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
lowerSymbolOperand(const MachineOperand & MO,MCSymbol * Sym) const26 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) {
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 // N.B. Should we use _GS fixups here to cope with >128k progmem?
46 Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_PM_LO8, Expr, IsNegated, Ctx);
47 } else {
48 Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_LO8, Expr, IsNegated, Ctx);
49 }
50 } else if (TF & AVRII::MO_HI) {
51 if (IsFunction) {
52 // N.B. Should we use _GS fixups here to cope with >128k progmem?
53 Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_PM_HI8, Expr, IsNegated, Ctx);
54 } else {
55 Expr = AVRMCExpr::create(AVRMCExpr::VK_AVR_HI8, Expr, IsNegated, Ctx);
56 }
57 } else if (TF != 0) {
58 llvm_unreachable("Unknown target flag on symbol operand");
59 }
60
61 return MCOperand::createExpr(Expr);
62 }
63
lowerInstruction(const MachineInstr & MI,MCInst & OutMI) const64 void AVRMCInstLower::lowerInstruction(const MachineInstr &MI,
65 MCInst &OutMI) const {
66 OutMI.setOpcode(MI.getOpcode());
67
68 for (MachineOperand const &MO : MI.operands()) {
69 MCOperand MCOp;
70
71 switch (MO.getType()) {
72 default:
73 MI.print(errs());
74 llvm_unreachable("unknown operand type");
75 case MachineOperand::MO_Register:
76 // Ignore all implicit register operands.
77 if (MO.isImplicit())
78 continue;
79 MCOp = MCOperand::createReg(MO.getReg());
80 break;
81 case MachineOperand::MO_Immediate:
82 MCOp = MCOperand::createImm(MO.getImm());
83 break;
84 case MachineOperand::MO_GlobalAddress:
85 MCOp = lowerSymbolOperand(MO, Printer.getSymbol(MO.getGlobal()));
86 break;
87 case MachineOperand::MO_ExternalSymbol:
88 MCOp = lowerSymbolOperand(
89 MO, Printer.GetExternalSymbolSymbol(MO.getSymbolName()));
90 break;
91 case MachineOperand::MO_MachineBasicBlock:
92 MCOp = MCOperand::createExpr(
93 MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx));
94 break;
95 case MachineOperand::MO_RegisterMask:
96 continue;
97 case MachineOperand::MO_BlockAddress:
98 MCOp = lowerSymbolOperand(
99 MO, Printer.GetBlockAddressSymbol(MO.getBlockAddress()));
100 break;
101 case MachineOperand::MO_JumpTableIndex:
102 MCOp = lowerSymbolOperand(MO, Printer.GetJTISymbol(MO.getIndex()));
103 break;
104 case MachineOperand::MO_ConstantPoolIndex:
105 MCOp = lowerSymbolOperand(MO, Printer.GetCPISymbol(MO.getIndex()));
106 break;
107 }
108
109 OutMI.addOperand(MCOp);
110 }
111 }
112
113 } // end of namespace llvm
114