From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=67.231.154.164; helo=dispatch1-us1.ppe-hosted.com; envelope-from=tpilar@solarflare.com; receiver=edk2-devel@lists.01.org Received: from dispatch1-us1.ppe-hosted.com (dispatch1-us1.ppe-hosted.com [67.231.154.164]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id C178720986AA6 for ; Wed, 4 Jul 2018 07:02:12 -0700 (PDT) X-Virus-Scanned: Proofpoint Essentials engine Received: from webmail.solarflare.com (webmail.solarflare.com [12.187.104.26]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1-us3.ppe-hosted.com (Proofpoint Essentials ESMTP Server) with ESMTPS id E0BB09C006D; Wed, 4 Jul 2018 14:02:10 +0000 (UTC) Received: from tp-desktop.uk.solarflarecom.com (10.17.20.51) by ocex03.SolarFlarecom.com (10.20.40.36) with Microsoft SMTP Server (TLS) id 15.0.1044.25; Wed, 4 Jul 2018 07:02:07 -0700 From: "Tomas Pilar (tpilar)" To: CC: Michael D Kinney , Liming Gao Message-ID: Date: Wed, 4 Jul 2018 15:02:06 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 X-Originating-IP: [10.17.20.51] X-MDID: 1530712931-i4wOY4tewSr8 Subject: [PATCH v3] MdePkg/BaseLib: Add bit field population calculating methods X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Jul 2018 14:02:13 -0000 Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit 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 Cc: Liming Gao Cc: Michael D Kinney --- 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