Ejemplo n.º 1
0
void DebugDatabase::addIRInstructions(GenerateRTL *hw) {
    Function *F = hw->getFunction();
    int instr_count = 0;
    for (Function::iterator b = F->begin(), be = F->end(); b != be; b++) {
        for (BasicBlock::iterator i = b->begin(), ie = b->end(); i != ie; i++) {

            instr_count++;

            bool isDummyDbgCall = false;
            if (isa<DbgDeclareInst>(i) || isa<DbgValueInst>(i))
                isDummyDbgCall = true;

            if (i->hasMetadata()) {
                MDNode *n = i->getMetadata("dbg");
                DILocation loc(n);
                int lineNumber = loc.getLineNumber();
                int columnNumber = loc.getColumnNumber();
                std::string filePath =
                    loc.getDirectory().str() + "/" + loc.getFilename().str();

                addIRInstruction(hw, i, instr_count, isDummyDbgCall, filePath,
                                 lineNumber, columnNumber);
            } else {
                addIRInstruction(hw, i, instr_count, isDummyDbgCall, "", 0, 0);
            }
        }
    }
}
Ejemplo n.º 2
0
/// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto,
/// except that it does some simple constant prop and DCE on the fly.  The
/// effect of this is to copy significantly less code in cases where (for
/// example) a function call with constant arguments is inlined, and those
/// constant arguments cause a significant amount of code in the callee to be
/// dead.  Since this doesn't produce an exact copy of the input, it can't be
/// used for things like CloneFunction or CloneModule.
void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc,
                                     DenseMap<const Value*, Value*> &ValueMap,
                                     SmallVectorImpl<ReturnInst*> &Returns,
                                     const char *NameSuffix, 
                                     ClonedCodeInfo *CodeInfo,
                                     const TargetData *TD,
                                     Instruction *TheCall) {
  assert(NameSuffix && "NameSuffix cannot be null!");
  
#ifndef NDEBUG
  for (Function::const_arg_iterator II = OldFunc->arg_begin(), 
       E = OldFunc->arg_end(); II != E; ++II)
    assert(ValueMap.count(II) && "No mapping from source argument specified!");
#endif

  PruningFunctionCloner PFC(NewFunc, OldFunc, ValueMap, Returns,
                            NameSuffix, CodeInfo, TD);

  // Clone the entry block, and anything recursively reachable from it.
  std::vector<const BasicBlock*> CloneWorklist;
  CloneWorklist.push_back(&OldFunc->getEntryBlock());
  while (!CloneWorklist.empty()) {
    const BasicBlock *BB = CloneWorklist.back();
    CloneWorklist.pop_back();
    PFC.CloneBlock(BB, CloneWorklist);
  }
  
  // Loop over all of the basic blocks in the old function.  If the block was
  // reachable, we have cloned it and the old block is now in the value map:
  // insert it into the new function in the right order.  If not, ignore it.
  //
  // Defer PHI resolution until rest of function is resolved.
  SmallVector<const PHINode*, 16> PHIToResolve;
  for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
       BI != BE; ++BI) {
    BasicBlock *NewBB = cast_or_null<BasicBlock>(ValueMap[BI]);
    if (NewBB == 0) continue;  // Dead block.

    // Add the new block to the new function.
    NewFunc->getBasicBlockList().push_back(NewBB);
    
    // Loop over all of the instructions in the block, fixing up operand
    // references as we go.  This uses ValueMap to do all the hard work.
    //
    BasicBlock::iterator I = NewBB->begin();

    LLVMContext &Context = OldFunc->getContext();
    unsigned DbgKind = Context.getMetadata().getMDKind("dbg");
    MDNode *TheCallMD = NULL;
    SmallVector<Value *, 4> MDVs;
    if (TheCall && TheCall->hasMetadata()) 
      TheCallMD = Context.getMetadata().getMD(DbgKind, TheCall);
    
    // Handle PHI nodes specially, as we have to remove references to dead
    // blocks.
    if (PHINode *PN = dyn_cast<PHINode>(I)) {
      // Skip over all PHI nodes, remembering them for later.
      BasicBlock::const_iterator OldI = BI->begin();
      for (; (PN = dyn_cast<PHINode>(I)); ++I, ++OldI) {
        if (I->hasMetadata()) {
          if (TheCallMD) {
            if (MDNode *IMD = Context.getMetadata().getMD(DbgKind, I)) {
              MDNode *NewMD = UpdateInlinedAtInfo(IMD, TheCallMD, Context);
              Context.getMetadata().addMD(DbgKind, NewMD, I);
            }
          } else {
            // The cloned instruction has dbg info but the call instruction
            // does not have dbg info. Remove dbg info from cloned instruction.
            Context.getMetadata().removeMD(DbgKind, I);
          }
        }
        PHIToResolve.push_back(cast<PHINode>(OldI));
      }
    }
    
    // Otherwise, remap the rest of the instructions normally.
    for (; I != NewBB->end(); ++I) {
      if (I->hasMetadata()) {
        if (TheCallMD) {
          if (MDNode *IMD = Context.getMetadata().getMD(DbgKind, I)) {
            MDNode *NewMD = UpdateInlinedAtInfo(IMD, TheCallMD, Context);
            Context.getMetadata().addMD(DbgKind, NewMD, I);
          }
        } else {
          // The cloned instruction has dbg info but the call instruction
          // does not have dbg info. Remove dbg info from cloned instruction.
          Context.getMetadata().removeMD(DbgKind, I);
        }
      }
      RemapInstruction(I, ValueMap);
    }
  }
  
