1 /*++ 2 3 Copyright (c) 2004 - 2006, Intel Corporation. All rights reserved.<BR> 4 This program and the accompanying materials 5 are licensed and made available under the terms and conditions of the BSD License 6 which accompanies this distribution. The full text of the license may be found at 7 http://opensource.org/licenses/bsd-license.php 8 9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 11 12 13 Module Name: 14 15 LowBitSet32.c 16 17 Abstract: 18 19 Math worker functions. 20 21 --*/ 22 23 #include "BaseLibInternals.h" 24 25 /** 26 Returns the bit position of the lowest bit set in a 32-bit value. 27 28 This function computes the bit position of the lowest bit set in the 32-bit 29 value specified by Operand. If Operand is zero, then -1 is returned. 30 Otherwise, a value between 0 and 31 is returned. 31 32 @param Operand The 32-bit operand to evaluate. 33 34 @return Position of the lowest bit set in Operand if found. 35 @retval -1 Operand is zero. 36 37 **/ 38 INTN 39 EFIAPI 40 LowBitSet32 ( 41 IN UINT32 Operand 42 ) 43 { 44 INTN BitIndex; 45 46 if (Operand == 0) { 47 return -1; 48 } 49 50 for (BitIndex = 0; (Operand & 1) == 0; BitIndex++, Operand >>= 1); 51 return BitIndex; 52 } 53
