xref: /freebsd/contrib/llvm-project/llvm/lib/Target/RISCV/GISel/RISCVPreLegalizerCombiner.cpp (revision 5b56413d04e608379c9a306373554a8e4d321bc0)
1 //=== RISCVPreLegalizerCombiner.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 "RISCVSubtarget.h"
15 #include "llvm/CodeGen/GlobalISel/CSEInfo.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/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 
28 #define GET_GICOMBINER_DEPS
29 #include "RISCVGenPreLegalizeGICombiner.inc"
30 #undef GET_GICOMBINER_DEPS
31 
32 #define DEBUG_TYPE "riscv-prelegalizer-combiner"
33 
34 using namespace llvm;
35 
36 namespace {
37 
38 #define GET_GICOMBINER_TYPES
39 #include "RISCVGenPreLegalizeGICombiner.inc"
40 #undef GET_GICOMBINER_TYPES
41 
42 class RISCVPreLegalizerCombinerImpl : public Combiner {
43 protected:
44   // TODO: Make CombinerHelper methods const.
45   mutable CombinerHelper Helper;
46   const RISCVPreLegalizerCombinerImplRuleConfig &RuleConfig;
47   const RISCVSubtarget &STI;
48 
49 public:
50   RISCVPreLegalizerCombinerImpl(
51       MachineFunction &MF, CombinerInfo &CInfo, const TargetPassConfig *TPC,
52       GISelKnownBits &KB, GISelCSEInfo *CSEInfo,
53       const RISCVPreLegalizerCombinerImplRuleConfig &RuleConfig,
54       const RISCVSubtarget &STI, MachineDominatorTree *MDT,
55       const LegalizerInfo *LI);
56 
57   static const char *getName() { return "RISCV00PreLegalizerCombiner"; }
58 
59   bool tryCombineAll(MachineInstr &I) const override;
60 
61 private:
62 #define GET_GICOMBINER_CLASS_MEMBERS
63 #include "RISCVGenPreLegalizeGICombiner.inc"
64 #undef GET_GICOMBINER_CLASS_MEMBERS
65 };
66 
67 #define GET_GICOMBINER_IMPL
68 #include "RISCVGenPreLegalizeGICombiner.inc"
69 #undef GET_GICOMBINER_IMPL
70 
71 RISCVPreLegalizerCombinerImpl::RISCVPreLegalizerCombinerImpl(
72     MachineFunction &MF, CombinerInfo &CInfo, const TargetPassConfig *TPC,
73     GISelKnownBits &KB, GISelCSEInfo *CSEInfo,
74     const RISCVPreLegalizerCombinerImplRuleConfig &RuleConfig,
75     const RISCVSubtarget &STI, MachineDominatorTree *MDT,
76     const LegalizerInfo *LI)
77     : Combiner(MF, CInfo, TPC, &KB, CSEInfo),
78       Helper(Observer, B, /*IsPreLegalize*/ true, &KB, MDT, LI),
79       RuleConfig(RuleConfig), STI(STI),
80 #define GET_GICOMBINER_CONSTRUCTOR_INITS
81 #include "RISCVGenPreLegalizeGICombiner.inc"
82 #undef GET_GICOMBINER_CONSTRUCTOR_INITS
83 {
84 }
85 
86 // Pass boilerplate
87 // ================
88 
89 class RISCVPreLegalizerCombiner : public MachineFunctionPass {
90 public:
91   static char ID;
92 
93   RISCVPreLegalizerCombiner();
94 
95   StringRef getPassName() const override { return "RISCVPreLegalizerCombiner"; }
96 
97   bool runOnMachineFunction(MachineFunction &MF) override;
98 
99   void getAnalysisUsage(AnalysisUsage &AU) const override;
100 
101 private:
102   RISCVPreLegalizerCombinerImplRuleConfig RuleConfig;
103 };
104 } // end anonymous namespace
105 
106 void RISCVPreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
107   AU.addRequired<TargetPassConfig>();
108   AU.setPreservesCFG();
109   getSelectionDAGFallbackAnalysisUsage(AU);
110   AU.addRequired<GISelKnownBitsAnalysis>();
111   AU.addPreserved<GISelKnownBitsAnalysis>();
112   AU.addRequired<MachineDominatorTree>();
113   AU.addPreserved<MachineDominatorTree>();
114   AU.addRequired<GISelCSEAnalysisWrapperPass>();
115   AU.addPreserved<GISelCSEAnalysisWrapperPass>();
116   MachineFunctionPass::getAnalysisUsage(AU);
117 }
118 
119 RISCVPreLegalizerCombiner::RISCVPreLegalizerCombiner()
120     : MachineFunctionPass(ID) {
121   initializeRISCVPreLegalizerCombinerPass(*PassRegistry::getPassRegistry());
122 
123   if (!RuleConfig.parseCommandLineOption())
124     report_fatal_error("Invalid rule identifier");
125 }
126 
127 bool RISCVPreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) {
128   if (MF.getProperties().hasProperty(
129           MachineFunctionProperties::Property::FailedISel))
130     return false;
131   auto &TPC = getAnalysis<TargetPassConfig>();
132 
133   // Enable CSE.
134   GISelCSEAnalysisWrapper &Wrapper =
135       getAnalysis<GISelCSEAnalysisWrapperPass>().getCSEWrapper();
136   auto *CSEInfo = &Wrapper.get(TPC.getCSEConfig());
137 
138   const RISCVSubtarget &ST = MF.getSubtarget<RISCVSubtarget>();
139   const auto *LI = ST.getLegalizerInfo();
140 
141   const Function &F = MF.getFunction();
142   bool EnableOpt =
143       MF.getTarget().getOptLevel() != CodeGenOptLevel::None && !skipFunction(F);
144   GISelKnownBits *KB = &getAnalysis<GISelKnownBitsAnalysis>().get(MF);
145   MachineDominatorTree *MDT = &getAnalysis<MachineDominatorTree>();
146   CombinerInfo CInfo(/*AllowIllegalOps*/ true, /*ShouldLegalizeIllegal*/ false,
147                      /*LegalizerInfo*/ nullptr, EnableOpt, F.hasOptSize(),
148                      F.hasMinSize());
149   RISCVPreLegalizerCombinerImpl Impl(MF, CInfo, &TPC, *KB, CSEInfo, RuleConfig,
150                                      ST, MDT, LI);
151   return Impl.combineMachineInstrs();
152 }
153 
154 char RISCVPreLegalizerCombiner::ID = 0;
155 INITIALIZE_PASS_BEGIN(RISCVPreLegalizerCombiner, DEBUG_TYPE,
156                       "Combine RISC-V machine instrs before legalization", false,
157                       false)
158 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
159 INITIALIZE_PASS_DEPENDENCY(GISelKnownBitsAnalysis)
160 INITIALIZE_PASS_DEPENDENCY(GISelCSEAnalysisWrapperPass)
161 INITIALIZE_PASS_END(RISCVPreLegalizerCombiner, DEBUG_TYPE,
162                     "Combine RISC-V machine instrs before legalization", false,
163                     false)
164 
165 namespace llvm {
166 FunctionPass *createRISCVPreLegalizerCombiner() {
167   return new RISCVPreLegalizerCombiner();
168 }
169 } // end namespace llvm
170