Add checking for ThunkAttribute to avoid THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL...

[mirror_edk2.git] / MdePkg / Library / BaseLib / GetPowerOfTwo32.c

diff --git a/MdePkg/Library/BaseLib/GetPowerOfTwo32.c b/MdePkg/Library/BaseLib/GetPowerOfTwo32.c
index dbf4ca65138cef6585e2c550afc359b0308e2098..3d253a871b9b866579b481fee830db28ff0513d5 100644 (file)
--- a/MdePkg/Library/BaseLib/GetPowerOfTwo32.c
+++ b/MdePkg/Library/BaseLib/GetPowerOfTwo32.c
@@ -1,7 +1,7 @@
 /** @file\r
   Math worker functions.\r
 \r
-  Copyright (c) 2006, Intel Corporation<BR>\r
+  Copyright (c) 2006 - 2008, Intel Corporation<BR>\r
   All rights reserved. This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
   which accompanies this distribution.  The full text of the license may be found at\r
@@ -12,11 +12,14 @@
 \r
 **/\r
 \r
+\r
+\r
+\r
 #include "BaseLibInternals.h"\r
 \r
 /**\r
   Returns the value of the highest bit set in a 32-bit value. Equivalent to\r
-  1 << HighBitSet32(x).\r
+  1 << log2(x).\r
 \r
   This function computes the value of the highest bit set in the 32-bit value\r
   specified by Operand. If Operand is zero, then zero is returned.\r
@@ -33,8 +36,9 @@ GetPowerOfTwo32 (
   IN      UINT32                    Operand\r
   )\r
 {\r
-  INTN                              BitPos;\r
-  \r
-  BitPos = HighBitSet32 (Operand);\r
-  return BitPos >= 0 ? 1ul << BitPos : 0;\r
+  if (0 == Operand) {\r
+    return 0;\r
+  }\r
+\r
+  return 1ul << HighBitSet32 (Operand);\r
 }\r