diff options
Diffstat (limited to 'UnixPkg/Library/UnixBaseLib/LowBitSet32.c')
-rw-r--r-- | UnixPkg/Library/UnixBaseLib/LowBitSet32.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/UnixPkg/Library/UnixBaseLib/LowBitSet32.c b/UnixPkg/Library/UnixBaseLib/LowBitSet32.c new file mode 100644 index 0000000000..64300367d6 --- /dev/null +++ b/UnixPkg/Library/UnixBaseLib/LowBitSet32.c @@ -0,0 +1,47 @@ +/** @file
+ Math worker functions.
+
+ Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
+ 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 32-bit value.
+
+ This function computes the bit position of the lowest bit set in the 32-bit
+ value specified by Operand. If Operand is zero, then -1 is returned.
+ Otherwise, a value between 0 and 31 is returned.
+
+ @param Operand The 32-bit operand to evaluate.
+
+ @retval 0..31 The lowest bit set in Operand was found.
+ @retval -1 Operand is zero.
+
+**/
+INTN
+EFIAPI
+LowBitSet32 (
+ IN UINT32 Operand
+ )
+{
+ INTN BitIndex;
+
+ if (Operand == 0) {
+ return -1;
+ }
+
+ for (BitIndex = 0; 0 == (Operand & 1); BitIndex++, Operand >>= 1);
+ return BitIndex;
+}
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