[amunger] 21801: "More efficient" IsPowerOf2 from Myria (myriachan at cox dot net).

Author: amunger
Date: Fri May  5 19:10:59 2006
New Revision: 21801

URL: http://svn.reactos.ru/svn/reactos?rev=21801&view=rev
Log:
"More efficient" IsPowerOf2 from Myria (myriachan at cox dot net).

Modified:
    trunk/reactos/ntoskrnl/mm/pe.c

Modified: trunk/reactos/ntoskrnl/mm/pe.c
URL:
http://svn.reactos.ru/svn/reactos/trunk/reactos/ntoskrnl/mm/pe.c?rev=21801&…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/pe.c (original)
+++ trunk/reactos/ntoskrnl/mm/pe.c Fri May  5 19:10:59 2006
@@ -103,12 +103,8 @@
 static __inline BOOLEAN IsPowerOf2(IN ULONG Number)
 {
     if(Number == 0)
-	return FALSE;
-
-    while((Number % 2) == 0)
-	Number /= 2;
-
-    return Number == 1;
+		return FALSE;
+    return (Number & (Number - 1)) == 0;
 }
 
 static __inline ULONG ModPow2(IN ULONG Address, IN ULONG Alignment)