Пример #1
0
/// A definition of a register may mark the end of a range.
void LiveDebugValues::transferRegisterDef(MachineInstr &MI,
                                          OpenRangesSet &OpenRanges,
                                          const VarLocMap &VarLocIDs) {
  MachineFunction *MF = MI.getParent()->getParent();
  const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
  unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
  SparseBitVector<> KillSet;
  for (const MachineOperand &MO : MI.operands()) {
    if (MO.isReg() && MO.isDef() && MO.getReg() &&
        TRI->isPhysicalRegister(MO.getReg())) {
      // Remove ranges of all aliased registers.
      for (MCRegAliasIterator RAI(MO.getReg(), TRI, true); RAI.isValid(); ++RAI)
        for (unsigned ID : OpenRanges.getVarLocs())
          if (VarLocIDs[ID].isDescribedByReg() == *RAI)
            KillSet.set(ID);
    } else if (MO.isRegMask()) {
      // Remove ranges of all clobbered registers. Register masks don't usually
      // list SP as preserved.  While the debug info may be off for an
      // instruction or two around callee-cleanup calls, transferring the
      // DEBUG_VALUE across the call is still a better user experience.
      for (unsigned ID : OpenRanges.getVarLocs()) {
        unsigned Reg = VarLocIDs[ID].isDescribedByReg();
        if (Reg && Reg != SP && MO.clobbersPhysReg(Reg))
          KillSet.set(ID);
      }
    }
  }
  OpenRanges.erase(KillSet, VarLocIDs);
}
Пример #2
0
Error llvm::pdb::writeSparseBitVector(BinaryStreamWriter &Writer,
                                      SparseBitVector<> &Vec) {
  constexpr int BitsPerWord = 8 * sizeof(uint32_t);

  int ReqBits = Vec.find_last() + 1;
  uint32_t ReqWords = alignTo(ReqBits, BitsPerWord) / BitsPerWord;
  if (auto EC = Writer.writeInteger(ReqWords))
    return joinErrors(
        std::move(EC),
        make_error<RawError>(raw_error_code::corrupt_file,
                             "Could not write linear map number of words"));

  uint32_t Idx = 0;
  for (uint32_t I = 0; I != ReqWords; ++I) {
    uint32_t Word = 0;
    for (uint32_t WordIdx = 0; WordIdx < 32; ++WordIdx, ++Idx) {
      if (Vec.test(Idx))
        Word |= (1 << WordIdx);
    }
    if (auto EC = Writer.writeInteger(Word))
      return joinErrors(std::move(EC), make_error<RawError>(
                                           raw_error_code::corrupt_file,
                                           "Could not write linear map word"));
  }
  return Error::success();
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SimpleDeadCodeElimination::RemoveDeadVariables(Function* function) {
    SparseBitVector liveVars;

    // Scan every instruction in the function and mark any local variable
    // that appears as an operand. All variables that are not marked are deleted.
    function->ForEachInstruction([&liveVars](Instruction* instr) -> bool {
        for(int i = 0; i < instr->SourceOpCount(); i++) {
            if(auto variableRef = instr->GetSourceOp(i)->As<VariableReference>()) {
                auto variable = variableRef->GetVariable(); // Only local variables.

                if(variable && (variable->IsParameter() == false)) {
                    liveVars.SetBit(variable->Id());
                }
            }
        }

        return true;
    });

    // Now removed all unused variables.
    for(int i = 0; i < function->VariableCount(); i++) {
        auto variable = function->Variables()[i];

        if(liveVars.IsSet(variable->Id()) == false) {
            function->RemoveVariable(variable);
            i--;
        }
    }
}
Пример #4
0
void LazyLiveness::computeBackedgeChain(MachineFunction& mf, 
                                        MachineBasicBlock* MBB) {
  SparseBitVector<128> tmp = rv[MBB];
  tmp.set(preorder[MBB]);
  tmp &= backedge_source;
  calculated.set(preorder[MBB]);
  
  for (SparseBitVector<128>::iterator I = tmp.begin(); I != tmp.end(); ++I) {
    assert(rev_preorder.size() > *I && "Unknown block!");
    
    MachineBasicBlock* SrcMBB = rev_preorder[*I];
    
    for (MachineBasicBlock::succ_iterator SI = SrcMBB->succ_begin(),
         SE = SrcMBB->succ_end(); SI != SE; ++SI) {
      MachineBasicBlock* TgtMBB = *SI;
      
      if (backedges.count(std::make_pair(SrcMBB, TgtMBB)) &&
          !rv[MBB].test(preorder[TgtMBB])) {
        if (!calculated.test(preorder[TgtMBB]))
          computeBackedgeChain(mf, TgtMBB);
        
        tv[MBB].set(preorder[TgtMBB]);
        SparseBitVector<128> right = tv[TgtMBB];
        tv[MBB] |= right;
      }
    }
    
    tv[MBB].reset(preorder[MBB]);
  }
}
Пример #5
0
void SIFixWWMLiveness::addDefs(const MachineInstr &MI, SparseBitVector<> &Regs)
{
  for (const MachineOperand &Op : MI.defs()) {
    if (Op.isReg()) {
      unsigned Reg = Op.getReg();
      if (TRI->isVGPR(*MRI, Reg))
        Regs.set(Reg);
    }
  }
}
Пример #6
0
	const TBlock* GetStartBlock(const TFunction* function) {
		// It's possible that the function has multiple exit blocks.
		// In this case we need to create a fake block that acts like an
		// "unique" exit block, whose predecessors are the real exit blocks.
        if(exitBlock_) {
            // A fake exit block has been already created.
            return exitBlock_;
        }

