BitField.c

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#include "BaseLibInternals.h"
 
UINTN
EFIAPI
InternalBaseLibBitFieldReadUint (
  IN      UINTN  Operand,
  IN      UINTN  StartBit,
  IN      UINTN  EndBit
  )
{
  //
  // ~((UINTN)-2 << EndBit) is a mask in which bit[0] thru bit[EndBit]
  // are 1's while bit[EndBit + 1] thru the most significant bit are 0's.
  //
  return (Operand & ~((UINTN)-2 << EndBit)) >> StartBit;
}
 
UINTN
EFIAPI
InternalBaseLibBitFieldOrUint (
  IN      UINTN  Operand,
  IN      UINTN  StartBit,
  IN      UINTN  EndBit,
  IN      UINTN  OrData
  )
{
  //
  // Higher bits in OrData those are not used must be zero.
  //
  // EndBit - StartBit + 1 might be 32 while the result right shifting 32 on a 32bit integer is undefined,
  // So the logic is updated to right shift (EndBit - StartBit) bits and compare the last bit directly.
  //
  ASSERT ((OrData >> (EndBit - StartBit)) == ((OrData >> (EndBit - StartBit)) & 1));
 
  //
  // ~((UINTN)-2 << EndBit) is a mask in which bit[0] thru bit[EndBit]
  // are 1's while bit[EndBit + 1] thru the most significant bit are 0's.
  //
  return Operand | ((OrData << StartBit) & ~((UINTN)-2 << EndBit));
}
 
UINTN
EFIAPI
InternalBaseLibBitFieldAndUint (
  IN      UINTN  Operand,
  IN      UINTN  StartBit,
  IN      UINTN  EndBit,
  IN      UINTN  AndData
  )
{
  //
  // Higher bits in AndData those are not used must be zero.
  //
  // EndBit - StartBit + 1 might be 32 while the result right shifting 32 on a 32bit integer is undefined,
  // So the logic is updated to right shift (EndBit - StartBit) bits and compare the last bit directly.
  //
  ASSERT ((AndData >> (EndBit - StartBit)) == ((AndData >> (EndBit - StartBit)) & 1));
 
  //
  // ~((UINTN)-2 << EndBit) is a mask in which bit[0] thru bit[EndBit]
  // are 1's while bit[EndBit + 1] thru the most significant bit are 0's.
  //
  return Operand & ~((~AndData << StartBit) & ~((UINTN)-2 << EndBit));
}
 
UINT8
EFIAPI
BitFieldRead8 (
  IN      UINT8  Operand,
  IN      UINTN  StartBit,
  IN      UINTN  EndBit
  )
{
  ASSERT (EndBit < 8);
  ASSERT (StartBit <= EndBit);
  return (UINT8)InternalBaseLibBitFieldReadUint (Operand, StartBit, EndBit);
}
 
UINT8
EFIAPI
BitFieldWrite8 (
  IN      UINT8  Operand,
  IN      UINTN  StartBit,
  IN      UINTN  EndBit,
  IN      UINT8  Value
  )
{
  ASSERT (EndBit < 8);
  ASSERT (StartBit <= EndBit);
  return BitFieldAndThenOr8 (Operand, StartBit, EndBit, 0, Value);
}
 
UINT8
EFIAPI
BitFieldOr8 (
  IN      UINT8  Operand,
  IN      UINTN  StartBit,
  IN      UINTN  EndBit,
  IN      UINT8  OrData
  )
{
  ASSERT (EndBit < 8);
  ASSERT (StartBit <= EndBit);
  return (UINT8)InternalBaseLibBitFieldOrUint (Operand, StartBit, EndBit, OrData);
}
 
UINT8
EFIAPI
BitFieldAnd8 (
  IN      UINT8  Operand,
  IN      UINTN  StartBit,
  IN      UINTN  EndBit,
  IN      UINT8  AndData
  )
{
  ASSERT (EndBit < 8);
  ASSERT (StartBit <= EndBit);
  return (UINT8)InternalBaseLibBitFieldAndUint (Operand, StartBit, EndBit, AndData);
}
 
