dart::BitField< S, T, position, size, sign_extend, Enable > Class Template Reference

#include <bitfield.h>

Public Types
typedef T	Type

Static Public Member Functions
static constexpr bool	is_valid (T value)
static constexpr S	mask ()
static constexpr S	mask_in_place ()
static constexpr int	shift ()
static constexpr int	bitsize ()
static constexpr S	encode (T value)
static constexpr T	decode (S value)
static constexpr S	update (T value, S original)

Static Public Attributes
static constexpr intptr_t	kNextBit = position + size

Detailed Description

template<typename S, typename T, int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>
class dart::BitField< S, T, position, size, sign_extend, Enable >

Definition at line 136 of file bitfield.h.

Member Typedef Documentation

Type

template<typename S , typename T , int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>

typedef T dart::BitField< S, T, position, size, sign_extend, Enable >::Type

Definition at line 138 of file bitfield.h.

Member Function Documentation

bitsize()

template<typename S , typename T , int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>

static constexpr int dart::BitField< S, T, position, size, sign_extend, Enable >::bitsize ( )

inlinestaticconstexpr

Definition at line 164 of file bitfield.h.

{ return size; }

decode()

template<typename S , typename T , int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>

static constexpr T dart::BitField< S, T, position, size, sign_extend, Enable >::decode ( S  value )

inlinestaticconstexpr

Definition at line 173 of file bitfield.h.

                                     {
    // Ensure we slide down the sign bit if the value in the bit field is signed
    // and negative. We use 64-bit ints inside the expression since we can have
    // both cases: sizeof(S) > sizeof(T) or sizeof(S) < sizeof(T).
    if constexpr (sign_extend) {
      auto const u = static_cast<uint64_t>(value);
      return static_cast<T>((static_cast<int64_t>(u << (64 - kNextBit))) >>
                            (64 - size));
    } else {
      auto const u = static_cast<typename std::make_unsigned<S>::type>(value);
      return static_cast<T>((u >> position) & mask());
    }
  }

encode()

template<typename S , typename T , int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>

static constexpr S dart::BitField< S, T, position, size, sign_extend, Enable >::encode ( T  value )

inlinestaticconstexpr

Definition at line 167 of file bitfield.h.

                                     {
    ASSERT(is_valid(value));
    return encode_unchecked(value);
  }

is_valid()

template<typename S , typename T , int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>

static constexpr bool dart::BitField< S, T, position, size, sign_extend, Enable >::is_valid ( T  value )

inlinestaticconstexpr

Definition at line 148 of file bitfield.h.

                                          {
    return decode(encode_unchecked(value)) == value;
  }

mask()

template<typename S , typename T , int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>

static constexpr S dart::BitField< S, T, position, size, sign_extend, Enable >::mask ( )

inlinestaticconstexpr

Definition at line 153 of file bitfield.h.

{ return (kUwordOne << size) - 1; }

mask_in_place()

template<typename S , typename T , int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>

static constexpr S dart::BitField< S, T, position, size, sign_extend, Enable >::mask_in_place ( )

inlinestaticconstexpr

Definition at line 157 of file bitfield.h.

{ return mask() << position; }

shift()

template<typename S , typename T , int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>

static constexpr int dart::BitField< S, T, position, size, sign_extend, Enable >::shift ( )

inlinestaticconstexpr

Definition at line 161 of file bitfield.h.

{ return position; }

update()

template<typename S , typename T , int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>

static constexpr S dart::BitField< S, T, position, size, sign_extend, Enable >::update ( T  value, S  original  )

inlinestaticconstexpr

Definition at line 190 of file bitfield.h.

                                                 {
    return encode(value) | (~mask_in_place() & original);
  }

Member Data Documentation

kNextBit

template<typename S , typename T , int position, int size = (sizeof(S) * kBitsPerByte) - position, bool sign_extend = false, typename Enable = void>

constexpr intptr_t dart::BitField< S, T, position, size, sign_extend, Enable >::kNextBit = position + size

staticconstexpr

Definition at line 145 of file bitfield.h.

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The documentation for this class was generated from the following file:

• third_party/dart-lang/sdk/runtime/vm/bitfield.h