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) { 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
lowerInstruction(const MachineInstr & MI,MCInst & OutMI) const62 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
112