mirror of
				https://github.com/c64scene-ar/llvm-6502.git
				synced 2025-11-04 05:17:07 +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
 |