UINT8
EFIAPI
BitFieldAndThenOr8 (
  IN      UINT8  Operand,
  IN      UINTN  StartBit,
  IN      UINTN  EndBit,
  IN      UINT8  AndData,
  IN      UINT8  OrData
  )
{
  ASSERT (EndBit < 8);
  ASSERT (StartBit <= EndBit);
  return BitFieldOr8 (
           BitFieldAnd8 (Operand, StartBit, EndBit, AndData),
           StartBit,
           EndBit,
           OrData
           );
}
 
UINT16
EFIAPI
BitFieldRead16 (
  IN      UINT16  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit
  )
{
  ASSERT (EndBit < 16);
  ASSERT (StartBit <= EndBit);
  return (UINT16)InternalBaseLibBitFieldReadUint (Operand, StartBit, EndBit);
}
 
UINT16
EFIAPI
BitFieldWrite16 (
  IN      UINT16  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT16  Value
  )
{
  ASSERT (EndBit < 16);
  ASSERT (StartBit <= EndBit);
  return BitFieldAndThenOr16 (Operand, StartBit, EndBit, 0, Value);
}
 
UINT16
EFIAPI
BitFieldOr16 (
  IN      UINT16  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT16  OrData
  )
{
  ASSERT (EndBit < 16);
  ASSERT (StartBit <= EndBit);
  return (UINT16)InternalBaseLibBitFieldOrUint (Operand, StartBit, EndBit, OrData);
}
 
UINT16
EFIAPI
BitFieldAnd16 (
  IN      UINT16  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT16  AndData
  )
{
  ASSERT (EndBit < 16);
  ASSERT (StartBit <= EndBit);
  return (UINT16)InternalBaseLibBitFieldAndUint (Operand, StartBit, EndBit, AndData);
}
 
UINT16
EFIAPI
BitFieldAndThenOr16 (
  IN      UINT16  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT16  AndData,
  IN      UINT16  OrData
  )
{
  ASSERT (EndBit < 16);
  ASSERT (StartBit <= EndBit);
  return BitFieldOr16 (
           BitFieldAnd16 (Operand, StartBit, EndBit, AndData),
           StartBit,
           EndBit,
           OrData
           );
}
 
UINT32
EFIAPI
BitFieldRead32 (
  IN      UINT32  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit
  )
{
  ASSERT (EndBit < 32);
  ASSERT (StartBit <= EndBit);
  return (UINT32)InternalBaseLibBitFieldReadUint (Operand, StartBit, EndBit);
}
 
UINT32
EFIAPI
BitFieldWrite32 (
  IN      UINT32  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT32  Value
  )
{
  ASSERT (EndBit < 32);
  ASSERT (StartBit <= EndBit);
  return BitFieldAndThenOr32 (Operand, StartBit, EndBit, 0, Value);
}
 
UINT32
EFIAPI
BitFieldOr32 (
  IN      UINT32  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT32  OrData
  )
{
  ASSERT (EndBit < 32);
  ASSERT (StartBit <= EndBit);
  return (UINT32)InternalBaseLibBitFieldOrUint (Operand, StartBit, EndBit, OrData);
}
 
UINT32
EFIAPI
BitFieldAnd32 (
  IN      UINT32  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT32  AndData
  )
{
  ASSERT (EndBit < 32);
  ASSERT (StartBit <= EndBit);
  return (UINT32)InternalBaseLibBitFieldAndUint (Operand, StartBit, EndBit, AndData);
}
 
UINT32
EFIAPI
BitFieldAndThenOr32 (
  IN      UINT32  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT32  AndData,
  IN      UINT32  OrData
  )
{
  ASSERT (EndBit < 32);
  ASSERT (StartBit <= EndBit);
  return BitFieldOr32 (
           BitFieldAnd32 (Operand, StartBit, EndBit, AndData),
           StartBit,
           EndBit,
           OrData
           );
}
 
UINT64
EFIAPI
BitFieldRead64 (
  IN      UINT64  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit
  )
{
  ASSERT (EndBit < 64);
  ASSERT (StartBit <= EndBit);
  return RShiftU64 (Operand & ~LShiftU64 ((UINT64)-2, EndBit), StartBit);
}
 
