kc3-lang/angle/src/common/BitSetIterator.h

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• Author : Olli Etuaho
  Date : 2017-01-21 10:51:27
  Hash : 9250cb24
  Message : Add ESSL 3.10 integer math built-ins This adds built-ins found in ESSL 3.10 section 8.8 Integer functions. This includes constant folding support for functions that may be constant folded, and support for both GLSL and HLSL output. In HLSL several of the functions need to be emulated. The precision qualification for the return value of some of these functions is determined by special rules, that are now part of type promotion for TIntermUnary nodes and determining the type of TIntermAggregate nodes. BUG=angleproject:1730 TEST=angle_unittests TEST=dEQP-GLES31.functional.shaders.builtin_functions.integer.* Change-Id: Ib0056c17671c42b6496c2f0ef059b99f8f25c122 Reviewed-on: https://chromium-review.googlesource.com/431310 Commit-Queue: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>

• src/common/BitSetIterator.h

• //
  // Copyright 2015 The ANGLE Project Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  //
  // BitSetIterator:
  //   A helper class to quickly bitscan bitsets for set bits.
  //
  
  #ifndef COMMON_BITSETITERATOR_H_
  #define COMMON_BITSETITERATOR_H_
  
  #include <stdint.h>
  
  #include <bitset>
  
  #include "common/angleutils.h"
  #include "common/debug.h"
  #include "common/mathutil.h"
  #include "common/platform.h"
  
  namespace angle
  {
  template <size_t N>
  class BitSetIterator final
  {
    public:
      BitSetIterator(const std::bitset<N> &bitset);
      BitSetIterator(const BitSetIterator &other);
      BitSetIterator &operator=(const BitSetIterator &other);
  
      class Iterator final
      {
        public:
          Iterator(const std::bitset<N> &bits);
          Iterator &operator++();
  
          bool operator==(const Iterator &other) const;
          bool operator!=(const Iterator &other) const;
          unsigned long operator*() const { return mCurrentBit; }
  
        private:
          unsigned long getNextBit();
  
          static const size_t BitsPerWord = sizeof(unsigned long) * 8;
          std::bitset<N> mBits;
          unsigned long mCurrentBit;
          unsigned long mOffset;
      };
  
      Iterator begin() const { return Iterator(mBits); }
      Iterator end() const { return Iterator(std::bitset<N>(0)); }
  
    private:
      const std::bitset<N> mBits;
  };
  
  template <size_t N>
  BitSetIterator<N>::BitSetIterator(const std::bitset<N> &bitset)
      : mBits(bitset)
  {
  }
  
  template <size_t N>
  BitSetIterator<N>::BitSetIterator(const BitSetIterator &other)
      : mBits(other.mBits)
  {
  }
  
  template <size_t N>
  BitSetIterator<N> &BitSetIterator<N>::operator=(const BitSetIterator &other)
  {
      mBits = other.mBits;
      return *this;
  }
  
  template <size_t N>
  BitSetIterator<N>::Iterator::Iterator(const std::bitset<N> &bits)
      : mBits(bits), mCurrentBit(0), mOffset(0)
  {
      if (bits.any())
      {
          mCurrentBit = getNextBit();
      }
      else
      {
          mOffset = static_cast<unsigned long>(rx::roundUp(N, BitsPerWord));
      }
  }
  
  template <size_t N>
  typename BitSetIterator<N>::Iterator &BitSetIterator<N>::Iterator::operator++()
  {
      ASSERT(mBits.any());
      mBits.set(mCurrentBit - mOffset, 0);
      mCurrentBit = getNextBit();
      return *this;
  }
  
  template <size_t N>
  bool BitSetIterator<N>::Iterator::operator==(const Iterator &other) const
  {
      return mOffset == other.mOffset && mBits == other.mBits;
  }
  
  template <size_t N>
  bool BitSetIterator<N>::Iterator::operator!=(const Iterator &other) const
  {
      return !(*this == other);
  }
  
  template <size_t N>
  unsigned long BitSetIterator<N>::Iterator::getNextBit()
  {
      static std::bitset<N> wordMask(std::numeric_limits<unsigned long>::max());
  
      while (mOffset < N)
      {
          unsigned long wordBits = (mBits & wordMask).to_ulong();
          if (wordBits != 0ul)
          {
              return gl::ScanForward(wordBits) + mOffset;
          }
  
          mBits >>= BitsPerWord;
          mOffset += BitsPerWord;
      }
      return 0;
  }
  
  // Helper to avoid needing to specify the template parameter size
  template <size_t N>
  BitSetIterator<N> IterateBitSet(const std::bitset<N> &bitset)
  {
      return BitSetIterator<N>(bitset);
  }
  
  }  // angle
  
  #endif  // COMMON_BITSETITERATOR_H_