1 //===- HexagonInstPrinter.cpp - Convert Hexagon 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 Hexagon MCInst to a .s file.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "HexagonAsmPrinter.h"
15 #include "Hexagon.h"
16 #include "HexagonInstPrinter.h"
17 #include "MCTargetDesc/HexagonMCInstrInfo.h"
18 #include "llvm/ADT/StringExtras.h"
19 #include "llvm/MC/MCAsmInfo.h"
20 #include "llvm/MC/MCExpr.h"
21 #include "llvm/MC/MCInst.h"
22 #include "llvm/Support/raw_ostream.h"
23 
24 using namespace llvm;
25 
26 #define DEBUG_TYPE "asm-printer"
27 
28 #define GET_INSTRUCTION_NAME
29 #include "HexagonGenAsmWriter.inc"
30 
31 const char HexagonInstPrinter::PacketPadding = '\t';
32 // Return the minimum value that a constant extendable operand can have
33 // without being extended.
getMinValue(uint64_t TSFlags)34 static int getMinValue(uint64_t TSFlags) {
35   unsigned isSigned =
36       (TSFlags >> HexagonII::ExtentSignedPos) & HexagonII::ExtentSignedMask;
37   unsigned bits =
38       (TSFlags >> HexagonII::ExtentBitsPos) & HexagonII::ExtentBitsMask;
39 
40   if (isSigned)
41     return -1U << (bits - 1);
42 
43   return 0;
44 }
45 
46 // Return the maximum value that a constant extendable operand can have
47 // without being extended.
getMaxValue(uint64_t TSFlags)48 static int getMaxValue(uint64_t TSFlags) {
49   unsigned isSigned =
50       (TSFlags >> HexagonII::ExtentSignedPos) & HexagonII::ExtentSignedMask;
51   unsigned bits =
52       (TSFlags >> HexagonII::ExtentBitsPos) & HexagonII::ExtentBitsMask;
53 
54   if (isSigned)
55     return ~(-1U << (bits - 1));
56 
57   return ~(-1U << bits);
58 }
59 
60 // Return true if the instruction must be extended.
isExtended(uint64_t TSFlags)61 static bool isExtended(uint64_t TSFlags) {
62   return (TSFlags >> HexagonII::ExtendedPos) & HexagonII::ExtendedMask;
63 }
64 
65 // Currently just used in an assert statement
66 static bool isExtendable(uint64_t TSFlags) LLVM_ATTRIBUTE_UNUSED;
67 // Return true if the instruction may be extended based on the operand value.
isExtendable(uint64_t TSFlags)68 static bool isExtendable(uint64_t TSFlags) {
69   return (TSFlags >> HexagonII::ExtendablePos) & HexagonII::ExtendableMask;
70 }
71 
getOpcodeName(unsigned Opcode) const72 StringRef HexagonInstPrinter::getOpcodeName(unsigned Opcode) const {
73   return MII.getName(Opcode);
74 }
75 
getRegName(unsigned RegNo) const76 StringRef HexagonInstPrinter::getRegName(unsigned RegNo) const {
77   return getRegisterName(RegNo);
78 }
79 
printInst(MCInst const * MI,raw_ostream & O,StringRef Annot,const MCSubtargetInfo & STI)80 void HexagonInstPrinter::printInst(MCInst const *MI, raw_ostream &O,
81                                    StringRef Annot,
82                                    const MCSubtargetInfo &STI) {
83   const char startPacket = '{',
84              endPacket = '}';
85   // TODO: add outer HW loop when it's supported too.
86   if (MI->getOpcode() == Hexagon::ENDLOOP0) {
87     // Ending a harware loop is different from ending an regular packet.
88     assert(HexagonMCInstrInfo::isPacketEnd(*MI) && "Loop-end must also end the packet");
89 
90     if (HexagonMCInstrInfo::isPacketBegin(*MI)) {
91       // There must be a packet to end a loop.
92       // FIXME: when shuffling is always run, this shouldn't be needed.
93       MCInst Nop;
94       StringRef NoAnnot;
95 
96       Nop.setOpcode (Hexagon::A2_nop);
97       HexagonMCInstrInfo::setPacketBegin (Nop, HexagonMCInstrInfo::isPacketBegin(*MI));
98       printInst (&Nop, O, NoAnnot, STI);
99     }
100 
101     // Close the packet.
102     if (HexagonMCInstrInfo::isPacketEnd(*MI))
103       O << PacketPadding << endPacket;
104 
105     printInstruction(MI, O);
106   }
107   else {
108     // Prefix the insn opening the packet.
109     if (HexagonMCInstrInfo::isPacketBegin(*MI))
110       O << PacketPadding << startPacket << '\n';
111 
112     printInstruction(MI, O);
113 
114     // Suffix the insn closing the packet.
115     if (HexagonMCInstrInfo::isPacketEnd(*MI))
116       // Suffix the packet in a new line always, since the GNU assembler has
117       // issues with a closing brace on the same line as CONST{32,64}.
