diff --git a/src/librustc_codegen_llvm/abi.rs b/src/librustc_codegen_llvm/abi.rs
index d699d786d1909e3e7bda5cfcdd42bdeb27a8ba2a..79343505c78a5b41705667d8ddf35c5994635df9 100644
--- a/src/librustc_codegen_llvm/abi.rs
+++ b/src/librustc_codegen_llvm/abi.rs
@@ -188,7 +188,7 @@ fn store(&self, bx: &Builder<'_, 'll, 'tcx>, val: &'ll Value, dst: PlaceRef<'ll,
         }
         let cx = bx.cx;
         if self.is_sized_indirect() {
-            OperandValue::Ref(val, self.layout.align).store(bx, dst)
+            OperandValue::Ref(val, None, self.layout.align).store(bx, dst)
         } else if self.is_unsized_indirect() {
             bug!("unsized ArgType must be handled through store_fn_arg");
         } else if let PassMode::Cast(cast) = self.mode {
@@ -249,7 +249,7 @@ fn store_fn_arg(&self, bx: &Builder<'a, 'll, 'tcx>, idx: &mut usize, dst: PlaceR
                 OperandValue::Pair(next(), next()).store(bx, dst);
             }
             PassMode::Indirect(_, Some(_)) => {
-                OperandValue::UnsizedRef(next(), next()).store(bx, dst);
+                OperandValue::Ref(next(), Some(next()), self.layout.align).store(bx, dst);
             }
             PassMode::Direct(_) | PassMode::Indirect(_, None) | PassMode::Cast(_) => {
                 self.store(bx, next(), dst);
diff --git a/src/librustc_codegen_llvm/base.rs b/src/librustc_codegen_llvm/base.rs
index 49db35f586524ac1fa59f0f4c908f25d0a308826..bd0c62e4766aed81588e0a0cdef2a048e7cbb337 100644
--- a/src/librustc_codegen_llvm/base.rs
+++ b/src/librustc_codegen_llvm/base.rs
@@ -295,7 +295,7 @@ pub fn coerce_unsized_into(
             OperandValue::Immediate(base) => {
                 unsize_thin_ptr(bx, base, src_ty, dst_ty)
             }
-            OperandValue::Ref(..) | OperandValue::UnsizedRef(..) => bug!()
+            OperandValue::Ref(..) => bug!()
         };
         OperandValue::Pair(base, info).store(bx, dst);
     };
diff --git a/src/librustc_codegen_llvm/intrinsic.rs b/src/librustc_codegen_llvm/intrinsic.rs
index 099d8562aa536ce025c4eef696e11fe99ff85a86..be3e0d9d4b1ed3a6a92d33f7eb7aae27b656397f 100644
--- a/src/librustc_codegen_llvm/intrinsic.rs
+++ b/src/librustc_codegen_llvm/intrinsic.rs
@@ -605,7 +605,7 @@ fn modify_as_needed(
                         // etc.
                         assert!(!bx.cx.type_needs_drop(arg.layout.ty));
                         let (ptr, align) = match arg.val {
-                            OperandValue::Ref(ptr, align) => (ptr, align),
+                            OperandValue::Ref(ptr, None, align) => (ptr, align),
                             _ => bug!()
                         };
                         let arg = PlaceRef::new_sized(ptr, arg.layout, align);
diff --git a/src/librustc_codegen_llvm/mir/block.rs b/src/librustc_codegen_llvm/mir/block.rs
index 1bd7bf48cda122e68d03048c9c758ee8c6866295..5f718ae456c4138ff8217f402e147288b9156c55 100644
--- a/src/librustc_codegen_llvm/mir/block.rs
+++ b/src/librustc_codegen_llvm/mir/block.rs
@@ -32,7 +32,7 @@
 use super::{FunctionCx, LocalRef};
 use super::place::PlaceRef;
 use super::operand::OperandRef;
-use super::operand::OperandValue::{Pair, Ref, UnsizedRef, Immediate};
+use super::operand::OperandValue::{Pair, Ref, Immediate};
 
 impl FunctionCx<'a, 'll, 'tcx> {
     pub fn codegen_block(&mut self, bb: mir::BasicBlock) {
@@ -232,10 +232,8 @@ fn codegen_terminator(&mut self,
 
