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   if (TF & AVRII::MO_LO) {
41     Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_LO8, Expr, IsNegated, Ctx);
42   } else if (TF & AVRII::MO_HI) {
43     Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_HI8, Expr, IsNegated, Ctx);
44   } else if (TF != 0) {
45     llvm_unreachable("Unknown target flag on symbol operand");
46   }
47 
48   return MCOperand::createExpr(Expr);
49 }
50 
51 void AVRMCInstLower::lowerInstruction(const MachineInstr &MI, MCInst &OutMI) const {
52   OutMI.setOpcode(MI.getOpcode());
53 
54   for (MachineOperand const &MO : MI.operands()) {
55     MCOperand MCOp;
56 
57     switch (MO.getType()) {
58     default:
59       MI.dump();
60       llvm_unreachable("unknown operand type");
61     case MachineOperand::MO_Register:
62       // Ignore all implicit register operands.
63       if (MO.isImplicit())
64         continue;
65       MCOp = MCOperand::createReg(MO.getReg());
66       break;
67     case MachineOperand::MO_Immediate:
68       MCOp = MCOperand::createImm(MO.getImm());
69       break;
70     case MachineOperand::MO_GlobalAddress:
71       MCOp = lowerSymbolOperand(MO, Printer.getSymbol(MO.getGlobal()));
72       break;
73     case MachineOperand::MO_ExternalSymbol:
74       MCOp = lowerSymbolOperand(
75           MO, Printer.GetExternalSymbolSymbol(MO.getSymbolName()));
76       break;
77     case MachineOperand::MO_MachineBasicBlock:
78       MCOp = MCOperand::createExpr(
79           MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx));
80       break;
81     case MachineOperand::MO_RegisterMask:
82       continue;
83     case MachineOperand::MO_BlockAddress:
84       MCOp = lowerSymbolOperand(
85           MO, Printer.GetBlockAddressSymbol(MO.getBlockAddress()));
86       break;
87     case MachineOperand::MO_JumpTableIndex:
88       MCOp = lowerSymbolOperand(MO, Printer.GetJTISymbol(MO.getIndex()));
89       break;
90     case MachineOperand::MO_ConstantPoolIndex:
91       MCOp = lowerSymbolOperand(MO, Printer.GetCPISymbol(MO.getIndex()));
92       break;
93     }
94 
95     OutMI.addOperand(MCOp);
96   }
97 }
98 
99 } // end of namespace llvm
100 
101