118       O << '\n' << PacketPadding << endPacket;
119   }
120 
121   printAnnotation(O, Annot);
122 }
123 
printOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const124 void HexagonInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
125                                       raw_ostream &O) const {
126   const MCOperand& MO = MI->getOperand(OpNo);
127 
128   if (MO.isReg()) {
129     O << getRegisterName(MO.getReg());
130   } else if(MO.isExpr()) {
131     O << *MO.getExpr();
132   } else if(MO.isImm()) {
133     printImmOperand(MI, OpNo, O);
134   } else {
135     llvm_unreachable("Unknown operand");
136   }
137 }
138 
printImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const139 void HexagonInstPrinter::printImmOperand(const MCInst *MI, unsigned OpNo,
140                                          raw_ostream &O) const {
141   const MCOperand& MO = MI->getOperand(OpNo);
142 
143   if(MO.isExpr()) {
144     O << *MO.getExpr();
145   } else if(MO.isImm()) {
146     O << MI->getOperand(OpNo).getImm();
147   } else {
148     llvm_unreachable("Unknown operand");
149   }
150 }
151 
printExtOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const152 void HexagonInstPrinter::printExtOperand(const MCInst *MI, unsigned OpNo,
153                                          raw_ostream &O) const {
154   const MCOperand &MO = MI->getOperand(OpNo);
155   const MCInstrDesc &MII = getMII().get(MI->getOpcode());
156 
157   assert((isExtendable(MII.TSFlags) || isExtended(MII.TSFlags)) &&
158          "Expecting an extendable operand");
159 
160   if (MO.isExpr() || isExtended(MII.TSFlags)) {
161     O << "#";
162   } else if (MO.isImm()) {
163     int ImmValue = MO.getImm();
164     if (ImmValue < getMinValue(MII.TSFlags) ||
165         ImmValue > getMaxValue(MII.TSFlags))
166       O << "#";
167   }
168   printOperand(MI, OpNo, O);
169 }
170 
printUnsignedImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const171 void HexagonInstPrinter::printUnsignedImmOperand(const MCInst *MI,
172                                     unsigned OpNo, raw_ostream &O) const {
173   O << MI->getOperand(OpNo).getImm();
174 }
175 
printNegImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const176 void HexagonInstPrinter::printNegImmOperand(const MCInst *MI, unsigned OpNo,
177                                             raw_ostream &O) const {
178   O << -MI->getOperand(OpNo).getImm();
179 }
180 
printNOneImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const181 void HexagonInstPrinter::printNOneImmOperand(const MCInst *MI, unsigned OpNo,
182                                              raw_ostream &O) const {
183   O << -1;
184 }
185 
printMEMriOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const186 void HexagonInstPrinter::printMEMriOperand(const MCInst *MI, unsigned OpNo,
187                                            raw_ostream &O) const {
188   const MCOperand& MO0 = MI->getOperand(OpNo);
189   const MCOperand& MO1 = MI->getOperand(OpNo + 1);
190 
191   O << getRegisterName(MO0.getReg());
192   O << " + #" << MO1.getImm();
193 }
194 
printFrameIndexOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const195 void HexagonInstPrinter::printFrameIndexOperand(const MCInst *MI, unsigned OpNo,
196                                                 raw_ostream &O) const {
197   const MCOperand& MO0 = MI->getOperand(OpNo);
198   const MCOperand& MO1 = MI->getOperand(OpNo + 1);
199 
200   O << getRegisterName(MO0.getReg()) << ", #" << MO1.getImm();
201 }
202 
printGlobalOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const203 void HexagonInstPrinter::printGlobalOperand(const MCInst *MI, unsigned OpNo,
204                                             raw_ostream &O) const {
205   assert(MI->getOperand(OpNo).isExpr() && "Expecting expression");
206 
207   printOperand(MI, OpNo, O);
208 }
209 
printJumpTable(const MCInst * MI,unsigned OpNo,raw_ostream & O) const210 void HexagonInstPrinter::printJumpTable(const MCInst *MI, unsigned OpNo,
211                                         raw_ostream &O) const {
212   assert(MI->getOperand(OpNo).isExpr() && "Expecting expression");
213 
214   printOperand(MI, OpNo, O);
215 }
216 
printConstantPool(const MCInst * MI,unsigned OpNo,raw_ostream & O) const217 void HexagonInstPrinter::printConstantPool(const MCInst *MI, unsigned OpNo,
218                                            raw_ostream &O) const {
219   assert(MI->getOperand(OpNo).isExpr() && "Expecting expression");
220 
221   printOperand(MI, OpNo, O);
222 }
223 
printBranchOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const224 void HexagonInstPrinter::printBranchOperand(const MCInst *MI, unsigned OpNo,
225                                             raw_ostream &O) const {
226   // Branches can take an immediate operand.  This is used by the branch
227   // selection pass to print $+8, an eight byte displacement from the PC.
228   llvm_unreachable("Unknown branch operand.");
229 }
230 
printCallOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const231 void HexagonInstPrinter::printCallOperand(const MCInst *MI, unsigned OpNo,
232                                           raw_ostream &O) const {
233 }
234 
printAbsAddrOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const235 void HexagonInstPrinter::printAbsAddrOperand(const MCInst *MI, unsigned OpNo,
236                                              raw_ostream &O) const {
237 }
238 
printPredicateOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O) const239 void HexagonInstPrinter::printPredicateOperand(const MCInst *MI, unsigned OpNo,
240                                                raw_ostream &O) const {
241 }
242 
printSymbol(const MCInst * MI,unsigned OpNo,raw_ostream & O,bool hi) const243 void HexagonInstPrinter::printSymbol(const MCInst *MI, unsigned OpNo,
244                                      raw_ostream &O, bool hi) const {
245   assert(MI->getOperand(OpNo).isImm() && "Unknown symbol operand");
246 
247   O << '#' << (hi ? "HI" : "LO") << "(#";
248   printOperand(MI, OpNo, O);
249   O << ')';
250 }
251