                     PassMode::Direct(_) | PassMode::Pair(..) => {
                         let op = self.codegen_consume(&bx, &mir::Place::Local(mir::RETURN_PLACE));
-                        if let Ref(llval, align) = op.val {
+                        if let Ref(llval, _, align) = op.val {
                             bx.load(llval, align)
-                        } else if let UnsizedRef(..) = op.val {
-                            bug!("return type must be sized");
                         } else {
                             op.immediate_or_packed_pair(&bx)
                         }
@@ -247,7 +245,7 @@ fn codegen_terminator(&mut self,
                             LocalRef::Operand(None) => bug!("use of return before def"),
                             LocalRef::Place(cg_place) => {
                                 OperandRef {
-                                    val: Ref(cg_place.llval, cg_place.align),
+                                    val: Ref(cg_place.llval, None, cg_place.align),
                                     layout: cg_place.layout
                                 }
                             }
@@ -259,12 +257,11 @@ fn codegen_terminator(&mut self,
                                 op.val.store(&bx, scratch);
                                 scratch.llval
                             }
-                            Ref(llval, align) => {
+                            Ref(llval, _, align) => {
                                 assert_eq!(align.abi(), op.layout.align.abi(),
                                            "return place is unaligned!");
                                 llval
                             }
-                            UnsizedRef(..) => bug!("return type must be sized"),
                         };
                         bx.load(
                             bx.pointercast(llslot, cast_ty.llvm_type(bx.cx).ptr_to()),
@@ -605,15 +602,11 @@ fn codegen_terminator(&mut self,
                     // The callee needs to own the argument memory if we pass it
                     // by-ref, so make a local copy of non-immediate constants.
                     match (arg, op.val) {
-                        (&mir::Operand::Copy(_), Ref(..)) |
-                        (&mir::Operand::Constant(_), Ref(..)) => {
+                        (&mir::Operand::Copy(_), Ref(_, None, _)) |
+                        (&mir::Operand::Constant(_), Ref(_, None, _)) => {
                             let tmp = PlaceRef::alloca(&bx, op.layout, "const");
                             op.val.store(&bx, tmp);
-                            op.val = Ref(tmp.llval, tmp.align);
-                        }
-                        (&mir::Operand::Copy(_), UnsizedRef(..)) |
-                        (&mir::Operand::Constant(_), UnsizedRef(..)) => {
-                            bug!("tried to pass an unsized argument by copy or constant")
+                            op.val = Ref(tmp.llval, None, tmp.align);
                         }
                         _ => {}
                     }
@@ -667,7 +660,7 @@ fn codegen_argument(&mut self,
             }
         } else if arg.is_unsized_indirect() {
             match op.val {
-                UnsizedRef(a, b) => {
+                Ref(a, Some(b), _) => {
                     llargs.push(a);
                     llargs.push(b);
                     return;
@@ -690,7 +683,7 @@ fn codegen_argument(&mut self,
                     }
                 }
             }
-            Ref(llval, align) => {
+            Ref(llval, _, align) => {
                 if arg.is_indirect() && align.abi() < arg.layout.align.abi() {
                     // `foo(packed.large_field)`. We can't pass the (unaligned) field directly. I
                     // think that ATM (Rust 1.16) we only pass temporaries, but we shouldn't
@@ -703,8 +696,6 @@ fn codegen_argument(&mut self,
                     (llval, align, true)
                 }
             }
-            UnsizedRef(..) =>
-                bug!("codegen_argument: tried to pass unsized operand to sized argument"),
         };
 
         if by_ref && !arg.is_indirect() {
@@ -740,13 +731,13 @@ fn codegen_arguments_untupled(&mut self,
         let tuple = self.codegen_operand(bx, operand);
 
         // Handle both by-ref and immediate tuples.
-        if let Ref(llval, align) = tuple.val {
+        if let Ref(llval, None, align) = tuple.val {
             let tuple_ptr = PlaceRef::new_sized(llval, tuple.layout, align);
             for i in 0..tuple.layout.fields.count() {
                 let field_ptr = tuple_ptr.project_field(bx, i);
                 self.codegen_argument(bx, field_ptr.load(bx), llargs, &args[i]);
             }
-        } else if let UnsizedRef(..) = tuple.val {
+        } else if let Ref(_, Some(_), _) = tuple.val {
             bug!("closure arguments must be sized")
         } else {
             // If the tuple is immediate, the elements are as well.
diff --git a/src/librustc_codegen_llvm/mir/operand.rs b/src/librustc_codegen_llvm/mir/operand.rs
index ae929681b55eeb87bdad9560a79d7d88d6b8af36..9537379813d522eaf08cc18f9b535c8557d8a0f3 100644
--- a/src/librustc_codegen_llvm/mir/operand.rs
+++ b/src/librustc_codegen_llvm/mir/operand.rs
@@ -37,11 +37,9 @@
 pub enum OperandValue<'ll> {
     /// A reference to the actual operand. The data is guaranteed
     /// to be valid for the operand's lifetime.
-    Ref(&'ll Value, Align),
-    /// A reference to the unsized operand. The data is guaranteed
-    /// to be valid for the operand's lifetime.
-    /// The second field is the extra.
-    UnsizedRef(&'ll Value, &'ll Value),
+    /// The second value, if any, is the extra data (vtable or length)
+    /// which indicates that it refers to an unsized rvalue.
+    Ref(&'ll Value, Option<&'ll Value>, Align),
     /// A single LLVM value.
     Immediate(&'ll Value),
     /// A pair of immediate LLVM values. Used by fat pointers too.
@@ -154,8 +152,7 @@ pub fn deref(self, cx: &CodegenCx<'ll, 'tcx>) -> PlaceRef<'ll, 'tcx> {
         let (llptr, llextra) = match self.val {
             OperandValue::Immediate(llptr) => (llptr, None),
             OperandValue::Pair(llptr, llextra) => (llptr, Some(llextra)),
-            OperandValue::Ref(..) |
-            OperandValue::UnsizedRef(..) => bug!("Deref of by-Ref operand {:?}", self)
+            OperandValue::Ref(..) => bug!("Deref of by-Ref operand {:?}", self)
         };
         let layout = cx.layout_of(projected_ty);
         PlaceRef {
@@ -250,8 +247,7 @@ pub fn extract_field(&self, bx: &Builder<'a, 'll, 'tcx>, i: usize) -> OperandRef
                 *a = bx.bitcast(*a, field.scalar_pair_element_llvm_type(bx.cx, 0, true));
                 *b = bx.bitcast(*b, field.scalar_pair_element_llvm_type(bx.cx, 1, true));
             }
-            OperandValue::Ref(..) |
-            OperandValue::UnsizedRef(..) => bug!()
+            OperandValue::Ref(..) => bug!()
         }
 
