1 //===-- AVRInstPrinter.cpp - Convert AVR MCInst to assembly syntax --------===//
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 class prints an AVR MCInst to a .s file.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "AVRInstPrinter.h"
15
16 #include "MCTargetDesc/AVRMCTargetDesc.h"
17
18 #include "llvm/MC/MCExpr.h"
19 #include "llvm/MC/MCInst.h"
20 #include "llvm/MC/MCInstrDesc.h"
21 #include "llvm/MC/MCInstrInfo.h"
22 #include "llvm/MC/MCRegisterInfo.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/FormattedStream.h"
25
26 #include <cstring>
27
28 #define DEBUG_TYPE "asm-printer"
29
30 namespace llvm {
31
32 // Include the auto-generated portion of the assembly writer.
33 #define PRINT_ALIAS_INSTR
34 #include "AVRGenAsmWriter.inc"
35
printInst(const MCInst * MI,raw_ostream & O,StringRef Annot,const MCSubtargetInfo & STI)36 void AVRInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
37 StringRef Annot, const MCSubtargetInfo &STI) {
38 unsigned Opcode = MI->getOpcode();
39
40 // First handle load and store instructions with postinc or predec
41 // of the form "ld reg, X+".
42 // TODO: We should be able to rewrite this using TableGen data.
43 switch (Opcode) {
44 case AVR::LDRdPtr:
45 case AVR::LDRdPtrPi:
46 case AVR::LDRdPtrPd:
47 O << "\tld\t";
48 printOperand(MI, 0, O);
49 O << ", ";
50
51 if (Opcode == AVR::LDRdPtrPd)
52 O << '-';
53
54 printOperand(MI, 1, O);
55
56 if (Opcode == AVR::LDRdPtrPi)
57 O << '+';
58 break;
59 case AVR::STPtrRr:
60 O << "\tst\t";
61 printOperand(MI, 0, O);
62 O << ", ";
63 printOperand(MI, 1, O);
64 break;
65 case AVR::STPtrPiRr:
66 case AVR::STPtrPdRr:
67 O << "\tst\t";
68
69 if (Opcode == AVR::STPtrPdRr)
70 O << '-';
71
72 printOperand(MI, 1, O);
73
74 if (Opcode == AVR::STPtrPiRr)
75 O << '+';
76
77 O << ", ";
78 printOperand(MI, 2, O);
79 break;
80 default:
81 if (!printAliasInstr(MI, O))
82 printInstruction(MI, O);
83
84 printAnnotation(O, Annot);
85 break;
86 }
87 }
88
getPrettyRegisterName(unsigned RegNum,MCRegisterInfo const & MRI)89 const char *AVRInstPrinter::getPrettyRegisterName(unsigned RegNum,
90 MCRegisterInfo const &MRI) {
91 // GCC prints register pairs by just printing the lower register
92 // If the register contains a subregister, print it instead
93 if (MRI.getNumSubRegIndices() > 0) {
94 unsigned RegLoNum = MRI.getSubReg(RegNum, AVR::sub_lo);
95 RegNum = (RegLoNum != AVR::NoRegister) ? RegLoNum : RegNum;
96 }
97
98 return getRegisterName(RegNum);
99 }
100
printOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)101 void AVRInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
102 raw_ostream &O) {
103 const MCOperand &Op = MI->getOperand(OpNo);
104 const MCOperandInfo &MOI = this->MII.get(MI->getOpcode()).OpInfo[OpNo];
105
106 if (Op.isReg()) {
107 bool isPtrReg = (MOI.RegClass == AVR::PTRREGSRegClassID) ||
108 (MOI.RegClass == AVR::PTRDISPREGSRegClassID) ||
109 (MOI.RegClass == AVR::ZREGRegClassID);
110
111 if (isPtrReg) {
112 O << getRegisterName(Op.getReg(), AVR::ptr);
113 } else {
114 O << getPrettyRegisterName(Op.getReg(), MRI);
115 }
116 } else if (Op.isImm()) {
117 O << Op.getImm();
118 } else {
119 assert(Op.isExpr() && "Unknown operand kind in printOperand");
120 O << *Op.getExpr();
121 }
122 }
123
124 /// This is used to print an immediate value that ends up
125 /// being encoded as a pc-relative value.
printPCRelImm(const MCInst * MI,unsigned OpNo,raw_ostream & O)126 void AVRInstPrinter::printPCRelImm(const MCInst *MI, unsigned OpNo,
127 raw_ostream &O) {
128 const MCOperand &Op = MI->getOperand(OpNo);
129
130 if (Op.isImm()) {
131 int64_t Imm = Op.getImm();
132 O << '.';
133
134 // Print a position sign if needed.
135 // Negative values have their sign printed automatically.
136 if (Imm >= 0)
137 O << '+';
138
139 O << Imm;
140 } else {
141 assert(Op.isExpr() && "Unknown pcrel immediate operand");
142 O << *Op.getExpr();
143 }
144 }
145
printMemri(const MCInst * MI,unsigned OpNo,raw_ostream & O)146 void AVRInstPrinter::printMemri(const MCInst *MI, unsigned OpNo,
147 raw_ostream &O) {
148 assert(MI->getOperand(OpNo).isReg() && "Expected a register for the first operand");
149
150 const MCOperand &OffsetOp = MI->getOperand(OpNo + 1);
151
152 // Print the register.
153 printOperand(MI, OpNo, O);
154
155 // Print the {+,-}offset.
156 if (OffsetOp.isImm()) {
157 int64_t Offset = OffsetOp.getImm();
158
159 if (Offset >= 0)
160 O << '+';
161
162 O << Offset;
163 } else if (OffsetOp.isExpr()) {
164 O << *OffsetOp.getExpr();
165 } else {
166 llvm_unreachable("unknown type for offset");
167 }
168 }
169
170 } // end of namespace llvm
171
172