[Patch V2 4/4] MdePkg: Fix Xcode 9 Beta treating 32-bit left shift as undefined

[Yonghong Zhu <yonghong.zhu@intel.com>]

Bug: https://bugzilla.tianocore.org/show_bug.cgi?id=635

Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Andrew Fish <afish@apple.com>
---
 MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c b/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c
index e3b2846..e818543 100644
--- a/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c
+++ b/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c
@@ -38,18 +38,18 @@ FillBuf (
   )
 {
   //
   // Left shift NumOfBits of bits in advance
   //
-  Sd->mBitBuf = (UINT32) (Sd->mBitBuf << NumOfBits);
+  Sd->mBitBuf = (UINT32) LShiftU64 (((UINT64)Sd->mBitBuf), NumOfBits);
 
   //
   // Copy data needed in bytes into mSbuBitBuf
   //
   while (NumOfBits > Sd->mBitCount) {
-
-    Sd->mBitBuf |= (UINT32) (Sd->mSubBitBuf << (NumOfBits = (UINT16) (NumOfBits - Sd->mBitCount)));
+    NumOfBits = (UINT16) (NumOfBits - Sd->mBitCount);
+    Sd->mBitBuf |= (UINT32) LShiftU64 (((UINT64)Sd->mSubBitBuf), NumOfBits);
 
     if (Sd->mCompSize > 0) {
       //
       // Get 1 byte into SubBitBuf
       //
-- 
2.6.1.windows.1