1 //===- InstrInfoEmitter.cpp - Generate a Instruction Set Desc. ------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This tablegen backend is responsible for emitting a description of the target
11 // instruction set for the code generator.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "InstrInfoEmitter.h"
16 #include "CodeGenWrappers.h"
17 #include "Record.h"
18 
19 namespace llvm {
20 
21 // runEnums - Print out enum values for all of the instructions.
22 void InstrInfoEmitter::runEnums(std::ostream &OS) {
23   std::vector<Record*> Insts = Records.getAllDerivedDefinitions("Instruction");
24 
25   if (Insts.size() == 0)
26     throw std::string("No 'Instruction' subclasses defined!");
27 
28   std::string Namespace = Insts[0]->getValueAsString("Namespace");
29 
30   EmitSourceFileHeader("Target Instruction Enum Values", OS);
31 
32   if (!Namespace.empty())
33     OS << "namespace " << Namespace << " {\n";
34   OS << "  enum {\n";
35 
36   CodeGenTarget Target;
37 
38   // We must emit the PHI opcode first...
39   Record *InstrInfo = Target.getInstructionSet();
40   Record *PHI = InstrInfo->getValueAsDef("PHIInst");
41 
42   OS << "    " << PHI->getName() << ", \t// 0 (fixed for all targets)\n";
43 
44   // Print out the rest of the instructions now...
45   for (unsigned i = 0, e = Insts.size(); i != e; ++i)
46     if (Insts[i] != PHI)
47       OS << "    " << Insts[i]->getName() << ", \t// " << i+1 << "\n";
48 
49   OS << "  };\n";
50   if (!Namespace.empty())
51     OS << "}\n";
52   EmitSourceFileTail(OS);
53 }
54 
55 void InstrInfoEmitter::printDefList(ListInit *LI, const std::string &Name,
56                                     std::ostream &OS) const {
57   OS << "static const unsigned " << Name << "[] = { ";
58   for (unsigned j = 0, e = LI->getSize(); j != e; ++j)
59     if (DefInit *DI = dynamic_cast<DefInit*>(LI->getElement(j)))
60       OS << getQualifiedName(DI->getDef()) << ", ";
61     else
62       throw "Illegal value in '" + Name + "' list!";
63   OS << "0 };\n";
64 }
65 
66 
67 // run - Emit the main instruction description records for the target...
68 void InstrInfoEmitter::run(std::ostream &OS) {
69   EmitSourceFileHeader("Target Instruction Descriptors", OS);
70   CodeGenTarget Target;
71   const std::string &TargetName = Target.getName();
72   Record *InstrInfo = Target.getInstructionSet();
73   Record *PHI = InstrInfo->getValueAsDef("PHIInst");
74 
75   std::vector<Record*> Instructions =
76     Records.getAllDerivedDefinitions("Instruction");
77 
78   // Emit empty implicit uses and defs lists
79   OS << "static const unsigned EmptyImpUses[] = { 0 };\n"
80      << "static const unsigned EmptyImpDefs[] = { 0 };\n";
81 
82   // Emit all of the instruction's implicit uses and defs...
83   for (unsigned i = 0, e = Instructions.size(); i != e; ++i) {
84     Record *Inst = Instructions[i];
85     ListInit *LI = Inst->getValueAsListInit("Uses");
86     if (LI->getSize()) printDefList(LI, Inst->getName()+"ImpUses", OS);
87     LI = Inst->getValueAsListInit("Defs");
88     if (LI->getSize()) printDefList(LI, Inst->getName()+"ImpDefs", OS);
89   }
90 
91   OS << "\nstatic const TargetInstrDescriptor " << TargetName
92      << "Insts[] = {\n";
93   emitRecord(PHI, 0, InstrInfo, OS);
94 
95   for (unsigned i = 0, e = Instructions.size(); i != e; ++i)
96     if (Instructions[i] != PHI)
97       emitRecord(Instructions[i], i+1, InstrInfo, OS);
98   OS << "};\n";
99   EmitSourceFileTail(OS);
100 }
101 
102 void InstrInfoEmitter::emitRecord(Record *R, unsigned Num, Record *InstrInfo,
103                                   std::ostream &OS) {
104   OS << "  { \"" << R->getValueAsString("Name")
105      << "\",\t-1, -1, 0, false, 0, 0, 0, 0";
106 
107   // Emit all of the target indepedent flags...
