mirror of
				https://github.com/c64scene-ar/llvm-6502.git
				synced 2025-10-31 08:16:47 +00:00 
			
		
		
		
	git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9903 91177308-0d34-0410-b5e6-96231b3b80d8
		
			
				
	
	
		
			231 lines
		
	
	
		
			8.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			231 lines
		
	
	
		
			8.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //===- CodeEmitterGen.cpp - Code Emitter Generator ------------------------===//
 | |
| // 
 | |
| //                     The LLVM Compiler Infrastructure
 | |
| //
 | |
| // This file was developed by the LLVM research group and is distributed under
 | |
| // the University of Illinois Open Source License. See LICENSE.TXT for details.
 | |
| // 
 | |
| //===----------------------------------------------------------------------===//
 | |
| //
 | |
| // FIXME: Document.
 | |
| //
 | |
| //===----------------------------------------------------------------------===//
 | |
| 
 | |
| #include "CodeEmitterGen.h"
 | |
| #include "Record.h"
 | |
| #include "Support/Debug.h"
 | |
| 
 | |
| namespace llvm {
 | |
| 
 | |
| void CodeEmitterGen::run(std::ostream &o) {
 | |
|   std::vector<Record*> Insts = Records.getAllDerivedDefinitions("Instruction");
 | |
| 
 | |
|   EmitSourceFileHeader("Machine Code Emitter", o);
 | |
| 
 | |
|   std::string Namespace = "V9::";
 | |
|   std::string ClassName = "SparcV9CodeEmitter::";
 | |
| 
 | |
|   //const std::string &Namespace = Inst->getValue("Namespace")->getName();
 | |
|   o << "unsigned " << ClassName
 | |
|     << "getBinaryCodeForInstr(MachineInstr &MI) {\n"
 | |
|     << "  unsigned Value = 0;\n"
 | |
|     << "  DEBUG(std::cerr << MI);\n"
 | |
|     << "  switch (MI.getOpcode()) {\n";
 | |
|   for (std::vector<Record*>::iterator I = Insts.begin(), E = Insts.end();
 | |
|        I != E; ++I) {
 | |
|     Record *R = *I;
 | |
|     o << "    case " << Namespace << R->getName() << ": {\n"
 | |
|       << "      DEBUG(std::cerr << \"Emitting " << R->getName() << "\\n\");\n";
 | |
| 
 | |
|     BitsInit *BI = R->getValueAsBitsInit("Inst");
 | |
| 
 | |
|     unsigned Value = 0;
 | |
|     const std::vector<RecordVal> &Vals = R->getValues();
 | |
| 
 | |
|     DEBUG(o << "      // prefilling: ");
 | |
|     // Start by filling in fixed values...
 | |
|     for (unsigned i = 0, e = BI->getNumBits(); i != e; ++i) {
 | |
|       if (BitInit *B = dynamic_cast<BitInit*>(BI->getBit(e-i-1))) {
 | |
|         Value |= B->getValue() << (e-i-1);
 | |
|         DEBUG(o << B->getValue());
 | |
|       } else {
 | |
|         DEBUG(o << "0");
 | |
|       }
 | |
|     }
 | |
|     DEBUG(o << "\n");
 | |
| 
 | |
|     DEBUG(o << "      // " << *R->getValue("Inst") << "\n");
 | |
|     o << "      Value = " << Value << "U;\n\n";
 | |
|     
 | |
|     // Loop over all of the fields in the instruction determining which are the
 | |
|     // operands to the instruction. 
 | |
|     //
 | |
|     unsigned op = 0;
 | |
|     std::map<std::string, unsigned> OpOrder;
 | |
|     std::map<std::string, bool> OpContinuous;
 | |
|     for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 | |
|       if (!Vals[i].getPrefix() &&  !Vals[i].getValue()->isComplete()) {
 | |
|         // Is the operand continuous? If so, we can just mask and OR it in
 | |
|         // instead of doing it bit-by-bit, saving a lot in runtime cost.        
 | |
|         const BitsInit *InstInit = BI;
 | |
|         int beginBitInVar = -1, endBitInVar = -1;
 | |
|         int beginBitInInst = -1, endBitInInst = -1;
 | |
|         bool continuous = true;
