserved<MachineDominatorTree>();
127 }
128 MachineFunctionPass::getAnalysisUsage(AU);
129 }
130
AArch64PreLegalizerCombiner(bool IsOptNone)131 AArch64PreLegalizerCombiner::AArch64PreLegalizerCombiner(bool IsOptNone)
132 : MachineFunctionPass(ID), IsOptNone(IsOptNone) {
133 initializeAArch64PreLegalizerCombinerPass(*PassRegistry::getPassRegistry());
134 }
135
runOnMachineFunction(MachineFunction & MF)136 bool AArch64PreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) {
137 if (MF.getProperties().hasProperty(
138 MachineFunctionProperties::Property::FailedISel))
139 return false;
140 auto *TPC = &getAnalysis<TargetPassConfig>();
141 const Function &F = MF.getFunction();
142 bool EnableOpt =
143 MF.getTarget().getOptLevel() != CodeGenOpt::None && !skipFunction(F);
144 GISelKnownBits *KB = &getAnalysis<GISelKnownBitsAnalysis>().get(MF);
145 MachineDominatorTree *MDT =
146 IsOptNone ? nullptr : &getAnalysis<MachineDominatorTree>();
147 AArch64PreLegalizerCombinerInfo PCInfo(EnableOpt, F.hasOptSize(),
148 F.hasMinSize(), KB, MDT);
149 Combiner C(PCInfo, TPC);
150 return C.combineMachineInstrs(MF, /*CSEInfo*/ nullptr);
151 }
152
153 char AArch64PreLegalizerCombiner::ID = 0;
154 INITIALIZE_PASS_BEGIN(AArch64PreLegalizerCombiner, DEBUG_TYPE,
155 "Combine AArch64 machine instrs before legalization",
156 false, false)
157 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
158 INITIALIZE_PASS_DEPENDENCY(GISelKnownBitsAnalysis)
159 INITIALIZE_PASS_END(AArch64PreLegalizerCombiner, DEBUG_TYPE,
160 "Combine AArch64 machine instrs before legalization", false,
161 false)
162
163
164 namespace llvm {
createAArch64PreLegalizeCombiner(bool IsOptNone)165 FunctionPass *createAArch64PreLegalizeCombiner(bool IsOptNone) {
166 return new AArch64PreLegalizerCombiner(IsOptNone);
167 }
168 } // end namespace llvm
169