diff --git a/src/abi.rs b/src/abi.rs
index 062e55a5ea8..0045866dfdd 100644
--- a/src/abi.rs
+++ b/src/abi.rs
@@ -346,14 +346,18 @@ fn local_place<'a, 'tcx: 'a>(
         {
             let TyLayout { ty, details } = layout;
             let ty::layout::LayoutDetails { size, align, abi: _, variants: _, fields: _ } = details;
-            let stack_slot = match place {
-                CPlace::Stack(stack_slot, _) => stack_slot,
+            match place {
+                CPlace::Stack(stack_slot, _) => fx.add_entity_comment(stack_slot, format!(
+                    "{:?}: {:?} size={} align={},{}",
+                    local, ty, size.bytes(), align.abi.bytes(), align.pref.bytes(),
+                )),
+                CPlace::NoPlace(_) => fx.add_global_comment(format!(
+                    "zst    {:?}: {:?} size={} align={}, {}",
+                    local, ty, size.bytes(), align.abi.bytes(), align.pref.bytes(),
+                )),
                 _ => unreachable!(),
             };
-            fx.add_entity_comment(stack_slot, format!(
-                "{:?}: {:?} size={} align={},{}",
-                local, ty, size.bytes(), align.abi.bytes(), align.pref.bytes(),
-            ));
+
         }
 
         // Take stack_addr in advance to avoid many duplicate instructions
@@ -456,11 +460,7 @@ pub fn codegen_fn_prelude<'a, 'tcx: 'a>(
 
     match output_pass_mode {
         PassMode::NoPass => {
-            let null = fx.bcx.ins().iconst(fx.pointer_type, 0);
-            fx.local_map.insert(
-                RETURN_PLACE,
-                CPlace::Addr(null, None, ret_layout),
-            );
+            fx.local_map.insert(RETURN_PLACE, CPlace::NoPlace(ret_layout));
         }
         PassMode::ByVal(_) => {
             let is_ssa = !ssa_analyzed
diff --git a/src/common.rs b/src/common.rs
index 248878a4be3..9723072364b 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -246,6 +246,7 @@ pub enum CPlace<'tcx> {
     Var(Local, TyLayout<'tcx>),
     Addr(Value, Option<Value>, TyLayout<'tcx>),
     Stack(StackSlot, TyLayout<'tcx>),
+    NoPlace(TyLayout<'tcx>)
 }
 
 impl<'a, 'tcx: 'a> CPlace<'tcx> {
@@ -253,13 +254,18 @@ impl<'a, 'tcx: 'a> CPlace<'tcx> {
         match *self {
             CPlace::Var(_, layout)
             | CPlace::Addr(_, _, layout)
-            | CPlace::Stack(_, layout) => layout,
+            | CPlace::Stack(_, layout)
+            | CPlace::NoPlace(layout)  => layout,
         }
     }
 
     pub fn new_stack_slot(fx: &mut FunctionCx<'a, 'tcx, impl Backend>, ty: Ty<'tcx>) -> CPlace<'tcx> {
         let layout = fx.layout_of(ty);
         assert!(!layout.is_unsized());
+        if layout.size.bytes() == 0 {
+            return CPlace::NoPlace(layout);
+        }
+
         let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
             kind: StackSlotKind::ExplicitSlot,
             size: layout.size.bytes() as u32,
@@ -278,6 +284,9 @@ impl<'a, 'tcx: 'a> CPlace<'tcx> {
             CPlace::Stack(stack_slot, layout) => {
                 CValue::ByRef(fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0), layout)
             }
+            CPlace::NoPlace(layout) => {
+                CValue::ByRef(fx.bcx.ins().iconst(fx.pointer_type, 0), layout)
+            }
         }
     }
 
@@ -297,6 +306,7 @@ impl<'a, 'tcx: 'a> CPlace<'tcx> {
             CPlace::Stack(stack_slot, _layout) => {
                 (fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0), None)
             }
+            CPlace::NoPlace(_) => (fx.bcx.ins().iconst(fx.pointer_type, 0), None),
             CPlace::Var(_, _) => bug!("Expected CPlace::Addr, found CPlace::Var"),
         }
     }
@@ -357,6 +367,11 @@ impl<'a, 'tcx: 'a> CPlace<'tcx> {
             CPlace::Stack(stack_slot, dst_layout) => {
                 (fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0), dst_layout)
             }
+            CPlace::NoPlace(layout) => {
+                assert!(layout.size.bytes() == 0);
+                assert!(from.layout().size.bytes() == 0);
+                return;
+            }
             CPlace::Addr(_, _, _) => bug!("Can't write value to unsized place {:?}", self),
         };
 
@@ -476,16 +491,19 @@ impl<'a, 'tcx: 'a> CPlace<'tcx> {
     }
 
     pub fn unchecked_cast_to(self, layout: TyLayout<'tcx>) -> Self {
+        assert!(!self.layout().is_unsized());
         match self {
             CPlace::Var(var, _) => CPlace::Var(var, layout),
             CPlace::Addr(addr, extra, _) => {
-                assert!(!layout.is_unsized());
                 CPlace::Addr(addr, extra, layout)
             }
             CPlace::Stack(stack_slot, _) => {
-                assert!(!layout.is_unsized());
                 CPlace::Stack(stack_slot, layout)
             }
+            CPlace::NoPlace(_) => {
+                assert!(layout.size.bytes() == 0);
+                CPlace::NoPlace(layout)
+            }
         }
     }