		StaticList<const TBlock*, 16> exitBlocks;
		const TBlock* block = function->FirstBlock();

		while(block) {
			if(block->SuccessorCount() == 0) {
				// This is an exit block.
				exitBlocks.Add(block);
                returnBlocks_.SetBit(block->Id());
			}

			block = block->NextBlock();
		}

        // Now return the exit block. If there is no unique block
        // we create a "fake" one that has all the exit blocks 
        // as its predecessors. This block will be deleted after the analysis.
		if(exitBlocks.Count() == 1) {
			// There is a single exit block.
			return exitBlocks[0];
		}
		else if(exitBlocks.Count() > 1) {
			// There are multiple exit blocks, create a fake block.
			exitBlock_ = TBlock::GetBlock("#fakeBlock");

			for(int i = 0; i < exitBlocks.Count(); i++) {
				exitBlock_->AddPredecessor(const_cast<TBlock*>(exitBlocks[i]));	
			}

			return exitBlock_;
		}
		else {
			// There is no exit block. This can happen, for example, if the last
			// block represents an infinite loop. In this case return the last block.
			return function->LastBlock();
		}
	}
Пример #7
0
Error llvm::pdb::readSparseBitVector(BinaryStreamReader &Stream,
                                     SparseBitVector<> &V) {
  uint32_t NumWords;
  if (auto EC = Stream.readInteger(NumWords))
    return joinErrors(
        std::move(EC),
        make_error<RawError>(raw_error_code::corrupt_file,
                             "Expected hash table number of words"));

  for (uint32_t I = 0; I != NumWords; ++I) {
    uint32_t Word;
    if (auto EC = Stream.readInteger(Word))
      return joinErrors(std::move(EC),
                        make_error<RawError>(raw_error_code::corrupt_file,
                                             "Expected hash table word"));
    for (unsigned Idx = 0; Idx < 32; ++Idx)
      if (Word & (1U << Idx))
        V.set((I * 32) + Idx);
  }
  return Error::success();
}
Пример #8
0
Error NameMap::load(StreamReader &Stream) {
  // This is some sort of weird string-set/hash table encoded in the stream.
  // It starts with the number of bytes in the table.
  uint32_t NumberOfBytes;
  if (auto EC = Stream.readInteger(NumberOfBytes))
    return joinErrors(std::move(EC),
                      make_error<RawError>(raw_error_code::corrupt_file,
                                           "Expected name map length"));
  if (Stream.bytesRemaining() < NumberOfBytes)
    return make_error<RawError>(raw_error_code::corrupt_file,
                                "Invalid name map length");

  // Following that field is the starting offset of strings in the name table.
  uint32_t StringsOffset = Stream.getOffset();
  Stream.setOffset(StringsOffset + NumberOfBytes);

  // This appears to be equivalent to the total number of strings *actually*
  // in the name table.
  uint32_t HashSize;
  if (auto EC = Stream.readInteger(HashSize))
    return joinErrors(std::move(EC),
                      make_error<RawError>(raw_error_code::corrupt_file,
                                           "Expected name map hash size"));

  // This appears to be an upper bound on the number of strings in the name
  // table.
  uint32_t MaxNumberOfStrings;
  if (auto EC = Stream.readInteger(MaxNumberOfStrings))
    return joinErrors(std::move(EC),
                      make_error<RawError>(raw_error_code::corrupt_file,
                                           "Expected name map max strings"));

  if (MaxNumberOfStrings > (UINT32_MAX / sizeof(uint32_t)))
    return make_error<RawError>(raw_error_code::corrupt_file,
                                "Implausible number of strings");

  const uint32_t MaxNumberOfWords = UINT32_MAX / (sizeof(uint32_t) * 8);

  // This appears to be a hash table which uses bitfields to determine whether
  // or not a bucket is 'present'.
  uint32_t NumPresentWords;
  if (auto EC = Stream.readInteger(NumPresentWords))
    return joinErrors(std::move(EC),
                      make_error<RawError>(raw_error_code::corrupt_file,
                                           "Expected name map num words"));

  if (NumPresentWords > MaxNumberOfWords)
    return make_error<RawError>(raw_error_code::corrupt_file,
                                "Number of present words is too large");

  SparseBitVector<> Present;
  for (uint32_t I = 0; I != NumPresentWords; ++I) {
    uint32_t Word;
    if (auto EC = Stream.readInteger(Word))
      return joinErrors(std::move(EC),
                        make_error<RawError>(raw_error_code::corrupt_file,
                                             "Expected name map word"));
    for (unsigned Idx = 0; Idx < 32; ++Idx)
      if (Word & (1U << Idx))
        Present.set((I * 32) + Idx);
  }

