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   case HexagonII::MO_GDGOT:
62     RelocationType = MCSymbolRefExpr::VK_Hexagon_GD_GOT;
63     break;
64   case HexagonII::MO_GDPLT:
65     RelocationType = MCSymbolRefExpr::VK_Hexagon_GD_PLT;
66     break;
67   case HexagonII::MO_IE:
68     RelocationType = MCSymbolRefExpr::VK_Hexagon_IE;
69     break;
70   case HexagonII::MO_IEGOT:
71     RelocationType = MCSymbolRefExpr::VK_Hexagon_IE_GOT;
72     break;
73   case HexagonII::MO_TPREL:
74     RelocationType = MCSymbolRefExpr::VK_TPREL;
75     break;
76   }
77 
78   ME = MCSymbolRefExpr::create(Symbol, RelocationType, MC);
79 
80   if (!MO.isJTI() && MO.getOffset())
81     ME = MCBinaryExpr::createAdd(ME, MCConstantExpr::create(MO.getOffset(), MC),
82                                  MC);
83 
84   return MCOperand::createExpr(HexagonMCExpr::create(ME, MC));
85 }
86 
87 // Create an MCInst from a MachineInstr
88 void llvm::HexagonLowerToMC(const MCInstrInfo &MCII, const MachineInstr *MI,
89                             MCInst &MCB, HexagonAsmPrinter &AP) {
90   if (MI->getOpcode() == Hexagon::ENDLOOP0) {
91     HexagonMCInstrInfo::setInnerLoop(MCB);
92     return;
93   }
94   if (MI->getOpcode() == Hexagon::ENDLOOP1) {
95     HexagonMCInstrInfo::setOuterLoop(MCB);
96     return;
97   }
98   MCInst *MCI = new (AP.OutContext) MCInst;
99   MCI->setOpcode(MI->getOpcode());
100   assert(MCI->getOpcode() == static_cast<unsigned>(MI->getOpcode()) &&
101          "MCI opcode should have been set on construction");
102   bool MustExtend = false;
103 
104   for (unsigned i = 0, e = MI->getNumOperands(); i < e; i++) {
105     const MachineOperand &MO = MI->getOperand(i);
106     MCOperand MCO;
107     if (MO.getTargetFlags() & HexagonII::HMOTF_ConstExtended)
108       MustExtend = true;
109 
110     switch (MO.getType()) {
111     default:
112       MI->dump();
113       llvm_unreachable("unknown operand type");
114     case MachineOperand::MO_Register:
115       // Ignore all implicit register operands.
116       if (MO.isImplicit()) continue;
117       MCO = MCOperand::createReg(MO.getReg());
118       break;
119     case MachineOperand::MO_FPImmediate: {
120       APFloat Val = MO.getFPImm()->getValueAPF();
121       // FP immediates are used only when setting GPRs, so they may be dealt
122       // with like regular immediates from this point on.
123       MCO = MCOperand::createExpr(
124         HexagonMCExpr::create(MCConstantExpr::create(*Val.bitcastToAPInt().getRawData(),
125                               AP.OutContext), AP.OutContext));
126       break;
127     }
128     case MachineOperand::MO_Immediate:
129       MCO = MCOperand::createExpr(
130         HexagonMCExpr::create(MCConstantExpr::create(MO.getImm(), AP.OutContext), AP.OutContext));
131       break;
132     case MachineOperand::MO_MachineBasicBlock:
133       MCO = MCOperand::createExpr
134               (HexagonMCExpr::create(MCSymbolRefExpr::create(MO.getMBB()->getSymbol(),
135                AP.OutContext), AP.OutContext));
136       break;
137     case MachineOperand::MO_GlobalAddress:
138       MCO = GetSymbolRef(MO, AP.getSymbol(MO.getGlobal()), AP);
139       break;
140     case MachineOperand::MO_ExternalSymbol:
141       MCO = GetSymbolRef(MO, AP.GetExternalSymbolSymbol(MO.getSymbolName()),
142                          AP);
143       break;
144     case MachineOperand::MO_JumpTableIndex:
145       MCO = GetSymbolRef(MO, AP.GetJTISymbol(MO.getIndex()), AP);
146       break;
147     case MachineOperand::MO_ConstantPoolIndex:
148       MCO = GetSymbolRef(MO, AP.GetCPISymbol(MO.getIndex()), AP);
149       break;
150     case MachineOperand::MO_BlockAddress:
151       MCO = GetSymbolRef(MO, AP.GetBlockAddressSymbol(MO.getBlockAddress()),AP);
152       break;
153     }
154 
155     MCI->addOperand(MCO);
156   }
157   AP.HexagonProcessInstruction(*MCI, *MI);
158   HexagonMCInstrInfo::extendIfNeeded(AP.OutContext, MCII, MCB, *MCI,
159                                      MustExtend);
160   MCB.addOperand(MCOperand::createInst(MCI));
161 }
162