  // Defer PHI resolution until rest of function is resolved, PHI resolution
  // requires the CFG to be up-to-date.
  for (unsigned phino = 0, e = PHIToResolve.size(); phino != e; ) {
    const PHINode *OPN = PHIToResolve[phino];
    unsigned NumPreds = OPN->getNumIncomingValues();
    const BasicBlock *OldBB = OPN->getParent();
    BasicBlock *NewBB = cast<BasicBlock>(ValueMap[OldBB]);

    // Map operands for blocks that are live and remove operands for blocks
    // that are dead.
    for (; phino != PHIToResolve.size() &&
         PHIToResolve[phino]->getParent() == OldBB; ++phino) {
      OPN = PHIToResolve[phino];
      PHINode *PN = cast<PHINode>(ValueMap[OPN]);
      for (unsigned pred = 0, e = NumPreds; pred != e; ++pred) {
        if (BasicBlock *MappedBlock = 
            cast_or_null<BasicBlock>(ValueMap[PN->getIncomingBlock(pred)])) {
          Value *InVal = MapValue(PN->getIncomingValue(pred),
                                  ValueMap);
          assert(InVal && "Unknown input value?");
          PN->setIncomingValue(pred, InVal);
          PN->setIncomingBlock(pred, MappedBlock);
        } else {
          PN->removeIncomingValue(pred, false);
          --pred, --e;  // Revisit the next entry.
        }
      } 
    }
    
    // The loop above has removed PHI entries for those blocks that are dead
    // and has updated others.  However, if a block is live (i.e. copied over)
    // but its terminator has been changed to not go to this block, then our
    // phi nodes will have invalid entries.  Update the PHI nodes in this
    // case.
    PHINode *PN = cast<PHINode>(NewBB->begin());
    NumPreds = std::distance(pred_begin(NewBB), pred_end(NewBB));
    if (NumPreds != PN->getNumIncomingValues()) {
      assert(NumPreds < PN->getNumIncomingValues());
      // Count how many times each predecessor comes to this block.
      std::map<BasicBlock*, unsigned> PredCount;
      for (pred_iterator PI = pred_begin(NewBB), E = pred_end(NewBB);
           PI != E; ++PI)
        --PredCount[*PI];
      
      // Figure out how many entries to remove from each PHI.
      for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
        ++PredCount[PN->getIncomingBlock(i)];
      
      // At this point, the excess predecessor entries are positive in the
      // map.  Loop over all of the PHIs and remove excess predecessor
      // entries.
      BasicBlock::iterator I = NewBB->begin();
      for (; (PN = dyn_cast<PHINode>(I)); ++I) {
        for (std::map<BasicBlock*, unsigned>::iterator PCI =PredCount.begin(),
             E = PredCount.end(); PCI != E; ++PCI) {
          BasicBlock *Pred     = PCI->first;
          for (unsigned NumToRemove = PCI->second; NumToRemove; --NumToRemove)
            PN->removeIncomingValue(Pred, false);
        }
      }
    }
    
    // If the loops above have made these phi nodes have 0 or 1 operand,
    // replace them with undef or the input value.  We must do this for
    // correctness, because 0-operand phis are not valid.
    PN = cast<PHINode>(NewBB->begin());
    if (PN->getNumIncomingValues() == 0) {
      BasicBlock::iterator I = NewBB->begin();
      BasicBlock::const_iterator OldI = OldBB->begin();
      while ((PN = dyn_cast<PHINode>(I++))) {
        Value *NV = UndefValue::get(PN->getType());
        PN->replaceAllUsesWith(NV);
        assert(ValueMap[OldI] == PN && "ValueMap mismatch");
        ValueMap[OldI] = NV;
        PN->eraseFromParent();
        ++OldI;
      }
    }
    // NOTE: We cannot eliminate single entry phi nodes here, because of
    // ValueMap.  Single entry phi nodes can have multiple ValueMap entries
    // pointing at them.  Thus, deleting one would require scanning the ValueMap
    // to update any entries in it that would require that.  This would be
    // really slow.
  }
  
  // Now that the inlined function body has been fully constructed, go through
  // and zap unconditional fall-through branches.  This happen all the time when
  // specializing code: code specialization turns conditional branches into
  // uncond branches, and this code folds them.
  Function::iterator I = cast<BasicBlock>(ValueMap[&OldFunc->getEntryBlock()]);
  while (I != NewFunc->end()) {
    BranchInst *BI = dyn_cast<BranchInst>(I->getTerminator());
    if (!BI || BI->isConditional()) { ++I; continue; }
    
    // Note that we can't eliminate uncond branches if the destination has
    // single-entry PHI nodes.  Eliminating the single-entry phi nodes would
    // require scanning the ValueMap to update any entries that point to the phi
    // node.
    BasicBlock *Dest = BI->getSuccessor(0);
    if (!Dest->getSinglePredecessor() || isa<PHINode>(Dest->begin())) {
      ++I; continue;
    }
    
    // We know all single-entry PHI nodes in the inlined function have been
    // removed, so we just need to splice the blocks.
    BI->eraseFromParent();
    
    // Move all the instructions in the succ to the pred.
    I->getInstList().splice(I->end(), Dest->getInstList());
    
    // Make all PHI nodes that referred to Dest now refer to I as their source.
    Dest->replaceAllUsesWith(I);

    // Remove the dest block.
    Dest->eraseFromParent();
    
    // Do not increment I, iteratively merge all things this block branches to.
  }
}