1 //===-- AVRAsmPrinter.cpp - AVR LLVM assembly writer ----------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains a printer that converts from our internal representation
11 // of machine-dependent LLVM code to GAS-format AVR assembly language.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "AVR.h"
16 #include "AVRMCInstLower.h"
17 #include "AVRSubtarget.h"
18 #include "InstPrinter/AVRInstPrinter.h"
19
20 #include "llvm/CodeGen/AsmPrinter.h"
21 #include "llvm/CodeGen/MachineFunction.h"
22 #include "llvm/CodeGen/MachineInstr.h"
23 #include "llvm/CodeGen/TargetRegisterInfo.h"
24 #include "llvm/CodeGen/TargetSubtargetInfo.h"
25 #include "llvm/IR/Mangler.h"
26 #include "llvm/MC/MCInst.h"
27 #include "llvm/MC/MCStreamer.h"
28 #include "llvm/MC/MCSymbol.h"
29 #include "llvm/Support/ErrorHandling.h"
30 #include "llvm/Support/TargetRegistry.h"
31 #include "llvm/Support/raw_ostream.h"
32
33 #define DEBUG_TYPE "avr-asm-printer"
34
35 namespace llvm {
36
37 /// An AVR assembly code printer.
38 class AVRAsmPrinter : public AsmPrinter {
39 public:
AVRAsmPrinter(TargetMachine & TM,std::unique_ptr<MCStreamer> Streamer)40 AVRAsmPrinter(TargetMachine &TM,
41 std::unique_ptr<MCStreamer> Streamer)
42 : AsmPrinter(TM, std::move(Streamer)), MRI(*TM.getMCRegisterInfo()) { }
43
getPassName() const44 StringRef getPassName() const override { return "AVR Assembly Printer"; }
45
46 void printOperand(const MachineInstr *MI, unsigned OpNo, raw_ostream &O,
47 const char *Modifier = 0);
48
49 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
50 unsigned AsmVariant, const char *ExtraCode,
51 raw_ostream &O) override;
52
53 bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
54 unsigned AsmVariant, const char *ExtraCode,
55 raw_ostream &O) override;
56
57 void EmitInstruction(const MachineInstr *MI) override;
58
59 private:
60 const MCRegisterInfo &MRI;
61 };
62
printOperand(const MachineInstr * MI,unsigned OpNo,raw_ostream & O,const char * Modifier)63 void AVRAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
64 raw_ostream &O, const char *Modifier) {
65 const MachineOperand &MO = MI->getOperand(OpNo);
66
67 switch (MO.getType()) {
68 case MachineOperand::MO_Register:
69 O << AVRInstPrinter::getPrettyRegisterName(MO.getReg(), MRI);
70 break;
71 case MachineOperand::MO_Immediate:
72 O << MO.getImm();
73 break;
74 case MachineOperand::MO_GlobalAddress:
75 O << getSymbol(MO.getGlobal());
76 break;
77 case MachineOperand::MO_ExternalSymbol:
78 O << *GetExternalSymbolSymbol(MO.getSymbolName());
79 break;
80 case MachineOperand::MO_MachineBasicBlock:
81 O << *MO.getMBB()->getSymbol();
82 break;
83 default:
84 llvm_unreachable("Not implemented yet!");
85 }
86 }
87
PrintAsmOperand(const MachineInstr * MI,unsigned OpNum,unsigned AsmVariant,const char * ExtraCode,raw_ostream & O)88 bool AVRAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
89 unsigned AsmVariant, const char *ExtraCode,
90 raw_ostream &O) {
91 // Default asm printer can only deal with some extra codes,
92 // so try it first.
93 bool Error = AsmPrinter::PrintAsmOperand(MI, OpNum, AsmVariant, ExtraCode, O);
94
95 if (Error && ExtraCode && ExtraCode[0]) {
96 if (ExtraCode[1] != 0)
97 return true; // Unknown modifier.
