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) {
33     IsNegated = true;
34   }
35 
36   if (!MO.isJTI() && MO.getOffset()) {
37     Expr = MCBinaryExpr::createAdd(
38         Expr, MCConstantExpr::create(MO.getOffset(), Ctx), Ctx);
39   }
40 
41   bool IsFunction = MO.isGlobal() && isa<Function>(MO.getGlobal());
42 
43   if (TF & AVRII::MO_LO) {
44     if (IsFunction) {
45       // N.B. Should we use _GS fixups here to cope with >128k progmem?
46       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_PM_LO8, Expr, IsNegated, Ctx);
47     } else {
48       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_LO8, Expr, IsNegated, Ctx);
49     }
50   } else if (TF & AVRII::MO_HI) {
51     if (IsFunction) {
52       // N.B. Should we use _GS fixups here to cope with >128k progmem?
53       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_PM_HI8, Expr, IsNegated, Ctx);
54     } else {
55       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_HI8, Expr, IsNegated, Ctx);
56     }
57   } else if (TF != 0) {
58     llvm_unreachable("Unknown target flag on symbol operand");
59   }
60 
61   return MCOperand::createExpr(Expr);
62 }
63 
64 void AVRMCInstLower::lowerInstruction(const MachineInstr &MI,
65                                       MCInst &OutMI) const {
66   OutMI.setOpcode(MI.getOpcode());
67 
68   for (MachineOperand const &MO : MI.operands()) {
69     MCOperand MCOp;
70 
71     switch (MO.getType()) {
72     default:
73       MI.print(errs());
74       llvm_unreachable("unknown operand type");
75     case MachineOperand::MO_Register:
76       // Ignore all implicit register operands.
77       if (MO.isImplicit())
78         continue;
79       MCOp = MCOperand::createReg(MO.getReg());
80       break;
81     case MachineOperand::MO_Immediate:
82       MCOp = MCOperand::createImm(MO.getImm());
83       break;
84     case MachineOperand::MO_GlobalAddress:
85       MCOp = lowerSymbolOperand(MO, Printer.getSymbol(MO.getGlobal()));
86       break;
87     case MachineOperand::MO_ExternalSymbol:
88       MCOp = lowerSymbolOperand(
89           MO, Printer.GetExternalSymbolSymbol(MO.getSymbolName()));
90       break;
91     case MachineOperand::MO_MachineBasicBlock:
92       MCOp = MCOperand::createExpr(
93           MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx));
94       break;
95     case MachineOperand::MO_RegisterMask:
96       continue;
97     case MachineOperand::MO_BlockAddress:
98       MCOp = lowerSymbolOperand(
99           MO, Printer.GetBlockAddressSymbol(MO.getBlockAddress()));
100       break;
101     case MachineOperand::MO_JumpTableIndex:
102       MCOp = lowerSymbolOperand(MO, Printer.GetJTISymbol(MO.getIndex()));
103       break;
104     case MachineOperand::MO_ConstantPoolIndex:
105       MCOp = lowerSymbolOperand(MO, Printer.GetCPISymbol(MO.getIndex()));
106       break;
107     }
108 
109     OutMI.addOperand(MCOp);
110   }
111 }
112 
113 } // end of namespace llvm
114