From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=134.134.136.24; helo=mga09.intel.com; envelope-from=liming.gao@intel.com; receiver=edk2-devel@lists.01.org Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id F3DCA20988775 for ; Tue, 3 Jul 2018 19:58:12 -0700 (PDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Jul 2018 19:58:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,306,1526367600"; d="scan'208";a="213246047" Received: from fmsmsx105.amr.corp.intel.com ([10.18.124.203]) by orsmga004.jf.intel.com with ESMTP; 03 Jul 2018 19:58:06 -0700 Received: from fmsmsx154.amr.corp.intel.com (10.18.116.70) by FMSMSX105.amr.corp.intel.com (10.18.124.203) with Microsoft SMTP Server (TLS) id 14.3.319.2; Tue, 3 Jul 2018 19:58:06 -0700 Received: from shsmsx151.ccr.corp.intel.com (10.239.6.50) by FMSMSX154.amr.corp.intel.com (10.18.116.70) with Microsoft SMTP Server (TLS) id 14.3.319.2; Tue, 3 Jul 2018 19:58:05 -0700 Received: from shsmsx152.ccr.corp.intel.com ([169.254.6.173]) by SHSMSX151.ccr.corp.intel.com ([169.254.3.17]) with mapi id 14.03.0319.002; Wed, 4 Jul 2018 10:58:04 +0800 From: "Gao, Liming" To: "Tomas Pilar (tpilar)" , "edk2-devel@lists.01.org" CC: "Kinney, Michael D" Thread-Topic: [PATCH v2] MdePkg/BaseLib: Add bit field population calculating methods Thread-Index: AQHUEt0zvSlpalgdLkCptA3kV6UPw6R+X1jQ Date: Wed, 4 Jul 2018 02:58:03 +0000 Message-ID: <4A89E2EF3DFEDB4C8BFDE51014F606A14E2AAD38@SHSMSX152.ccr.corp.intel.com> References: <2418b796-365f-cec2-d276-2b8972e1c554@solarflare.com> In-Reply-To: <2418b796-365f-cec2-d276-2b8972e1c554@solarflare.com> Accept-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] MIME-Version: 1.0 Subject: Re: [PATCH v2] 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 02:58:13 -0000 Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Tom: There are two issues here.=20 1) BitFieldHammingWeight32 should be replaced by BitFieldCountOnes32.=20 2) edk2 coding style requires the local variable is declared first, then as= sign the value to it. Don't assign the value in its declaration.=20 Thanks Liming >-----Original Message----- >From: Tomas Pilar (tpilar) [mailto:tpilar@solarflare.com] >Sent: Tuesday, July 03, 2018 10:50 PM >To: edk2-devel@lists.01.org >Cc: Kinney, Michael D ; Gao, Liming > >Subject: [PATCH v2] MdePkg/BaseLib: Add bit field population calculating >methods > >Add 32-bit and 64-bit functions that count number of set bits in a bit fie= ld >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 | 79 >+++++++++++++++++++++++++++++++++++++++ > 2 files changed, 135 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 f= ield. >+ Range 0..31. >+ @param EndBit The ordinal of the most significant bit in the bit fi= eld. >+ 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 f= ield. >+ 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..56b8eb2 100644 >--- a/MdePkg/Library/BaseLib/BitField.c >+++ b/MdePkg/Library/BaseLib/BitField.c >@@ -920,3 +920,82 @@ 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 f= ield. >+ Range 0..31. >+ @param EndBit The ordinal of the most significant bit in the bit fi= eld. >+ 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 >+ ) >+{ >+ ASSERT (EndBit < 32); >+ ASSERT (StartBit <=3D EndBit); >+ >+ UINT32 Count =3D BitFieldRead32 (Operand, StartBit, EndBit); >+ Count -=3D ((Count >> 1) & 0x55555555); >+ Count =3D (Count & 0x33333333) + ((Count >> 2) & 0x33333333); >+ Count +=3D Count >> 4; >+ Count &=3D 0x0F0F0F0F; >+ Count +=3D Count >> 8; >+ Count +=3D 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 f= ield. >+ 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 >+ ) >+{ >+ ASSERT (EndBit < 64); >+ ASSERT (StartBit <=3D EndBit); >+ >+ UINT64 BitField =3D BitFieldRead64 (Operand, StartBit, EndBit); >+ UINT8 Count =3D BitFieldHammingWeight32 (BitField, 0, 31); >+ return Count + BitFieldHammingWeight32 (RShiftU64(BitField, 32), 0, 31)= ; >+} >+ >-- >2.9.5