MdePkg/Include/Library/BaseLib.h | 56 ++++++++++++++++++++++++++ MdePkg/Library/BaseLib/BitField.c | 85 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 141 insertions(+)
Add 32-bit and 64-bit functions that count number of set bits in a bitfield
using a divide-and-count method.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Tomas Pilar <tpilar@solarflare.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
---
MdePkg/Include/Library/BaseLib.h | 56 ++++++++++++++++++++++++++
MdePkg/Library/BaseLib/BitField.c | 85 +++++++++++++++++++++++++++++++++++++++
2 files changed, 141 insertions(+)
diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h
index 1db3a04..123ae19 100644
--- a/MdePkg/Include/Library/BaseLib.h
+++ b/MdePkg/Include/Library/BaseLib.h
@@ -4609,6 +4609,62 @@ BitFieldAndThenOr64 (
IN UINT64 OrData
);
+/**
+ Reads a bit field from a 32-bit value, counts and returns
+ the number of set bits.
+
+ Counts the number of set bits in the bit field specified by
+ StartBit and EndBit in Operand. The count is returned.
+
+ If StartBit is greater than 31, then ASSERT().
+ If EndBit is greater than 31, then ASSERT().
+ If EndBit is less than StartBit, then ASSERT().
+
+ @param Operand Operand on which to perform the bitfield operation.
+ @param StartBit The ordinal of the least significant bit in the bit field.
+ Range 0..31.
+ @param EndBit The ordinal of the most significant bit in the bit field.
+ Range 0..31.
+
+ @return The number of bits set between StartBit and EndBit.
+
+**/
+UINT8
+EFIAPI
+BitFieldCountOnes32 (
+ IN UINT32 Operand,
+ IN UINTN StartBit,
+ IN UINTN EndBit
+ );
+
+/**
+ Reads a bit field from a 64-bit value, counts and returns
+ the number of set bits.
+
+ Counts the number of set bits in the bit field specified by
+ StartBit and EndBit in Operand. The count is returned.
+
+ If StartBit is greater than 63, then ASSERT().
+ If EndBit is greater than 63, then ASSERT().
+ If EndBit is less than StartBit, then ASSERT().
+
+ @param Operand Operand on which to perform the bitfield operation.
+ @param StartBit The ordinal of the least significant bit in the bit field.
+ Range 0..63.
+ @param EndBit The ordinal of the most significant bit in the bit field.
+ Range 0..63.
+
+ @return The number of bits set between StartBit and EndBit.
+
+**/
+UINT8
+EFIAPI
+BitFieldCountOnes64 (
+ IN UINT64 Operand,
+ IN UINTN StartBit,
+ IN UINTN EndBit
+ );
+
//
// Base Library Checksum Functions
//
diff --git a/MdePkg/Library/BaseLib/BitField.c b/MdePkg/Library/BaseLib/BitField.c
index d2d3150..8acd345 100644
--- a/MdePkg/Library/BaseLib/BitField.c
+++ b/MdePkg/Library/BaseLib/BitField.c
@@ -920,3 +920,88 @@ BitFieldAndThenOr64 (
OrData
);
}
+
+/**
+ Reads a bit field from a 32-bit value, counts and returns
+ the number of set bits.
+
+ Counts the number of set bits in the bit field specified by
+ StartBit and EndBit in Operand. The count is returned.
+
+ If StartBit is greater than 31, then ASSERT().
+ If EndBit is greater than 31, then ASSERT().
+ If EndBit is less than StartBit, then ASSERT().
+
+ @param Operand Operand on which to perform the bitfield operation.
+ @param StartBit The ordinal of the least significant bit in the bit field.
+ Range 0..31.
+ @param EndBit The ordinal of the most significant bit in the bit field.
+ Range 0..31.
+
+ @return The number of bits set between StartBit and EndBit.
+
+**/
+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;
+}
+
+/**
+ Reads a bit field from a 64-bit value, counts and returns
+ the number of set bits.
+
+ Counts the number of set bits in the bit field specified by
+ StartBit and EndBit in Operand. The count is returned.
+
+ If StartBit is greater than 63, then ASSERT().
+ If EndBit is greater than 63, then ASSERT().
+ If EndBit is less than StartBit, then ASSERT().
+
+ @param Operand Operand on which to perform the bitfield operation.
+ @param StartBit The ordinal of the least significant bit in the bit field.
+ Range 0..63.
+ @param EndBit The ordinal of the most significant bit in the bit field.
+ Range 0..63.
+
+ @return The number of bits set between StartBit and EndBit.
