1 //===-- AVRMCInstLower.cpp - Convert AVR 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 AVR MachineInstrs to their corresponding
10 // MCInst records.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "AVRMCInstLower.h"
15 
16 #include "AVRInstrInfo.h"
17 #include "MCTargetDesc/AVRMCExpr.h"
18 
19 #include "llvm/CodeGen/AsmPrinter.h"
20 #include "llvm/IR/Mangler.h"
21 #include "llvm/MC/MCInst.h"
22 #include "llvm/Support/ErrorHandling.h"
23 
24 namespace llvm {
25 
26 MCOperand AVRMCInstLower::lowerSymbolOperand(const MachineOperand &MO,
27                                              MCSymbol *Sym) const {
28   unsigned char TF = MO.getTargetFlags();
29   const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx);
30 
31   bool IsNegated = false;
32   if (TF & AVRII::MO_NEG) { IsNegated = true; }
33 
34   if (!MO.isJTI() && MO.getOffset()) {
35     Expr = MCBinaryExpr::createAdd(
36         Expr, MCConstantExpr::create(MO.getOffset(), Ctx), Ctx);
37   }
38 
39   bool IsFunction = MO.isGlobal() && isa<Function>(MO.getGlobal());
40 
41   if (TF & AVRII::MO_LO) {
42     if (IsFunction) {
43       // N.B. Should we use _GS fixups here to cope with >128k progmem?
44       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_PM_LO8, Expr, IsNegated, Ctx);
45     } else {
46       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_LO8, Expr, IsNegated, Ctx);
47     }
48   } else if (TF & AVRII::MO_HI) {
49     if (IsFunction) {
50       // N.B. Should we use _GS fixups here to cope with >128k progmem?
51       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_PM_HI8, Expr, IsNegated, Ctx);
52     } else {
53       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_HI8, Expr, IsNegated, Ctx);
54     }
55   } else if (TF != 0) {
56     llvm_unreachable("Unknown target flag on symbol operand");
57   }
58 
59   return MCOperand::createExpr(Expr);
60 }
61 
62 void AVRMCInstLower::lowerInstruction(const MachineInstr &MI, MCInst &OutMI) const {
63   OutMI.setOpcode(MI.getOpcode());
64 
65   for (MachineOperand const &MO : MI.operands()) {
66     MCOperand MCOp;
67 
68     switch (MO.getType()) {
69     default:
70       MI.print(errs());
71       llvm_unreachable("unknown operand type");
72     case MachineOperand::MO_Register:
73       // Ignore all implicit register operands.
74       if (MO.isImplicit())
75         continue;
76       MCOp = MCOperand::createReg(MO.getReg());
77       break;
78     case MachineOperand::MO_Immediate:
79       MCOp = MCOperand::createImm(MO.getImm());
80       break;
81     case MachineOperand::MO_GlobalAddress:
82       MCOp = lowerSymbolOperand(MO, Printer.getSymbol(MO.getGlobal()));
83       break;
84     case MachineOperand::MO_ExternalSymbol:
85       MCOp = lowerSymbolOperand(
86           MO, Printer.GetExternalSymbolSymbol(MO.getSymbolName()));
87       break;
88     case MachineOperand::MO_MachineBasicBlock:
89       MCOp = MCOperand::createExpr(
90           MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx));
91       break;
92     case MachineOperand::MO_RegisterMask:
93       continue;
94     case MachineOperand::MO_BlockAddress:
95       MCOp = lowerSymbolOperand(
96           MO, Printer.GetBlockAddressSymbol(MO.getBlockAddress()));
97       break;
98     case MachineOperand::MO_JumpTableIndex:
99       MCOp = lowerSymbolOperand(MO, Printer.GetJTISymbol(MO.getIndex()));
100       break;
101     case MachineOperand::MO_ConstantPoolIndex:
102       MCOp = lowerSymbolOperand(MO, Printer.GetCPISymbol(MO.getIndex()));
103       break;
104     }
105 
106     OutMI.addOperand(MCOp);
107   }
108 }
109 
110 } // end of namespace llvm
111 
112