1 //===-- SystemZMCInstLower.cpp - Lower MachineInstr to 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 #include "SystemZMCInstLower.h"
11 #include "SystemZAsmPrinter.h"
12 #include "llvm/IR/Mangler.h"
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/MC/MCStreamer.h"
15
16 using namespace llvm;
17
18 // Return the VK_* enumeration for MachineOperand target flags Flags.
getVariantKind(unsigned Flags)19 static MCSymbolRefExpr::VariantKind getVariantKind(unsigned Flags) {
20 switch (Flags & SystemZII::MO_SYMBOL_MODIFIER) {
21 case 0:
22 return MCSymbolRefExpr::VK_None;
23 case SystemZII::MO_GOT:
24 return MCSymbolRefExpr::VK_GOT;
25 }
26 llvm_unreachable("Unrecognised MO_ACCESS_MODEL");
27 }
28
SystemZMCInstLower(MCContext & ctx,SystemZAsmPrinter & asmprinter)29 SystemZMCInstLower::SystemZMCInstLower(MCContext &ctx,
30 SystemZAsmPrinter &asmprinter)
31 : Ctx(ctx), AsmPrinter(asmprinter) {}
32
33 const MCExpr *
getExpr(const MachineOperand & MO,MCSymbolRefExpr::VariantKind Kind) const34 SystemZMCInstLower::getExpr(const MachineOperand &MO,
35 MCSymbolRefExpr::VariantKind Kind) const {
36 const MCSymbol *Symbol;
37 bool HasOffset = true;
38 switch (MO.getType()) {
39 case MachineOperand::MO_MachineBasicBlock:
40 Symbol = MO.getMBB()->getSymbol();
41 HasOffset = false;
42 break;
43
44 case MachineOperand::MO_GlobalAddress:
45 Symbol = AsmPrinter.getSymbol(MO.getGlobal());
46 break;
47
48 case MachineOperand::MO_ExternalSymbol:
49 Symbol = AsmPrinter.GetExternalSymbolSymbol(MO.getSymbolName());
50 break;
51
52 case MachineOperand::MO_JumpTableIndex:
53 Symbol = AsmPrinter.GetJTISymbol(MO.getIndex());
54 HasOffset = false;
55 break;
56
57 case MachineOperand::MO_ConstantPoolIndex:
58 Symbol = AsmPrinter.GetCPISymbol(MO.getIndex());
59 break;
60
61 case MachineOperand::MO_BlockAddress:
62 Symbol = AsmPrinter.GetBlockAddressSymbol(MO.getBlockAddress());
63 break;
64
65 default:
66 llvm_unreachable("unknown operand type");
67 }
68 const MCExpr *Expr = MCSymbolRefExpr::Create(Symbol, Kind, Ctx);
69 if (HasOffset)
70 if (int64_t Offset = MO.getOffset()) {
71 const MCExpr *OffsetExpr = MCConstantExpr::Create(Offset, Ctx);
72 Expr = MCBinaryExpr::CreateAdd(Expr, OffsetExpr, Ctx);
73 }
74 return Expr;
75 }
76
lowerOperand(const MachineOperand & MO) const77 MCOperand SystemZMCInstLower::lowerOperand(const MachineOperand &MO) const {
78 switch (MO.getType()) {
79 case MachineOperand::MO_Register:
80 return MCOperand::CreateReg(MO.getReg());
81
82 case MachineOperand::MO_Immediate:
83 return MCOperand::CreateImm(MO.getImm());
84
85 default: {
86 MCSymbolRefExpr::VariantKind Kind = getVariantKind(MO.getTargetFlags());
87 return MCOperand::CreateExpr(getExpr(MO, Kind));
88 }
89 }
90 }
91
lower(const MachineInstr * MI,MCInst & OutMI) const92 void SystemZMCInstLower::lower(const MachineInstr *MI, MCInst &OutMI) const {
93 OutMI.setOpcode(MI->getOpcode());
94 for (unsigned I = 0, E = MI->getNumOperands(); I != E; ++I) {
95 const MachineOperand &MO = MI->getOperand(I);
96 // Ignore all implicit register operands.
97 if (!MO.isReg() || !MO.isImplicit())
98 OutMI.addOperand(lowerOperand(MO));
99 }
100 }
101