+
+**/
+UINT8
+EFIAPI
+BitFieldCountOnes64 (
+ IN UINT64 Operand,
+ IN UINTN StartBit,
+ IN UINTN EndBit
+ )
+{
+ UINT32 BitField;
+ UINT8 Count;
+
+ ASSERT (EndBit < 64);
+ ASSERT (StartBit <= EndBit);
+
+ BitField = BitFieldRead64 (Operand, StartBit, EndBit);
+ Count = BitFieldCountOnes32 (BitField, 0, 31);
+
+ return Count + BitFieldCountOnes32 (RShiftU64(BitField, 32), 0, 31);
+}
+
--
2.9.5
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Tom: When I use VS2015 to compile it, I meet with below error. Could you fix them? Edk2\MdePkg\Library\BaseLib\BitField.c(1002): error C2220: warning treated as error - no 'object' file generated Edk2\MdePkg\Library\BaseLib\BitField.c(1002): warning C4244: '=': conversion from 'UINT64' to 'UINT32', possible loss of data Edk2\MdePkg\Library\BaseLib\BitField.c(1005): warning C4244: 'function': conversion from 'UINT64' to 'UINT32', possible loss of data Thanks Liming > -----Original Message----- > From: Tomas Pilar (tpilar) [mailto:tpilar@solarflare.com] > Sent: Wednesday, July 4, 2018 10:02 PM > To: edk2-devel@lists.01.org > Cc: Kinney, Michael D <michael.d.kinney@intel.com>; Gao, Liming <liming.gao@intel.com> > Subject: [PATCH v3] MdePkg/BaseLib: Add bit field population calculating methods > > Add 32-bit and 64-bit functions that count number of set bits in a bitfield > using a divide-and-count method. > > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Tomas Pilar <tpilar@solarflare.com> > Cc: Liming Gao <liming.gao@intel.com> > Cc: Michael D Kinney <michael.d.kinney@intel.com> > --- > MdePkg/Include/Library/BaseLib.h | 56 ++++++++++++++++++++++++++ > MdePkg/Library/BaseLib/BitField.c | 85 +++++++++++++++++++++++++++++++++++++++ > 2 files changed, 141 insertions(+) > > diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h > index 1db3a04..123ae19 100644 > --- a/MdePkg/Include/Library/BaseLib.h > +++ b/MdePkg/Include/Library/BaseLib.h > @@ -4609,6 +4609,62 @@ BitFieldAndThenOr64 ( > IN UINT64 OrData > ); > > +/** > + Reads a bit field from a 32-bit value, counts and returns > + the number of set bits. > + > + Counts the number of set bits in the bit field specified by > + StartBit and EndBit in Operand. The count is returned. > + > + If StartBit is greater than 31, then ASSERT(). > + If EndBit is greater than 31, then ASSERT(). > + If EndBit is less than StartBit, then ASSERT(). > + > + @param Operand Operand on which to perform the bitfield operation. > + @param StartBit The ordinal of the least significant bit in the bit field. > + Range 0..31. > + @param EndBit The ordinal of the most significant bit in the bit field. > + Range 0..31. > + > + @return The number of bits set between StartBit and EndBit. > + > +**/ > +UINT8 > +EFIAPI > +BitFieldCountOnes32 ( > + IN UINT32 Operand, > + IN UINTN StartBit, > + IN UINTN EndBit > + ); > + > +/** > + Reads a bit field from a 64-bit value, counts and returns > + the number of set bits. > + > + Counts the number of set bits in the bit field specified by > + StartBit and EndBit in Operand. The count is returned. > + > + If StartBit is greater than 63, then ASSERT(). > + If EndBit is greater than 63, then ASSERT(). > + If EndBit is less than StartBit, then ASSERT(). > + > + @param Operand Operand on which to perform the bitfield operation. > + @param StartBit The ordinal of the least significant bit in the bit field. > + Range 0..63. > + @param EndBit The ordinal of the most significant bit in the bit field. > + Range 0..63. > + > + @return The number of bits set between StartBit and EndBit. > + > +**/ > +UINT8 > +EFIAPI > +BitFieldCountOnes64 ( > + IN UINT64 Operand, > + IN UINTN StartBit, > + IN UINTN EndBit > + ); > + > // > // Base Library Checksum Functions > // > diff --git a/MdePkg/Library/BaseLib/BitField.c b/MdePkg/Library/BaseLib/BitField.c > index d2d3150..8acd345 100644 > --- a/MdePkg/Library/BaseLib/BitField.c > +++ b/MdePkg/Library/BaseLib/BitField.c > @@ -920,3 +920,88 @@ BitFieldAndThenOr64 ( > OrData > ); > } > + > +/** > + Reads a bit field from a 32-bit value, counts and returns > + the number of set bits. > + > + Counts the number of set bits in the bit field specified by > + StartBit and EndBit in Operand. The count is returned. > + > + If StartBit is greater than 31, then ASSERT(). > + If EndBit is greater than 31, then ASSERT(). > + If EndBit is less than StartBit, then ASSERT(). > + > + @param Operand Operand on which to perform the bitfield operation. > + @param StartBit The ordinal of the least significant bit in the bit field. > + Range 0..31. > + @param EndBit The ordinal of the most significant bit in the bit field. > + Range 0..31. > + > + @return The number of bits set between StartBit and EndBit. > + > +**/ > +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; > +} > + > +/** > + Reads a bit field from a 64-bit value, counts and returns > + the number of set bits. > + > + Counts the number of set bits in the bit field specified by > + StartBit and EndBit in Operand. The count is returned. > + > + If StartBit is greater than 63, then ASSERT(). > + If EndBit is greater than 63, then ASSERT(). > + If EndBit is less than StartBit, then ASSERT(). > + > + @param Operand Operand on which to perform the bitfield operation. > + @param StartBit The ordinal of the least significant bit in the bit field. > + Range 0..63. > + @param EndBit The ordinal of the most significant bit in the bit field. > + Range 0..63. > + > + @return The number of bits set between StartBit and EndBit. > + > +**/ > +UINT8 > +EFIAPI > +BitFieldCountOnes64 ( > + IN UINT64 Operand, > + IN UINTN StartBit, > + IN UINTN EndBit > + ) > +{ > + UINT32 BitField; > + UINT8 Count; > + > + ASSERT (EndBit < 64); > + ASSERT (StartBit <= EndBit); > + > + BitField = BitFieldRead64 (Operand, StartBit, EndBit); > + Count = BitFieldCountOnes32 (BitField, 0, 31); > + > + return Count + BitFieldCountOnes32 (RShiftU64(BitField, 32), 0, 31); > +} > + > -- > 2.9.5 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
Apologies, I usually compile with GCC49 since I work on linux. Respinning now. Cheers Tom On 05/07/18 15:07, Gao, Liming wrote: > warning C4244 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
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