//===- SPIRVBasicBlock.h - SPIR-V Basic Block -------------------*- C++ -*-===//
//
//                     The LLVM/SPIRV Translator
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
// Copyright (c) 2014 Advanced Micro Devices, Inc. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal with the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimers.
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// this list of conditions and the following disclaimers in the documentation
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//
//===----------------------------------------------------------------------===//
/// \file
///
/// This file defines Basic Block class for SPIR-V.
///
//===----------------------------------------------------------------------===//

#ifndef SPIRV_LIBSPIRV_SPIRVBASICBLOCK_H
#define SPIRV_LIBSPIRV_SPIRVBASICBLOCK_H

#include "SPIRVValue.h"
#include <algorithm>

namespace SPIRV {
class SPIRVFunction;
class SPIRVInstruction;
class SPIRVDecoder;
class SPIRVBasicBlock : public SPIRVValue {

public:
  SPIRVBasicBlock(SPIRVId TheId, SPIRVFunction *Func);

  SPIRVBasicBlock() : SPIRVValue(OpLabel), ParentF(NULL) { setAttr(); }

  SPIRVDecoder getDecoder(std::istream &IS) override;
  SPIRVFunction *getParent() const { return ParentF; }
  size_t getNumInst() const { return InstVec.size(); }
  SPIRVInstruction *getInst(size_t I) const { return InstVec[I]; }
  SPIRVInstruction *getPrevious(const SPIRVInstruction *I) const {
    auto Loc = find(I);
    if (Loc == InstVec.end() || Loc == InstVec.begin())
      return nullptr;
    return *(--Loc);
  }
  SPIRVInstruction *getNext(const SPIRVInstruction *I) const {
    auto Loc = find(I);
    if (Loc == InstVec.end())
      return nullptr;
    ++Loc;
    if (Loc == InstVec.end())
      return nullptr;
    return *Loc;
  }
  // Return the last instruction in the BB or nullptr if the BB is empty.
  const SPIRVInstruction *getTerminateInstr() const {
    return InstVec.empty() ? nullptr : InstVec.back();
  }
  // Variables must be the first instructions in the block,
  // intermixed with OpLine and OpNoLine instructions. Return first instruction
  // not being an OpVariable, OpUntypedVariableKHR, OpLine or OpNoLine.
  SPIRVInstruction *getVariableInsertionPoint() const;

  void setScope(SPIRVEntry *Scope) override;
  void setParent(SPIRVFunction *F) { ParentF = F; }
  SPIRVInstruction *
  addInstruction(SPIRVInstruction *I,
                 const SPIRVInstruction *InsertBefore = nullptr);
  void eraseInstruction(const SPIRVInstruction *I) {
    auto Loc = find(I);
    assert(Loc != InstVec.end());
    InstVec.erase(Loc);
  }

  void setAttr() { setHasNoType(); }
  _SPIRV_DCL_ENCDEC
  void encodeChildren(spv_ostream &) const override;
  void validate() const override {
    SPIRVValue::validate();
    assert(ParentF && "Invalid parent function");
  }

private:
  SPIRVFunction *ParentF;
  typedef std::vector<SPIRVInstruction *> SPIRVInstructionVector;
  SPIRVInstructionVector InstVec;

  SPIRVInstructionVector::const_iterator
  find(const SPIRVInstruction *Inst) const {
    return std::find(InstVec.begin(), InstVec.end(), Inst);
  }

  SPIRVInstructionVector::iterator find(const SPIRVInstruction *Inst) {
    return std::find(InstVec.begin(), InstVec.end(), Inst);
  }
};

typedef SPIRVBasicBlock SPIRVLabel;
} // namespace SPIRV

#endif // SPIRV_LIBSPIRV_SPIRVBASICBLOCK_H