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 #include "AVRInstrInfo.h"
16 #include "MCTargetDesc/AVRMCExpr.h"
17 
18 #include "llvm/CodeGen/AsmPrinter.h"
19 #include "llvm/IR/Mangler.h"
20 #include "llvm/MC/MCInst.h"
21 #include "llvm/Support/ErrorHandling.h"
22 
23 namespace llvm {
24 
25 MCOperand
26 AVRMCInstLower::lowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym,
27                                    const AVRSubtarget &Subtarget) 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       Expr =
46           AVRMCExpr::create(Subtarget.hasEIJMPCALL() ? AVRMCExpr::VK_AVR_LO8_GS
47                                                      : AVRMCExpr::VK_AVR_PM_LO8,
48                             Expr, IsNegated, Ctx);
49     } else {
50       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_LO8, Expr, IsNegated, Ctx);
51     }
52   } else if (TF & AVRII::MO_HI) {
53     if (IsFunction) {
54       Expr =
55           AVRMCExpr::create(Subtarget.hasEIJMPCALL() ? AVRMCExpr::VK_AVR_HI8_GS
56                                                      : AVRMCExpr::VK_AVR_PM_HI8,
57                             Expr, IsNegated, Ctx);
58     } else {
59       Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_HI8, Expr, IsNegated, Ctx);
60     }
61   } else if (TF != 0) {
62     llvm_unreachable("Unknown target flag on symbol operand");
63   }
64 
65   return MCOperand::createExpr(Expr);
66 }
67 
68 void AVRMCInstLower::lowerInstruction(const MachineInstr &MI,
69                                       MCInst &OutMI) const {
70   auto &Subtarget = MI.getParent()->getParent()->getSubtarget<AVRSubtarget>();
71   OutMI.setOpcode(MI.getOpcode());
72 
73   for (MachineOperand const &MO : MI.operands()) {
74     MCOperand MCOp;
75 
76     switch (MO.getType()) {
77     default:
78       MI.print(errs());
79       llvm_unreachable("unknown operand type");
80     case MachineOperand::MO_Register:
81       // Ignore all implicit register operands.
82       if (MO.isImplicit())
83         continue;
84       MCOp = MCOperand::createReg(MO.getReg());
85       break;
86     case MachineOperand::MO_Immediate:
87       MCOp = MCOperand::createImm(MO.getImm());
88       break;
89     case MachineOperand::MO_GlobalAddress:
90       MCOp =
91           lowerSymbolOperand(MO, Printer.getSymbol(MO.getGlobal()), Subtarget);
92       break;
93     case MachineOperand::MO_ExternalSymbol:
94       MCOp = lowerSymbolOperand(
95           MO, Printer.GetExternalSymbolSymbol(MO.getSymbolName()), Subtarget);
96       break;
97     case MachineOperand::MO_MachineBasicBlock:
98       MCOp = MCOperand::createExpr(
99           MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx));
100       break;
101     case MachineOperand::MO_RegisterMask:
102       continue;
103     case MachineOperand::MO_BlockAddress:
104       MCOp = lowerSymbolOperand(
105           MO, Printer.GetBlockAddressSymbol(MO.getBlockAddress()), Subtarget);
106       break;
107     case MachineOperand::MO_JumpTableIndex:
108       MCOp = lowerSymbolOperand(MO, Printer.GetJTISymbol(MO.getIndex()),
109                                 Subtarget);
110       break;
111     case MachineOperand::MO_ConstantPoolIndex:
112       MCOp = lowerSymbolOperand(MO, Printer.GetCPISymbol(MO.getIndex()),
113                                 Subtarget);
114       break;
115     }
116 
117     OutMI.addOperand(MCOp);
118   }
119 }
120 
121 } // end of namespace llvm
122