// Copyright (c) 2015-2016 The Khronos Group Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#ifndef LIBSPIRV_UTIL_BITUTILS_H_

#define LIBSPIRV_UTIL_BITUTILS_H_

#include <cstdint>

#include <cstring>

namespace spvutils {

// Performs a bitwise copy of source to the destination type Dest.

template <typename Dest, typename Src>

Dest BitwiseCast(Src source) {

  Dest dest;

  static_assert(sizeof(source) == sizeof(dest),

                "BitwiseCast: Source and destination must have the same size");

  std::memcpy(static_cast<void*>(&dest), &source, sizeof(dest));

  return dest;

}

unsigned int spvutils::BitwiseCast<unsigned int, float>(float)

Line

Count

Source

25

1.31k

Dest BitwiseCast(Src source) {

26

1.31k

  Dest dest;

27

1.31k

  static_assert(sizeof(source) == sizeof(dest),

28

1.31k

                "BitwiseCast: Source and destination must have the same size");

29

1.31k

  std::memcpy(static_cast<void*>(&dest), &source, sizeof(dest));

30

1.31k

  return dest;

31

1.31k

}

unsigned int spvutils::BitwiseCast<unsigned int, spvutils::FloatProxy<float> >(spvutils::FloatProxy<float>)

Line

Count

Source

25

10.6k

Dest BitwiseCast(Src source) {

26

10.6k

  Dest dest;

27

10.6k

  static_assert(sizeof(source) == sizeof(dest),

28

10.6k

                "BitwiseCast: Source and destination must have the same size");

29

10.6k

  std::memcpy(static_cast<void*>(&dest), &source, sizeof(dest));

30

10.6k

  return dest;

31

10.6k

}

Unexecuted instantiation: unsigned short spvutils::BitwiseCast<unsigned short, unsigned short>(unsigned short)

spvutils::FloatProxy<spvutils::Float16> spvutils::BitwiseCast<spvutils::FloatProxy<spvutils::Float16>, unsigned short>(unsigned short)

Line

Count

Source

25

1.11k

Dest BitwiseCast(Src source) {

26

1.11k

  Dest dest;

27

1.11k

  static_assert(sizeof(source) == sizeof(dest),

28

1.11k

                "BitwiseCast: Source and destination must have the same size");

29

1.11k

  std::memcpy(static_cast<void*>(&dest), &source, sizeof(dest));

30

1.11k

  return dest;

31

1.11k

}

spvutils::Float16 spvutils::BitwiseCast<spvutils::Float16, unsigned short>(unsigned short)

Line

Count

Source

25

1.31k

Dest BitwiseCast(Src source) {

26

1.31k

  Dest dest;

27

1.31k

  static_assert(sizeof(source) == sizeof(dest),

28

1.31k

                "BitwiseCast: Source and destination must have the same size");

29

1.31k

  std::memcpy(static_cast<void*>(&dest), &source, sizeof(dest));

30

1.31k

  return dest;

31

1.31k

}

Unexecuted instantiation: unsigned char spvutils::BitwiseCast<unsigned char, unsigned char>(unsigned char)

Unexecuted instantiation: spvutils::FloatProxy<spvutils::FloatE5M2> spvutils::BitwiseCast<spvutils::FloatProxy<spvutils::FloatE5M2>, unsigned char>(unsigned char)

Unexecuted instantiation: spvutils::FloatE5M2 spvutils::BitwiseCast<spvutils::FloatE5M2, unsigned char>(unsigned char)

Unexecuted instantiation: spvutils::FloatProxy<spvutils::FloatE4M3> spvutils::BitwiseCast<spvutils::FloatProxy<spvutils::FloatE4M3>, unsigned char>(unsigned char)

Unexecuted instantiation: spvutils::FloatE4M3 spvutils::BitwiseCast<spvutils::FloatE4M3, unsigned char>(unsigned char)

Unexecuted instantiation: float spvutils::BitwiseCast<float, unsigned int>(unsigned int)

Unexecuted instantiation: unsigned short spvutils::BitwiseCast<unsigned short, spvutils::FloatProxy<spvutils::Float16> >(spvutils::FloatProxy<spvutils::Float16>)

Unexecuted instantiation: unsigned short spvutils::BitwiseCast<unsigned short, spvutils::Float16>(spvutils::Float16)

// SetBits<T, First, Num> returns an integer of type <T> with bits set

// for position <First> through <First + Num - 1>, counting from the least

// significant bit. In particular when Num == 0, no positions are set to 1.

// A static assert will be triggered if First + Num > sizeof(T) * 8, that is,

// a bit that will not fit in the underlying type is set.

template <typename T, size_t First = 0, size_t Num = 0>

struct SetBits {

  static_assert(First < sizeof(T) * 8,

                "Tried to set a bit that is shifted too far.");

  const static T get = (T(1) << First) | SetBits<T, First + 1, Num - 1>::get;

};

template <typename T, size_t Last>

struct SetBits<T, Last, 0> {

  const static T get = T(0);

};

// This is all compile-time so we can put our tests right here.

static_assert(SetBits<uint32_t, 0, 0>::get == uint32_t(0x00000000),

              "SetBits failed");

static_assert(SetBits<uint32_t, 0, 1>::get == uint32_t(0x00000001),

              "SetBits failed");

static_assert(SetBits<uint32_t, 31, 1>::get == uint32_t(0x80000000),

              "SetBits failed");

static_assert(SetBits<uint32_t, 1, 2>::get == uint32_t(0x00000006),

              "SetBits failed");

static_assert(SetBits<uint32_t, 30, 2>::get == uint32_t(0xc0000000),

              "SetBits failed");

static_assert(SetBits<uint32_t, 0, 31>::get == uint32_t(0x7FFFFFFF),

              "SetBits failed");

static_assert(SetBits<uint32_t, 0, 32>::get == uint32_t(0xFFFFFFFF),

              "SetBits failed");

static_assert(SetBits<uint32_t, 16, 16>::get == uint32_t(0xFFFF0000),

              "SetBits failed");

static_assert(SetBits<uint64_t, 0, 1>::get == uint64_t(0x0000000000000001LL),

              "SetBits failed");

static_assert(SetBits<uint64_t, 63, 1>::get == uint64_t(0x8000000000000000LL),

              "SetBits failed");

static_assert(SetBits<uint64_t, 62, 2>::get == uint64_t(0xc000000000000000LL),

              "SetBits failed");

static_assert(SetBits<uint64_t, 31, 1>::get == uint64_t(0x0000000080000000LL),

              "SetBits failed");

static_assert(SetBits<uint64_t, 16, 16>::get == uint64_t(0x00000000FFFF0000LL),

              "SetBits failed");

}  // namespace spvutils

#endif  // LIBSPIRV_UTIL_BITUTILS_H_