1 //===- CodeEmitterGen.cpp - Code Emitter Generator ------------------------===//
5 //===----------------------------------------------------------------------===//
7 #include "CodeEmitterGen.h"
9 #include "Support/Debug.h"
11 void CodeEmitterGen::run(std::ostream &o) {
12 std::vector<Record*> Insts = Records.getAllDerivedDefinitions("Instruction");
14 std::string Namespace = "V9::";
15 std::string ClassName = "SparcV9CodeEmitter::";
17 //const std::string &Namespace = Inst->getValue("Namespace")->getName();
18 o << "unsigned " << ClassName
19 << "getBinaryCodeForInstr(MachineInstr &MI) {\n"
20 << " unsigned Value = 0;\n"
21 << " DEBUG(std::cerr << MI);\n"
22 << " switch (MI.getOpcode()) {\n";
23 for (std::vector<Record*>::iterator I = Insts.begin(), E = Insts.end();
26 o << " case " << Namespace << R->getName() << ": {\n"
27 << " DEBUG(std::cerr << \"Emitting " << R->getName() << "\\n\");\n";
29 BitsInit *BI = R->getValueAsBitsInit("Inst");
32 const std::vector<RecordVal> &Vals = R->getValues();
34 DEBUG(o << " // prefilling: ");
35 // Start by filling in fixed values...
36 for (unsigned i = 0, e = BI->getNumBits(); i != e; ++i) {
37 if (BitInit *B = dynamic_cast<BitInit*>(BI->getBit(e-i-1))) {
38 Value |= B->getValue() << (e-i-1);
39 DEBUG(o << B->getValue());
46 DEBUG(o << " // " << *R->getValue("Inst") << "\n");
47 o << " Value = " << Value << "U;\n\n";
49 // Loop over all of the fields in the instruction determining which are the
50 // operands to the instruction.
53 std::map<std::string, unsigned> OpOrder;
54 std::map<std::string, bool> OpContinuous;
55 for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
56 if (!Vals[i].getPrefix() && !Vals[i].getValue()->isComplete()) {
57 // Is the operand continuous? If so, we can just mask and OR it in
58 // instead of doing it bit-by-bit, saving a lot in runtime cost.
59 const BitsInit *InstInit = BI;
60 int beginBitInVar = -1, endBitInVar = -1;
61 int beginBitInInst = -1, endBitInInst = -1;
62 bool continuous = true;
64 for (int bit = InstInit->getNumBits()-1; bit >= 0; --bit) {
66 dynamic_cast<VarBitInit*>(InstInit->getBit(bit))) {
67 TypedInit *TI = VBI->getVariable();
68 if (VarInit *VI = dynamic_cast<VarInit*>(TI)) {
69 // only process the current variable
70 if (VI->getName() != Vals[i].getName())
73 if (beginBitInVar == -1)
74 beginBitInVar = VBI->getBitNum();
76 if (endBitInVar == -1)
77 endBitInVar = VBI->getBitNum();
79 if (endBitInVar == (int)VBI->getBitNum() + 1)
80 endBitInVar = VBI->getBitNum();
87 if (beginBitInInst == -1)
89 if (endBitInInst == -1)
92 if (endBitInInst == bit + 1)
100 // maintain same distance between bits in field and bits in
101 // instruction. if the relative distances stay the same
103 if (beginBitInVar - (int)VBI->getBitNum() !=
104 beginBitInInst - bit) {
112 // If we have found no bit in "Inst" which comes from this field, then
113 // this is not an operand!!
114 if (beginBitInInst != -1) {
115 o << " // op" << op << ": " << Vals[i].getName() << "\n"
116 << " int64_t op" << op
117 <<" = getMachineOpValue(MI, MI.getOperand("<<op<<"));\n";
118 //<< " MachineOperand &op" << op <<" = MI.getOperand("<<op<<");\n";
119 OpOrder[Vals[i].getName()] = op++;
121 DEBUG(o << " // Var: begin = " << beginBitInVar
122 << ", end = " << endBitInVar
123 << "; Inst: begin = " << beginBitInInst
124 << ", end = " << endBitInInst << "\n");
127 DEBUG(o << " // continuous: op" << OpOrder[Vals[i].getName()]
130 // Mask off the right bits
131 // Low mask (ie. shift, if necessary)
132 if (endBitInVar != 0) {
133 o << " op" << OpOrder[Vals[i].getName()]
134 << " >>= " << endBitInVar << ";\n";
135 beginBitInVar -= endBitInVar;
140 o << " op" << OpOrder[Vals[i].getName()]
141 << " &= (1<<" << beginBitInVar+1 << ") - 1;\n";
143 // Shift the value to the correct place (according to place in inst)
144 if (endBitInInst != 0)
145 o << " op" << OpOrder[Vals[i].getName()]
146 << " <<= " << endBitInInst << ";\n";
148 // Just OR in the result
149 o << " Value |= op" << OpOrder[Vals[i].getName()] << ";\n";
152 // otherwise, will be taken care of in the loop below using this
154 OpContinuous[Vals[i].getName()] = continuous;
159 for (unsigned f = 0, e = Vals.size(); f != e; ++f) {
160 if (Vals[f].getPrefix()) {
161 BitsInit *FieldInitializer = (BitsInit*)Vals[f].getValue();
163 // Scan through the field looking for bit initializers of the current
165 for (int i = FieldInitializer->getNumBits()-1; i >= 0; --i) {
166 if (BitInit *BI = dynamic_cast<BitInit*>(FieldInitializer->getBit(i)))
168 DEBUG(o << " // bit init: f: " << f << ", i: " << i << "\n");
169 } else if (UnsetInit *UI =
170 dynamic_cast<UnsetInit*>(FieldInitializer->getBit(i))) {
171 DEBUG(o << " // unset init: f: " << f << ", i: " << i << "\n");
172 } else if (VarBitInit *VBI =
173 dynamic_cast<VarBitInit*>(FieldInitializer->getBit(i))) {
174 TypedInit *TI = VBI->getVariable();
175 if (VarInit *VI = dynamic_cast<VarInit*>(TI)) {
176 // If the bits of the field are laid out consecutively in the
177 // instruction, then instead of separately ORing in bits, just
178 // mask and shift the entire field for efficiency.
179 if (OpContinuous[VI->getName()]) {
180 // already taken care of in the loop above, thus there is no
181 // need to individually OR in the bits
183 // for debugging, output the regular version anyway, commented
184 DEBUG(o << " // Value |= getValueBit(op"
185 << OpOrder[VI->getName()] << ", " << VBI->getBitNum()
186 << ")" << " << " << i << ";\n");
188 o << " Value |= getValueBit(op" << OpOrder[VI->getName()]
189 << ", " << VBI->getBitNum()
190 << ")" << " << " << i << ";\n";
192 } else if (FieldInit *FI = dynamic_cast<FieldInit*>(TI)) {
193 // FIXME: implement this!
194 o << "FIELD INIT not implemented yet!\n";
196 o << "Error: UNIMPLEMENTED\n";
208 << " DEBUG(std::cerr << \"Not supported instr: \" << MI << \"\\n\");\n"
211 << " return Value;\n"