1 files changed, 7 insertions, 1 deletions
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 5bbc9ea5341..c73a6e1b061 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1139,7 +1139,13 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
   case Builtin::BI_alloca:
   case Builtin::BI__builtin_alloca: {
     Value *Size = EmitScalarExpr(E->getArg(0));
-    return RValue::get(Builder.CreateAlloca(Builder.getInt8Ty(), Size));
+    const TargetInfo &TI = getContext().getTargetInfo();
+    // The alignment of the alloca should correspond to __BIGGEST_ALIGNMENT__.
+    unsigned SuitableAlignmentInBytes =
+        TI.getSuitableAlign() / TI.getCharWidth();
+    AllocaInst *AI = Builder.CreateAlloca(Builder.getInt8Ty(), Size);
+    AI->setAlignment(SuitableAlignmentInBytes);
+    return RValue::get(AI);
   }
   case Builtin::BIbzero:
   case Builtin::BI__builtin_bzero: {