From 5fc3b5d6c8f3f23823069f060e8ffc8f80bccdf7 Mon Sep 17 00:00:00 2001 From: andrewfish Date: Thu, 22 Jul 2010 19:22:34 +0000 Subject: Added to support X64 port (with SV5 ABI). May be able to remove after we port everything, but Sec, to EFI X64 ABI. git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10683 6f19259b-4bc3-4df7-8a09-765794883524 --- UnixPkg/Library/UnixBaseLib/LowBitSet64.c | 50 +++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 UnixPkg/Library/UnixBaseLib/LowBitSet64.c (limited to 'UnixPkg/Library/UnixBaseLib/LowBitSet64.c') diff --git a/UnixPkg/Library/UnixBaseLib/LowBitSet64.c b/UnixPkg/Library/UnixBaseLib/LowBitSet64.c new file mode 100644 index 0000000000..2bc8bc3910 --- /dev/null +++ b/UnixPkg/Library/UnixBaseLib/LowBitSet64.c @@ -0,0 +1,50 @@ +/** @file + Math worker functions. + + Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.
+ This program and the accompanying materials + are licensed and made available under the terms and conditions of the BSD License + which accompanies this distribution. The full text of the license may be found at + http://opensource.org/licenses/bsd-license.php. + + THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, + WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. + +**/ + + + + +#include "BaseLibInternals.h" + +/** + Returns the bit position of the lowest bit set in a 64-bit value. + + This function computes the bit position of the lowest bit set in the 64-bit + value specified by Operand. If Operand is zero, then -1 is returned. + Otherwise, a value between 0 and 63 is returned. + + @param Operand The 64-bit operand to evaluate. + + @retval 0..63 The lowest bit set in Operand was found. + @retval -1 Operand is zero. + + +**/ +INTN +EFIAPI +LowBitSet64 ( + IN UINT64 Operand + ) +{ + INTN BitIndex; + + if (Operand == 0) { + return -1; + } + + for (BitIndex = 0; + (Operand & 1) == 0; + BitIndex++, Operand = RShiftU64 (Operand, 1)); + return BitIndex; +} -- cgit v1.2.3