Optimized HighBitSetXX() functions

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@1689 6f19259b-4bc3-4df7-8a09-765794883524
2006-10-08 08:45:59 +00:00
parent b1288fcac3
commit 73c47db8c7
2 changed files with 18 additions and 6 deletions
--- a/MdePkg/Library/BaseLib/HighBitSet32.c
+++ b/MdePkg/Library/BaseLib/HighBitSet32.c
@@ -36,6 +36,9 @@ HighBitSet32 (
 {
  INTN                              BitIndex;

-  for (BitIndex = -1; Operand != 0; BitIndex++, Operand >>= 1);
+  if (Operand == 0) {
+    return - 1;
+  }
+  for (BitIndex = 31; (INT32)Operand > 0; BitIndex--, Operand <<= 1);
  return BitIndex;
 }