xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Mips/MipsPreLegalizerCombiner.cpp (revision 85868e8a1daeaae7a0e48effb2ea2310ae3b02c6)
1 //=== lib/CodeGen/GlobalISel/MipsPreLegalizerCombiner.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 "MipsTargetMachine.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/MIPatternMatch.h"
19 #include "llvm/CodeGen/TargetPassConfig.h"
20 
21 #define DEBUG_TYPE "mips-prelegalizer-combiner"
22 
23 using namespace llvm;
24 
25 namespace {
26 class MipsPreLegalizerCombinerInfo : public CombinerInfo {
27 public:
28   MipsPreLegalizerCombinerInfo()
29       : CombinerInfo(/*AllowIllegalOps*/ true, /*ShouldLegalizeIllegal*/ false,
30                      /*LegalizerInfo*/ nullptr, /*EnableOpt*/ false,
31                      /*EnableOptSize*/ false, /*EnableMinSize*/ false) {}
32   virtual bool combine(GISelChangeObserver &Observer, MachineInstr &MI,
33                        MachineIRBuilder &B) const override;
34 };
35 
36 bool MipsPreLegalizerCombinerInfo::combine(GISelChangeObserver &Observer,
37                                            MachineInstr &MI,
38                                            MachineIRBuilder &B) const {
39   CombinerHelper Helper(Observer, B);
40 
41   switch (MI.getOpcode()) {
42   default:
43     return false;
44   case TargetOpcode::G_LOAD:
45   case TargetOpcode::G_SEXTLOAD:
46   case TargetOpcode::G_ZEXTLOAD:
47     return Helper.tryCombineExtendingLoads(MI);
48   }
49   return false;
50 }
51 
52 // Pass boilerplate
53 // ================
54 
55 class MipsPreLegalizerCombiner : public MachineFunctionPass {
56 public:
57   static char ID;
58 
59   MipsPreLegalizerCombiner();
60 
61   StringRef getPassName() const override { return "MipsPreLegalizerCombiner"; }
62 
63   bool runOnMachineFunction(MachineFunction &MF) override;
64 
65   void getAnalysisUsage(AnalysisUsage &AU) const override;
66 };
67 } // end anonymous namespace
68 
69 void MipsPreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
70   AU.addRequired<TargetPassConfig>();
71   AU.setPreservesCFG();
72   getSelectionDAGFallbackAnalysisUsage(AU);
73   MachineFunctionPass::getAnalysisUsage(AU);
74 }
75 
76 MipsPreLegalizerCombiner::MipsPreLegalizerCombiner() : MachineFunctionPass(ID) {
77   initializeMipsPreLegalizerCombinerPass(*PassRegistry::getPassRegistry());
78 }
79 
80 bool MipsPreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) {
81   if (MF.getProperties().hasProperty(
82           MachineFunctionProperties::Property::FailedISel))
83     return false;
84   auto *TPC = &getAnalysis<TargetPassConfig>();
85   MipsPreLegalizerCombinerInfo PCInfo;
86   Combiner C(PCInfo, TPC);
87   return C.combineMachineInstrs(MF, nullptr);
88 }
89 
90 char MipsPreLegalizerCombiner::ID = 0;
91 INITIALIZE_PASS_BEGIN(MipsPreLegalizerCombiner, DEBUG_TYPE,
92                       "Combine Mips machine instrs before legalization", false,
93                       false)
94 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
95 INITIALIZE_PASS_END(MipsPreLegalizerCombiner, DEBUG_TYPE,
96                     "Combine Mips machine instrs before legalization", false,
97                     false)
98 
99 namespace llvm {
100 FunctionPass *createMipsPreLegalizeCombiner() {
101   return new MipsPreLegalizerCombiner();
102 }
103 } // end namespace llvm
104