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
37 using namespace llvm;
38 using namespace MIPatternMatch;
39 namespace {
40 #define GET_GICOMBINER_TYPES
41 #include "AArch64GenO0PreLegalizeGICombiner.inc"
42 #undef GET_GICOMBINER_TYPES
43
44 class AArch64O0PreLegalizerCombinerImpl : public Combiner {
45 protected:
46 // TODO: Make CombinerHelper methods const.
47 mutable CombinerHelper Helper;
48 const AArch64O0PreLegalizerCombinerImplRuleConfig &RuleConfig;
49 const AArch64Subtarget &STI;
50
51 public:
52 AArch64O0PreLegalizerCombinerImpl(
53 MachineFunction &MF, CombinerInfo &CInfo, const TargetPassConfig *TPC,
54 GISelKnownBits &KB, GISelCSEInfo *CSEInfo,
55 const AArch64O0PreLegalizerCombinerImplRuleConfig &RuleConfig,
56 const AArch64Subtarget &STI);
57
getName()58 static const char *getName() { return "AArch64O0PreLegalizerCombiner"; }
59
60 bool tryCombineAll(MachineInstr &I) const override;
61
62 bool tryCombineAllImpl(MachineInstr &I) const;
63
64 private:
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
AArch64O0PreLegalizerCombinerImpl(MachineFunction & MF,CombinerInfo & CInfo,const TargetPassConfig * TPC,GISelKnownBits & KB,GISelCSEInfo * CSEInfo,const AArch64O0PreLegalizerCombinerImplRuleConfig & RuleConfig,const AArch64Subtarget & STI)74 AArch64O0PreLegalizerCombinerImpl::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
tryCombineAll(MachineInstr & MI) const88 bool 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
120 class AArch64O0PreLegalizerCombiner : public MachineFunctionPass {
121 public:
122 static char ID;
123
124 AArch64O0PreLegalizerCombiner();
125
getPassName() const126 StringRef getPassName() const override {
127 return "AArch64O0PreLegalizerCombiner";
128 }
129
130 bool runOnMachineFunction(MachineFunction &MF) override;
131
132 void getAnalysisUsage(AnalysisUsage &AU) const override;
133
134 private:
135 AArch64O0PreLegalizerCombinerImplRuleConfig RuleConfig;
136 };
137 } // end anonymous namespace
138
getAnalysisUsage(AnalysisUsage & AU) const139 void 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
AArch64O0PreLegalizerCombiner()148 AArch64O0PreLegalizerCombiner::AArch64O0PreLegalizerCombiner()
149 : MachineFunctionPass(ID) {
150 initializeAArch64O0PreLegalizerCombinerPass(*PassRegistry::getPassRegistry());
151
152 if (!RuleConfig.parseCommandLineOption())
153 report_fatal_error("Invalid rule identifier");
154 }
155
runOnMachineFunction(MachineFunction & MF)156 bool 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
175 char AArch64O0PreLegalizerCombiner::ID = 0;
176 INITIALIZE_PASS_BEGIN(AArch64O0PreLegalizerCombiner, DEBUG_TYPE,
177 "Combine AArch64 machine instrs before legalization",
178 false, false)
179 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
180 INITIALIZE_PASS_DEPENDENCY(GISelKnownBitsAnalysis)
181 INITIALIZE_PASS_DEPENDENCY(GISelCSEAnalysisWrapperPass)
182 INITIALIZE_PASS_END(AArch64O0PreLegalizerCombiner, DEBUG_TYPE,
183 "Combine AArch64 machine instrs before legalization", false,
184 false)
185
186 namespace llvm {
createAArch64O0PreLegalizerCombiner()187 FunctionPass *createAArch64O0PreLegalizerCombiner() {
188 return new AArch64O0PreLegalizerCombiner();
189 }
190 } // end namespace llvm
191