 | |
| 
 | |
|         for (int bit = InstInit->getNumBits()-1; bit >= 0; --bit) {
 | |
|           if (VarBitInit *VBI =
 | |
|               dynamic_cast<VarBitInit*>(InstInit->getBit(bit))) {
 | |
|             TypedInit *TI = VBI->getVariable();
 | |
|             if (VarInit *VI = dynamic_cast<VarInit*>(TI)) {
 | |
|               // only process the current variable
 | |
|               if (VI->getName() != Vals[i].getName())
 | |
|                 continue;
 | |
| 
 | |
|               if (beginBitInVar == -1)
 | |
|                 beginBitInVar = VBI->getBitNum();
 | |
| 
 | |
|               if (endBitInVar == -1)
 | |
|                 endBitInVar = VBI->getBitNum();
 | |
|               else {
 | |
|                 if (endBitInVar == (int)VBI->getBitNum() + 1)
 | |
|                   endBitInVar = VBI->getBitNum();
 | |
|                 else {
 | |
|                   continuous = false;
 | |
|                   break;
 | |
|                 }
 | |
|               }
 | |
| 
 | |
|               if (beginBitInInst == -1)
 | |
|                 beginBitInInst = bit;
 | |
|               if (endBitInInst == -1)
 | |
|                 endBitInInst = bit;
 | |
|               else {
 | |
|                 if (endBitInInst == bit + 1)
 | |
|                   endBitInInst = bit;
 | |
|                 else {
 | |
|                   continuous = false;
 | |
|                   break;
 | |
|                 }
 | |
|               }
 | |
| 
 | |
|               // maintain same distance between bits in field and bits in
 | |
|               // instruction. if the relative distances stay the same
 | |
|               // throughout,
 | |
|               if (beginBitInVar - (int)VBI->getBitNum() !=
 | |
|                   beginBitInInst - bit) {
 | |
|                 continuous = false;
 | |
|                 break;
 | |
|               }
 | |
|             }
 | |
|           }
 | |
|         }
 | |
| 
 | |
|         // If we have found no bit in "Inst" which comes from this field, then
 | |
|         // this is not an operand!!
 | |
|         if (beginBitInInst != -1) {
 | |
|           o << "      // op" << op << ": " << Vals[i].getName() << "\n"
 | |
|             << "      int64_t op" << op 
 | |
|             <<" = getMachineOpValue(MI, MI.getOperand("<<op<<"));\n";
 | |
|           //<< "   MachineOperand &op" << op <<" = MI.getOperand("<<op<<");\n";
 | |
|           OpOrder[Vals[i].getName()] = op++;
 | |
|           
 | |
|           DEBUG(o << "      // Var: begin = " << beginBitInVar 
 | |
|                   << ", end = " << endBitInVar
 | |
|                   << "; Inst: begin = " << beginBitInInst
 | |
|                   << ", end = " << endBitInInst << "\n");
 | |
|           
 | |
|           if (continuous) {
 | |
|             DEBUG(o << "      // continuous: op" << OpOrder[Vals[i].getName()]
 | |
|                     << "\n");
 | |
|             
 | |
|             // Mask off the right bits
 | |
|             // Low mask (ie. shift, if necessary)
 | |
|             assert(endBitInVar >= 0 && "Negative shift amount in masking!");
 | |
|             if (endBitInVar != 0) {
 | |
|               o << "      op" << OpOrder[Vals[i].getName()]
 | |
|                 << " >>= " << endBitInVar << ";\n";
 | |
|               beginBitInVar -= endBitInVar;
 | |
|               endBitInVar = 0;
 | |
|             }
 | |
|             
 | |
|             // High mask
 | |
|             o << "      op" << OpOrder[Vals[i].getName()]
 | |
|               << " &= (1<<" << beginBitInVar+1 << ") - 1;\n";
 | |