108   if (R->getValueAsBit("isReturn"))     OS << "|M_RET_FLAG";
109   if (R->getValueAsBit("isBranch"))     OS << "|M_BRANCH_FLAG";
110   if (R->getValueAsBit("isCall"  ))     OS << "|M_CALL_FLAG";
111   if (R->getValueAsBit("isTwoAddress")) OS << "|M_2_ADDR_FLAG";
112   if (R->getValueAsBit("isTerminator")) OS << "|M_TERMINATOR_FLAG";
113   OS << ", 0";
114 
115   // Emit all of the target-specific flags...
116   ListInit *LI    = InstrInfo->getValueAsListInit("TSFlagsFields");
117   ListInit *Shift = InstrInfo->getValueAsListInit("TSFlagsShifts");
118   if (LI->getSize() != Shift->getSize())
119     throw "Lengths of " + InstrInfo->getName() +
120           ":(TargetInfoFields, TargetInfoPositions) must be equal!";
121 
122   for (unsigned i = 0, e = LI->getSize(); i != e; ++i)
123     emitShiftedValue(R, dynamic_cast<StringInit*>(LI->getElement(i)),
124                      dynamic_cast<IntInit*>(Shift->getElement(i)), OS);
125 
126   OS << ", ";
127 
128   // Emit the implicit uses and defs lists...
129   LI = R->getValueAsListInit("Uses");
130   if (!LI->getSize())
131     OS << "EmptyImpUses, ";
132   else
133     OS << R->getName() << "ImpUses, ";
134 
135   LI = R->getValueAsListInit("Defs");
136   if (!LI->getSize())
137     OS << "EmptyImpDefs ";
138   else
139     OS << R->getName() << "ImpDefs ";
140 
141   OS << " },  // Inst #" << Num << " = " << R->getName() << "\n";
142 }
143 
144 void InstrInfoEmitter::emitShiftedValue(Record *R, StringInit *Val,
145                                         IntInit *ShiftInt, std::ostream &OS) {
146   if (Val == 0 || ShiftInt == 0)
147     throw std::string("Illegal value or shift amount in TargetInfo*!");
148   RecordVal *RV = R->getValue(Val->getValue());
149   int Shift = ShiftInt->getValue();
150 
151   if (RV == 0 || RV->getValue() == 0)
152     throw R->getName() + " doesn't have a field named '" + Val->getValue()+"'!";
153 
154   Init *Value = RV->getValue();
155   if (BitInit *BI = dynamic_cast<BitInit*>(Value)) {
156     if (BI->getValue()) OS << "|(1<<" << Shift << ")";
157     return;
158   } else if (BitsInit *BI = dynamic_cast<BitsInit*>(Value)) {
159     // Convert the Bits to an integer to print...
160     Init *I = BI->convertInitializerTo(new IntRecTy());
161     if (I)
162       if (IntInit *II = dynamic_cast<IntInit*>(I)) {
163         if (II->getValue())
164           OS << "|(" << II->getValue() << "<<" << Shift << ")";
165         return;
166       }
167 
168   } else if (IntInit *II = dynamic_cast<IntInit*>(Value)) {
169     if (II->getValue()) OS << "|(" << II->getValue() << "<<" << Shift << ")";
170     return;
171   }
172 
173   std::cerr << "Unhandled initializer: " << *Val << "\n";
174   throw "In record '" + R->getName() + "' for TSFlag emission.";
175 }
176 
177 } // End llvm namespace
178