r202098 - IRGen: Simplify alignment calculation in setBitFieldInfo

[David Majnemer]

Author: majnemer
Date: Mon Feb 24 19:20:15 2014
New Revision: 202098

URL: http://llvm.org/viewvc/llvm-project?rev=202098&view=rev
Log:
IRGen: Simplify alignment calculation in setBitFieldInfo

Take advantage of CharUnits::alignmentAtOffset instead of calculating it
by hand.

Differential Revision: http://llvm-reviews.chandlerc.com/D2862

Modified:
    cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp

Modified: cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp?rev=202098&r1=202097&r2=202098&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp Mon Feb 24 19:20:15 2014
@@ -220,10 +220,8 @@ void CGRecordLowering::setBitFieldInfo(
   // Here we calculate the actual storage alignment of the bits.  E.g if we've
   // got an alignment >= 2 and the bitfield starts at offset 6 we've got an
   // alignment of 2.
-  Info.StorageAlignment = (unsigned)(
-      StartOffset % Layout.getAlignment() ?
-      1ll << llvm::countTrailingZeros((uint64_t)StartOffset.getQuantity()) :
-      Layout.getAlignment().getQuantity());
+  Info.StorageAlignment =
+      Layout.getAlignment().alignmentAtOffset(StartOffset).getQuantity();
   if (Info.Size > Info.StorageSize)
     Info.Size = Info.StorageSize;
   // Reverse the bit offsets for big endian machines. Because we represent