98
99 if (ExtraCode[0] >= 'A' && ExtraCode[0] <= 'Z') {
100 const MachineOperand &RegOp = MI->getOperand(OpNum);
101
102 assert(RegOp.isReg() && "Operand must be a register when you're"
103 "using 'A'..'Z' operand extracodes.");
104 unsigned Reg = RegOp.getReg();
105
106 unsigned ByteNumber = ExtraCode[0] - 'A';
107
108 unsigned OpFlags = MI->getOperand(OpNum - 1).getImm();
109 unsigned NumOpRegs = InlineAsm::getNumOperandRegisters(OpFlags);
110 (void)NumOpRegs;
111
112 const AVRSubtarget &STI = MF->getSubtarget<AVRSubtarget>();
113 const TargetRegisterInfo &TRI = *STI.getRegisterInfo();
114
115 const TargetRegisterClass *RC = TRI.getMinimalPhysRegClass(Reg);
116 unsigned BytesPerReg = TRI.getRegSizeInBits(*RC) / 8;
117 assert(BytesPerReg <= 2 && "Only 8 and 16 bit regs are supported.");
118
119 unsigned RegIdx = ByteNumber / BytesPerReg;
120 assert(RegIdx < NumOpRegs && "Multibyte index out of range.");
121
122 Reg = MI->getOperand(OpNum + RegIdx).getReg();
123
124 if (BytesPerReg == 2) {
125 Reg = TRI.getSubReg(Reg, ByteNumber % BytesPerReg ? AVR::sub_hi
126 : AVR::sub_lo);
127 }
128
129 O << AVRInstPrinter::getPrettyRegisterName(Reg, MRI);
130 return false;
131 }
132 }
133
134 if (Error)
135 printOperand(MI, OpNum, O);
136
137 return false;
138 }
139
PrintAsmMemoryOperand(const MachineInstr * MI,unsigned OpNum,unsigned AsmVariant,const char * ExtraCode,raw_ostream & O)140 bool AVRAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
141 unsigned OpNum, unsigned AsmVariant,
142 const char *ExtraCode,
143 raw_ostream &O) {
144 if (ExtraCode && ExtraCode[0]) {
145 llvm_unreachable("This branch is not implemented yet");
146 }
147
148 const MachineOperand &MO = MI->getOperand(OpNum);
149 (void)MO;
150 assert(MO.isReg() && "Unexpected inline asm memory operand");
151
152 // TODO: We should be able to look up the alternative name for
153 // the register if it's given.
154 // TableGen doesn't expose a way of getting retrieving names
155 // for registers.
156 if (MI->getOperand(OpNum).getReg() == AVR::R31R30) {
157 O << "Z";
158 } else {
159 assert(MI->getOperand(OpNum).getReg() == AVR::R29R28 &&
160 "Wrong register class for memory operand.");
161 O << "Y";
162 }
163
164 // If NumOpRegs == 2, then we assume it is product of a FrameIndex expansion
165 // and the second operand is an Imm.
166 unsigned OpFlags = MI->getOperand(OpNum - 1).getImm();
167 unsigned NumOpRegs = InlineAsm::getNumOperandRegisters(OpFlags);
168
169 if (NumOpRegs == 2) {
170 O << '+' << MI->getOperand(OpNum + 1).getImm();
171 }
172
173 return false;
174 }
175
EmitInstruction(const MachineInstr * MI)176 void AVRAsmPrinter::EmitInstruction(const MachineInstr *MI) {
177 AVRMCInstLower MCInstLowering(OutContext, *this);
178
179 MCInst I;
180 MCInstLowering.lowerInstruction(*MI, I);
181 EmitToStreamer(*OutStreamer, I);
182 }
183
184 } // end of namespace llvm
185
LLVMInitializeAVRAsmPrinter()186 extern "C" void LLVMInitializeAVRAsmPrinter() {
187 llvm::RegisterAsmPrinter<llvm::AVRAsmPrinter> X(llvm::getTheAVRTarget());
188 }
189
190