1 //===-- MSP430MCInstLower.cpp - Convert MSP430 MachineInstr to an MCInst --===//
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 file contains code to lower MSP430 MachineInstrs to their corresponding
10 // MCInst records.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MSP430MCInstLower.h"
15 #include "llvm/ADT/SmallString.h"
16 #include "llvm/CodeGen/AsmPrinter.h"
17 #include "llvm/CodeGen/MachineBasicBlock.h"
18 #include "llvm/CodeGen/MachineInstr.h"
19 #include "llvm/IR/DataLayout.h"
20 #include "llvm/IR/Mangler.h"
21 #include "llvm/MC/MCAsmInfo.h"
22 #include "llvm/MC/MCContext.h"
23 #include "llvm/MC/MCExpr.h"
24 #include "llvm/MC/MCInst.h"
25 #include "llvm/Support/ErrorHandling.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include "llvm/Target/TargetMachine.h"
28 using namespace llvm;
29 
30 MCSymbol *MSP430MCInstLower::
GetGlobalAddressSymbol(const MachineOperand & MO) const31 GetGlobalAddressSymbol(const MachineOperand &MO) const {
32   switch (MO.getTargetFlags()) {
33   default: llvm_unreachable("Unknown target flag on GV operand");
34   case 0: break;
35   }
36 
37   return Printer.getSymbol(MO.getGlobal());
38 }
39 
40 MCSymbol *MSP430MCInstLower::
GetExternalSymbolSymbol(const MachineOperand & MO) const41 GetExternalSymbolSymbol(const MachineOperand &MO) const {
42   switch (MO.getTargetFlags()) {
43   default: llvm_unreachable("Unknown target flag on GV operand");
44   case 0: break;
45   }
46 
47   return Printer.GetExternalSymbolSymbol(MO.getSymbolName());
48 }
49 
50 MCSymbol *MSP430MCInstLower::
GetJumpTableSymbol(const MachineOperand & MO) const51 GetJumpTableSymbol(const MachineOperand &MO) const {
52   const DataLayout &DL = Printer.getDataLayout();
53   SmallString<256> Name;
54   raw_svector_ostream(Name) << DL.getPrivateGlobalPrefix() << "JTI"
55                             << Printer.getFunctionNumber() << '_'
56                             << MO.getIndex();
57 
58   switch (MO.getTargetFlags()) {
59   default: llvm_unreachable("Unknown target flag on GV operand");
60   case 0: break;
61   }
62 
63   // Create a symbol for the name.
64   return Ctx.getOrCreateSymbol(Name);
65 }
66 
67 MCSymbol *MSP430MCInstLower::
GetConstantPoolIndexSymbol(const MachineOperand & MO) const68 GetConstantPoolIndexSymbol(const MachineOperand &MO) const {
69   const DataLayout &DL = Printer.getDataLayout();
70   SmallString<256> Name;
71   raw_svector_ostream(Name) << DL.getPrivateGlobalPrefix() << "CPI"
72                             << Printer.getFunctionNumber() << '_'
73                             << MO.getIndex();
74 
75   switch (MO.getTargetFlags()) {
76   default: llvm_unreachable("Unknown target flag on GV operand");
77   case 0: break;
78   }
79 
80   // Create a symbol for the name.
81   return Ctx.getOrCreateSymbol(Name);
82 }
83 
84 MCSymbol *MSP430MCInstLower::
GetBlockAddressSymbol(const MachineOperand & MO) const85 GetBlockAddressSymbol(const MachineOperand &MO) const {
86   switch (MO.getTargetFlags()) {
87   default: llvm_unreachable("Unknown target flag on GV operand");
88   case 0: break;
89   }
90 
91   return Printer.GetBlockAddressSymbol(MO.getBlockAddress());
92 }
93 
94 MCOperand MSP430MCInstLower::
LowerSymbolOperand(const MachineOperand & MO,MCSymbol * Sym) const95 LowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym) const {
96   // FIXME: We would like an efficient form for this, so we don't have to do a
97   // lot of extra uniquing.
98   const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx);
99 
100   switch (MO.getTargetFlags()) {
101   default: llvm_unreachable("Unknown target flag on GV operand");
102   case 0: break;
103   }
104 
105   if (!MO.isJTI() && MO.getOffset())
106     Expr = MCBinaryExpr::createAdd(Expr,
107                                    MCConstantExpr::create(MO.getOffset(), Ctx),
108                                    Ctx);
109   return MCOperand::createExpr(Expr);
110 }
111 
112 #define GET_REGINFO_ENUM
113 #include "MSP430GenRegisterInfo.inc"
114 
Lower(const MachineInstr * MI,MCInst & OutMI) const115 void MSP430MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
116   OutMI.setOpcode(MI->getOpcode());
117 
118   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
119     const MachineOperand &MO = MI->getOperand(i);
120 
121     MCOperand MCOp;
122     switch (MO.getType()) {
123     default:
124       MI->print(errs());
125       llvm_unreachable("unknown operand type");
126     case MachineOperand::MO_Register:
127       // Ignore all implicit register operands.
128       if (MO.isImplicit()) continue;
129       MCOp = MCOperand::createReg(MO.getReg());
130       break;
131     case MachineOperand::MO_Immediate:
132       MCOp = MCOperand::createImm(MO.getImm());
133       break;
134     case MachineOperand::MO_MachineBasicBlock:
135       MCOp = MCOperand::createExpr(MCSymbolRefExpr::create(
136                          MO.getMBB()->getSymbol(), Ctx));
137       break;
138     case MachineOperand::MO_GlobalAddress:
139       MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));
140       break;
141     case MachineOperand::MO_ExternalSymbol:
142       MCOp = LowerSymbolOperand(MO, GetExternalSymbolSymbol(MO));
143       break;
144     case MachineOperand::MO_JumpTableIndex:
145       MCOp = LowerSymbolOperand(MO, GetJumpTableSymbol(MO));
146       break;
147     case MachineOperand::MO_ConstantPoolIndex:
148       MCOp = LowerSymbolOperand(MO, GetConstantPoolIndexSymbol(MO));
149       break;
150     case MachineOperand::MO_BlockAddress:
151       MCOp = LowerSymbolOperand(MO, GetBlockAddressSymbol(MO));
152       break;
153     case MachineOperand::MO_RegisterMask:
154       continue;
155     }
156 
157     OutMI.addOperand(MCOp);
158   }
159 }
160