UINT64
EFIAPI
BitFieldWrite64 (
  IN      UINT64  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT64  Value
  )
{
  ASSERT (EndBit < 64);
  ASSERT (StartBit <= EndBit);
  return BitFieldAndThenOr64 (Operand, StartBit, EndBit, 0, Value);
}
 
UINT64
EFIAPI
BitFieldOr64 (
  IN      UINT64  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT64  OrData
  )
{
  UINT64  Value1;
  UINT64  Value2;
 
  ASSERT (EndBit < 64);
  ASSERT (StartBit <= EndBit);
  //
  // Higher bits in OrData those are not used must be zero.
  //
  // EndBit - StartBit + 1 might be 64 while the result right shifting 64 on RShiftU64() API is invalid,
  // So the logic is updated to right shift (EndBit - StartBit) bits and compare the last bit directly.
  //
  ASSERT (RShiftU64 (OrData, EndBit - StartBit) == (RShiftU64 (OrData, EndBit - StartBit) & 1));
 
  Value1 = LShiftU64 (OrData, StartBit);
  Value2 = LShiftU64 ((UINT64)-2, EndBit);
 
  return Operand | (Value1 & ~Value2);
}
 
UINT64
EFIAPI
BitFieldAnd64 (
  IN      UINT64  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT64  AndData
  )
{
  UINT64  Value1;
  UINT64  Value2;
 
  ASSERT (EndBit < 64);
  ASSERT (StartBit <= EndBit);
  //
  // Higher bits in AndData those are not used must be zero.
  //
  // EndBit - StartBit + 1 might be 64 while the right shifting 64 on RShiftU64() API is invalid,
  // So the logic is updated to right shift (EndBit - StartBit) bits and compare the last bit directly.
  //
  ASSERT (RShiftU64 (AndData, EndBit - StartBit) == (RShiftU64 (AndData, EndBit - StartBit) & 1));
 
  Value1 = LShiftU64 (~AndData, StartBit);
  Value2 = LShiftU64 ((UINT64)-2, EndBit);
 
  return Operand & ~(Value1 & ~Value2);
}
 
UINT64
EFIAPI
BitFieldAndThenOr64 (
  IN      UINT64  Operand,
  IN      UINTN   StartBit,
  IN      UINTN   EndBit,
  IN      UINT64  AndData,
  IN      UINT64  OrData
  )
{
  ASSERT (EndBit < 64);
  ASSERT (StartBit <= EndBit);
  return BitFieldOr64 (
           BitFieldAnd64 (Operand, StartBit, EndBit, AndData),
           StartBit,
           EndBit,
           OrData
           );
}
 
UINT8
EFIAPI
BitFieldCountOnes32 (
  IN       UINT32  Operand,
  IN       UINTN   StartBit,
  IN       UINTN   EndBit
  )
{
  UINT32  Count;
 
  ASSERT (EndBit < 32);
  ASSERT (StartBit <= EndBit);
 
  Count  = BitFieldRead32 (Operand, StartBit, EndBit);
  Count -= ((Count >> 1) & 0x55555555);
  Count  = (Count & 0x33333333) + ((Count >> 2) & 0x33333333);
  Count += Count >> 4;
  Count &= 0x0F0F0F0F;
  Count += Count >> 8;
  Count += Count >> 16;
 
  return (UINT8)Count & 0x3F;
}
 
UINT8
EFIAPI
BitFieldCountOnes64 (
  IN       UINT64  Operand,
  IN       UINTN   StartBit,
  IN       UINTN   EndBit
  )
{
  UINT64  BitField;
  UINT8   Count;
 
  ASSERT (EndBit < 64);
  ASSERT (StartBit <= EndBit);
 
  BitField = BitFieldRead64 (Operand, StartBit, EndBit);
  Count    = BitFieldCountOnes32 ((UINT32)BitField, 0, 31);
  Count   += BitFieldCountOnes32 ((UINT32)RShiftU64 (BitField, 32), 0, 31);
 
  return Count;
}