From: bxing <bxing@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Mon, 21 Aug 2006 09:32:26 +0000 (+0000)
Subject: A workaround to a compiler bug that causes the high order 32 bits of GetPerformanceCo... 
X-Git-Tag: edk2-stable201903~24537
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=f094c270ee43515a3337e2b8e8327ca7e09d2581

A workaround to a compiler bug that causes the high order 32 bits of GetPerformanceCounter() being indeterminate.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@1336 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c b/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c
index dd240d88d0..fe18878d19 100644
--- a/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c
+++ b/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c
@@ -210,7 +210,8 @@ GetPerformanceCounter (
   VOID
   )
 {
-  return (UINT32)InternalX86GetTimerTick (InternalX86GetApicBase ());
+  volatile static UINT64 Mask = 0xffffffff;
+  return InternalX86GetTimerTick (InternalX86GetApicBase ()) & Mask;
 }
 
 /**