xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AArch64/GISel/AArch64O0PreLegalizerCombiner.cpp (revision 5b56413d04e608379c9a306373554a8e4d321bc0)
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 
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 
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 
88 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 
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 
134 private:
135   AArch64O0PreLegalizerCombinerImplRuleConfig RuleConfig;
136 };
137 } // end anonymous namespace
138 
139 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 
148 AArch64O0PreLegalizerCombiner::AArch64O0PreLegalizerCombiner()
149     : MachineFunctionPass(ID) {
150   initializeAArch64O0PreLegalizerCombinerPass(*PassRegistry::getPassRegistry());
151 
152   if (!RuleConfig.parseCommandLineOption())
153     report_fatal_error("Invalid rule identifier");
154 }
155 
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 {
187 FunctionPass *createAArch64O0PreLegalizerCombiner() {
188   return new AArch64O0PreLegalizerCombiner();
189 }
190 } // end namespace llvm
191