1 files changed, 2 insertions, 1 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
index 96a04473aba..66c4af4c935 100644
--- a/compiler/rustc_codegen_ssa/src/mir/mod.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -26,6 +26,7 @@ pub mod place;
 mod rvalue;
 mod statement;
 
+pub use self::block::store_cast;
 use self::debuginfo::{FunctionDebugContext, PerLocalVarDebugInfo};
 use self::operand::{OperandRef, OperandValue};
 use self::place::PlaceRef;
@@ -259,7 +260,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
                     }
                     PassMode::Cast { ref cast, .. } => {
                         debug!("alloc: {:?} (return place) -> place", local);
-                        let size = cast.size(&start_bx);
+                        let size = cast.size(&start_bx).max(layout.size);
                         return LocalRef::Place(PlaceRef::alloca_size(&mut start_bx, size, layout));
                     }
                     _ => {}