1 //===- HexagonMCInstLower.cpp - Convert Hexagon MachineInstr to an MCInst -===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains code to lower Hexagon MachineInstrs to their corresponding
11 // MCInst records.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "Hexagon.h"
16 #include "HexagonAsmPrinter.h"
17 #include "HexagonMachineFunctionInfo.h"
18 #include "MCTargetDesc/HexagonMCInstrInfo.h"
19 
20 #include "llvm/CodeGen/MachineBasicBlock.h"
21 #include "llvm/IR/Constants.h"
22 #include "llvm/IR/Mangler.h"
23 #include "llvm/MC/MCContext.h"
24 #include "llvm/MC/MCExpr.h"
25 #include "llvm/MC/MCInst.h"
26 
27 using namespace llvm;
28 
29 namespace llvm {
30   void HexagonLowerToMC(const MCInstrInfo &MCII, const MachineInstr *MI,
31                         MCInst &MCB, HexagonAsmPrinter &AP);
32 }
33 
34 static MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol,
35                               HexagonAsmPrinter &Printer) {
36   MCContext &MC = Printer.OutContext;
37   const MCExpr *ME;
38 
39   // Populate the relocation type based on Hexagon target flags
40   // set on an operand
41   MCSymbolRefExpr::VariantKind RelocationType;
42   switch (MO.getTargetFlags()) {
43   default:
44     RelocationType = MCSymbolRefExpr::VK_None;
45     break;
46   case HexagonII::MO_PCREL:
47     RelocationType = MCSymbolRefExpr::VK_Hexagon_PCREL;
48     break;
49   case HexagonII::MO_GOT:
50     RelocationType = MCSymbolRefExpr::VK_GOT;
51     break;
52   case HexagonII::MO_LO16:
53     RelocationType = MCSymbolRefExpr::VK_Hexagon_LO16;
54     break;
55   case HexagonII::MO_HI16:
56     RelocationType = MCSymbolRefExpr::VK_Hexagon_HI16;
57     break;
58   case HexagonII::MO_GPREL:
59     RelocationType = MCSymbolRefExpr::VK_Hexagon_GPREL;
60     break;
61   }
62 
63   ME = MCSymbolRefExpr::create(Symbol, RelocationType, MC);
64 
65   if (!MO.isJTI() && MO.getOffset())
66     ME = MCBinaryExpr::createAdd(ME, MCConstantExpr::create(MO.getOffset(), MC),
67                                  MC);
68 
69   return MCOperand::createExpr(ME);
70 }
71 
72 // Create an MCInst from a MachineInstr
73 void llvm::HexagonLowerToMC(const MCInstrInfo &MCII, const MachineInstr *MI,
74                             MCInst &MCB, HexagonAsmPrinter &AP) {
75   if (MI->getOpcode() == Hexagon::ENDLOOP0) {
76     HexagonMCInstrInfo::setInnerLoop(MCB);
77     return;
78   }
79   if (MI->getOpcode() == Hexagon::ENDLOOP1) {
80     HexagonMCInstrInfo::setOuterLoop(MCB);
81     return;
82   }
83   MCInst *MCI = new (AP.OutContext) MCInst;
84   MCI->setOpcode(MI->getOpcode());
85   assert(MCI->getOpcode() == static_cast<unsigned>(MI->getOpcode()) &&
86          "MCI opcode should have been set on construction");
87   bool MustExtend = false;
88 
89   for (unsigned i = 0, e = MI->getNumOperands(); i < e; i++) {
90     const MachineOperand &MO = MI->getOperand(i);
91     MCOperand MCO;
92     if (MO.getTargetFlags() & HexagonII::HMOTF_ConstExtended)
93       MustExtend = true;
94 
95     switch (MO.getType()) {
96     default:
97       MI->dump();
98       llvm_unreachable("unknown operand type");
99     case MachineOperand::MO_Register:
100       // Ignore all implicit register operands.
101       if (MO.isImplicit()) continue;
102       MCO = MCOperand::createReg(MO.getReg());
103       break;
104     case MachineOperand::MO_FPImmediate: {
105       APFloat Val = MO.getFPImm()->getValueAPF();
106       // FP immediates are used only when setting GPRs, so they may be dealt
107       // with like regular immediates from this point on.
108       MCO = MCOperand::createExpr(
109         MCConstantExpr::create(*Val.bitcastToAPInt().getRawData(),
110                                AP.OutContext));
111       break;
112     }
113     case MachineOperand::MO_Immediate:
114       MCO = MCOperand::createExpr(
115         MCConstantExpr::create(MO.getImm(), AP.OutContext));
116       break;
117     case MachineOperand::MO_MachineBasicBlock:
118       MCO = MCOperand::createExpr
119               (MCSymbolRefExpr::create(MO.getMBB()->getSymbol(),
120                AP.OutContext));
121       break;
122     case MachineOperand::MO_GlobalAddress:
123       MCO = GetSymbolRef(MO, AP.getSymbol(MO.getGlobal()), AP);
124       break;
125     case MachineOperand::MO_ExternalSymbol:
126       MCO = GetSymbolRef(MO, AP.GetExternalSymbolSymbol(MO.getSymbolName()),
127                          AP);
128       break;
129     case MachineOperand::MO_JumpTableIndex:
130       MCO = GetSymbolRef(MO, AP.GetJTISymbol(MO.getIndex()), AP);
131       break;
132     case MachineOperand::MO_ConstantPoolIndex:
133       MCO = GetSymbolRef(MO, AP.GetCPISymbol(MO.getIndex()), AP);
134       break;
135     case MachineOperand::MO_BlockAddress:
136       MCO = GetSymbolRef(MO, AP.GetBlockAddressSymbol(MO.getBlockAddress()),AP);
137       break;
138     }
139 
140     MCI->addOperand(MCO);
141   }
142   AP.HexagonProcessInstruction(*MCI, *MI);
143   HexagonMCInstrInfo::extendIfNeeded(AP.OutContext, MCII, MCB, *MCI,
144                                      MustExtend);
145   MCB.addOperand(MCOperand::createInst(MCI));
146 }
147