  // This appears to be a hash table which uses bitfields to determine whether
  // or not a bucket is 'deleted'.
  uint32_t NumDeletedWords;
  if (auto EC = Stream.readInteger(NumDeletedWords))
    return joinErrors(
        std::move(EC),
        make_error<RawError>(raw_error_code::corrupt_file,
                             "Expected name map num deleted words"));

  if (NumDeletedWords > MaxNumberOfWords)
    return make_error<RawError>(raw_error_code::corrupt_file,
                                "Number of deleted words is too large");

  SparseBitVector<> Deleted;
  for (uint32_t I = 0; I != NumDeletedWords; ++I) {
    uint32_t Word;
    if (auto EC = Stream.readInteger(Word))
      return joinErrors(std::move(EC),
                        make_error<RawError>(raw_error_code::corrupt_file,
                                             "Expected name map word"));
    for (unsigned Idx = 0; Idx < 32; ++Idx)
      if (Word & (1U << Idx))
        Deleted.set((I * 32) + Idx);
  }

  for (unsigned I : Present) {
    // For all present entries, dump out their mapping.
    (void)I;

    // This appears to be an offset relative to the start of the strings.
    // It tells us where the null-terminated string begins.
    uint32_t NameOffset;
    if (auto EC = Stream.readInteger(NameOffset))
      return joinErrors(std::move(EC),
                        make_error<RawError>(raw_error_code::corrupt_file,
                                             "Expected name map name offset"));

    // This appears to be a stream number into the stream directory.
    uint32_t NameIndex;
    if (auto EC = Stream.readInteger(NameIndex))
      return joinErrors(std::move(EC),
                        make_error<RawError>(raw_error_code::corrupt_file,
                                             "Expected name map name index"));

    // Compute the offset of the start of the string relative to the stream.
    uint32_t StringOffset = StringsOffset + NameOffset;
    uint32_t OldOffset = Stream.getOffset();
    // Pump out our c-string from the stream.
    StringRef Str;
    Stream.setOffset(StringOffset);
    if (auto EC = Stream.readZeroString(Str))
      return joinErrors(std::move(EC),
                        make_error<RawError>(raw_error_code::corrupt_file,
                                             "Expected name map name"));

    Stream.setOffset(OldOffset);
    // Add this to a string-map from name to stream number.
    Mapping.insert({Str, NameIndex});
  }

  return Error::success();
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void AggregateCopyPropagation::IterateToFixedpoint() {
    // We use an iterative data-flow algorithm to propagate the copies
    // that are available on entry of each block. Add the blocks
    // in reverse-postorder, this minimizes the number of iterations.
    StaticList<Block*, 64> worklist;
    SparseBitVector inWorklist;

    CFGInfo<Block, Function> cfgInfo(funct_->FirstBlock(), false);
    auto& postorderList = cfgInfo.PostorderList();
    int copyCount = infoList_.Count();

    // Add all blocks to the worklist.
    for(int i = 0; i < postorderList.Count(); i++) {
        auto block = const_cast<Block*>(postorderList[i]);
        worklist.Add(block);
        inWorklist.SetBit(block->Id());
    }

    while(worklist.IsNotEmpty()) {
        // Extract a block from the worklist.
        auto block = worklist.RemoveLast();
        inWorklist.ResetBit(block->Id());

        // Compute the 'in' set, which is the intersection
        // out the 'out' sets of the predecessors.
        BitVector inSet(copyCount, false);
        auto predecessorEnum = block->GetPredecessorEnum();
        bool first = true;

        while(predecessorEnum.IsValid()) {
            auto predecessorBlock = predecessorEnum.Next();

            if(first) {
                inSet = outSets_[predecessorBlock];
                first = false;
            }
            else inSet.And(outSets_[predecessorBlock]);
        }

        // Save the 'in' set, it's needed later
        // when we want to eliminate the copies.
        inSets_.Add(block, inSet);

        // Now compute the new 'out' set, which is the union of the 'copy' set
        // with the 'in' set, from which the 'kill' set has been subtracted.
        // Out(B) = Copy(B) U (In(B) - Kill(B))
        BitVector outSet = copySets_[block];
        inSet.Difference(killSets_[block]);
        outSet.Or(inSet);

        if(outSets_[block] != outSet) {
            // The 'out' set must be updated, and all successors
            // must be added to the worklist and reprocessed.
            outSets_[block] = outSet;

            auto successorEnum = block->GetSuccessorEnum();

            while(successorEnum.IsValid()) {
                auto successorBlock = successorEnum.Next();

                if(inWorklist.IsSet(successorBlock->Id()) == false) {
                    worklist.Add(successorBlock);
                    inWorklist.IsSet(successorBlock->Id());
                }
            }
        }
    }
}
Пример #10
0
 bool IsReturnBlock(const TBlock* block) {
     return returnBlocks_.IsSet(block->Id());
 }