lib/Target/AVR/AVRMCInstLower.cpp

   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