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
24namespace llvm {
25
26MCOperand 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
62void 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