         OperandRef {
@@ -291,11 +287,11 @@ fn store_with_flags(
             return;
         }
         match self {
-            OperandValue::Ref(r, source_align) => {
+            OperandValue::Ref(r, None, source_align) => {
                 base::memcpy_ty(bx, dest.llval, r, dest.layout,
                                 source_align.min(dest.align), flags)
             }
-            OperandValue::UnsizedRef(..) => {
+            OperandValue::Ref(_, Some(_), _) => {
                 bug!("cannot directly store unsized values");
             }
             OperandValue::Immediate(s) => {
@@ -321,7 +317,7 @@ pub fn store_unsized(self, bx: &Builder<'a, 'll, 'tcx>, indirect_dest: PlaceRef<
             .unwrap_or_else(|| bug!("indirect_dest has non-pointer type: {:?}", indirect_dest)).ty;
 
         let (llptr, llextra) =
-            if let OperandValue::UnsizedRef(llptr, llextra) = self {
+            if let OperandValue::Ref(llptr, Some(llextra), _) = self {
                 (llptr, llextra)
             } else {
                 bug!("store_unsized called with a sized value")
diff --git a/src/librustc_codegen_llvm/mir/place.rs b/src/librustc_codegen_llvm/mir/place.rs
index 6e5d3dad252266e323ccaf288c970b9f9b8ee0d6..89d41dcc8e9946029ab19d81c80cacf7aa584832 100644
--- a/src/librustc_codegen_llvm/mir/place.rs
+++ b/src/librustc_codegen_llvm/mir/place.rs
@@ -132,7 +132,7 @@ pub fn load(&self, bx: &Builder<'a, 'll, 'tcx>) -> OperandRef<'ll, 'tcx> {
         };
 
         let val = if let Some(llextra) = self.llextra {
-            OperandValue::UnsizedRef(self.llval, llextra)
+            OperandValue::Ref(self.llval, Some(llextra), self.align)
         } else if self.layout.is_llvm_immediate() {
             let mut const_llval = None;
             unsafe {
@@ -163,7 +163,7 @@ pub fn load(&self, bx: &Builder<'a, 'll, 'tcx>) -> OperandRef<'ll, 'tcx> {
             };
             OperandValue::Pair(load(0, a), load(1, b))
         } else {
-            OperandValue::Ref(self.llval, self.align)
+            OperandValue::Ref(self.llval, None, self.align)
         };
 
         OperandRef { val, layout: self.layout }
diff --git a/src/librustc_codegen_llvm/mir/rvalue.rs b/src/librustc_codegen_llvm/mir/rvalue.rs
index ae318cda2022b80076094f643cffcb212cd5eda4..84427d8b40f79f70aff82a69eb5777f437dc6374 100644
--- a/src/librustc_codegen_llvm/mir/rvalue.rs
+++ b/src/librustc_codegen_llvm/mir/rvalue.rs
@@ -83,11 +83,11 @@ pub fn codegen_rvalue(&mut self,
                         base::coerce_unsized_into(&bx, scratch, dest);
                         scratch.storage_dead(&bx);
                     }
-                    OperandValue::Ref(llref, align) => {
+                    OperandValue::Ref(llref, None, align) => {
                         let source = PlaceRef::new_sized(llref, operand.layout, align);
                         base::coerce_unsized_into(&bx, source, dest);
                     }
-                    OperandValue::UnsizedRef(..) => {
+                    OperandValue::Ref(_, Some(_), _) => {
                         bug!("unsized coercion on an unsized rvalue")
                     }
                 }
@@ -268,9 +268,6 @@ pub fn codegen_rvalue_operand(&mut self,
                                 bug!("by-ref operand {:?} in codegen_rvalue_operand",
                                      operand);
                             }
-                            OperandValue::UnsizedRef(..) => {
-                                bug!("unsized coercion on an unsized rvalue")
-                            }
                         }
                     }
                     mir::CastKind::Misc if operand.layout.is_llvm_scalar_pair() => {