1 //===-- AVRMCInstLower.cpp - Convert AVR 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 AVR MachineInstrs to their corresponding
11 // MCInst records.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "AVRMCInstLower.h"
16 
17 #include "AVRInstrInfo.h"
18 #include "MCTargetDesc/AVRMCExpr.h"
19 
20 #include "llvm/CodeGen/AsmPrinter.h"
21 #include "llvm/IR/Mangler.h"
22 #include "llvm/MC/MCInst.h"
23 #include "llvm/Support/ErrorHandling.h"
24 
25 namespace llvm {
26 
27 MCOperand AVRMCInstLower::lowerSymbolOperand(const MachineOperand &MO,
28                                              MCSymbol *Sym) const {
29   unsigned char TF = MO.getTargetFlags();
30   const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx);
31 
32   bool IsNegated = false;
33   if (TF & AVRII::MO_NEG) { IsNegated = true; }
34 
35   if (!MO.isJTI() && MO.getOffset()) {
36     Expr = MCBinaryExpr::createAdd(
37         Expr, MCConstantExpr::create(MO.getOffset(), Ctx), Ctx);
38   }
39 
40   bool IsFunction = MO.isGlobal() && isa<Function>(MO.getGlobal());
41 
42   if (TF & AVRII::MO_LO) {
43     if (IsFunction) {
44       // N.B. Should we use _GS fixups here to cope with >128k progmem?
45       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_PM_LO8, Expr, IsNegated, Ctx);
46     } else {
47       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_LO8, Expr, IsNegated, Ctx);
48     }
49   } else if (TF & AVRII::MO_HI) {
50     if (IsFunction) {
51       // N.B. Should we use _GS fixups here to cope with >128k progmem?
52       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_PM_HI8, Expr, IsNegated, Ctx);
53     } else {
54       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_HI8, Expr, IsNegated, Ctx);
55     }
56   } else if (TF != 0) {
57     llvm_unreachable("Unknown target flag on symbol operand");
58   }
59 
60   return MCOperand::createExpr(Expr);
61 }
62 
63 void AVRMCInstLower::lowerInstruction(const MachineInstr &MI, MCInst &OutMI) const {
64   OutMI.setOpcode(MI.getOpcode());
65 
66   for (MachineOperand const &MO : MI.operands()) {
67     MCOperand MCOp;
68 
69     switch (MO.getType()) {
70     default:
71       MI.print(errs());
72       llvm_unreachable("unknown operand type");
73     case MachineOperand::MO_Register:
74       // Ignore all implicit register operands.
75       if (MO.isImplicit())
76         continue;
77       MCOp = MCOperand::createReg(MO.getReg());
78       break;
79     case MachineOperand::MO_Immediate:
80       MCOp = MCOperand::createImm(MO.getImm());
81       break;
82     case MachineOperand::MO_GlobalAddress:
83       MCOp = lowerSymbolOperand(MO, Printer.getSymbol(MO.getGlobal()));
84       break;
85     case MachineOperand::MO_ExternalSymbol:
86       MCOp = lowerSymbolOperand(
87           MO, Printer.GetExternalSymbolSymbol(MO.getSymbolName()));
88       break;
89     case MachineOperand::MO_MachineBasicBlock:
90       MCOp = MCOperand::createExpr(
91           MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx));
92       break;
93     case MachineOperand::MO_RegisterMask:
94       continue;
95     case MachineOperand::MO_BlockAddress:
96       MCOp = lowerSymbolOperand(
97           MO, Printer.GetBlockAddressSymbol(MO.getBlockAddress()));
98       break;
99     case MachineOperand::MO_JumpTableIndex:
100       MCOp = lowerSymbolOperand(MO, Printer.GetJTISymbol(MO.getIndex()));
101       break;
102     case MachineOperand::MO_ConstantPoolIndex:
103       MCOp = lowerSymbolOperand(MO, Printer.GetCPISymbol(MO.getIndex()));
104       break;
105     }
106 
107     OutMI.addOperand(MCOp);
108   }
109 }
110 
111 } // end of namespace llvm
112 
113