IRgen: Set alignment correctly on bit-field accesses.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@102046 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/CodeGen/CGRecordLayoutBuilder.cpp b/lib/CodeGen/CGRecordLayoutBuilder.cpp
index 530a41c3d6..17c5640c64 100644
--- a/lib/CodeGen/CGRecordLayoutBuilder.cpp
+++ b/lib/CodeGen/CGRecordLayoutBuilder.cpp
@@ -152,8 +152,9 @@ static CGBitFieldInfo ComputeBitFieldInfo(CodeGenTypes &Types,
                                           uint64_t FieldOffset,
                                           uint64_t FieldSize) {
   const RecordDecl *RD = FD->getParent();
-  uint64_t ContainingTypeSizeInBits =
-    Types.getContext().getASTRecordLayout(RD).getSize();
+  const ASTRecordLayout &RL = Types.getContext().getASTRecordLayout(RD);
+  uint64_t ContainingTypeSizeInBits = RL.getSize();
+  unsigned ContainingTypeAlign = RL.getAlignment();
 
   const llvm::Type *Ty = Types.ConvertTypeForMemRecursive(FD->getType());
   uint64_t TypeSizeInBytes = Types.getTargetData().getTypeAllocSize(Ty);
@@ -223,8 +224,7 @@ static CGBitFieldInfo ComputeBitFieldInfo(CodeGenTypes &Types,
     AI.FieldByteOffset = AccessStart / 8;
     AI.FieldBitStart = AccessBitsInFieldStart - AccessStart;
     AI.AccessWidth = AccessWidth;
-    // FIXME: This might be wrong!
-    AI.AccessAlignment = 0;
+    AI.AccessAlignment = llvm::MinAlign(ContainingTypeAlign, AccessStart) / 8;
     AI.TargetBitOffset = AccessedTargetBits;
     AI.TargetBitWidth = AccessBitsInFieldSize;