|             
 | |
|             // Shift the value to the correct place (according to place in inst)
 | |
|             assert(endBitInInst >= 0 && "Negative shift amount in inst position!");
 | |
|             if (endBitInInst != 0)
 | |
|               o << "      op" << OpOrder[Vals[i].getName()]
 | |
|               << " <<= " << endBitInInst << ";\n";
 | |
|             
 | |
|             // Just OR in the result
 | |
|             o << "      Value |= op" << OpOrder[Vals[i].getName()] << ";\n";
 | |
|           }
 | |
|           
 | |
|           // otherwise, will be taken care of in the loop below using this
 | |
|           // value:
 | |
|           OpContinuous[Vals[i].getName()] = continuous;
 | |
|         }
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     for (unsigned f = 0, e = Vals.size(); f != e; ++f) {
 | |
|       if (Vals[f].getPrefix()) {
 | |
|         BitsInit *FieldInitializer = (BitsInit*)Vals[f].getValue();
 | |
| 
 | |
|         // Scan through the field looking for bit initializers of the current
 | |
|         // variable...
 | |
|         for (int i = FieldInitializer->getNumBits()-1; i >= 0; --i) {
 | |
|           if (BitInit *BI = dynamic_cast<BitInit*>(FieldInitializer->getBit(i)))
 | |
|           {
 | |
|             DEBUG(o << "      // bit init: f: " << f << ", i: " << i << "\n");
 | |
|           } else if (UnsetInit *UI =
 | |
|                      dynamic_cast<UnsetInit*>(FieldInitializer->getBit(i))) {
 | |
|             DEBUG(o << "      // unset init: f: " << f << ", i: " << i << "\n");
 | |
|           } else if (VarBitInit *VBI =
 | |
|                      dynamic_cast<VarBitInit*>(FieldInitializer->getBit(i))) {
 | |
|             TypedInit *TI = VBI->getVariable();
 | |
|             if (VarInit *VI = dynamic_cast<VarInit*>(TI)) {
 | |
|               // If the bits of the field are laid out consecutively in the
 | |
|               // instruction, then instead of separately ORing in bits, just
 | |
|               // mask and shift the entire field for efficiency.
 | |
|               if (OpContinuous[VI->getName()]) {
 | |
|                 // already taken care of in the loop above, thus there is no
 | |
|                 // need to individually OR in the bits
 | |
| 
 | |
|                 // for debugging, output the regular version anyway, commented
 | |
|                 DEBUG(o << "      // Value |= getValueBit(op"
 | |
|                         << OpOrder[VI->getName()] << ", " << VBI->getBitNum()
 | |
|                         << ")" << " << " << i << ";\n");
 | |
|               } else {
 | |
|                 o << "      Value |= getValueBit(op" << OpOrder[VI->getName()]
 | |
|                   << ", " << VBI->getBitNum()
 | |
|                   << ")" << " << " << i << ";\n";
 | |
|               }
 | |
|             } else if (FieldInit *FI = dynamic_cast<FieldInit*>(TI)) {
 | |
|               // FIXME: implement this!
 | |
|               o << "FIELD INIT not implemented yet!\n";
 | |
|             } else {
 | |
|               o << "Error: UNIMPLEMENTED\n";
 | |
|             }
 | |
|           }
 | |
|         }
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     o << "      break;\n"
 | |
|       << "    }\n";
 | |
|   }
 | |
| 
 | |
|   o << "  default:\n"
 | |
|     << "    std::cerr << \"Not supported instr: \" << MI << \"\\n\";\n"
 | |
|     << "    abort();\n"
 | |
|     << "  }\n"
 | |
|     << "  return Value;\n"
 | |
|     << "}\n";
 | |
| 
 | |
|   EmitSourceFileTail(o);
 | |
| }
 | |
| 
 | |
| } // End llvm namespace
 |